From b8f06b7c33533cf88b5ddfb3b6eb95f50ec9d25b Mon Sep 17 00:00:00 2001 From: nathan Date: Tue, 24 Feb 2015 14:26:32 +0100 Subject: [PATCH] Changed to single access for sub/unsub (now passes unit tests). Changed to ConcurrentHashMapV8, 174/87 ns/op --- .../engio/mbassy/multi/MultiMBassador.java | 30 +- .../SubscriptionManager.java | 325 +- .../multi/common/AbstractConcurrentSet.java | 34 +- .../multi/common/ConcurrentHashMapV8.java | 4349 +++++++++++++++++ .../multi/common/IdentityObjectTree.java | 8 +- .../multi/common/NamedThreadFactory.java | 9 +- .../multi/common/StrongConcurrentSet.java | 3 +- .../mbassy/multi/listener/MessageHandler.java | 1 + .../multi/listener/MessageListener.java | 10 +- .../multi/subscription/EventProcessor.java | 47 + .../multi/subscription/MessageHolder.java | 18 + .../multi/subscription/MessageType.java | 8 + .../multi/subscription/Subscription.java | 30 +- .../net/engio/mbassy/multi/MBassadorTest.java | 20 +- .../mbassy/multi/MethodDispatchTest.java | 1 - .../mbassy/multi/SubscriptionManagerTest.java | 11 +- .../mbassy/multi/common/MessageBusTest.java | 1 - .../multi/common/SubscriptionValidator.java | 20 +- .../engio/mbassy/multi/common/TestUtil.java | 13 +- 19 files changed, 4715 insertions(+), 223 deletions(-) rename src/main/java/net/engio/mbassy/multi/{subscription => }/SubscriptionManager.java (68%) create mode 100644 src/main/java/net/engio/mbassy/multi/common/ConcurrentHashMapV8.java create mode 100644 src/main/java/net/engio/mbassy/multi/subscription/EventProcessor.java create mode 100644 src/main/java/net/engio/mbassy/multi/subscription/MessageHolder.java create mode 100644 src/main/java/net/engio/mbassy/multi/subscription/MessageType.java diff --git a/src/main/java/net/engio/mbassy/multi/MultiMBassador.java b/src/main/java/net/engio/mbassy/multi/MultiMBassador.java index ac7bafc..987bc87 100644 --- a/src/main/java/net/engio/mbassy/multi/MultiMBassador.java +++ b/src/main/java/net/engio/mbassy/multi/MultiMBassador.java @@ -1,10 +1,8 @@ package net.engio.mbassy.multi; import java.util.ArrayDeque; -import java.util.ArrayList; import java.util.Collection; import java.util.Iterator; -import java.util.List; import java.util.concurrent.TimeUnit; import java.util.concurrent.locks.LockSupport; @@ -15,7 +13,6 @@ import net.engio.mbassy.multi.common.TransferQueue; import net.engio.mbassy.multi.error.IPublicationErrorHandler; import net.engio.mbassy.multi.error.PublicationError; import net.engio.mbassy.multi.subscription.Subscription; -import net.engio.mbassy.multi.subscription.SubscriptionManager; /** * The base class for all message bus implementations with support for asynchronous message dispatch @@ -30,12 +27,16 @@ public class MultiMBassador implements IMessageBus { // this handler will receive all errors that occur during message dispatch or message handling private final Collection errorHandlers = new ArrayDeque(); - private final SubscriptionManager subscriptionManager; private final TransferQueue dispatchQueue = new LinkedTransferQueue(); + private final SubscriptionManager subscriptionManager; + // all threads that are available for asynchronous message dispatching - private List threads; + private final int numberOfThreads; + private final Collection threads; + + public MultiMBassador() { this(Runtime.getRuntime().availableProcessors()); @@ -46,9 +47,10 @@ public class MultiMBassador implements IMessageBus { if (numberOfThreads < 1) { numberOfThreads = 1; // at LEAST 1 thread } + this.numberOfThreads = numberOfThreads; this.subscriptionManager = new SubscriptionManager(numberOfThreads); - this.threads = new ArrayList(numberOfThreads); + this.threads = new ArrayDeque(numberOfThreads); NamedThreadFactory dispatchThreadFactory = new NamedThreadFactory("MessageBus"); for (int i = 0; i < numberOfThreads; i++) { @@ -57,7 +59,7 @@ public class MultiMBassador implements IMessageBus { @SuppressWarnings("null") @Override public void run() { - TransferQueue IN_QUEUE= MultiMBassador.this.dispatchQueue; + TransferQueue IN_QUEUE = MultiMBassador.this.dispatchQueue; Runnable event = null; int counter; @@ -88,6 +90,8 @@ public class MultiMBassador implements IMessageBus { this.threads.add(runner); runner.start(); } + + } @Override @@ -105,19 +109,19 @@ public class MultiMBassador implements IMessageBus { } @Override - public void unsubscribe(Object listener) { - this.subscriptionManager.unsubscribe(listener); + public void subscribe(final Object listener) { + MultiMBassador.this.subscriptionManager.subscribe(listener); } - @Override - public void subscribe(Object listener) { - this.subscriptionManager.subscribe(listener); + public void unsubscribe(final Object listener) { + MultiMBassador.this.subscriptionManager.unsubscribe(listener); } + @Override public boolean hasPendingMessages() { - return !this.dispatchQueue.isEmpty(); + return this.dispatchQueue.getWaitingConsumerCount() != this.numberOfThreads; } @Override diff --git a/src/main/java/net/engio/mbassy/multi/subscription/SubscriptionManager.java b/src/main/java/net/engio/mbassy/multi/SubscriptionManager.java similarity index 68% rename from src/main/java/net/engio/mbassy/multi/subscription/SubscriptionManager.java rename to src/main/java/net/engio/mbassy/multi/SubscriptionManager.java index 123d4cd..4cf842b 100644 --- a/src/main/java/net/engio/mbassy/multi/subscription/SubscriptionManager.java +++ b/src/main/java/net/engio/mbassy/multi/SubscriptionManager.java @@ -1,17 +1,18 @@ -package net.engio.mbassy.multi.subscription; +package net.engio.mbassy.multi; import java.util.Collection; import java.util.Iterator; import java.util.Map; import java.util.Set; -import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.locks.ReentrantLock; +import net.engio.mbassy.multi.common.ConcurrentHashMapV8; import net.engio.mbassy.multi.common.IdentityObjectTree; import net.engio.mbassy.multi.common.ReflectionUtils; import net.engio.mbassy.multi.common.StrongConcurrentSet; import net.engio.mbassy.multi.listener.MessageHandler; import net.engio.mbassy.multi.listener.MetadataReader; -import sun.reflect.generics.reflectiveObjects.NotImplementedException; +import net.engio.mbassy.multi.subscription.Subscription; /** * The subscription managers responsibility is to consistently handle and synchronize the message listener subscription process. @@ -19,31 +20,43 @@ import sun.reflect.generics.reflectiveObjects.NotImplementedException; * listener is subscribed and takes care of creating new set of subscriptions for any unknown class that defines * message handlers. * + * + * Subscribe/Unsubscribe, while it is possible for them to be 100% concurrent (in relation to listeners per subscription), + * getting an accurate reflection of the number of subscriptions, or guaranteeing a "HAPPENS-BEFORE" relationship really + * complicates this. + * + * Given these restrictions and complexity, it is much easier to create a MPSC blocking queue, and have a single thread + * manage sub/unsub. + * * @author bennidi * Date: 5/11/13 * @author dorkbox, llc * Date: 2/2/15 */ public class SubscriptionManager { - private final int MAP_STRIPING; + private final int STRIPE_SIZE; private float LOAD_FACTOR; // the metadata reader that is used to inspect objects passed to the subscribe method private static final MetadataReader metadataReader = new MetadataReader(); + // remember already processed classes that do not contain any message handlers + private final Map, Boolean> nonListeners; + // all subscriptions per message type. We perpetually KEEP the types, as this lowers the amount of locking required // this is the primary list for dispatching a specific message // write access is synchronized and happens only when a listener of a specific class is registered the first time - private final ConcurrentHashMap, Collection> subscriptionsPerMessageSingle; + private final Map, Collection> subscriptionsPerMessageSingle; private final IdentityObjectTree, Collection> subscriptionsPerMessageMulti; + // synchronize read/write access to the subscription maps + private final ReentrantLock lock = new ReentrantLock(); + // all subscriptions per messageHandler type // this map provides fast access for subscribing and unsubscribing // write access is synchronized and happens very infrequently // once a collection of subscriptions is stored it does not change - private final ConcurrentHashMap, Collection> subscriptionsPerListener; - - private final Object holder = new Object[0]; + private final Map, Collection> subscriptionsPerListener; private final Map, Set>> superClassesCache; @@ -54,62 +67,36 @@ public class SubscriptionManager { // private final IdentityObjectTree, Collection> superClassSubscriptionsMulti = new IdentityObjectTree, Collection>(); - // remember already processed classes that do not contain any message handlers - private final Map, Object> nonListeners; - - - public SubscriptionManager(int numberOfThreads) { - this.MAP_STRIPING = numberOfThreads; + SubscriptionManager(int numberOfThreads) { + this.STRIPE_SIZE = numberOfThreads; this.LOAD_FACTOR = 0.8f; - this.subscriptionsPerMessageSingle = new ConcurrentHashMap, Collection>(4, this.LOAD_FACTOR, this.MAP_STRIPING); + this.nonListeners = new ConcurrentHashMapV8, Boolean>(4, 0.8F, this.STRIPE_SIZE); + + this.subscriptionsPerMessageSingle = new ConcurrentHashMapV8, Collection>(4, this.LOAD_FACTOR); this.subscriptionsPerMessageMulti = new IdentityObjectTree, Collection>(); // only used during SUB/UNSUB - this.subscriptionsPerListener = new ConcurrentHashMap, Collection>(4, this.LOAD_FACTOR, this.MAP_STRIPING); + this.subscriptionsPerListener = new ConcurrentHashMapV8, Collection>(4, this.LOAD_FACTOR); - this.superClassesCache = new ConcurrentHashMap, Set>>(8, this.LOAD_FACTOR, this.MAP_STRIPING); + this.superClassesCache = new ConcurrentHashMapV8, Set>>(8, this.LOAD_FACTOR, this.STRIPE_SIZE); // superClassSubscriptions keeps track of all subscriptions of super classes. SUB/UNSUB dumps it, so it is recreated dynamically. // it's a hit on SUB/UNSUB, but improves performance on handlers - this.superClassSubscriptions = new ConcurrentHashMap, Set>(8, this.LOAD_FACTOR, this.MAP_STRIPING); - - this.nonListeners = new ConcurrentHashMap, Object>(4, this.LOAD_FACTOR, this.MAP_STRIPING); + this.superClassSubscriptions = new ConcurrentHashMapV8, Set>(8, this.LOAD_FACTOR, this.STRIPE_SIZE); } private final void resetSuperClassSubs() { this.superClassSubscriptions.clear(); } - public void unsubscribe(Object listener) { + /** + * Can ONLY be called by a single thread, in order to guarantee a "happens-before" relationship to subscriptions + */ + public void subscribe(Object listener) { if (listener == null) { return; } - Class listenerClass = listener.getClass(); - // these are a concurrent collection - Collection subscriptions = this.subscriptionsPerListener.get(listenerClass); - - if (subscriptions != null) { - for (Subscription subscription : subscriptions) { - subscription.unsubscribe(listener); - - // purposefully DO NOT do anything else. We keep references to Class/subscription, because - // it acts as a "cache" of sorts, so that future add operations are quicker. - } - } - - return; - } - - private final ThreadLocal> subInitialValue = new ThreadLocal>() { - @Override - protected java.util.Collection initialValue() { - return new StrongConcurrentSet(8, SubscriptionManager.this.LOAD_FACTOR); - } - }; - - // when a class is subscribed, the registrations for that class are permanent in the "subscriptionsPerListener"? - public void subscribe(Object listener) { Class listenerClass = listener.getClass(); if (this.nonListeners.containsKey(listenerClass)) { @@ -117,72 +104,76 @@ public class SubscriptionManager { return; } - Collection subscriptions = this.subscriptionsPerListener.get(listenerClass); - if (subscriptions == null) { - // a listener is subscribed for the first time - Collection messageHandlers = SubscriptionManager.metadataReader.getMessageListener(listenerClass).getHandlers(); - int handlersSize = messageHandlers.size(); - - if (handlersSize == 0) { - // remember the class as non listening class if no handlers are found - this.nonListeners.put(listenerClass, this.holder); - } else { - Collection putIfAbsent = this.subscriptionsPerListener.putIfAbsent(listenerClass, this.subInitialValue.get()); - if (putIfAbsent != null) { - subscriptions = putIfAbsent; - } else { - subscriptions = this.subInitialValue.get(); - this.subInitialValue.set(new StrongConcurrentSet(8, this.LOAD_FACTOR)); - } - + this.lock.lock(); + try { + Collection subscriptions = this.subscriptionsPerListener.get(listenerClass); + if (subscriptions == null) { + // a listener is subscribed for the first time resetSuperClassSubs(); - // create NEW subscriptions for all detected message handlers - for (MessageHandler messageHandler : messageHandlers) { - // create the subscription - Subscription subscription = new Subscription(messageHandler); - subscription.subscribe(listener); + Collection messageHandlers = SubscriptionManager.metadataReader.getMessageListener(listenerClass).getHandlers(); + int handlersSize = messageHandlers.size(); - subscriptions.add(subscription); + if (handlersSize == 0) { + // remember the class as non listening class if no handlers are found + this.nonListeners.put(listener.getClass(), Boolean.TRUE); + return; + } else { + subscriptions = new StrongConcurrentSet(messageHandlers.size(), this.LOAD_FACTOR); - // - // save the subscription per message type - // - Class[] handledMessageTypes = subscription.getHandledMessageTypes(); - int size = handledMessageTypes.length; - boolean acceptsSubtypes = subscription.acceptsSubtypes(); + // create NEW subscriptions for all detected message handlers + for (MessageHandler messageHandler : messageHandlers) { + // create the subscription + Subscription subscription = new Subscription(messageHandler); + subscription.subscribe(listener); - if (size == 1) { - // single - Class clazz = handledMessageTypes[0]; + subscriptions.add(subscription); - Collection subs = this.subscriptionsPerMessageSingle.get(clazz); - if (subs == null) { - putIfAbsent = this.subscriptionsPerMessageSingle.putIfAbsent(clazz, this.subInitialValue.get()); - if (putIfAbsent != null) { - subs = putIfAbsent; - } else { - subs = this.subInitialValue.get(); - this.subInitialValue.set(new StrongConcurrentSet(8, this.LOAD_FACTOR)); + // now add this subscription to each of the handled types + Class[] handledMessageTypes = subscription.getHandledMessageTypes(); + int size = handledMessageTypes.length; + if (size == 1) { + // single + Class clazz = handledMessageTypes[0]; + + Collection subs = this.subscriptionsPerMessageSingle.get(clazz); + if (subs == null || subs.isEmpty()) { + subs = new StrongConcurrentSet(8, this.LOAD_FACTOR); + this.subscriptionsPerMessageSingle.put(clazz, subs); } - } - subs.add(subscription); - - if (acceptsSubtypes) { - // race conditions will result in duplicate answers, which we don't care about + subs.add(subscription); setupSuperClassCache(clazz); + } else { + // multiversion } } + + // order is critical for safe publication + this.subscriptionsPerListener.put(listenerClass, subscriptions); + } + } else { + // subscriptions already exist and must only be updated + for (Subscription subscription : subscriptions) { + subscription.subscribe(listener); } } - } else { - // subscriptions already exist and must only be updated - for (Subscription subscription : subscriptions) { - subscription.subscribe(listener); - } + + } finally { + this.lock.unlock(); } + + + + +// } else { +// // subscriptions already exist and must only be updated +// for (Subscription subscription : subscriptions) { +// subscription.subscribe(listener); +// } +// } + // // if (subscriptions != null) { // // subscriptions already exist and must only be updated @@ -293,6 +284,85 @@ public class SubscriptionManager { // } } + /** + * Can ONLY be called by a single thread, in order to guarantee a "happens-before" relationship to subscriptions + */ + public final void unsubscribe(Object listener) { + if (listener == null) { + return; + } + + Class listenerClass = listener.getClass(); + if (this.nonListeners.containsKey(listenerClass)) { + // early reject of known classes that do not define message handlers + return; + } + + resetSuperClassSubs(); + + this.lock.lock(); + try { + // these are a concurrent collection + Collection subscriptions = this.subscriptionsPerListener.get(listenerClass); + if (subscriptions != null) { + + for (Subscription subscription : subscriptions) { + subscription.unsubscribe(listener); // this is thread safe, but the following stuff is NOT thread safe. + + boolean isEmpty = subscription.isEmpty(); + + if (isEmpty) { + // single or multi? + Class[] handledMessageTypes = subscription.getHandledMessageTypes(); + int size = handledMessageTypes.length; + if (size == 1) { + // single + Class clazz = handledMessageTypes[0]; + + Collection subs = this.subscriptionsPerMessageSingle.get(clazz); + if (subs != null) { + subs.remove(subscription); + + if (subs.isEmpty()) { + // remove element + this.subscriptionsPerMessageSingle.remove(clazz); + } + } + } else { +// // NOTE: Not thread-safe! must be synchronized in outer scope +// IdentityObjectTree, Collection> tree; + // +// switch (size) { +// case 2: tree = this.subscriptionsPerMessageMulti.getLeaf(handledMessageTypes[0], handledMessageTypes[1]); break; +// case 3: tree = this.subscriptionsPerMessageMulti.getLeaf(handledMessageTypes[1], handledMessageTypes[1], handledMessageTypes[2]); break; +// default: tree = this.subscriptionsPerMessageMulti.getLeaf(handledMessageTypes); break; +// } + // +// if (tree != null) { +// Collection subs = tree.getValue(); +// if (subs != null) { +// subs.remove(subscription); + // +// if (subs.isEmpty()) { +// // remove tree element +// switch (size) { +// case 2: this.subscriptionsPerMessageMulti.remove(handledMessageTypes[0], handledMessageTypes[1]); break; +// case 3: this.subscriptionsPerMessageMulti.remove(handledMessageTypes[1], handledMessageTypes[1], handledMessageTypes[2]); break; +// default: this.subscriptionsPerMessageMulti.remove(handledMessageTypes); break; +// } +// } +// } +// } + } + } + } + } + } finally { + this.lock.unlock(); + } + } + + // CAN RETURN NULL public final Collection getSubscriptionsByMessageType(Class messageType) { return this.subscriptionsPerMessageSingle.get(messageType); @@ -323,11 +393,10 @@ public class SubscriptionManager { if (subsPerType == null) { // this caches our class hierarchy. This is never cleared. - Set> types = this.superClassesCache.get(superType); - if (types == null || types.isEmpty()) { + Collection> types = setupSuperClassCache(superType); + if (types.isEmpty()) { return null; } - subsPerType = new StrongConcurrentSet(types.size() + 1, this.LOAD_FACTOR); Iterator> iterator = types.iterator(); @@ -474,11 +543,13 @@ public class SubscriptionManager { /** * race conditions will result in duplicate answers, which we don't care if happens + * never returns null */ - private void setupSuperClassCache(Class clazz) { - if (!this.superClassesCache.containsKey(clazz)) { + private Collection> setupSuperClassCache(Class clazz) { + Collection> superTypes = this.superClassesCache.get(clazz); + if (superTypes == null) { // it doesn't matter if concurrent access stomps on values, since they are always the same. - Set> superTypes = ReflectionUtils.getSuperTypes(clazz); + superTypes = ReflectionUtils.getSuperTypes(clazz); StrongConcurrentSet> set = new StrongConcurrentSet>(superTypes.size() + 1, this.LOAD_FACTOR); for (Class c : superTypes) { set.add(c); @@ -487,53 +558,7 @@ public class SubscriptionManager { // race conditions will result in duplicate answers, which we don't care about this.superClassesCache.put(clazz, set); } - } - public static class SuperClassIterator implements Iterator> { - private final Iterator> iterator; - private Class clazz; - - public SuperClassIterator(Class clazz, Collection> types) { - this.clazz = clazz; - if (types != null) { - this.iterator = types.iterator(); - } else { - this.iterator = null; - } - } - - @Override - public boolean hasNext() { - if (this.clazz != null) { - return true; - } - - if (this.iterator != null) { - return this.iterator.hasNext(); - } - - return false; - } - - @Override - public Class next() { - if (this.clazz != null) { - Class clazz2 = this.clazz; - this.clazz = null; - - return clazz2; - } - - if (this.iterator != null) { - return this.iterator.next(); - } - - return null; - } - - @Override - public void remove() { - throw new NotImplementedException(); - } + return superTypes; } } diff --git a/src/main/java/net/engio/mbassy/multi/common/AbstractConcurrentSet.java b/src/main/java/net/engio/mbassy/multi/common/AbstractConcurrentSet.java index abd98aa..4a9338a 100644 --- a/src/main/java/net/engio/mbassy/multi/common/AbstractConcurrentSet.java +++ b/src/main/java/net/engio/mbassy/multi/common/AbstractConcurrentSet.java @@ -3,6 +3,7 @@ package net.engio.mbassy.multi.common; import java.util.Collection; import java.util.Map; import java.util.Set; +import java.util.concurrent.atomic.AtomicLong; import java.util.concurrent.locks.Lock; import sun.reflect.generics.reflectiveObjects.NotImplementedException; @@ -19,6 +20,8 @@ import com.googlecode.concurentlocks.ReentrantReadWriteUpdateLock; * Date: 2/12/12 */ public abstract class AbstractConcurrentSet implements Set { + private static final AtomicLong id = new AtomicLong(); + private final long ID = id.getAndIncrement(); // Internal state protected final transient ReentrantReadWriteUpdateLock lock = new ReentrantReadWriteUpdateLock(); @@ -135,13 +138,12 @@ public abstract class AbstractConcurrentSet implements Set { @Override public Object[] toArray() { - throw new NotImplementedException(); + return this.entries.entrySet().toArray(); } - @SuppressWarnings("hiding") @Override public T[] toArray(T[] a) { - throw new NotImplementedException(); + return this.entries.entrySet().toArray(a); } @Override @@ -164,6 +166,32 @@ public abstract class AbstractConcurrentSet implements Set { throw new NotImplementedException(); } + @Override + public int hashCode() { + final int prime = 31; + int result = 1; + result = prime * result + (int) (this.ID ^ this.ID >>> 32); + return result; + } + + @Override + public boolean equals(Object obj) { + if (this == obj) { + return true; + } + if (obj == null) { + return false; + } + if (getClass() != obj.getClass()) { + return false; + } + AbstractConcurrentSet other = (AbstractConcurrentSet) obj; + if (this.ID != other.ID) { + return false; + } + return true; + } + public abstract static class Entry implements ISetEntry { diff --git a/src/main/java/net/engio/mbassy/multi/common/ConcurrentHashMapV8.java b/src/main/java/net/engio/mbassy/multi/common/ConcurrentHashMapV8.java new file mode 100644 index 0000000..04a0f76 --- /dev/null +++ b/src/main/java/net/engio/mbassy/multi/common/ConcurrentHashMapV8.java @@ -0,0 +1,4349 @@ +/* + * Written by Doug Lea with assistance from members of JCP JSR-166 + * Expert Group and released to the public domain, as explained at + * http://creativecommons.org/publicdomain/zero/1.0/ + */ +package net.engio.mbassy.multi.common; + +import java.io.ObjectStreamField; +import java.io.Serializable; +import java.lang.reflect.ParameterizedType; +import java.lang.reflect.Type; +import java.util.AbstractMap; +import java.util.Arrays; +import java.util.Collection; +import java.util.ConcurrentModificationException; +import java.util.Enumeration; +import java.util.HashMap; +import java.util.Hashtable; +import java.util.Iterator; +import java.util.Map; +import java.util.NoSuchElementException; +import java.util.Set; +import java.util.concurrent.ConcurrentMap; +import java.util.concurrent.ForkJoinPool; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.locks.LockSupport; +import java.util.concurrent.locks.ReentrantLock; + +/* + * Bulk operations removed in Java 6 backport. + */ + +/** + * A hash table supporting full concurrency of retrievals and + * high expected concurrency for updates. This class obeys the + * same functional specification as {@link java.util.Hashtable}, and + * includes versions of methods corresponding to each method of + * {@code Hashtable}. However, even though all operations are + * thread-safe, retrieval operations do not entail locking, + * and there is not any support for locking the entire table + * in a way that prevents all access. This class is fully + * interoperable with {@code Hashtable} in programs that rely on its + * thread safety but not on its synchronization details. + * + *

