4349 lines
169 KiB
Java
4349 lines
169 KiB
Java
/*
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* Written by Doug Lea with assistance from members of JCP JSR-166
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* Expert Group and released to the public domain, as explained at
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* http://creativecommons.org/publicdomain/zero/1.0/
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*/
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package dorkbox.util.messagebus.common.adapter;
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import java.io.ObjectStreamField;
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import java.io.Serializable;
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import java.lang.reflect.ParameterizedType;
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import java.lang.reflect.Type;
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import java.util.AbstractMap;
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import java.util.Arrays;
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import java.util.Collection;
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import java.util.ConcurrentModificationException;
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import java.util.Enumeration;
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import java.util.HashMap;
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import java.util.Hashtable;
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import java.util.Iterator;
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import java.util.Map;
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import java.util.NoSuchElementException;
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import java.util.Set;
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import java.util.concurrent.ConcurrentMap;
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import java.util.concurrent.atomic.AtomicInteger;
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import java.util.concurrent.locks.LockSupport;
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import java.util.concurrent.locks.ReentrantLock;
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/*
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* Bulk operations removed in Java 6 backport.
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*/
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/**
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* A hash table supporting full concurrency of retrievals and
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* high expected concurrency for updates. This class obeys the
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* same functional specification as {@link java.util.Hashtable}, and
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* includes versions of methods corresponding to each method of
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* {@code Hashtable}. However, even though all operations are
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* thread-safe, retrieval operations do <em>not</em> entail locking,
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* and there is <em>not</em> any support for locking the entire table
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* in a way that prevents all access. This class is fully
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* interoperable with {@code Hashtable} in programs that rely on its
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* thread safety but not on its synchronization details.
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*
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* <p>Retrieval operations (including {@code get}) generally do