Retrieval operations (including {@code get}) generally do not + * block, so may overlap with update operations (including {@code put} + * and {@code remove}). Retrievals reflect the results of the most + * recently completed update operations holding upon their + * onset. (More formally, an update operation for a given key bears a + * happens-before relation with any (non-null) retrieval for + * that key reporting the updated value.) For aggregate operations + * such as {@code putAll} and {@code clear}, concurrent retrievals may + * reflect insertion or removal of only some entries. Similarly, + * Iterators and Enumerations return elements reflecting the state of + * the hash table at some point at or since the creation of the + * iterator/enumeration. They do not throw {@link + * ConcurrentModificationException}. However, iterators are designed + * to be used by only one thread at a time. Bear in mind that the + * results of aggregate status methods including {@code size}, {@code + * isEmpty}, and {@code containsValue} are typically useful only when + * a map is not undergoing concurrent updates in other threads. + * Otherwise the results of these methods reflect transient states + * that may be adequate for monitoring or estimation purposes, but not + * for program control. + * + *

The table is dynamically expanded when there are too many + * collisions (i.e., keys that have distinct hash codes but fall into + * the same slot modulo the table size), with the expected average + * effect of maintaining roughly two bins per mapping (corresponding + * to a 0.75 load factor threshold for resizing). There may be much + * variance around this average as mappings are added and removed, but + * overall, this maintains a commonly accepted time/space tradeoff for + * hash tables. However, resizing this or any other kind of hash + * table may be a relatively slow operation. When possible, it is a + * good idea to provide a size estimate as an optional {@code + * initialCapacity} constructor argument. An additional optional + * {@code loadFactor} constructor argument provides a further means of + * customizing initial table capacity by specifying the table density + * to be used in calculating the amount of space to allocate for the + * given number of elements. Also, for compatibility with previous + * versions of this class, constructors may optionally specify an + * expected {@code concurrencyLevel} as an additional hint for + * internal sizing. Note that using many keys with exactly the same + * {@code hashCode()} is a sure way to slow down performance of any + * hash table. To ameliorate impact, when keys are {@link Comparable}, + * this class may use comparison order among keys to help break ties. + * + *

A {@link Set} projection of a ConcurrentHashMapV8 may be created + * (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed + * (using {@link #keySet(Object)} when only keys are of interest, and the + * mapped values are (perhaps transiently) not used or all take the + * same mapping value. + * + *

This class and its views and iterators implement all of the + * optional methods of the {@link Map} and {@link Iterator} + * interfaces. + * + *

Like {@link Hashtable} but unlike {@link HashMap}, this class + * does not allow {@code null} to be used as a key or value. + * + *

ConcurrentHashMapV8s support a set of sequential and parallel bulk + * operations that are designed + * to be safely, and often sensibly, applied even with maps that are + * being concurrently updated by other threads; for example, when + * computing a snapshot summary of the values in a shared registry. + * There are three kinds of operation, each with four forms, accepting + * functions with Keys, Values, Entries, and (Key, Value) arguments + * and/or return values. Because the elements of a ConcurrentHashMapV8 + * are not ordered in any particular way, and may be processed in + * different orders in different parallel executions, the correctness + * of supplied functions should not depend on any ordering, or on any + * other objects or values that may transiently change while + * computation is in progress; and except for forEach actions, should + * ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry} + * objects do not support method {@code setValue}. + * + *

    + *
  • forEach: Perform a given action on each element. + * A variant form applies a given transformation on each element + * before performing the action.
    • + * + *
  • search: Return the first available non-null result of + * applying a given function on each element; skipping further + * search when a result is found.
    • + * + *
  • reduce: Accumulate each element. The supplied reduction + * function cannot rely on ordering (more formally, it should be + * both associative and commutative). There are five variants: + * + *
      + * + *
    • Plain reductions. (There is not a form of this method for + * (key, value) function arguments since there is no corresponding + * return type.)
      • + * + *
    • Mapped reductions that accumulate the results of a given + * function applied to each element.
      • + * + *
    • Reductions to scalar doubles, longs, and ints, using a + * given basis value.
      • + * + *
    + *
    • + *
+ * + *

These bulk operations accept a {@code parallelismThreshold} + * argument. Methods proceed sequentially if the current map size is + * estimated to be less than the given threshold. Using a value of + * {@code Long.MAX_VALUE} suppresses all parallelism. Using a value + * of {@code 1} results in maximal parallelism by partitioning into + * enough subtasks to fully utilize the {@link + * ForkJoinPool#commonPool()} that is used for all parallel + * computations. Normally, you would initially choose one of these + * extreme values, and then measure performance of using in-between + * values that trade off overhead versus throughput. + * + *

The concurrency properties of bulk operations follow + * from those of ConcurrentHashMapV8: Any non-null result returned + * from {@code get(key)} and related access methods bears a + * happens-before relation with the associated insertion or + * update. The result of any bulk operation reflects the + * composition of these per-element relations (but is not + * necessarily atomic with respect to the map as a whole unless it + * is somehow known to be quiescent). Conversely, because keys + * and values in the map are never null, null serves as a reliable + * atomic indicator of the current lack of any result. To + * maintain this property, null serves as an implicit basis for + * all non-scalar reduction operations. For the double, long, and + * int versions, the basis should be one that, when combined with + * any other value, returns that other value (more formally, it + * should be the identity element for the reduction). Most common + * reductions have these properties; for example, computing a sum + * with basis 0 or a minimum with basis MAX_VALUE. + * + *

Search and transformation functions provided as arguments + * should similarly return null to indicate the lack of any result + * (in which case it is not used). In the case of mapped + * reductions, this also enables transformations to serve as + * filters, returning null (or, in the case of primitive + * specializations, the identity basis) if the element should not + * be combined. You can create compound transformations and + * filterings by composing them yourself under this "null means + * there is nothing there now" rule before using them in search or + * reduce operations. + * + *

Methods accepting and/or returning Entry arguments maintain + * key-value associations. They may be useful for example when + * finding the key for the greatest value. Note that "plain" Entry + * arguments can be supplied using {@code new + * AbstractMap.SimpleEntry(k,v)}. + * + *

Bulk operations may complete abruptly, throwing an + * exception encountered in the application of a supplied + * function. Bear in mind when handling such exceptions that other + * concurrently executing functions could also have thrown + * exceptions, or would have done so if the first exception had + * not occurred. + * + *

Speedups for parallel compared to sequential forms are common + * but not guaranteed. Parallel operations involving brief functions + * on small maps may execute more slowly than sequential forms if the + * underlying work to parallelize the computation is more expensive + * than the computation itself. Similarly, parallelization may not + * lead to much actual parallelism if all processors are busy + * performing unrelated tasks. + * + *

All arguments to all task methods must be non-null. + * + *

jsr166e note: During transition, this class + * uses nested functional interfaces with different names but the + * same forms as those expected for JDK8. + * + *

This class is a member of the + * + * Java Collections Framework. + * + * @since 1.5 + * @author Doug Lea + * @param the type of keys maintained by this map + * @param the type of mapped values + */ +@SuppressWarnings("all") +public class ConcurrentHashMapV8 extends AbstractMap + implements ConcurrentMap, Serializable { + private static final long serialVersionUID = 7249069246763182397L; + + /** + * An object for traversing and partitioning elements of a source. + * This interface provides a subset of the functionality of JDK8 + * java.util.Spliterator. + */ + public static interface ConcurrentHashMapSpliterator { + /** + * If possible, returns a new spliterator covering + * approximately one half of the elements, which will not be + * covered by this spliterator. Returns null if cannot be + * split. + */ + ConcurrentHashMapSpliterator trySplit(); + /** + * Returns an estimate of the number of elements covered by + * this Spliterator. + */ + long estimateSize(); + + /** Applies the action to each untraversed element */ + void forEachRemaining(Action action); + /** If an element remains, applies the action and returns true. */ + boolean tryAdvance(Action action); + } + + // Sams + /** Interface describing a void action of one argument */ + public interface Action { void apply(A a); } + /** Interface describing a void action of two arguments */ + public interface BiAction { void apply(A a, B b); } + /** Interface describing a function of one argument */ + public interface Fun { T apply(A a); } + /** Interface describing a function of two arguments */ + public interface BiFun { T apply(A a, B b); } + /** Interface describing a function mapping its argument to a double */ + public interface ObjectToDouble { double apply(A a); } + /** Interface describing a function mapping its argument to a long */ + public interface ObjectToLong { long apply(A a); } + /** Interface describing a function mapping its argument to an int */ + public interface ObjectToInt {int apply(A a); } + /** Interface describing a function mapping two arguments to a double */ + public interface ObjectByObjectToDouble { double apply(A a, B b); } + /** Interface describing a function mapping two arguments to a long */ + public interface ObjectByObjectToLong { long apply(A a, B b); } + /** Interface describing a function mapping two arguments to an int */ + public interface ObjectByObjectToInt {int apply(A a, B b); } + /** Interface describing a function mapping two doubles to a double */ + public interface DoubleByDoubleToDouble { double apply(double a, double b); } + /** Interface describing a function mapping two longs to a long */ + public interface LongByLongToLong { long apply(long a, long b); } + /** Interface describing a function mapping two ints to an int */ + public interface IntByIntToInt { int apply(int a, int b); } + + /* + * Overview: + * + * The primary design goal of this hash table is to maintain + * concurrent readability (typically method get(), but also + * iterators and related methods) while minimizing update + * contention. Secondary goals are to keep space consumption about + * the same or better than java.util.HashMap, and to support high + * initial insertion rates on an empty table by many threads. + * + * This map usually acts as a binned (bucketed) hash table. Each + * key-value mapping is held in a Node. Most nodes are instances + * of the basic Node class with hash, key, value, and next + * fields. However, various subclasses exist: TreeNodes are + * arranged in balanced trees, not lists. TreeBins hold the roots + * of sets of TreeNodes. ForwardingNodes are placed at the heads + * of bins during resizing. ReservationNodes are used as + * placeholders while establishing values in computeIfAbsent and + * related methods. The types TreeBin, ForwardingNode, and + * ReservationNode do not hold normal user keys, values, or + * hashes, and are readily distinguishable during search etc + * because they have negative hash fields and null key and value + * fields. (These special nodes are either uncommon or transient, + * so the impact of carrying around some unused fields is + * insignificant.) + * + * The table is lazily initialized to a power-of-two size upon the + * first insertion. Each bin in the table normally contains a + * list of Nodes (most often, the list has only zero or one Node). + * Table accesses require volatile/atomic reads, writes, and + * CASes. Because there is no other way to arrange this without + * adding further indirections, we use intrinsics + * (sun.misc.Unsafe) operations. + * + * We use the top (sign) bit of Node hash fields for control + * purposes -- it is available anyway because of addressing + * constraints. Nodes with negative hash fields are specially + * handled or ignored in map methods. + * + * Insertion (via put or its variants) of the first node in an + * empty bin is performed by just CASing it to the bin. This is + * by far the most common case for put operations under most + * key/hash distributions. Other update operations (insert, + * delete, and replace) require locks. We do not want to waste + * the space required to associate a distinct lock object with + * each bin, so instead use the first node of a bin list itself as + * a lock. Locking support for these locks relies on builtin + * "synchronized" monitors. + * + * Using the first node of a list as a lock does not by itself + * suffice though: When a node is locked, any update must first + * validate that it is still the first node after locking it, and + * retry if not. Because new nodes are always appended to lists, + * once a node is first in a bin, it remains first until deleted + * or the bin becomes invalidated (upon resizing). + * + * The main disadvantage of per-bin locks is that other update + * operations on other nodes in a bin list protected by the same + * lock can stall, for example when user equals() or mapping + * functions take a long time. However, statistically, under + * random hash codes, this is not a common problem. Ideally, the + * frequency of nodes in bins follows a Poisson distribution + * (http://en.wikipedia.org/wiki/Poisson_distribution) with a + * parameter of about 0.5 on average, given the resizing threshold + * of 0.75, although with a large variance because of resizing + * granularity. Ignoring variance, the expected occurrences of + * list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The + * first values are: + * + * 0: 0.60653066 + * 1: 0.30326533 + * 2: 0.07581633 + * 3: 0.01263606 + * 4: 0.00157952 + * 5: 0.00015795 + * 6: 0.00001316 + * 7: 0.00000094 + * 8: 0.00000006 + * more: less than 1 in ten million + * + * Lock contention probability for two threads accessing distinct + * elements is roughly 1 / (8 * #elements) under random hashes. + * + * Actual hash code distributions encountered in practice + * sometimes deviate significantly from uniform randomness. This + * includes the case when N > (1<<30), so some keys MUST collide. + * Similarly for dumb or hostile usages in which multiple keys are + * designed to have identical hash codes or ones that differs only + * in masked-out high bits. So we use a secondary strategy that + * applies when the number of nodes in a bin exceeds a + * threshold. These TreeBins use a balanced tree to hold nodes (a + * specialized form of red-black trees), bounding search time to + * O(log N). Each search step in a TreeBin is at least twice as + * slow as in a regular list, but given that N cannot exceed + * (1<<64) (before running out of addresses) this bounds search + * steps, lock hold times, etc, to reasonable constants (roughly + * 100 nodes inspected per operation worst case) so long as keys + * are Comparable (which is very common -- String, Long, etc). + * TreeBin nodes (TreeNodes) also maintain the same "next" + * traversal pointers as regular nodes, so can be traversed in + * iterators in the same way. + * + * The table is resized when occupancy exceeds a percentage + * threshold (nominally, 0.75, but see below). Any thread + * noticing an overfull bin may assist in resizing after the + * initiating thread allocates and sets up the replacement + * array. However, rather than stalling, these other threads may + * proceed with insertions etc. The use of TreeBins shields us + * from the worst case effects of overfilling while resizes are in + * progress. Resizing proceeds by transferring bins, one by one, + * from the table to the next table. To enable concurrency, the + * next table must be (incrementally) prefilled with place-holders + * serving as reverse forwarders to the old table. Because we are + * using power-of-two expansion, the elements from each bin must + * either stay at same index, or move with a power of two + * offset. We eliminate unnecessary node creation by catching + * cases where old nodes can be reused because their next fields + * won't change. On average, only about one-sixth of them need + * cloning when a table doubles. The nodes they replace will be + * garbage collectable as soon as they are no longer referenced by + * any reader thread that may be in the midst of concurrently + * traversing table. Upon transfer, the old table bin contains + * only a special forwarding node (with hash field "MOVED") that + * contains the next table as its key. On encountering a + * forwarding node, access and update operations restart, using + * the new table. + * + * Each bin transfer requires its bin lock, which can stall + * waiting for locks while resizing. However, because other + * threads can join in and help resize rather than contend for + * locks, average aggregate waits become shorter as resizing + * progresses. The transfer operation must also ensure that all + * accessible bins in both the old and new table are usable by any + * traversal. This is arranged by proceeding from the last bin + * (table.length - 1) up towards the first. Upon seeing a + * forwarding node, traversals (see class Traverser) arrange to + * move to the new table without revisiting nodes. However, to + * ensure that no intervening nodes are skipped, bin splitting can + * only begin after the associated reverse-forwarders are in + * place. + * + * The traversal scheme also applies to partial traversals of + * ranges of bins (via an alternate Traverser constructor) + * to support partitioned aggregate operations. Also, read-only + * operations give up if ever forwarded to a null table, which + * provides support for shutdown-style clearing, which is also not + * currently implemented. + * + * Lazy table initialization minimizes footprint until first use, + * and also avoids resizings when the first operation is from a + * putAll, constructor with map argument, or deserialization. + * These cases attempt to override the initial capacity settings, + * but harmlessly fail to take effect in cases of races. + * + * The element count is maintained using a specialization of + * LongAdder. We need to incorporate a specialization rather than + * just use a LongAdder in order to access implicit + * contention-sensing that leads to creation of multiple + * CounterCells. The counter mechanics avoid contention on + * updates but can encounter cache thrashing if read too + * frequently during concurrent access. To avoid reading so often, + * resizing under contention is attempted only upon adding to a + * bin already holding two or more nodes. Under uniform hash + * distributions, the probability of this occurring at threshold + * is around 13%, meaning that only about 1 in 8 puts check + * threshold (and after resizing, many fewer do so). + * + * TreeBins use a special form of comparison for search and + * related operations (which is the main reason we cannot use + * existing collections such as TreeMaps). TreeBins contain + * Comparable elements, but may contain others, as well as + * elements that are Comparable but not necessarily Comparable for + * the same T, so we cannot invoke compareTo among them. To handle + * this, the tree is ordered primarily by hash value, then by + * Comparable.compareTo order if applicable. On lookup at a node, + * if elements are not comparable or compare as 0 then both left + * and right children may need to be searched in the case of tied + * hash values. (This corresponds to the full list search that + * would be necessary if all elements were non-Comparable and had + * tied hashes.) On insertion, to keep a total ordering (or as + * close as is required here) across rebalancings, we compare + * classes and identityHashCodes as tie-breakers. The red-black + * balancing code is updated from pre-jdk-collections + * (http://gee.cs.oswego.edu/dl/classes/collections/RBCell.java) + * based in turn on Cormen, Leiserson, and Rivest "Introduction to + * Algorithms" (CLR). + * + * TreeBins also require an additional locking mechanism. While + * list traversal is always possible by readers even during + * updates, tree traversal is not, mainly because of tree-rotations + * that may change the root node and/or its linkages. TreeBins + * include a simple read-write lock mechanism parasitic on the + * main bin-synchronization strategy: Structural adjustments + * associated with an insertion or removal are already bin-locked + * (and so cannot conflict with other writers) but must wait for + * ongoing readers to finish. Since there can be only one such + * waiter, we use a simple scheme using a single "waiter" field to + * block writers. However, readers need never block. If the root + * lock is held, they proceed along the slow traversal path (via + * next-pointers) until the lock becomes available or the list is + * exhausted, whichever comes first. These cases are not fast, but + * maximize aggregate expected throughput. + * + * Maintaining API and serialization compatibility with previous + * versions of this class introduces several oddities. Mainly: We + * leave untouched but unused constructor arguments refering to + * concurrencyLevel. We accept a loadFactor constructor argument, + * but apply it only to initial table capacity (which is the only + * time that we can guarantee to honor it.) We also declare an + * unused "Segment" class that is instantiated in minimal form + * only when serializing. + * + * Also, solely for compatibility with previous versions of this + * class, it extends AbstractMap, even though all of its methods + * are overridden, so it is just useless baggage. + * + * This file is organized to make things a little easier to follow + * while reading than they might otherwise: First the main static + * declarations and utilities, then fields, then main public + * methods (with a few factorings of multiple public methods into + * internal ones), then sizing methods, trees, traversers, and + * bulk operations. + */ + + /* ---------------- Constants -------------- */ + + /** + * The largest possible table capacity. This value must be + * exactly 1<<30 to stay within Java array allocation and indexing + * bounds for power of two table sizes, and is further required + * because the top two bits of 32bit hash fields are used for + * control purposes. + */ + private static final int MAXIMUM_CAPACITY = 1 << 30; + + /** + * The default initial table capacity. Must be a power of 2 + * (i.e., at least 1) and at most MAXIMUM_CAPACITY. + */ + private static final int DEFAULT_CAPACITY = 16; + + /** + * The largest possible (non-power of two) array size. + * Needed by toArray and related methods. + */ + static final int MAX_ARRAY_SIZE = Integer.MAX_VALUE - 8; + + /** + * The default concurrency level for this table. Unused but + * defined for compatibility with previous versions of this class. + */ + private static final int DEFAULT_CONCURRENCY_LEVEL = 16; + + /** + * The load factor for this table. Overrides of this value in + * constructors affect only the initial table capacity. The + * actual floating point value isn't normally used -- it is + * simpler to use expressions such as {@code n - (n >>> 2)} for + * the associated resizing threshold. + */ + private static final float LOAD_FACTOR = 0.75f; + + /** + * The bin count threshold for using a tree rather than list for a + * bin. Bins are converted to trees when adding an element to a + * bin with at least this many nodes. The value must be greater + * than 2, and should be at least 8 to mesh with assumptions in + * tree removal about conversion back to plain bins upon + * shrinkage. + */ + static final int TREEIFY_THRESHOLD = 8; + + /** + * The bin count threshold for untreeifying a (split) bin during a + * resize operation. Should be less than TREEIFY_THRESHOLD, and at + * most 6 to mesh with shrinkage detection under removal. + */ + static final int UNTREEIFY_THRESHOLD = 6; + + /** + * The smallest table capacity for which bins may be treeified. + * (Otherwise the table is resized if too many nodes in a bin.) + * The value should be at least 4 * TREEIFY_THRESHOLD to avoid + * conflicts between resizing and treeification thresholds. + */ + static final int MIN_TREEIFY_CAPACITY = 64; + + /** + * Minimum number of rebinnings per transfer step. Ranges are + * subdivided to allow multiple resizer threads. This value + * serves as a lower bound to avoid resizers encountering + * excessive memory contention. The value should be at least + * DEFAULT_CAPACITY. + */ + private static final int MIN_TRANSFER_STRIDE = 16; + + /* + * Encodings for Node hash fields. See above for explanation. + */ + static final int MOVED = -1; // hash for forwarding nodes + static final int TREEBIN = -2; // hash for roots of trees + static final int RESERVED = -3; // hash for transient reservations + static final int HASH_BITS = 0x7fffffff; // usable bits of normal node hash + + /** Number of CPUS, to place bounds on some sizings */ + static final int NCPU = Runtime.getRuntime().availableProcessors(); + + /** For serialization compatibility. */ + private static final ObjectStreamField[] serialPersistentFields = { + new ObjectStreamField("segments", Segment[].class), + new ObjectStreamField("segmentMask", Integer.TYPE), + new ObjectStreamField("segmentShift", Integer.TYPE) + }; + + /* ---------------- Nodes -------------- */ + + /** + * Key-value entry. This class is never exported out as a + * user-mutable Map.Entry (i.e., one supporting setValue; see + * MapEntry below), but can be used for read-only traversals used + * in bulk tasks. Subclasses of Node with a negative hash field + * are special, and contain null keys and values (but are never + * exported). Otherwise, keys and vals are never null. + */ + static class Node implements Map.Entry { + final int hash; + final K key; + volatile V val; + volatile Node next; + + Node(int hash, K key, V val, Node next) { + this.hash = hash; + this.key = key; + this.val = val; + this.next = next; + } + + @Override + public final K getKey() { return this.key; } + @Override + public final V getValue() { return this.val; } + @Override + public final int hashCode() { return this.key.hashCode() ^ this.val.hashCode(); } + @Override + public final String toString(){ return this.key + "=" + this.val; } + @Override + public final V setValue(V value) { + throw new UnsupportedOperationException(); + } + + @Override + public final boolean equals(Object o) { + Object k, v, u; Map.Entry e; + return o instanceof Map.Entry && + (k = (e = (Map.Entry)o).getKey()) != null && + (v = e.getValue()) != null && + (k == this.key || k.equals(this.key)) && + (v == (u = this.val) || v.equals(u)); + } + + /** + * Virtualized support for map.get(); overridden in subclasses. + */ + Node find(int h, Object k) { + Node e = this; + if (k != null) { + do { + K ek; + if (e.hash == h && + ((ek = e.key) == k || ek != null && k.equals(ek))) { + return e; + } + } while ((e = e.next) != null); + } + return null; + } + } + + /* ---------------- Static utilities -------------- */ + + /** + * Spreads (XORs) higher bits of hash to lower and also forces top + * bit to 0. Because the table uses power-of-two masking, sets of + * hashes that vary only in bits above the current mask will + * always collide. (Among known examples are sets of Float keys + * holding consecutive whole numbers in small tables.) So we + * apply a transform that spreads the impact of higher bits + * downward. There is a tradeoff between speed, utility, and + * quality of bit-spreading. Because many common sets of hashes + * are already reasonably distributed (so don't benefit from + * spreading), and because we use trees to handle large sets of + * collisions in bins, we just XOR some shifted bits in the + * cheapest possible way to reduce systematic lossage, as well as + * to incorporate impact of the highest bits that would otherwise + * never be used in index calculations because of table bounds. + */ + static final int spread(int h) { + return (h ^ h >>> 16) & HASH_BITS; + } + + /** + * Returns a power of two table size for the given desired capacity. + * See Hackers Delight, sec 3.2 + */ + private static final int tableSizeFor(int c) { + int n = c - 1; + n |= n >>> 1; + n |= n >>> 2; + n |= n >>> 4; + n |= n >>> 8; + n |= n >>> 16; + return n < 0 ? 1 : n >= MAXIMUM_CAPACITY ? MAXIMUM_CAPACITY : n + 1; + } + + /** + * Returns x's Class if it is of the form "class C implements + * Comparable", else null. + */ + static Class comparableClassFor(Object x) { + if (x instanceof Comparable) { + Class c; Type[] ts, as; Type t; ParameterizedType p; + if ((c = x.getClass()) == String.class) { + return c; + } + if ((ts = c.getGenericInterfaces()) != null) { + for (int i = 0; i < ts.length; ++i) { + if ((t = ts[i]) instanceof ParameterizedType && + (p = (ParameterizedType)t).getRawType() == + Comparable.class && + (as = p.getActualTypeArguments()) != null && + as.length == 1 && as[0] == c) { + return c; + } + } + } + } + return null; + } + + /** + * Returns k.compareTo(x) if x matches kc (k's screened comparable + * class), else 0. + */ + @SuppressWarnings({"rawtypes","unchecked"}) // for cast to Comparable + static int compareComparables(Class kc, Object k, Object x) { + return x == null || x.getClass() != kc ? 0 : + ((Comparable)k).compareTo(x); + } + + /* ---------------- Table element access -------------- */ + + /* + * Volatile access methods are used for table elements as well as + * elements of in-progress next table while resizing. All uses of + * the tab arguments must be null checked by callers. All callers + * also paranoically precheck that tab's length is not zero (or an + * equivalent check), thus ensuring that any index argument taking + * the form of a hash value anded with (length - 1) is a valid + * index. Note that, to be correct wrt arbitrary concurrency + * errors by users, these checks must operate on local variables, + * which accounts for some odd-looking inline assignments below. + * Note that calls to setTabAt always occur within locked regions, + * and so in principle require only release ordering, not need + * full volatile semantics, but are currently coded as volatile + * writes to be conservative. + */ + + @SuppressWarnings("unchecked") + static final Node tabAt(Node[] tab, int i) { + return (Node)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE); + } + + static final boolean casTabAt(Node[] tab, int i, + Node c, Node v) { + return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v); + } + + static final void setTabAt(Node[] tab, int i, Node v) { + U.putObjectVolatile(tab, ((long)i << ASHIFT) + ABASE, v); + } + + /* ---------------- Fields -------------- */ + + /** + * The array of bins. Lazily initialized upon first insertion. + * Size is always a power of two. Accessed directly by iterators. + */ + transient volatile Node[] table; + + /** + * The next table to use; non-null only while resizing. + */ + private transient volatile Node[] nextTable; + + /** + * Base counter value, used mainly when there is no contention, + * but also as a fallback during table initialization + * races. Updated via CAS. + */ + private transient volatile long baseCount; + + /** + * Table initialization and resizing control. When negative, the + * table is being initialized or resized: -1 for initialization, + * else -(1 + the number of active resizing threads). Otherwise, + * when table is null, holds the initial table size to use upon + * creation, or 0 for default. After initialization, holds the + * next element count value upon which to resize the table. + */ + private transient volatile int sizeCtl; + + /** + * The next table index (plus one) to split while resizing. + */ + private transient volatile int transferIndex; + + /** + * The least available table index to split while resizing. + */ + private transient volatile int transferOrigin; + + /** + * Spinlock (locked via CAS) used when resizing and/or creating CounterCells. + */ + private transient volatile int cellsBusy; + + /** + * Table of counter cells. When non-null, size is a power of 2. + */ + private transient volatile CounterCell[] counterCells; + + // views + private transient KeySetView keySet; + private transient ValuesView values; + private transient EntrySetView entrySet; + + + /* ---------------- Public operations -------------- */ + + /** + * Creates a new, empty map with the default initial table size (16). + */ + public ConcurrentHashMapV8() { + } + + /** + * Creates a new, empty map with an initial table size + * accommodating the specified number of elements without the need + * to dynamically resize. + * + * @param initialCapacity The implementation performs internal + * sizing to accommodate this many elements. + * @throws IllegalArgumentException if the initial capacity of + * elements is negative + */ + public ConcurrentHashMapV8(int initialCapacity) { + if (initialCapacity < 0) { + throw new IllegalArgumentException(); + } + int cap = initialCapacity >= MAXIMUM_CAPACITY >>> 1 ? + MAXIMUM_CAPACITY : + tableSizeFor(initialCapacity + (initialCapacity >>> 1) + 1); + this.sizeCtl = cap; + } + + /** + * Creates a new map with the same mappings as the given map. + * + * @param m the map + */ + public ConcurrentHashMapV8(Map m) { + this.sizeCtl = DEFAULT_CAPACITY; + putAll(m); + } + + /** + * Creates a new, empty map with an initial table size based on + * the given number of elements ({@code initialCapacity}) and + * initial table density ({@code loadFactor}). + * + * @param initialCapacity the initial capacity. The implementation + * performs internal sizing to accommodate this many elements, + * given the specified load factor. + * @param loadFactor the load factor (table density) for + * establishing the initial table size + * @throws IllegalArgumentException if the initial capacity of + * elements is negative or the load factor is nonpositive + * + * @since 1.6 + */ + public ConcurrentHashMapV8(int initialCapacity, float loadFactor) { + this(initialCapacity, loadFactor, 1); + } + + /** + * Creates a new, empty map with an initial table size based on + * the given number of elements ({@code initialCapacity}), table + * density ({@code loadFactor}), and number of concurrently + * updating threads ({@code concurrencyLevel}). + * + * @param initialCapacity the initial capacity. The implementation + * performs internal sizing to accommodate this many elements, + * given the specified load factor. + * @param loadFactor the load factor (table density) for + * establishing the initial table size + * @param concurrencyLevel the estimated number of concurrently + * updating threads. The implementation may use this value as + * a sizing hint. + * @throws IllegalArgumentException if the initial capacity is + * negative or the load factor or concurrencyLevel are + * nonpositive + */ + public ConcurrentHashMapV8(int initialCapacity, + float loadFactor, int concurrencyLevel) { + if (!(loadFactor > 0.0f) || initialCapacity < 0 || concurrencyLevel <= 0) { + throw new IllegalArgumentException(); + } + if (initialCapacity < concurrencyLevel) + { + initialCapacity = concurrencyLevel; // as estimated threads + } + long size = (long)(1.0 + initialCapacity / loadFactor); + int cap = size >= MAXIMUM_CAPACITY ? + MAXIMUM_CAPACITY : tableSizeFor((int)size); + this.sizeCtl = cap; + } + + // Original (since JDK1.2) Map methods + + /** + * {@inheritDoc} + */ + @Override + public int size() { + long n = sumCount(); + return n < 0L ? 0 : + n > Integer.MAX_VALUE ? Integer.MAX_VALUE : + (int)n; + } + + /** + * {@inheritDoc} + */ + @Override + public boolean isEmpty() { + return sumCount() <= 0L; // ignore transient negative values + } + + /** + * Returns the value to which the specified key is mapped, + * or {@code null} if this map contains no mapping for the key. + * + *

More formally, if this map contains a mapping from a key + * {@code k} to a value {@code v} such that {@code key.equals(k)}, + * then this method returns {@code v}; otherwise it returns + * {@code null}. (There can be at most one such mapping.) + * + * @throws NullPointerException if the specified key is null + */ + @Override + public V get(Object key) { + Node[] tab; Node e, p; int n, eh; K ek; + int h = spread(key.hashCode()); + if ((tab = this.table) != null && (n = tab.length) > 0 && + (e = tabAt(tab, n - 1 & h)) != null) { + if ((eh = e.hash) == h) { + if ((ek = e.key) == key || ek != null && key.equals(ek)) { + return e.val; + } + } + else if (eh < 0) { + return (p = e.find(h, key)) != null ? p.val : null; + } + while ((e = e.next) != null) { + if (e.hash == h && + ((ek = e.key) == key || ek != null && key.equals(ek))) { + return e.val; + } + } + } + return null; + } + + /** + * Tests if the specified object is a key in this table. + * + * @param key possible key + * @return {@code true} if and only if the specified object + * is a key in this table, as determined by the + * {@code equals} method; {@code false} otherwise + * @throws NullPointerException if the specified key is null + */ + @Override + public boolean containsKey(Object key) { + return get(key) != null; + } + + /** + * Returns {@code true} if this map maps one or more keys to the + * specified value. Note: This method may require a full traversal + * of the map, and is much slower than method {@code containsKey}. + * + * @param value value whose presence in this map is to be tested + * @return {@code true} if this map maps one or more keys to the + * specified value + * @throws NullPointerException if the specified value is null + */ + @Override + public boolean containsValue(Object value) { + if (value == null) { + throw new NullPointerException(); + } + Node[] t; + if ((t = this.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + V v; + if ((v = p.val) == value || v != null && value.equals(v)) { + return true; + } + } + } + return false; + } + + /** + * Maps the specified key to the specified value in this table. + * Neither the key nor the value can be null. + * + *

The value can be retrieved by calling the {@code get} method + * with a key that is equal to the original key. + * + * @param key key with which the specified value is to be associated + * @param value value to be associated with the specified key + * @return the previous value associated with {@code key}, or + * {@code null} if there was no mapping for {@code key} + * @throws NullPointerException if the specified key or value is null + */ + @Override + public V put(K key, V value) { + return putVal(key, value, false); + } + + /** Implementation for put and putIfAbsent */ + final V putVal(K key, V value, boolean onlyIfAbsent) { + if (key == null || value == null) { + throw new NullPointerException(); + } + int hash = spread(key.hashCode()); + int binCount = 0; + for (Node[] tab = this.table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) { + tab = initTable(); + } else if ((f = tabAt(tab, i = n - 1 & hash)) == null) { + if (casTabAt(tab, i, null, + new Node(hash, key, value, null))) + { + break; // no lock when adding to empty bin + } + } + else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + } else { + V oldVal = null; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f;; ++binCount) { + K ek; + if (e.hash == hash && + ((ek = e.key) == key || + ek != null && key.equals(ek))) { + oldVal = e.val; + if (!onlyIfAbsent) { + e.val = value; + } + break; + } + Node pred = e; + if ((e = e.next) == null) { + pred.next = new Node(hash, key, + value, null); + break; + } + } + } + else if (f instanceof TreeBin) { + Node p; + binCount = 2; + if ((p = ((TreeBin)f).putTreeVal(hash, key, + value)) != null) { + oldVal = p.val; + if (!onlyIfAbsent) { + p.val = value; + } + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) { + treeifyBin(tab, i); + } + if (oldVal != null) { + return oldVal; + } + break; + } + } + } + addCount(1L, binCount); + return null; + } + + /** + * Copies all of the mappings from the specified map to this one. + * These mappings replace any mappings that this map had for any of the + * keys currently in the specified map. + * + * @param m mappings to be stored in this map + */ + @Override + public void putAll(Map m) { + tryPresize(m.size()); + for (Map.Entry e : m.entrySet()) { + putVal(e.getKey(), e.getValue(), false); + } + } + + /** + * Removes the key (and its corresponding value) from this map. + * This method does nothing if the key is not in the map. + * + * @param key the key that needs to be removed + * @return the previous value associated with {@code key}, or + * {@code null} if there was no mapping for {@code key} + * @throws NullPointerException if the specified key is null + */ + @Override + public V remove(Object key) { + return replaceNode(key, null, null); + } + + /** + * Implementation for the four public remove/replace methods: + * Replaces node value with v, conditional upon match of cv if + * non-null. If resulting value is null, delete. + */ + final V replaceNode(Object key, V value, Object cv) { + int hash = spread(key.hashCode()); + for (Node[] tab = this.table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0 || + (f = tabAt(tab, i = n - 1 & hash)) == null) { + break; + } else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + } else { + V oldVal = null; + boolean validated = false; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + validated = true; + for (Node e = f, pred = null;;) { + K ek; + if (e.hash == hash && + ((ek = e.key) == key || + ek != null && key.equals(ek))) { + V ev = e.val; + if (cv == null || cv == ev || + ev != null && cv.equals(ev)) { + oldVal = ev; + if (value != null) { + e.val = value; + } else if (pred != null) { + pred.next = e.next; + } else { + setTabAt(tab, i, e.next); + } + } + break; + } + pred = e; + if ((e = e.next) == null) { + break; + } + } + } + else if (f instanceof TreeBin) { + validated = true; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(hash, key, null)) != null) { + V pv = p.val; + if (cv == null || cv == pv || + pv != null && cv.equals(pv)) { + oldVal = pv; + if (value != null) { + p.val = value; + } else if (t.removeTreeNode(p)) { + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + } + } + if (validated) { + if (oldVal != null) { + if (value == null) { + addCount(-1L, -1); + } + return oldVal; + } + break; + } + } + } + return null; + } + + /** + * Removes all of the mappings from this map. + */ + @Override + public void clear() { + long delta = 0L; // negative number of deletions + int i = 0; + Node[] tab = this.table; + while (tab != null && i < tab.length) { + int fh; + Node f = tabAt(tab, i); + if (f == null) { + ++i; + } else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + i = 0; // restart + } + else { + synchronized (f) { + if (tabAt(tab, i) == f) { + Node p = fh >= 0 ? f : + f instanceof TreeBin ? + ((TreeBin)f).first : null; + while (p != null) { + --delta; + p = p.next; + } + setTabAt(tab, i++, null); + } + } + } + } + if (delta != 0L) { + addCount(delta, -1); + } + } + + /** + * Returns a {@link Set} view of the keys contained in this map. + * The set is backed by the map, so changes to the map are + * reflected in the set, and vice-versa. The set supports element + * removal, which removes the corresponding mapping from this map, + * via the {@code Iterator.remove}, {@code Set.remove}, + * {@code removeAll}, {@code retainAll}, and {@code clear} + * operations. It does not support the {@code add} or + * {@code addAll} operations. + * + *

The view's {@code iterator} is a "weakly consistent" iterator + * that will never throw {@link ConcurrentModificationException}, + * and guarantees to traverse elements as they existed upon + * construction of the iterator, and may (but is not guaranteed to) + * reflect any modifications subsequent to construction. + * + * @return the set view + */ + @Override + public KeySetView keySet() { + KeySetView ks; + return (ks = this.keySet) != null ? ks : (this.keySet = new KeySetView(this, null)); + } + + /** + * Returns a {@link Collection} view of the values contained in this map. + * The collection is backed by the map, so changes to the map are + * reflected in the collection, and vice-versa. The collection + * supports element removal, which removes the corresponding + * mapping from this map, via the {@code Iterator.remove}, + * {@code Collection.remove}, {@code removeAll}, + * {@code retainAll}, and {@code clear} operations. It does not + * support the {@code add} or {@code addAll} operations. + * + *

The view's {@code iterator} is a "weakly consistent" iterator + * that will never throw {@link ConcurrentModificationException}, + * and guarantees to traverse elements as they existed upon + * construction of the iterator, and may (but is not guaranteed to) + * reflect any modifications subsequent to construction. + * + * @return the collection view + */ + @Override + public Collection values() { + ValuesView vs; + return (vs = this.values) != null ? vs : (this.values = new ValuesView(this)); + } + + /** + * Returns a {@link Set} view of the mappings contained in this map. + * The set is backed by the map, so changes to the map are + * reflected in the set, and vice-versa. The set supports element + * removal, which removes the corresponding mapping from the map, + * via the {@code Iterator.remove}, {@code Set.remove}, + * {@code removeAll}, {@code retainAll}, and {@code clear} + * operations. + * + *

The view's {@code iterator} is a "weakly consistent" iterator + * that will never throw {@link ConcurrentModificationException}, + * and guarantees to traverse elements as they existed upon + * construction of the iterator, and may (but is not guaranteed to) + * reflect any modifications subsequent to construction. + * + * @return the set view + */ + @Override + public Set> entrySet() { + EntrySetView es; + return (es = this.entrySet) != null ? es : (this.entrySet = new EntrySetView(this)); + } + + /** + * Returns the hash code value for this {@link Map}, i.e., + * the sum of, for each key-value pair in the map, + * {@code key.hashCode() ^ value.hashCode()}. + * + * @return the hash code value for this map + */ + @Override + public int hashCode() { + int h = 0; + Node[] t; + if ((t = this.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + h += p.key.hashCode() ^ p.val.hashCode(); + } + } + return h; + } + + /** + * Returns a string representation of this map. The string + * representation consists of a list of key-value mappings (in no + * particular order) enclosed in braces ("{@code {}}"). Adjacent + * mappings are separated by the characters {@code ", "} (comma + * and space). Each key-value mapping is rendered as the key + * followed by an equals sign ("{@code =}") followed by the + * associated value. + * + * @return a string representation of this map + */ + @Override + public String toString() { + Node[] t; + int f = (t = this.table) == null ? 0 : t.length; + Traverser it = new Traverser(t, f, 0, f); + StringBuilder sb = new StringBuilder(); + sb.append('{'); + Node p; + if ((p = it.advance()) != null) { + for (;;) { + K k = p.key; + V v = p.val; + sb.append(k == this ? "(this Map)" : k); + sb.append('='); + sb.append(v == this ? "(this Map)" : v); + if ((p = it.advance()) == null) { + break; + } + sb.append(',').append(' '); + } + } + return sb.append('}').toString(); + } + + /** + * Compares the specified object with this map for equality. + * Returns {@code true} if the given object is a map with the same + * mappings as this map. This operation may return misleading + * results if either map is concurrently modified during execution + * of this method. + * + * @param o object to be compared for equality with this map + * @return {@code true} if the specified object is equal to this map + */ + @Override + public boolean equals(Object o) { + if (o != this) { + if (!(o instanceof Map)) { + return false; + } + Map m = (Map) o; + Node[] t; + int f = (t = this.table) == null ? 0 : t.length; + Traverser it = new Traverser(t, f, 0, f); + for (Node p; (p = it.advance()) != null; ) { + V val = p.val; + Object v = m.get(p.key); + if (v == null || v != val && !v.equals(val)) { + return false; + } + } + for (Map.Entry e : m.entrySet()) { + Object mk, mv, v; + if ((mk = e.getKey()) == null || + (mv = e.getValue()) == null || + (v = get(mk)) == null || + mv != v && !mv.equals(v)) { + return false; + } + } + } + return true; + } + + /** + * Stripped-down version of helper class used in previous version, + * declared for the sake of serialization compatibility + */ + static class Segment extends ReentrantLock implements Serializable { + private static final long serialVersionUID = 2249069246763182397L; + final float loadFactor; + Segment(float lf) { this.loadFactor = lf; } + } + + /** + * Saves the state of the {@code ConcurrentHashMapV8} instance to a + * stream (i.e., serializes it). + * @param s the stream + * @throws java.io.IOException if an I/O error occurs + * @serialData + * the key (Object) and value (Object) + * for each key-value mapping, followed by a null pair. + * The key-value mappings are emitted in no particular order. + */ + private void writeObject(java.io.ObjectOutputStream s) + throws java.io.IOException { + // For serialization compatibility + // Emulate segment calculation from previous version of this class + int sshift = 0; + int ssize = 1; + while (ssize < DEFAULT_CONCURRENCY_LEVEL) { + ++sshift; + ssize <<= 1; + } + int segmentShift = 32 - sshift; + int segmentMask = ssize - 1; + @SuppressWarnings("unchecked") Segment[] segments = (Segment[]) + new Segment[DEFAULT_CONCURRENCY_LEVEL]; + for (int i = 0; i < segments.length; ++i) { + segments[i] = new Segment(LOAD_FACTOR); + } + s.putFields().put("segments", segments); + s.putFields().put("segmentShift", segmentShift); + s.putFields().put("segmentMask", segmentMask); + s.writeFields(); + + Node[] t; + if ((t = this.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + s.writeObject(p.key); + s.writeObject(p.val); + } + } + s.writeObject(null); + s.writeObject(null); + segments = null; // throw away + } + + /** + * Reconstitutes the instance from a stream (that is, deserializes it). + * @param s the stream + * @throws ClassNotFoundException if the class of a serialized object + * could not be found + * @throws java.io.IOException if an I/O error occurs + */ + private void readObject(java.io.ObjectInputStream s) + throws java.io.IOException, ClassNotFoundException { + /* + * To improve performance in typical cases, we create nodes + * while reading, then place in table once size is known. + * However, we must also validate uniqueness and deal with + * overpopulated bins while doing so, which requires + * specialized versions of putVal mechanics. + */ + this.sizeCtl = -1; // force exclusion for table construction + s.defaultReadObject(); + long size = 0L; + Node p = null; + for (;;) { + @SuppressWarnings("unchecked") K k = (K) s.readObject(); + @SuppressWarnings("unchecked") V v = (V) s.readObject(); + if (k != null && v != null) { + p = new Node(spread(k.hashCode()), k, v, p); + ++size; + } else { + break; + } + } + if (size == 0L) { + this.sizeCtl = 0; + } else { + int n; + if (size >= MAXIMUM_CAPACITY >>> 1) { + n = MAXIMUM_CAPACITY; + } else { + int sz = (int)size; + n = tableSizeFor(sz + (sz >>> 1) + 1); + } + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] tab = new Node[n]; + int mask = n - 1; + long added = 0L; + while (p != null) { + boolean insertAtFront; + Node next = p.next, first; + int h = p.hash, j = h & mask; + if ((first = tabAt(tab, j)) == null) { + insertAtFront = true; + } else { + K k = p.key; + if (first.hash < 0) { + TreeBin t = (TreeBin)first; + if (t.putTreeVal(h, k, p.val) == null) { + ++added; + } + insertAtFront = false; + } + else { + int binCount = 0; + insertAtFront = true; + Node q; K qk; + for (q = first; q != null; q = q.next) { + if (q.hash == h && + ((qk = q.key) == k || + qk != null && k.equals(qk))) { + insertAtFront = false; + break; + } + ++binCount; + } + if (insertAtFront && binCount >= TREEIFY_THRESHOLD) { + insertAtFront = false; + ++added; + p.next = first; + TreeNode hd = null, tl = null; + for (q = p; q != null; q = q.next) { + TreeNode t = new TreeNode + (q.hash, q.key, q.val, null, null); + if ((t.prev = tl) == null) { + hd = t; + } else { + tl.next = t; + } + tl = t; + } + setTabAt(tab, j, new TreeBin(hd)); + } + } + } + if (insertAtFront) { + ++added; + p.next = first; + setTabAt(tab, j, p); + } + p = next; + } + this.table = tab; + this.sizeCtl = n - (n >>> 2); + this.baseCount = added; + } + } + + // ConcurrentMap methods + + /** + * {@inheritDoc} + * + * @return the previous value associated with the specified key, + * or {@code null} if there was no mapping for the key + * @throws NullPointerException if the specified key or value is null + */ + @Override + public V putIfAbsent(K key, V value) { + return putVal(key, value, true); + } + + /** + * {@inheritDoc} + * + * @throws NullPointerException if the specified key is null + */ + @Override + public boolean remove(Object key, Object value) { + if (key == null) { + throw new NullPointerException(); + } + return value != null && replaceNode(key, null, value) != null; + } + + /** + * {@inheritDoc} + * + * @throws NullPointerException if any of the arguments are null + */ + @Override + public boolean replace(K key, V oldValue, V newValue) { + if (key == null || oldValue == null || newValue == null) { + throw new NullPointerException(); + } + return replaceNode(key, newValue, oldValue) != null; + } + + /** + * {@inheritDoc} + * + * @return the previous value associated with the specified key, + * or {@code null} if there was no mapping for the key + * @throws NullPointerException if the specified key or value is null + */ + @Override + public V replace(K key, V value) { + if (key == null || value == null) { + throw new NullPointerException(); + } + return replaceNode(key, value, null); + } + + // Overrides of JDK8+ Map extension method defaults + + /** + * Returns the value to which the specified key is mapped, or the + * given default value if this map contains no mapping for the + * key. + * + * @param key the key whose associated value is to be returned + * @param defaultValue the value to return if this map contains + * no mapping for the given key + * @return the mapping for the key, if present; else the default value + * @throws NullPointerException if the specified key is null + */ + public V getOrDefault(Object key, V defaultValue) { + V v; + return (v = get(key)) == null ? defaultValue : v; + } + + public void forEach(BiAction action) { + if (action == null) { + throw new NullPointerException(); + } + Node[] t; + if ((t = this.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + action.apply(p.key, p.val); + } + } + } + + public void replaceAll(BiFun function) { + if (function == null) { + throw new NullPointerException(); + } + Node[] t; + if ((t = this.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + V oldValue = p.val; + for (K key = p.key;;) { + V newValue = function.apply(key, oldValue); + if (newValue == null) { + throw new NullPointerException(); + } + if (replaceNode(key, newValue, oldValue) != null || + (oldValue = get(key)) == null) { + break; + } + } + } + } + } + + /** + * If the specified key is not already associated with a value, + * attempts to compute its value using the given mapping function + * and enters it into this map unless {@code null}. The entire + * method invocation is performed atomically, so the function is + * applied at most once per key. Some attempted update operations + * on this map by other threads may be blocked while computation + * is in progress, so the computation should be short and simple, + * and must not attempt to update any other mappings of this map. + * + * @param key key with which the specified value is to be associated + * @param mappingFunction the function to compute a value + * @return the current (existing or computed) value associated with + * the specified key, or null if the computed value is null + * @throws NullPointerException if the specified key or mappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the mappingFunction does so, + * in which case the mapping is left unestablished + */ + public V computeIfAbsent(K key, Fun mappingFunction) { + if (key == null || mappingFunction == null) { + throw new NullPointerException(); + } + int h = spread(key.hashCode()); + V val = null; + int binCount = 0; + for (Node[] tab = this.table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) { + tab = initTable(); + } else if ((f = tabAt(tab, i = n - 1 & h)) == null) { + Node r = new ReservationNode(); + synchronized (r) { + if (casTabAt(tab, i, null, r)) { + binCount = 1; + Node node = null; + try { + if ((val = mappingFunction.apply(key)) != null) { + node = new Node(h, key, val, null); + } + } finally { + setTabAt(tab, i, node); + } + } + } + if (binCount != 0) { + break; + } + } + else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + } else { + boolean added = false; + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f;; ++binCount) { + K ek; V ev; + if (e.hash == h && + ((ek = e.key) == key || + ek != null && key.equals(ek))) { + val = e.val; + break; + } + Node pred = e; + if ((e = e.next) == null) { + if ((val = mappingFunction.apply(key)) != null) { + added = true; + pred.next = new Node(h, key, val, null); + } + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(h, key, null)) != null) { + val = p.val; + } else if ((val = mappingFunction.apply(key)) != null) { + added = true; + t.putTreeVal(h, key, val); + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) { + treeifyBin(tab, i); + } + if (!added) { + return val; + } + break; + } + } + } + if (val != null) { + addCount(1L, binCount); + } + return val; + } + + /** + * If the value for the specified key is present, attempts to + * compute a new mapping given the key and its current mapped + * value. The entire method invocation is performed atomically. + * Some attempted update operations on this map by other threads + * may be blocked while computation is in progress, so the + * computation should be short and simple, and must not attempt to + * update any other mappings of this map. + * + * @param key key with which a value may be associated + * @param remappingFunction the function to compute a value + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or remappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V computeIfPresent(K key, BiFun remappingFunction) { + if (key == null || remappingFunction == null) { + throw new NullPointerException(); + } + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = this.table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) { + tab = initTable(); + } else if ((f = tabAt(tab, i = n - 1 & h)) == null) { + break; + } else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + } else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + ek != null && key.equals(ek))) { + val = remappingFunction.apply(key, e.val); + if (val != null) { + e.val = val; + } else { + delta = -1; + Node en = e.next; + if (pred != null) { + pred.next = en; + } else { + setTabAt(tab, i, en); + } + } + break; + } + pred = e; + if ((e = e.next) == null) { + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null && + (p = r.findTreeNode(h, key, null)) != null) { + val = remappingFunction.apply(key, p.val); + if (val != null) { + p.val = val; + } else { + delta = -1; + if (t.removeTreeNode(p)) { + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + } + } + if (binCount != 0) { + break; + } + } + } + if (delta != 0) { + addCount(delta, binCount); + } + return val; + } + + /** + * Attempts to compute a mapping for the specified key and its + * current mapped value (or {@code null} if there is no current + * mapping). The entire method invocation is performed atomically. + * Some attempted update operations on this map by other threads + * may be blocked while computation is in progress, so the + * computation should be short and simple, and must not attempt to + * update any other mappings of this Map. + * + * @param key key with which the specified value is to be associated + * @param remappingFunction the function to compute a value + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or remappingFunction + * is null + * @throws IllegalStateException if the computation detectably + * attempts a recursive update to this map that would + * otherwise never complete + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V compute(K key, + BiFun remappingFunction) { + if (key == null || remappingFunction == null) { + throw new NullPointerException(); + } + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = this.table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) { + tab = initTable(); + } else if ((f = tabAt(tab, i = n - 1 & h)) == null) { + Node r = new ReservationNode(); + synchronized (r) { + if (casTabAt(tab, i, null, r)) { + binCount = 1; + Node node = null; + try { + if ((val = remappingFunction.apply(key, null)) != null) { + delta = 1; + node = new Node(h, key, val, null); + } + } finally { + setTabAt(tab, i, node); + } + } + } + if (binCount != 0) { + break; + } + } + else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + } else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + ek != null && key.equals(ek))) { + val = remappingFunction.apply(key, e.val); + if (val != null) { + e.val = val; + } else { + delta = -1; + Node en = e.next; + if (pred != null) { + pred.next = en; + } else { + setTabAt(tab, i, en); + } + } + break; + } + pred = e; + if ((e = e.next) == null) { + val = remappingFunction.apply(key, null); + if (val != null) { + delta = 1; + pred.next = + new Node(h, key, val, null); + } + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 1; + TreeBin t = (TreeBin)f; + TreeNode r, p; + if ((r = t.root) != null) { + p = r.findTreeNode(h, key, null); + } else { + p = null; + } + V pv = p == null ? null : p.val; + val = remappingFunction.apply(key, pv); + if (val != null) { + if (p != null) { + p.val = val; + } else { + delta = 1; + t.putTreeVal(h, key, val); + } + } + else if (p != null) { + delta = -1; + if (t.removeTreeNode(p)) { + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) { + treeifyBin(tab, i); + } + break; + } + } + } + if (delta != 0) { + addCount(delta, binCount); + } + return val; + } + + /** + * If the specified key is not already associated with a + * (non-null) value, associates it with the given value. + * Otherwise, replaces the value with the results of the given + * remapping function, or removes if {@code null}. The entire + * method invocation is performed atomically. Some attempted + * update operations on this map by other threads may be blocked + * while computation is in progress, so the computation should be + * short and simple, and must not attempt to update any other + * mappings of this Map. + * + * @param key key with which the specified value is to be associated + * @param value the value to use if absent + * @param remappingFunction the function to recompute a value if present + * @return the new value associated with the specified key, or null if none + * @throws NullPointerException if the specified key or the + * remappingFunction is null + * @throws RuntimeException or Error if the remappingFunction does so, + * in which case the mapping is unchanged + */ + public V merge(K key, V value, BiFun remappingFunction) { + if (key == null || value == null || remappingFunction == null) { + throw new NullPointerException(); + } + int h = spread(key.hashCode()); + V val = null; + int delta = 0; + int binCount = 0; + for (Node[] tab = this.table;;) { + Node f; int n, i, fh; + if (tab == null || (n = tab.length) == 0) { + tab = initTable(); + } else if ((f = tabAt(tab, i = n - 1 & h)) == null) { + if (casTabAt(tab, i, null, new Node(h, key, value, null))) { + delta = 1; + val = value; + break; + } + } + else if ((fh = f.hash) == MOVED) { + tab = helpTransfer(tab, f); + } else { + synchronized (f) { + if (tabAt(tab, i) == f) { + if (fh >= 0) { + binCount = 1; + for (Node e = f, pred = null;; ++binCount) { + K ek; + if (e.hash == h && + ((ek = e.key) == key || + ek != null && key.equals(ek))) { + val = remappingFunction.apply(e.val, value); + if (val != null) { + e.val = val; + } else { + delta = -1; + Node en = e.next; + if (pred != null) { + pred.next = en; + } else { + setTabAt(tab, i, en); + } + } + break; + } + pred = e; + if ((e = e.next) == null) { + delta = 1; + val = value; + pred.next = + new Node(h, key, val, null); + break; + } + } + } + else if (f instanceof TreeBin) { + binCount = 2; + TreeBin t = (TreeBin)f; + TreeNode r = t.root; + TreeNode p = r == null ? null : + r.findTreeNode(h, key, null); + val = p == null ? value : + remappingFunction.apply(p.val, value); + if (val != null) { + if (p != null) { + p.val = val; + } else { + delta = 1; + t.putTreeVal(h, key, val); + } + } + else if (p != null) { + delta = -1; + if (t.removeTreeNode(p)) { + setTabAt(tab, i, untreeify(t.first)); + } + } + } + } + } + if (binCount != 0) { + if (binCount >= TREEIFY_THRESHOLD) { + treeifyBin(tab, i); + } + break; + } + } + } + if (delta != 0) { + addCount(delta, binCount); + } + return val; + } + + // Hashtable legacy methods + + /** + * Legacy method testing if some key maps into the specified value + * in this table. This method is identical in functionality to + * {@link #containsValue(Object)}, and exists solely to ensure + * full compatibility with class {@link java.util.Hashtable}, + * which supported this method prior to introduction of the + * Java Collections framework. + * + * @param value a value to search for + * @return {@code true} if and only if some key maps to the + * {@code value} argument in this table as + * determined by the {@code equals} method; + * {@code false} otherwise + * @throws NullPointerException if the specified value is null + */ + @Deprecated public boolean contains(Object value) { + return containsValue(value); + } + + /** + * Returns an enumeration of the keys in this table. + * + * @return an enumeration of the keys in this table + * @see #keySet() + */ + public Enumeration keys() { + Node[] t; + int f = (t = this.table) == null ? 0 : t.length; + return new KeyIterator(t, f, 0, f, this); + } + + /** + * Returns an enumeration of the values in this table. + * + * @return an enumeration of the values in this table + * @see #values() + */ + public Enumeration elements() { + Node[] t; + int f = (t = this.table) == null ? 0 : t.length; + return new ValueIterator(t, f, 0, f, this); + } + + // ConcurrentHashMapV8-only methods + + /** + * Returns the number of mappings. This method should be used + * instead of {@link #size} because a ConcurrentHashMapV8 may + * contain more mappings than can be represented as an int. The + * value returned is an estimate; the actual count may differ if + * there are concurrent insertions or removals. + * + * @return the number of mappings + * @since 1.8 + */ + public long mappingCount() { + long n = sumCount(); + return n < 0L ? 0L : n; // ignore transient negative values + } + + /** + * Creates a new {@link Set} backed by a ConcurrentHashMapV8 + * from the given type to {@code Boolean.TRUE}. + * + * @return the new set + * @since 1.8 + */ + public static KeySetView newKeySet() { + return new KeySetView + (new ConcurrentHashMapV8(), Boolean.TRUE); + } + + /** + * Creates a new {@link Set} backed by a ConcurrentHashMapV8 + * from the given type to {@code Boolean.TRUE}. + * + * @param initialCapacity The implementation performs internal + * sizing to accommodate this many elements. + * @return the new set + * @throws IllegalArgumentException if the initial capacity of + * elements is negative + * @since 1.8 + */ + public static KeySetView newKeySet(int initialCapacity) { + return new KeySetView + (new ConcurrentHashMapV8(initialCapacity), Boolean.TRUE); + } + + /** + * Returns a {@link Set} view of the keys in this map, using the + * given common mapped value for any additions (i.e., {@link + * Collection#add} and {@link Collection#addAll(Collection)}). + * This is of course only appropriate if it is acceptable to use + * the same value for all additions from this view. + * + * @param mappedValue the mapped value to use for any additions + * @return the set view + * @throws NullPointerException if the mappedValue is null + */ + public KeySetView keySet(V mappedValue) { + if (mappedValue == null) { + throw new NullPointerException(); + } + return new KeySetView(this, mappedValue); + } + + /* ---------------- Special Nodes -------------- */ + + /** + * A node inserted at head of bins during transfer operations. + */ + static final class ForwardingNode extends Node { + final Node[] nextTable; + ForwardingNode(Node[] tab) { + super(MOVED, null, null, null); + this.nextTable = tab; + } + + @Override + Node find(int h, Object k) { + // loop to avoid arbitrarily deep recursion on forwarding nodes + outer: for (Node[] tab = this.nextTable;;) { + Node e; int n; + if (k == null || tab == null || (n = tab.length) == 0 || + (e = tabAt(tab, n - 1 & h)) == null) { + return null; + } + for (;;) { + int eh; K ek; + if ((eh = e.hash) == h && + ((ek = e.key) == k || ek != null && k.equals(ek))) { + return e; + } + if (eh < 0) { + if (e instanceof ForwardingNode) { + tab = ((ForwardingNode)e).nextTable; + continue outer; + } else { + return e.find(h, k); + } + } + if ((e = e.next) == null) { + return null; + } + } + } + } + } + + /** + * A place-holder node used in computeIfAbsent and compute + */ + static final class ReservationNode extends Node { + ReservationNode() { + super(RESERVED, null, null, null); + } + + @Override + Node find(int h, Object k) { + return null; + } + } + + /* ---------------- Table Initialization and Resizing -------------- */ + + /** + * Initializes table, using the size recorded in sizeCtl. + */ + private final Node[] initTable() { + Node[] tab; int sc; + while ((tab = this.table) == null || tab.length == 0) { + if ((sc = this.sizeCtl) < 0) { + Thread.yield(); // lost initialization race; just spin + } else if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { + try { + if ((tab = this.table) == null || tab.length == 0) { + int n = sc > 0 ? sc : DEFAULT_CAPACITY; + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] nt = new Node[n]; + this.table = tab = nt; + sc = n - (n >>> 2); + } + } finally { + this.sizeCtl = sc; + } + break; + } + } + return tab; + } + + /** + * Adds to count, and if table is too small and not already + * resizing, initiates transfer. If already resizing, helps + * perform transfer if work is available. Rechecks occupancy + * after a transfer to see if another resize is already needed + * because resizings are lagging additions. + * + * @param x the count to add + * @param check if <0, don't check resize, if <= 1 only check if uncontended + */ + private final void addCount(long x, int check) { + CounterCell[] as; long b, s; + if ((as = this.counterCells) != null || + !U.compareAndSwapLong(this, BASECOUNT, b = this.baseCount, s = b + x)) { + CounterHashCode hc; CounterCell a; long v; int m; + boolean uncontended = true; + if ((hc = threadCounterHashCode.get()) == null || + as == null || (m = as.length - 1) < 0 || + (a = as[m & hc.code]) == null || + !(uncontended = + U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x))) { + fullAddCount(x, hc, uncontended); + return; + } + if (check <= 1) { + return; + } + s = sumCount(); + } + if (check >= 0) { + Node[] tab, nt; int sc; + while (s >= (sc = this.sizeCtl) && (tab = this.table) != null && + tab.length < MAXIMUM_CAPACITY) { + if (sc < 0) { + if (sc == -1 || this.transferIndex <= this.transferOrigin || + (nt = this.nextTable) == null) { + break; + } + if (U.compareAndSwapInt(this, SIZECTL, sc, sc - 1)) { + transfer(tab, nt); + } + } + else if (U.compareAndSwapInt(this, SIZECTL, sc, -2)) { + transfer(tab, null); + } + s = sumCount(); + } + } + } + + /** + * Helps transfer if a resize is in progress. + */ + final Node[] helpTransfer(Node[] tab, Node f) { + Node[] nextTab; int sc; + if (f instanceof ForwardingNode && + (nextTab = ((ForwardingNode)f).nextTable) != null) { + if (nextTab == this.nextTable && tab == this.table && + this.transferIndex > this.transferOrigin && (sc = this.sizeCtl) < -1 && + U.compareAndSwapInt(this, SIZECTL, sc, sc - 1)) { + transfer(tab, nextTab); + } + return nextTab; + } + return this.table; + } + + /** + * Tries to presize table to accommodate the given number of elements. + * + * @param size number of elements (doesn't need to be perfectly accurate) + */ + private final void tryPresize(int size) { + int c = size >= MAXIMUM_CAPACITY >>> 1 ? MAXIMUM_CAPACITY : + tableSizeFor(size + (size >>> 1) + 1); + int sc; + while ((sc = this.sizeCtl) >= 0) { + Node[] tab = this.table; int n; + if (tab == null || (n = tab.length) == 0) { + n = sc > c ? sc : c; + if (U.compareAndSwapInt(this, SIZECTL, sc, -1)) { + try { + if (this.table == tab) { + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] nt = new Node[n]; + this.table = nt; + sc = n - (n >>> 2); + } + } finally { + this.sizeCtl = sc; + } + } + } + else if (c <= sc || n >= MAXIMUM_CAPACITY) { + break; + } else if (tab == this.table && + U.compareAndSwapInt(this, SIZECTL, sc, -2)) { + transfer(tab, null); + } + } + } + + /** + * Moves and/or copies the nodes in each bin to new table. See + * above for explanation. + */ + private final void transfer(Node[] tab, Node[] nextTab) { + int n = tab.length, stride; + if ((stride = NCPU > 1 ? (n >>> 3) / NCPU : n) < MIN_TRANSFER_STRIDE) + { + stride = MIN_TRANSFER_STRIDE; // subdivide range + } + if (nextTab == null) { // initiating + try { + @SuppressWarnings({"rawtypes","unchecked"}) + Node[] nt = new Node[n << 1]; + nextTab = nt; + } catch (Throwable ex) { // try to cope with OOME + this.sizeCtl = Integer.MAX_VALUE; + return; + } + this.nextTable = nextTab; + this.transferOrigin = n; + this.transferIndex = n; + ForwardingNode rev = new ForwardingNode(tab); + for (int k = n; k > 0;) { // progressively reveal ready slots + int nextk = k > stride ? k - stride : 0; + for (int m = nextk; m < k; ++m) { + nextTab[m] = rev; + } + for (int m = n + nextk; m < n + k; ++m) { + nextTab[m] = rev; + } + U.putOrderedInt(this, TRANSFERORIGIN, k = nextk); + } + } + int nextn = nextTab.length; + ForwardingNode fwd = new ForwardingNode(nextTab); + boolean advance = true; + boolean finishing = false; // to ensure sweep before committing nextTab + for (int i = 0, bound = 0;;) { + int nextIndex, nextBound, fh; Node f; + while (advance) { + if (--i >= bound || finishing) { + advance = false; + } else if ((nextIndex = this.transferIndex) <= this.transferOrigin) { + i = -1; + advance = false; + } + else if (U.compareAndSwapInt + (this, TRANSFERINDEX, nextIndex, + nextBound = nextIndex > stride ? + nextIndex - stride : 0)) { + bound = nextBound; + i = nextIndex - 1; + advance = false; + } + } + if (i < 0 || i >= n || i + n >= nextn) { + if (finishing) { + this.nextTable = null; + this.table = nextTab; + this.sizeCtl = (n << 1) - (n >>> 1); + return; + } + for (int sc;;) { + if (U.compareAndSwapInt(this, SIZECTL, sc = this.sizeCtl, ++sc)) { + if (sc != -1) { + return; + } + finishing = advance = true; + i = n; // recheck before commit + break; + } + } + } + else if ((f = tabAt(tab, i)) == null) { + if (casTabAt(tab, i, null, fwd)) { + setTabAt(nextTab, i, null); + setTabAt(nextTab, i + n, null); + advance = true; + } + } + else if ((fh = f.hash) == MOVED) { + advance = true; // already processed + } else { + synchronized (f) { + if (tabAt(tab, i) == f) { + Node ln, hn; + if (fh >= 0) { + int runBit = fh & n; + Node lastRun = f; + for (Node p = f.next; p != null; p = p.next) { + int b = p.hash & n; + if (b != runBit) { + runBit = b; + lastRun = p; + } + } + if (runBit == 0) { + ln = lastRun; + hn = null; + } + else { + hn = lastRun; + ln = null; + } + for (Node p = f; p != lastRun; p = p.next) { + int ph = p.hash; K pk = p.key; V pv = p.val; + if ((ph & n) == 0) { + ln = new Node(ph, pk, pv, ln); + } else { + hn = new Node(ph, pk, pv, hn); + } + } + setTabAt(nextTab, i, ln); + setTabAt(nextTab, i + n, hn); + setTabAt(tab, i, fwd); + advance = true; + } + else if (f instanceof TreeBin) { + TreeBin t = (TreeBin)f; + TreeNode lo = null, loTail = null; + TreeNode hi = null, hiTail = null; + int lc = 0, hc = 0; + for (Node e = t.first; e != null; e = e.next) { + int h = e.hash; + TreeNode p = new TreeNode + (h, e.key, e.val, null, null); + if ((h & n) == 0) { + if ((p.prev = loTail) == null) { + lo = p; + } else { + loTail.next = p; + } + loTail = p; + ++lc; + } + else { + if ((p.prev = hiTail) == null) { + hi = p; + } else { + hiTail.next = p; + } + hiTail = p; + ++hc; + } + } + ln = lc <= UNTREEIFY_THRESHOLD ? untreeify(lo) : + hc != 0 ? new TreeBin(lo) : t; + hn = hc <= UNTREEIFY_THRESHOLD ? untreeify(hi) : + lc != 0 ? new TreeBin(hi) : t; + setTabAt(nextTab, i, ln); + setTabAt(nextTab, i + n, hn); + setTabAt(tab, i, fwd); + advance = true; + } + } + } + } + } + } + + /* ---------------- Conversion from/to TreeBins -------------- */ + + /** + * Replaces all linked nodes in bin at given index unless table is + * too small, in which case resizes instead. + */ + private final void treeifyBin(Node[] tab, int index) { + Node b; int n, sc; + if (tab != null) { + if ((n = tab.length) < MIN_TREEIFY_CAPACITY) { + if (tab == this.table && (sc = this.sizeCtl) >= 0 && + U.compareAndSwapInt(this, SIZECTL, sc, -2)) { + transfer(tab, null); + } + } + else if ((b = tabAt(tab, index)) != null && b.hash >= 0) { + synchronized (b) { + if (tabAt(tab, index) == b) { + TreeNode hd = null, tl = null; + for (Node e = b; e != null; e = e.next) { + TreeNode p = + new TreeNode(e.hash, e.key, e.val, + null, null); + if ((p.prev = tl) == null) { + hd = p; + } else { + tl.next = p; + } + tl = p; + } + setTabAt(tab, index, new TreeBin(hd)); + } + } + } + } + } + + /** + * Returns a list on non-TreeNodes replacing those in given list. + */ + static Node untreeify(Node b) { + Node hd = null, tl = null; + for (Node q = b; q != null; q = q.next) { + Node p = new Node(q.hash, q.key, q.val, null); + if (tl == null) { + hd = p; + } else { + tl.next = p; + } + tl = p; + } + return hd; + } + + /* ---------------- TreeNodes -------------- */ + + /** + * Nodes for use in TreeBins + */ + static final class TreeNode extends Node { + TreeNode parent; // red-black tree links + TreeNode left; + TreeNode right; + TreeNode prev; // needed to unlink next upon deletion + boolean red; + + TreeNode(int hash, K key, V val, Node next, + TreeNode parent) { + super(hash, key, val, next); + this.parent = parent; + } + + @Override + Node find(int h, Object k) { + return findTreeNode(h, k, null); + } + + /** + * Returns the TreeNode (or null if not found) for the given key + * starting at given root. + */ + final TreeNode findTreeNode(int h, Object k, Class kc) { + if (k != null) { + TreeNode p = this; + do { + int ph, dir; K pk; TreeNode q; + TreeNode pl = p.left, pr = p.right; + if ((ph = p.hash) > h) { + p = pl; + } else if (ph < h) { + p = pr; + } else if ((pk = p.key) == k || pk != null && k.equals(pk)) { + return p; + } else if (pl == null) { + p = pr; + } else if (pr == null) { + p = pl; + } else if ((kc != null || + (kc = comparableClassFor(k)) != null) && + (dir = compareComparables(kc, k, pk)) != 0) { + p = dir < 0 ? pl : pr; + } else if ((q = pr.findTreeNode(h, k, kc)) != null) { + return q; + } else { + p = pl; + } + } while (p != null); + } + return null; + } + } + + /* ---------------- TreeBins -------------- */ + + /** + * TreeNodes used at the heads of bins. TreeBins do not hold user + * keys or values, but instead point to list of TreeNodes and + * their root. They also maintain a parasitic read-write lock + * forcing writers (who hold bin lock) to wait for readers (who do + * not) to complete before tree restructuring operations. + */ + static final class TreeBin extends Node { + TreeNode root; + volatile TreeNode first; + volatile Thread waiter; + volatile int lockState; + // values for lockState + static final int WRITER = 1; // set while holding write lock + static final int WAITER = 2; // set when waiting for write lock + static final int READER = 4; // increment value for setting read lock + + /** + * Tie-breaking utility for ordering insertions when equal + * hashCodes and non-comparable. We don't require a total + * order, just a consistent insertion rule to maintain + * equivalence across rebalancings. Tie-breaking further than + * necessary simplifies testing a bit. + */ + static int tieBreakOrder(Object a, Object b) { + int d; + if (a == null || b == null || + (d = a.getClass().getName(). + compareTo(b.getClass().getName())) == 0) { + d = System.identityHashCode(a) <= System.identityHashCode(b) ? + -1 : 1; + } + return d; + } + + /** + * Creates bin with initial set of nodes headed by b. + */ + TreeBin(TreeNode b) { + super(TREEBIN, null, null, null); + this.first = b; + TreeNode r = null; + for (TreeNode x = b, next; x != null; x = next) { + next = (TreeNode)x.next; + x.left = x.right = null; + if (r == null) { + x.parent = null; + x.red = false; + r = x; + } + else { + K k = x.key; + int h = x.hash; + Class kc = null; + for (TreeNode p = r;;) { + int dir, ph; + K pk = p.key; + if ((ph = p.hash) > h) { + dir = -1; + } else if (ph < h) { + dir = 1; + } else if (kc == null && + (kc = comparableClassFor(k)) == null || + (dir = compareComparables(kc, k, pk)) == 0) { + dir = tieBreakOrder(k, pk); + } + TreeNode xp = p; + if ((p = dir <= 0 ? p.left : p.right) == null) { + x.parent = xp; + if (dir <= 0) { + xp.left = x; + } else { + xp.right = x; + } + r = balanceInsertion(r, x); + break; + } + } + } + } + this.root = r; + assert checkInvariants(this.root); + } + + /** + * Acquires write lock for tree restructuring. + */ + private final void lockRoot() { + if (!U.compareAndSwapInt(this, LOCKSTATE, 0, WRITER)) + { + contendedLock(); // offload to separate method + } + } + + /** + * Releases write lock for tree restructuring. + */ + private final void unlockRoot() { + this.lockState = 0; + } + + /** + * Possibly blocks awaiting root lock. + */ + private final void contendedLock() { + boolean waiting = false; + for (int s;;) { + if (((s = this.lockState) & WRITER) == 0) { + if (U.compareAndSwapInt(this, LOCKSTATE, s, WRITER)) { + if (waiting) { + this.waiter = null; + } + return; + } + } + else if ((s | WAITER) == 0) { + if (U.compareAndSwapInt(this, LOCKSTATE, s, s | WAITER)) { + waiting = true; + this.waiter = Thread.currentThread(); + } + } + else if (waiting) { + LockSupport.park(this); + } + } + } + + /** + * Returns matching node or null if none. Tries to search + * using tree comparisons from root, but continues linear + * search when lock not available. + */ +@Override +final Node find(int h, Object k) { + if (k != null) { + for (Node e = this.first; e != null; e = e.next) { + int s; K ek; + if (((s = this.lockState) & (WAITER|WRITER)) != 0) { + if (e.hash == h && + ((ek = e.key) == k || ek != null && k.equals(ek))) { + return e; + } + } + else if (U.compareAndSwapInt(this, LOCKSTATE, s, + s + READER)) { + TreeNode r, p; + try { + p = (r = this.root) == null ? null : + r.findTreeNode(h, k, null); + } finally { + Thread w; + int ls; + do {} while (!U.compareAndSwapInt + (this, LOCKSTATE, + ls = this.lockState, ls - READER)); + if (ls == (READER|WAITER) && (w = this.waiter) != null) { + LockSupport.unpark(w); + } + } + return p; + } + } + } + return null; + } + + /** + * Finds or adds a node. + * @return null if added + */ + final TreeNode putTreeVal(int h, K k, V v) { + Class kc = null; + boolean searched = false; + for (TreeNode p = this.root;;) { + int dir, ph; K pk; + if (p == null) { + this.first = this.root = new TreeNode(h, k, v, null, null); + break; + } + else if ((ph = p.hash) > h) { + dir = -1; + } else if (ph < h) { + dir = 1; + } else if ((pk = p.key) == k || pk != null && k.equals(pk)) { + return p; + } else if (kc == null && + (kc = comparableClassFor(k)) == null || + (dir = compareComparables(kc, k, pk)) == 0) { + if (!searched) { + TreeNode q, ch; + searched = true; + if ((ch = p.left) != null && + (q = ch.findTreeNode(h, k, kc)) != null || + (ch = p.right) != null && + (q = ch.findTreeNode(h, k, kc)) != null) { + return q; + } + } + dir = tieBreakOrder(k, pk); + } + + TreeNode xp = p; + if ((p = dir <= 0 ? p.left : p.right) == null) { + TreeNode x, f = this.first; + this.first = x = new TreeNode(h, k, v, f, xp); + if (f != null) { + f.prev = x; + } + if (dir <= 0) { + xp.left = x; + } else { + xp.right = x; + } + if (!xp.red) { + x.red = true; + } else { + lockRoot(); + try { + this.root = balanceInsertion(this.root, x); + } finally { + unlockRoot(); + } + } + break; + } + } + assert checkInvariants(this.root); + return null; + } + + /** + * Removes the given node, that must be present before this + * call. This is messier than typical red-black deletion code + * because we cannot swap the contents of an interior node + * with a leaf successor that is pinned by "next" pointers + * that are accessible independently of lock. So instead we + * swap the tree linkages. + * + * @return true if now too small, so should be untreeified + */ + final boolean removeTreeNode(TreeNode p) { + TreeNode next = (TreeNode)p.next; + TreeNode pred = p.prev; // unlink traversal pointers + TreeNode r, rl; + if (pred == null) { + this.first = next; + } else { + pred.next = next; + } + if (next != null) { + next.prev = pred; + } + if (this.first == null) { + this.root = null; + return true; + } + if ((r = this.root) == null || r.right == null || // too small + (rl = r.left) == null || rl.left == null) { + return true; + } + lockRoot(); + try { + TreeNode replacement; + TreeNode pl = p.left; + TreeNode pr = p.right; + if (pl != null && pr != null) { + TreeNode s = pr, sl; + while ((sl = s.left) != null) { + s = sl; + } + boolean c = s.red; s.red = p.red; p.red = c; // swap colors + TreeNode sr = s.right; + TreeNode pp = p.parent; + if (s == pr) { // p was s's direct parent + p.parent = s; + s.right = p; + } + else { + TreeNode sp = s.parent; + if ((p.parent = sp) != null) { + if (s == sp.left) { + sp.left = p; + } else { + sp.right = p; + } + } + if ((s.right = pr) != null) { + pr.parent = s; + } + } + p.left = null; + if ((p.right = sr) != null) { + sr.parent = p; + } + if ((s.left = pl) != null) { + pl.parent = s; + } + if ((s.parent = pp) == null) { + r = s; + } else if (p == pp.left) { + pp.left = s; + } else { + pp.right = s; + } + if (sr != null) { + replacement = sr; + } else { + replacement = p; + } + } + else if (pl != null) { + replacement = pl; + } else if (pr != null) { + replacement = pr; + } else { + replacement = p; + } + if (replacement != p) { + TreeNode pp = replacement.parent = p.parent; + if (pp == null) { + r = replacement; + } else if (p == pp.left) { + pp.left = replacement; + } else { + pp.right = replacement; + } + p.left = p.right = p.parent = null; + } + + this.root = p.red ? r : balanceDeletion(r, replacement); + + if (p == replacement) { // detach pointers + TreeNode pp; + if ((pp = p.parent) != null) { + if (p == pp.left) { + pp.left = null; + } else if (p == pp.right) { + pp.right = null; + } + p.parent = null; + } + } + } finally { + unlockRoot(); + } + assert checkInvariants(this.root); + return false; + } + + /* ------------------------------------------------------------ */ + // Red-black tree methods, all adapted from CLR + + static TreeNode rotateLeft(TreeNode root, + TreeNode p) { + TreeNode r, pp, rl; + if (p != null && (r = p.right) != null) { + if ((rl = p.right = r.left) != null) { + rl.parent = p; + } + if ((pp = r.parent = p.parent) == null) { + (root = r).red = false; + } else if (pp.left == p) { + pp.left = r; + } else { + pp.right = r; + } + r.left = p; + p.parent = r; + } + return root; + } + + static TreeNode rotateRight(TreeNode root, + TreeNode p) { + TreeNode l, pp, lr; + if (p != null && (l = p.left) != null) { + if ((lr = p.left = l.right) != null) { + lr.parent = p; + } + if ((pp = l.parent = p.parent) == null) { + (root = l).red = false; + } else if (pp.right == p) { + pp.right = l; + } else { + pp.left = l; + } + l.right = p; + p.parent = l; + } + return root; + } + + static TreeNode balanceInsertion(TreeNode root, + TreeNode x) { + x.red = true; + for (TreeNode xp, xpp, xppl, xppr;;) { + if ((xp = x.parent) == null) { + x.red = false; + return x; + } + else if (!xp.red || (xpp = xp.parent) == null) { + return root; + } + if (xp == (xppl = xpp.left)) { + if ((xppr = xpp.right) != null && xppr.red) { + xppr.red = false; + xp.red = false; + xpp.red = true; + x = xpp; + } + else { + if (x == xp.right) { + root = rotateLeft(root, x = xp); + xpp = (xp = x.parent) == null ? null : xp.parent; + } + if (xp != null) { + xp.red = false; + if (xpp != null) { + xpp.red = true; + root = rotateRight(root, xpp); + } + } + } + } + else { + if (xppl != null && xppl.red) { + xppl.red = false; + xp.red = false; + xpp.red = true; + x = xpp; + } + else { + if (x == xp.left) { + root = rotateRight(root, x = xp); + xpp = (xp = x.parent) == null ? null : xp.parent; + } + if (xp != null) { + xp.red = false; + if (xpp != null) { + xpp.red = true; + root = rotateLeft(root, xpp); + } + } + } + } + } + } + + static TreeNode balanceDeletion(TreeNode root, + TreeNode x) { + for (TreeNode xp, xpl, xpr;;) { + if (x == null || x == root) { + return root; + } else if ((xp = x.parent) == null) { + x.red = false; + return x; + } + else if (x.red) { + x.red = false; + return root; + } + else if ((xpl = xp.left) == x) { + if ((xpr = xp.right) != null && xpr.red) { + xpr.red = false; + xp.red = true; + root = rotateLeft(root, xp); + xpr = (xp = x.parent) == null ? null : xp.right; + } + if (xpr == null) { + x = xp; + } else { + TreeNode sl = xpr.left, sr = xpr.right; + if ((sr == null || !sr.red) && + (sl == null || !sl.red)) { + xpr.red = true; + x = xp; + } + else { + if (sr == null || !sr.red) { + if (sl != null) { + sl.red = false; + } + xpr.red = true; + root = rotateRight(root, xpr); + xpr = (xp = x.parent) == null ? + null : xp.right; + } + if (xpr != null) { + xpr.red = xp == null ? false : xp.red; + if ((sr = xpr.right) != null) { + sr.red = false; + } + } + if (xp != null) { + xp.red = false; + root = rotateLeft(root, xp); + } + x = root; + } + } + } + else { // symmetric + if (xpl != null && xpl.red) { + xpl.red = false; + xp.red = true; + root = rotateRight(root, xp); + xpl = (xp = x.parent) == null ? null : xp.left; + } + if (xpl == null) { + x = xp; + } else { + TreeNode sl = xpl.left, sr = xpl.right; + if ((sl == null || !sl.red) && + (sr == null || !sr.red)) { + xpl.red = true; + x = xp; + } + else { + if (sl == null || !sl.red) { + if (sr != null) { + sr.red = false; + } + xpl.red = true; + root = rotateLeft(root, xpl); + xpl = (xp = x.parent) == null ? + null : xp.left; + } + if (xpl != null) { + xpl.red = xp == null ? false : xp.red; + if ((sl = xpl.left) != null) { + sl.red = false; + } + } + if (xp != null) { + xp.red = false; + root = rotateRight(root, xp); + } + x = root; + } + } + } + } + } + + /** + * Recursive invariant check + */ + static boolean checkInvariants(TreeNode t) { + TreeNode tp = t.parent, tl = t.left, tr = t.right, + tb = t.prev, tn = (TreeNode)t.next; + if (tb != null && tb.next != t) { + return false; + } + if (tn != null && tn.prev != t) { + return false; + } + if (tp != null && t != tp.left && t != tp.right) { + return false; + } + if (tl != null && (tl.parent != t || tl.hash > t.hash)) { + return false; + } + if (tr != null && (tr.parent != t || tr.hash < t.hash)) { + return false; + } + if (t.red && tl != null && tl.red && tr != null && tr.red) { + return false; + } + if (tl != null && !checkInvariants(tl)) { + return false; + } + if (tr != null && !checkInvariants(tr)) { + return false; + } + return true; + } + + private static final sun.misc.Unsafe U; + private static final long LOCKSTATE; + static { + try { + U = getUnsafe(); + Class k = TreeBin.class; + LOCKSTATE = U.objectFieldOffset + (k.getDeclaredField("lockState")); + } catch (Exception e) { + throw new Error(e); + } + } + } + + /* ----------------Table Traversal -------------- */ + + /** + * Encapsulates traversal for methods such as containsValue; also + * serves as a base class for other iterators and spliterators. + * + * Method advance visits once each still-valid node that was + * reachable upon iterator construction. It might miss some that + * were added to a bin after the bin was visited, which is OK wrt + * consistency guarantees. Maintaining this property in the face + * of possible ongoing resizes requires a fair amount of + * bookkeeping state that is difficult to optimize away amidst + * volatile accesses. Even so, traversal maintains reasonable + * throughput. + * + * Normally, iteration proceeds bin-by-bin traversing lists. + * However, if the table has been resized, then all future steps + * must traverse both the bin at the current index as well as at + * (index + baseSize); and so on for further resizings. To + * paranoically cope with potential sharing by users of iterators + * across threads, iteration terminates if a bounds checks fails + * for a table read. + */ + static class Traverser { + Node[] tab; // current table; updated if resized + Node next; // the next entry to use + int index; // index of bin to use next + int baseIndex; // current index of initial table + int baseLimit; // index bound for initial table + final int baseSize; // initial table size + + Traverser(Node[] tab, int size, int index, int limit) { + this.tab = tab; + this.baseSize = size; + this.baseIndex = this.index = index; + this.baseLimit = limit; + this.next = null; + } + + /** + * Advances if possible, returning next valid node, or null if none. + */ + final Node advance() { + Node e; + if ((e = this.next) != null) { + e = e.next; + } + for (;;) { + Node[] t; int i, n; K ek; // must use locals in checks + if (e != null) { + return this.next = e; + } + if (this.baseIndex >= this.baseLimit || (t = this.tab) == null || + (n = t.length) <= (i = this.index) || i < 0) { + return this.next = null; + } + if ((e = tabAt(t, this.index)) != null && e.hash < 0) { + if (e instanceof ForwardingNode) { + this.tab = ((ForwardingNode)e).nextTable; + e = null; + continue; + } + else if (e instanceof TreeBin) { + e = ((TreeBin)e).first; + } else { + e = null; + } + } + if ((this.index += this.baseSize) >= n) + { + this.index = ++this.baseIndex; // visit upper slots if present + } + } + } + } + + /** + * Base of key, value, and entry Iterators. Adds fields to + * Traverser to support iterator.remove. + */ + static class BaseIterator extends Traverser { + final ConcurrentHashMapV8 map; + Node lastReturned; + BaseIterator(Node[] tab, int size, int index, int limit, + ConcurrentHashMapV8 map) { + super(tab, size, index, limit); + this.map = map; + advance(); + } + + public final boolean hasNext() { return this.next != null; } + public final boolean hasMoreElements() { return this.next != null; } + + public final void remove() { + Node p; + if ((p = this.lastReturned) == null) { + throw new IllegalStateException(); + } + this.lastReturned = null; + this.map.replaceNode(p.key, null, null); + } + } + + static final class KeyIterator extends BaseIterator + implements Iterator, Enumeration { + KeyIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); + } + + @Override + public final K next() { + Node p; + if ((p = this.next) == null) { + throw new NoSuchElementException(); + } + K k = p.key; + this.lastReturned = p; + advance(); + return k; + } + + @Override + public final K nextElement() { return next(); } + } + + static final class ValueIterator extends BaseIterator + implements Iterator, Enumeration { + ValueIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); + } + + @Override + public final V next() { + Node p; + if ((p = this.next) == null) { + throw new NoSuchElementException(); + } + V v = p.val; + this.lastReturned = p; + advance(); + return v; + } + + @Override + public final V nextElement() { return next(); } + } + + static final class EntryIterator extends BaseIterator + implements Iterator> { + EntryIterator(Node[] tab, int index, int size, int limit, + ConcurrentHashMapV8 map) { + super(tab, index, size, limit, map); + } + + @Override + public final Map.Entry next() { + Node p; + if ((p = this.next) == null) { + throw new NoSuchElementException(); + } + K k = p.key; + V v = p.val; + this.lastReturned = p; + advance(); + return new MapEntry(k, v, this.map); + } + } + + /** + * Exported Entry for EntryIterator + */ + static final class MapEntry implements Map.Entry { + final K key; // non-null + V val; // non-null + final ConcurrentHashMapV8 map; + MapEntry(K key, V val, ConcurrentHashMapV8 map) { + this.key = key; + this.val = val; + this.map = map; + } + @Override + public K getKey() { return this.key; } + @Override + public V getValue() { return this.val; } + @Override + public int hashCode() { return this.key.hashCode() ^ this.val.hashCode(); } + @Override + public String toString() { return this.key + "=" + this.val; } + + @Override + public boolean equals(Object o) { + Object k, v; Map.Entry e; + return o instanceof Map.Entry && + (k = (e = (Map.Entry)o).getKey()) != null && + (v = e.getValue()) != null && + (k == this.key || k.equals(this.key)) && + (v == this.val || v.equals(this.val)); + } + + /** + * Sets our entry's value and writes through to the map. The + * value to return is somewhat arbitrary here. Since we do not + * necessarily track asynchronous changes, the most recent + * "previous" value could be different from what we return (or + * could even have been removed, in which case the put will + * re-establish). We do not and cannot guarantee more. + */ + @Override + public V setValue(V value) { + if (value == null) { + throw new NullPointerException(); + } + V v = this.val; + this.val = value; + this.map.put(this.key, value); + return v; + } + } + + static final class KeySpliterator extends Traverser + implements ConcurrentHashMapSpliterator { + long est; // size estimate + KeySpliterator(Node[] tab, int size, int index, int limit, + long est) { + super(tab, size, index, limit); + this.est = est; + } + + @Override + public ConcurrentHashMapSpliterator trySplit() { + int i, f, h; + return (h = (i = this.baseIndex) + (f = this.baseLimit) >>> 1) <= i ? null : + new KeySpliterator(this.tab, this.baseSize, this.baseLimit = h, + f, this.est >>>= 1); + } + + @Override + public void forEachRemaining(Action action) { + if (action == null) { + throw new NullPointerException(); + } + for (Node p; (p = advance()) != null;) { + action.apply(p.key); + } + } + + @Override + public boolean tryAdvance(Action action) { + if (action == null) { + throw new NullPointerException(); + } + Node p; + if ((p = advance()) == null) { + return false; + } + action.apply(p.key); + return true; + } + + @Override + public long estimateSize() { return this.est; } + + } + + static final class ValueSpliterator extends Traverser + implements ConcurrentHashMapSpliterator { + long est; // size estimate + ValueSpliterator(Node[] tab, int size, int index, int limit, + long est) { + super(tab, size, index, limit); + this.est = est; + } + + @Override + public ConcurrentHashMapSpliterator trySplit() { + int i, f, h; + return (h = (i = this.baseIndex) + (f = this.baseLimit) >>> 1) <= i ? null : + new ValueSpliterator(this.tab, this.baseSize, this.baseLimit = h, + f, this.est >>>= 1); + } + + @Override + public void forEachRemaining(Action action) { + if (action == null) { + throw new NullPointerException(); + } + for (Node p; (p = advance()) != null;) { + action.apply(p.val); + } + } + + @Override + public boolean tryAdvance(Action action) { + if (action == null) { + throw new NullPointerException(); + } + Node p; + if ((p = advance()) == null) { + return false; + } + action.apply(p.val); + return true; + } + + @Override + public long estimateSize() { return this.est; } + + } + + static final class EntrySpliterator extends Traverser + implements ConcurrentHashMapSpliterator> { + final ConcurrentHashMapV8 map; // To export MapEntry + long est; // size estimate + EntrySpliterator(Node[] tab, int size, int index, int limit, + long est, ConcurrentHashMapV8 map) { + super(tab, size, index, limit); + this.map = map; + this.est = est; + } + + @Override + public ConcurrentHashMapSpliterator> trySplit() { + int i, f, h; + return (h = (i = this.baseIndex) + (f = this.baseLimit) >>> 1) <= i ? null : + new EntrySpliterator(this.tab, this.baseSize, this.baseLimit = h, + f, this.est >>>= 1, this.map); + } + + @Override + public void forEachRemaining(Action> action) { + if (action == null) { + throw new NullPointerException(); + } + for (Node p; (p = advance()) != null; ) { + action.apply(new MapEntry(p.key, p.val, this.map)); + } + } + + @Override + public boolean tryAdvance(Action> action) { + if (action == null) { + throw new NullPointerException(); + } + Node p; + if ((p = advance()) == null) { + return false; + } + action.apply(new MapEntry(p.key, p.val, this.map)); + return true; + } + + @Override + public long estimateSize() { return this.est; } + + } + + /* ----------------Views -------------- */ + + /** + * Base class for views. + */ + abstract static class CollectionView + implements Collection, java.io.Serializable { + private static final long serialVersionUID = 7249069246763182397L; + final ConcurrentHashMapV8 map; + CollectionView(ConcurrentHashMapV8 map) { this.map = map; } + + /** + * Returns the map backing this view. + * + * @return the map backing this view + */ + public ConcurrentHashMapV8 getMap() { return this.map; } + + /** + * Removes all of the elements from this view, by removing all + * the mappings from the map backing this view. + */ + @Override + public final void clear() { this.map.clear(); } + @Override + public final int size() { return this.map.size(); } + @Override + public final boolean isEmpty() { return this.map.isEmpty(); } + + // implementations below rely on concrete classes supplying these + // abstract methods + /** + * Returns a "weakly consistent" iterator that will never + * throw {@link ConcurrentModificationException}, and + * guarantees to traverse elements as they existed upon + * construction of the iterator, and may (but is not + * guaranteed to) reflect any modifications subsequent to + * construction. + */ + @Override + public abstract Iterator iterator(); + @Override + public abstract boolean contains(Object o); + @Override + public abstract boolean remove(Object o); + + private static final String oomeMsg = "Required array size too large"; + + @Override + public final Object[] toArray() { + long sz = this.map.mappingCount(); + if (sz > MAX_ARRAY_SIZE) { + throw new OutOfMemoryError(oomeMsg); + } + int n = (int)sz; + Object[] r = new Object[n]; + int i = 0; + for (E e : this) { + if (i == n) { + if (n >= MAX_ARRAY_SIZE) { + throw new OutOfMemoryError(oomeMsg); + } + if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1) { + n = MAX_ARRAY_SIZE; + } else { + n += (n >>> 1) + 1; + } + r = Arrays.copyOf(r, n); + } + r[i++] = e; + } + return i == n ? r : Arrays.copyOf(r, i); + } + + @Override + @SuppressWarnings("unchecked") + public final T[] toArray(T[] a) { + long sz = this.map.mappingCount(); + if (sz > MAX_ARRAY_SIZE) { + throw new OutOfMemoryError(oomeMsg); + } + int m = (int)sz; + T[] r = a.length >= m ? a : + (T[])java.lang.reflect.Array + .newInstance(a.getClass().getComponentType(), m); + int n = r.length; + int i = 0; + for (E e : this) { + if (i == n) { + if (n >= MAX_ARRAY_SIZE) { + throw new OutOfMemoryError(oomeMsg); + } + if (n >= MAX_ARRAY_SIZE - (MAX_ARRAY_SIZE >>> 1) - 1) { + n = MAX_ARRAY_SIZE; + } else { + n += (n >>> 1) + 1; + } + r = Arrays.copyOf(r, n); + } + r[i++] = (T)e; + } + if (a == r && i < n) { + r[i] = null; // null-terminate + return r; + } + return i == n ? r : Arrays.copyOf(r, i); + } + + /** + * Returns a string representation of this collection. + * The string representation consists of the string representations + * of the collection's elements in the order they are returned by + * its iterator, enclosed in square brackets ({@code "[]"}). + * Adjacent elements are separated by the characters {@code ", "} + * (comma and space). Elements are converted to strings as by + * {@link String#valueOf(Object)}. + * + * @return a string representation of this collection + */ + @Override + public final String toString() { + StringBuilder sb = new StringBuilder(); + sb.append('['); + Iterator it = iterator(); + if (it.hasNext()) { + for (;;) { + Object e = it.next(); + sb.append(e == this ? "(this Collection)" : e); + if (!it.hasNext()) { + break; + } + sb.append(',').append(' '); + } + } + return sb.append(']').toString(); + } + + @Override + public final boolean containsAll(Collection c) { + if (c != this) { + for (Object e : c) { + if (e == null || !contains(e)) { + return false; + } + } + } + return true; + } + + @Override + public final boolean removeAll(Collection c) { + boolean modified = false; + for (Iterator it = iterator(); it.hasNext();) { + if (c.contains(it.next())) { + it.remove(); + modified = true; + } + } + return modified; + } + + @Override + public final boolean retainAll(Collection c) { + boolean modified = false; + for (Iterator it = iterator(); it.hasNext();) { + if (!c.contains(it.next())) { + it.remove(); + modified = true; + } + } + return modified; + } + + } + + /** + * A view of a ConcurrentHashMapV8 as a {@link Set} of keys, in + * which additions may optionally be enabled by mapping to a + * common value. This class cannot be directly instantiated. + * See {@link #keySet() keySet()}, + * {@link #keySet(Object) keySet(V)}, + * {@link #newKeySet() newKeySet()}, + * {@link #newKeySet(int) newKeySet(int)}. + * + * @since 1.8 + */ + public static class KeySetView extends CollectionView + implements Set, java.io.Serializable { + private static final long serialVersionUID = 7249069246763182397L; + private final V value; + KeySetView(ConcurrentHashMapV8 map, V value) { // non-public + super(map); + this.value = value; + } + + /** + * Returns the default mapped value for additions, + * or {@code null} if additions are not supported. + * + * @return the default mapped value for additions, or {@code null} + * if not supported + */ + public V getMappedValue() { return this.value; } + + /** + * {@inheritDoc} + * @throws NullPointerException if the specified key is null + */ + @Override + public boolean contains(Object o) { return this.map.containsKey(o); } + + /** + * Removes the key from this map view, by removing the key (and its + * corresponding value) from the backing map. This method does + * nothing if the key is not in the map. + * + * @param o the key to be removed from the backing map + * @return {@code true} if the backing map contained the specified key + * @throws NullPointerException if the specified key is null + */ + @Override + public boolean remove(Object o) { return this.map.remove(o) != null; } + + /** + * @return an iterator over the keys of the backing map + */ + @Override + public Iterator iterator() { + Node[] t; + ConcurrentHashMapV8 m = this.map; + int f = (t = m.table) == null ? 0 : t.length; + return new KeyIterator(t, f, 0, f, m); + } + + /** + * Adds the specified key to this set view by mapping the key to + * the default mapped value in the backing map, if defined. + * + * @param e key to be added + * @return {@code true} if this set changed as a result of the call + * @throws NullPointerException if the specified key is null + * @throws UnsupportedOperationException if no default mapped value + * for additions was provided + */ + @Override + public boolean add(K e) { + V v; + if ((v = this.value) == null) { + throw new UnsupportedOperationException(); + } + return this.map.putVal(e, v, true) == null; + } + + /** + * Adds all of the elements in the specified collection to this set, + * as if by calling {@link #add} on each one. + * + * @param c the elements to be inserted into this set + * @return {@code true} if this set changed as a result of the call + * @throws NullPointerException if the collection or any of its + * elements are {@code null} + * @throws UnsupportedOperationException if no default mapped value + * for additions was provided + */ + @Override + public boolean addAll(Collection c) { + boolean added = false; + V v; + if ((v = this.value) == null) { + throw new UnsupportedOperationException(); + } + for (K e : c) { + if (this.map.putVal(e, v, true) == null) { + added = true; + } + } + return added; + } + + @Override + public int hashCode() { + int h = 0; + for (K e : this) { + h += e.hashCode(); + } + return h; + } + + @Override + public boolean equals(Object o) { + Set c; + return o instanceof Set && + ((c = (Set)o) == this || + containsAll(c) && c.containsAll(this)); + } + + public ConcurrentHashMapSpliterator spliterator() { + Node[] t; + ConcurrentHashMapV8 m = this.map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new KeySpliterator(t, f, 0, f, n < 0L ? 0L : n); + } + + public void forEach(Action action) { + if (action == null) { + throw new NullPointerException(); + } + Node[] t; + if ((t = this.map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + action.apply(p.key); + } + } + } + } + + /** + * A view of a ConcurrentHashMapV8 as a {@link Collection} of + * values, in which additions are disabled. This class cannot be + * directly instantiated. See {@link #values()}. + */ + static final class ValuesView extends CollectionView + implements Collection, java.io.Serializable { + private static final long serialVersionUID = 2249069246763182397L; + ValuesView(ConcurrentHashMapV8 map) { super(map); } + @Override + public final boolean contains(Object o) { + return this.map.containsValue(o); + } + + @Override + public final boolean remove(Object o) { + if (o != null) { + for (Iterator it = iterator(); it.hasNext();) { + if (o.equals(it.next())) { + it.remove(); + return true; + } + } + } + return false; + } + + @Override + public final Iterator iterator() { + ConcurrentHashMapV8 m = this.map; + Node[] t; + int f = (t = m.table) == null ? 0 : t.length; + return new ValueIterator(t, f, 0, f, m); + } + + @Override + public final boolean add(V e) { + throw new UnsupportedOperationException(); + } + @Override + public final boolean addAll(Collection c) { + throw new UnsupportedOperationException(); + } + + public ConcurrentHashMapSpliterator spliterator() { + Node[] t; + ConcurrentHashMapV8 m = this.map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new ValueSpliterator(t, f, 0, f, n < 0L ? 0L : n); + } + + public void forEach(Action action) { + if (action == null) { + throw new NullPointerException(); + } + Node[] t; + if ((t = this.map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + action.apply(p.val); + } + } + } + } + + /** + * A view of a ConcurrentHashMapV8 as a {@link Set} of (key, value) + * entries. This class cannot be directly instantiated. See + * {@link #entrySet()}. + */ + static final class EntrySetView extends CollectionView> + implements Set>, java.io.Serializable { + private static final long serialVersionUID = 2249069246763182397L; + EntrySetView(ConcurrentHashMapV8 map) { super(map); } + + @Override + public boolean contains(Object o) { + Object k, v, r; Map.Entry e; + return o instanceof Map.Entry && + (k = (e = (Map.Entry)o).getKey()) != null && + (r = this.map.get(k)) != null && + (v = e.getValue()) != null && + (v == r || v.equals(r)); + } + + @Override + public boolean remove(Object o) { + Object k, v; Map.Entry e; + return o instanceof Map.Entry && + (k = (e = (Map.Entry)o).getKey()) != null && + (v = e.getValue()) != null && + this.map.remove(k, v); + } + + /** + * @return an iterator over the entries of the backing map + */ + @Override + public Iterator> iterator() { + ConcurrentHashMapV8 m = this.map; + Node[] t; + int f = (t = m.table) == null ? 0 : t.length; + return new EntryIterator(t, f, 0, f, m); + } + + @Override + public boolean add(Entry e) { + return this.map.putVal(e.getKey(), e.getValue(), false) == null; + } + + @Override + public boolean addAll(Collection> c) { + boolean added = false; + for (Entry e : c) { + if (add(e)) { + added = true; + } + } + return added; + } + + @Override + public final int hashCode() { + int h = 0; + Node[] t; + if ((t = this.map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + h += p.hashCode(); + } + } + return h; + } + + @Override + public final boolean equals(Object o) { + Set c; + return o instanceof Set && + ((c = (Set)o) == this || + containsAll(c) && c.containsAll(this)); + } + + public ConcurrentHashMapSpliterator> spliterator() { + Node[] t; + ConcurrentHashMapV8 m = this.map; + long n = m.sumCount(); + int f = (t = m.table) == null ? 0 : t.length; + return new EntrySpliterator(t, f, 0, f, n < 0L ? 0L : n, m); + } + + public void forEach(Action> action) { + if (action == null) { + throw new NullPointerException(); + } + Node[] t; + if ((t = this.map.table) != null) { + Traverser it = new Traverser(t, t.length, 0, t.length); + for (Node p; (p = it.advance()) != null; ) { + action.apply(new MapEntry(p.key, p.val, this.map)); + } + } + } + + } + + /* ---------------- Counters -------------- */ + + // Adapted from LongAdder and Striped64. + // See their internal docs for explanation. + + // A padded cell for distributing counts + static final class CounterCell { + volatile long p0, p1, p2, p3, p4, p5, p6; + volatile long value; + volatile long q0, q1, q2, q3, q4, q5, q6; + CounterCell(long x) { this.value = x; } + } + + /** + * Holder for the thread-local hash code determining which + * CounterCell to use. The code is initialized via the + * counterHashCodeGenerator, but may be moved upon collisions. + */ + static final class CounterHashCode { + int code; + } + + /** + * Generates initial value for per-thread CounterHashCodes. + */ + static final AtomicInteger counterHashCodeGenerator = new AtomicInteger(); + + /** + * Increment for counterHashCodeGenerator. See class ThreadLocal + * for explanation. + */ + static final int SEED_INCREMENT = 0x61c88647; + + /** + * Per-thread counter hash codes. Shared across all instances. + */ + static final ThreadLocal threadCounterHashCode = + new ThreadLocal(); + + + final long sumCount() { + CounterCell[] as = this.counterCells; CounterCell a; + long sum = this.baseCount; + if (as != null) { + for (int i = 0; i < as.length; ++i) { + if ((a = as[i]) != null) { + sum += a.value; + } + } + } + return sum; + } + + // See LongAdder version for explanation + private final void fullAddCount(long x, CounterHashCode hc, + boolean wasUncontended) { + int h; + if (hc == null) { + hc = new CounterHashCode(); + int s = counterHashCodeGenerator.addAndGet(SEED_INCREMENT); + h = hc.code = s == 0 ? 1 : s; // Avoid zero + threadCounterHashCode.set(hc); + } else { + h = hc.code; + } + boolean collide = false; // True if last slot nonempty + for (;;) { + CounterCell[] as; CounterCell a; int n; long v; + if ((as = this.counterCells) != null && (n = as.length) > 0) { + if ((a = as[n - 1 & h]) == null) { + if (this.cellsBusy == 0) { // Try to attach new Cell + CounterCell r = new CounterCell(x); // Optimistic create + if (this.cellsBusy == 0 && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + boolean created = false; + try { // Recheck under lock + CounterCell[] rs; int m, j; + if ((rs = this.counterCells) != null && + (m = rs.length) > 0 && + rs[j = m - 1 & h] == null) { + rs[j] = r; + created = true; + } + } finally { + this.cellsBusy = 0; + } + if (created) { + break; + } + continue; // Slot is now non-empty + } + } + collide = false; + } + else if (!wasUncontended) { + wasUncontended = true; // Continue after rehash + } else if (U.compareAndSwapLong(a, CELLVALUE, v = a.value, v + x)) { + break; + } else if (this.counterCells != as || n >= NCPU) { + collide = false; // At max size or stale + } else if (!collide) { + collide = true; + } else if (this.cellsBusy == 0 && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + try { + if (this.counterCells == as) {// Expand table unless stale + CounterCell[] rs = new CounterCell[n << 1]; + for (int i = 0; i < n; ++i) { + rs[i] = as[i]; + } + this.counterCells = rs; + } + } finally { + this.cellsBusy = 0; + } + collide = false; + continue; // Retry with expanded table + } + h ^= h << 13; // Rehash + h ^= h >>> 17; + h ^= h << 5; + } + else if (this.cellsBusy == 0 && this.counterCells == as && + U.compareAndSwapInt(this, CELLSBUSY, 0, 1)) { + boolean init = false; + try { // Initialize table + if (this.counterCells == as) { + CounterCell[] rs = new CounterCell[2]; + rs[h & 1] = new CounterCell(x); + this.counterCells = rs; + init = true; + } + } finally { + this.cellsBusy = 0; + } + if (init) { + break; + } + } + else if (U.compareAndSwapLong(this, BASECOUNT, v = this.baseCount, v + x)) + { + break; // Fall back on using base + } + } + hc.code = h; // Record index for next time + } + + // Unsafe mechanics + private static final sun.misc.Unsafe U; + private static final long SIZECTL; + private static final long TRANSFERINDEX; + private static final long TRANSFERORIGIN; + private static final long BASECOUNT; + private static final long CELLSBUSY; + private static final long CELLVALUE; + private static final long ABASE; + private static final int ASHIFT; + + static { + try { + U = getUnsafe(); + Class k = ConcurrentHashMapV8.class; + SIZECTL = U.objectFieldOffset + (k.getDeclaredField("sizeCtl")); + TRANSFERINDEX = U.objectFieldOffset + (k.getDeclaredField("transferIndex")); + TRANSFERORIGIN = U.objectFieldOffset + (k.getDeclaredField("transferOrigin")); + BASECOUNT = U.objectFieldOffset + (k.getDeclaredField("baseCount")); + CELLSBUSY = U.objectFieldOffset + (k.getDeclaredField("cellsBusy")); + Class ck = CounterCell.class; + CELLVALUE = U.objectFieldOffset + (ck.getDeclaredField("value")); + Class ak = Node[].class; + ABASE = U.arrayBaseOffset(ak); + int scale = U.arrayIndexScale(ak); + if ((scale & scale - 1) != 0) { + throw new Error("data type scale not a power of two"); + } + ASHIFT = 31 - Integer.numberOfLeadingZeros(scale); + } catch (Exception e) { + throw new Error(e); + } + } + + /** + * Returns a sun.misc.Unsafe. Suitable for use in a 3rd party package. + * Replace with a simple call to Unsafe.getUnsafe when integrating + * into a jdk. + * + * @return a sun.misc.Unsafe + */ + private static sun.misc.Unsafe getUnsafe() { + try { + return sun.misc.Unsafe.getUnsafe(); + } catch (SecurityException tryReflectionInstead) {} + try { + return java.security.AccessController.doPrivileged + (new java.security.PrivilegedExceptionAction() { + @Override + public sun.misc.Unsafe run() throws Exception { + Class k = sun.misc.Unsafe.class; + for (java.lang.reflect.Field f : k.getDeclaredFields()) { + f.setAccessible(true); + Object x = f.get(null); + if (k.isInstance(x)) { + return k.cast(x); + } + } + throw new NoSuchFieldError("the Unsafe"); + }}); + } catch (java.security.PrivilegedActionException e) { + throw new RuntimeException("Could not initialize intrinsics", + e.getCause()); + } + } +} \ No newline at end of file diff --git a/src/main/java/net/engio/mbassy/multi/common/IdentityObjectTree.java b/src/main/java/net/engio/mbassy/multi/common/IdentityObjectTree.java index 334159e..195338d 100644 --- a/src/main/java/net/engio/mbassy/multi/common/IdentityObjectTree.java +++ b/src/main/java/net/engio/mbassy/multi/common/IdentityObjectTree.java @@ -21,12 +21,12 @@ public class IdentityObjectTree { public IdentityObjectTree() { } - // can be overridded to provide a custom backing map + /** + * can be overridden to provide a custom backing map + */ protected Map> createChildren() { -//TODO: this needs to be concurrent?!?!? return new ConcurrentHashMap>(2, 0.75f, 1); -// return new Reference2ReferenceOpenHashMap>(2, 0.75f); - } + } public VALUE getValue() { VALUE returnValue = this.value; diff --git a/src/main/java/net/engio/mbassy/multi/common/NamedThreadFactory.java b/src/main/java/net/engio/mbassy/multi/common/NamedThreadFactory.java index 189e2f4..2393c49 100644 --- a/src/main/java/net/engio/mbassy/multi/common/NamedThreadFactory.java +++ b/src/main/java/net/engio/mbassy/multi/common/NamedThreadFactory.java @@ -76,11 +76,16 @@ public class NamedThreadFactory implements ThreadFactory { stringBuilder.append('-'); stringBuilder.append(this.threadID.getAndIncrement()); - // stack size is arbitrary based on JVM implementation. Default is 0 + + return newThread(stringBuilder.toString(), r); + } + + public Thread newThread(String name, Runnable r) { + // stack size is arbitrary based on JVM implementation. Default is 0 // 8k is the size of the android stack. Depending on the version of android, this can either change, or will always be 8k // To be honest, 8k is pretty reasonable for an asynchronous/event based system (32bit) or 16k (64bit) // Setting the size MAY or MAY NOT have any effect!!! - Thread t = new Thread(this.group, r, stringBuilder.toString(), NamedThreadFactory.stackSizeForThreads); + Thread t = new Thread(this.group, r, name, NamedThreadFactory.stackSizeForThreads); t.setDaemon(true);// FORCE these threads to finish before allowing the JVM to exit if (t.getPriority() != Thread.NORM_PRIORITY) { t.setPriority(Thread.NORM_PRIORITY); diff --git a/src/main/java/net/engio/mbassy/multi/common/StrongConcurrentSet.java b/src/main/java/net/engio/mbassy/multi/common/StrongConcurrentSet.java index 4205563..1acfcb2 100644 --- a/src/main/java/net/engio/mbassy/multi/common/StrongConcurrentSet.java +++ b/src/main/java/net/engio/mbassy/multi/common/StrongConcurrentSet.java @@ -1,6 +1,5 @@ package net.engio.mbassy.multi.common; import java.util.Iterator; -import java.util.concurrent.ConcurrentHashMap; /** * This implementation uses strong references to the elements. @@ -17,7 +16,7 @@ public class StrongConcurrentSet extends AbstractConcurrentSet { } public StrongConcurrentSet(int size, float loadFactor) { - super(new ConcurrentHashMap>(size, loadFactor, 1)); + super(new ConcurrentHashMapV8>(size, loadFactor)); } @Override diff --git a/src/main/java/net/engio/mbassy/multi/listener/MessageHandler.java b/src/main/java/net/engio/mbassy/multi/listener/MessageHandler.java index 8412fc8..c0b594a 100644 --- a/src/main/java/net/engio/mbassy/multi/listener/MessageHandler.java +++ b/src/main/java/net/engio/mbassy/multi/listener/MessageHandler.java @@ -61,6 +61,7 @@ public class MessageHandler { return this.isSynchronized; } + // only in unit test public boolean isFromListener(Class listener){ return this.listenerConfig.isFromListener(listener); } diff --git a/src/main/java/net/engio/mbassy/multi/listener/MessageListener.java b/src/main/java/net/engio/mbassy/multi/listener/MessageListener.java index 4e4e42a..1e67957 100644 --- a/src/main/java/net/engio/mbassy/multi/listener/MessageListener.java +++ b/src/main/java/net/engio/mbassy/multi/listener/MessageListener.java @@ -28,15 +28,11 @@ public class MessageListener { this.listenerDefinition = listenerDefinition; } + // only in unit test public boolean isFromListener(Class listener) { return this.listenerDefinition.equals(listener); } - public MessageListener addHandlers(Collection c) { - this.handlers.addAll(c); - return this; - } - public boolean addHandler(MessageHandler messageHandler) { return this.handlers.add(messageHandler); } @@ -44,8 +40,4 @@ public class MessageListener { public Collection getHandlers() { return this.handlers; } - - public Class getListerDefinition() { - return this.listenerDefinition; - } } diff --git a/src/main/java/net/engio/mbassy/multi/subscription/EventProcessor.java b/src/main/java/net/engio/mbassy/multi/subscription/EventProcessor.java new file mode 100644 index 0000000..5a43374 --- /dev/null +++ b/src/main/java/net/engio/mbassy/multi/subscription/EventProcessor.java @@ -0,0 +1,47 @@ +package net.engio.mbassy.multi.subscription; + +import net.engio.mbassy.multi.PubSubSupport; + +import com.lmax.disruptor.WorkHandler; + +/** + * @author dorkbox, llc + * Date: 2/2/15 + */ +public class EventProcessor implements WorkHandler { + private final PubSubSupport publisher; + + public EventProcessor(PubSubSupport publisher) { + this.publisher = publisher; + } + + @Override + public void onEvent(MessageHolder event) throws Exception { + MessageType messageType = event.messageType; + switch (messageType) { + case ONE: { + this.publisher.publish(event.message1); + event.message1 = null; // cleanup + return; + } + case TWO: { + this.publisher.publish(event.message1, event.message2); + event.message1 = null; // cleanup + event.message2 = null; // cleanup + return; + } + case THREE: { + this.publisher.publish(event.message1, event.message2, event.message3); + event.message1 = null; // cleanup + event.message2 = null; // cleanup + event.message3 = null; // cleanup + return; + } + case ARRAY: { + this.publisher.publish(event.messages); + event.messages = null; // cleanup + return; + } + } + } +} \ No newline at end of file diff --git a/src/main/java/net/engio/mbassy/multi/subscription/MessageHolder.java b/src/main/java/net/engio/mbassy/multi/subscription/MessageHolder.java new file mode 100644 index 0000000..2070afe --- /dev/null +++ b/src/main/java/net/engio/mbassy/multi/subscription/MessageHolder.java @@ -0,0 +1,18 @@ +package net.engio.mbassy.multi.subscription; + + +/** + * @author dorkbox, llc + * Date: 2/2/15 + */ +public class MessageHolder { + public MessageType messageType = MessageType.ONE; + + public Object message1 = null; + public Object message2 = null; + public Object message3 = null; + public Object[] messages = null; + + public MessageHolder() { + } +} \ No newline at end of file diff --git a/src/main/java/net/engio/mbassy/multi/subscription/MessageType.java b/src/main/java/net/engio/mbassy/multi/subscription/MessageType.java new file mode 100644 index 0000000..bd7a811 --- /dev/null +++ b/src/main/java/net/engio/mbassy/multi/subscription/MessageType.java @@ -0,0 +1,8 @@ +package net.engio.mbassy.multi.subscription; +/** + * @author dorkbox, llc + * Date: 2/2/15 + */ +public enum MessageType { + ONE, TWO, THREE, ARRAY +} \ No newline at end of file diff --git a/src/main/java/net/engio/mbassy/multi/subscription/Subscription.java b/src/main/java/net/engio/mbassy/multi/subscription/Subscription.java index f998dc3..51b4e93 100644 --- a/src/main/java/net/engio/mbassy/multi/subscription/Subscription.java +++ b/src/main/java/net/engio/mbassy/multi/subscription/Subscription.java @@ -38,9 +38,9 @@ public class Subscription { private final MessageHandler handlerMetadata; private final IHandlerInvocation invocation; - private final Collection listeners; + private final StrongConcurrentSet listeners; - Subscription(MessageHandler handler) { + public Subscription(MessageHandler handler) { this.handlerMetadata = handler; this.listeners = new StrongConcurrentSet(); @@ -60,6 +60,10 @@ public class Subscription { return this.handlerMetadata.acceptsSubtypes(); } + public boolean isEmpty() { + return this.listeners.isEmpty(); + } + public void subscribe(Object listener) { this.listeners.add(listener); } @@ -96,38 +100,34 @@ public class Subscription { try { invocation.invoke(listener, handler, handleIndex, message); } catch (IllegalAccessException e) { - e.printStackTrace(); errorHandler.handlePublicationError(new PublicationError() - .setMessage("Error during invocation of message handler. " + - "The class or method is not accessible") + .setMessage("Error during invocation of message handler. " + + "The class or method is not accessible") .setCause(e) .setMethodName(handler.getMethodNames()[handleIndex]) .setListener(listener) .setPublishedObject(message)); } catch (IllegalArgumentException e) { - e.printStackTrace(); errorHandler.handlePublicationError(new PublicationError() - .setMessage("Error during invocation of message handler. " + - "Wrong arguments passed to method. Was: " + message.getClass() - + "Expected: " + handler.getParameterTypes()[0]) + .setMessage("Error during invocation of message handler. " + + "Wrong arguments passed to method. Was: " + message.getClass() + + "Expected: " + handler.getParameterTypes()[0]) .setCause(e) .setMethodName(handler.getMethodNames()[handleIndex]) .setListener(listener) .setPublishedObject(message)); } catch (InvocationTargetException e) { - e.printStackTrace(); errorHandler.handlePublicationError(new PublicationError() - .setMessage("Error during invocation of message handler. " + - "Message handler threw exception") + .setMessage("Error during invocation of message handler. " + + "Message handler threw exception") .setCause(e) .setMethodName(handler.getMethodNames()[handleIndex]) .setListener(listener) .setPublishedObject(message)); } catch (Throwable e) { - e.printStackTrace(); errorHandler.handlePublicationError(new PublicationError() - .setMessage("Error during invocation of message handler. " + - "The handler code threw an exception") + .setMessage("Error during invocation of message handler. " + + "The handler code threw an exception") .setCause(e) .setMethodName(handler.getMethodNames()[handleIndex]) .setListener(listener) diff --git a/src/test/java/net/engio/mbassy/multi/MBassadorTest.java b/src/test/java/net/engio/mbassy/multi/MBassadorTest.java index 92673fc..5405112 100644 --- a/src/test/java/net/engio/mbassy/multi/MBassadorTest.java +++ b/src/test/java/net/engio/mbassy/multi/MBassadorTest.java @@ -2,7 +2,6 @@ package net.engio.mbassy.multi; import java.util.concurrent.atomic.AtomicInteger; -import net.engio.mbassy.multi.MultiMBassador; import net.engio.mbassy.multi.common.ConcurrentExecutor; import net.engio.mbassy.multi.common.ListenerFactory; import net.engio.mbassy.multi.common.MessageBusTest; @@ -77,19 +76,22 @@ public class MBassadorTest extends MessageBusTest { Runnable publishAndCheck = new Runnable() { @Override public void run() { - bus.publishAsync(MessageTypes.Simple); - } }; ConcurrentExecutor.runConcurrent(publishAndCheck, 1); - messageManager.waitForMessages(processingTimeInMS); + while (bus.hasPendingMessages()) { + pause(10); + } MessageTypes.resetAll(); ConcurrentExecutor.runConcurrent(publishAndCheck, ConcurrentUnits); - messageManager.waitForMessages(processingTimeInMS); + while (bus.hasPendingMessages()) { + pause(10); + } + messageManager.waitForMessages(600); } @@ -119,14 +121,18 @@ public class MBassadorTest extends MessageBusTest { // single threaded ConcurrentExecutor.runConcurrent(publishAndCheck, 1); - pause(processingTimeInMS); + while (bus.hasPendingMessages()) { + pause(10); + } assertEquals(InstancesPerListener, exceptionCount.get()); // multi threaded exceptionCount.set(0); ConcurrentExecutor.runConcurrent(publishAndCheck, ConcurrentUnits); - pause(processingTimeInMS); + while (bus.hasPendingMessages()) { + pause(10); + } assertEquals(InstancesPerListener * ConcurrentUnits, exceptionCount.get()); bus.shutdown(); diff --git a/src/test/java/net/engio/mbassy/multi/MethodDispatchTest.java b/src/test/java/net/engio/mbassy/multi/MethodDispatchTest.java index 6f6d358..1c73753 100644 --- a/src/test/java/net/engio/mbassy/multi/MethodDispatchTest.java +++ b/src/test/java/net/engio/mbassy/multi/MethodDispatchTest.java @@ -1,6 +1,5 @@ package net.engio.mbassy.multi; -import net.engio.mbassy.multi.IMessageBus; import net.engio.mbassy.multi.annotations.Handler; import net.engio.mbassy.multi.common.MessageBusTest; diff --git a/src/test/java/net/engio/mbassy/multi/SubscriptionManagerTest.java b/src/test/java/net/engio/mbassy/multi/SubscriptionManagerTest.java index 7bf6939..4bfeee9 100644 --- a/src/test/java/net/engio/mbassy/multi/SubscriptionManagerTest.java +++ b/src/test/java/net/engio/mbassy/multi/SubscriptionManagerTest.java @@ -20,7 +20,6 @@ import net.engio.mbassy.multi.messages.IMultipartMessage; import net.engio.mbassy.multi.messages.MessageTypes; import net.engio.mbassy.multi.messages.MultipartMessage; import net.engio.mbassy.multi.messages.StandardMessage; -import net.engio.mbassy.multi.subscription.SubscriptionManager; import org.junit.Test; @@ -162,8 +161,8 @@ public class SubscriptionManagerTest extends AssertSupport { Overloading.ListenerBase.class, Overloading.ListenerSub.class); - SubscriptionManager subscriptionManager = new SubscriptionManager(ConcurrentUnits); - ConcurrentExecutor.runConcurrent(TestUtil.subscriber(subscriptionManager, listeners), ConcurrentUnits); + SubscriptionManager subscriptionManager = new SubscriptionManager(1); + ConcurrentExecutor.runConcurrent(TestUtil.subscriber(subscriptionManager, listeners), 1); SubscriptionValidator expectedSubscriptions = new SubscriptionValidator(listeners) .listener(Overloading.ListenerBase.class).handles(Overloading.TestMessageA.class, Overloading.TestMessageA.class) @@ -181,13 +180,13 @@ public class SubscriptionManagerTest extends AssertSupport { } private void runTestWith(final ListenerFactory listeners, final SubscriptionValidator validator){ - final SubscriptionManager subscriptionManager = new SubscriptionManager(ConcurrentUnits); + final SubscriptionManager subscriptionManager = new SubscriptionManager(1); - ConcurrentExecutor.runConcurrent(TestUtil.subscriber(subscriptionManager, listeners), ConcurrentUnits); + ConcurrentExecutor.runConcurrent(TestUtil.subscriber(subscriptionManager, listeners), 1); validator.validate(subscriptionManager); - ConcurrentExecutor.runConcurrent(TestUtil.unsubscriber(subscriptionManager, listeners), ConcurrentUnits); + ConcurrentExecutor.runConcurrent(TestUtil.unsubscriber(subscriptionManager, listeners), 1); listeners.clear(); validator.clear(); diff --git a/src/test/java/net/engio/mbassy/multi/common/MessageBusTest.java b/src/test/java/net/engio/mbassy/multi/common/MessageBusTest.java index 997539c..1bfa546 100644 --- a/src/test/java/net/engio/mbassy/multi/common/MessageBusTest.java +++ b/src/test/java/net/engio/mbassy/multi/common/MessageBusTest.java @@ -20,7 +20,6 @@ public abstract class MessageBusTest extends AssertSupport { // this value probably needs to be adjusted depending on the performance of the underlying plattform // otherwise the tests will fail since asynchronous processing might not have finished when // evaluation is run - protected static final int processingTimeInMS = 6000; protected static final int InstancesPerListener = 5000; protected static final int ConcurrentUnits = 10; protected static final int IterationsPerThread = 100; diff --git a/src/test/java/net/engio/mbassy/multi/common/SubscriptionValidator.java b/src/test/java/net/engio/mbassy/multi/common/SubscriptionValidator.java index 6410a79..e1d7aec 100644 --- a/src/test/java/net/engio/mbassy/multi/common/SubscriptionValidator.java +++ b/src/test/java/net/engio/mbassy/multi/common/SubscriptionValidator.java @@ -1,13 +1,14 @@ package net.engio.mbassy.multi.common; +import java.util.ArrayDeque; import java.util.Collection; import java.util.HashSet; import java.util.LinkedList; import java.util.List; import java.util.Set; +import net.engio.mbassy.multi.SubscriptionManager; import net.engio.mbassy.multi.subscription.Subscription; -import net.engio.mbassy.multi.subscription.SubscriptionManager; /** * @@ -39,13 +40,24 @@ public class SubscriptionValidator extends AssertSupport{ // for each tuple of subscriber and message type the specified number of listeners must exist public void validate(SubscriptionManager manager) { for (Class messageType : this.messageTypes) { - Collection subscriptions = manager.getSubscriptionsByMessageType(messageType); Collection validationEntries = getEntries(messageType); - assertEquals(subscriptions.size(), validationEntries.size()); + + // we split subs + superSubs into TWO calls. + Collection collection = new ArrayDeque(8); + Collection subscriptions = manager.getSubscriptionsByMessageType(messageType); + if (subscriptions != null) { + collection.addAll(subscriptions); + } + Collection superSubs = manager.getSuperSubscriptions(messageType); + if (superSubs != null) { + collection.addAll(superSubs); + } + + assertEquals(validationEntries.size(), collection.size()); for(ValidationEntry validationValidationEntry : validationEntries){ Subscription matchingSub = null; // one of the subscriptions must belong to the subscriber type - for(Subscription sub : subscriptions){ + for(Subscription sub : collection){ if(sub.belongsTo(validationValidationEntry.subscriber)){ matchingSub = sub; break; diff --git a/src/test/java/net/engio/mbassy/multi/common/TestUtil.java b/src/test/java/net/engio/mbassy/multi/common/TestUtil.java index 89c5772..d5f7d94 100644 --- a/src/test/java/net/engio/mbassy/multi/common/TestUtil.java +++ b/src/test/java/net/engio/mbassy/multi/common/TestUtil.java @@ -1,12 +1,12 @@ package net.engio.mbassy.multi.common; -import net.engio.mbassy.multi.MultiMBassador; -import net.engio.mbassy.multi.PubSubSupport; -import net.engio.mbassy.multi.subscription.SubscriptionManager; - import java.util.Iterator; import java.util.List; +import net.engio.mbassy.multi.MultiMBassador; +import net.engio.mbassy.multi.PubSubSupport; +import net.engio.mbassy.multi.SubscriptionManager; + /** * Todo: Add javadoc * @@ -81,15 +81,16 @@ public class TestUtil { for(int i = 0; i < numberOfThreads; i++){ final int partitionStart = i * partitionSize; - final int partitionEnd = (i+1 < numberOfThreads) + final int partitionEnd = i+1 < numberOfThreads ? partitionStart + partitionSize + 1 : listeners.size(); setupUnits[i] = new Runnable() { private List listenerSubset = listeners.subList(partitionStart, partitionEnd); + @Override public void run() { - for(Object listener : listenerSubset){ + for(Object listener : this.listenerSubset){ bus.subscribe(listener); } }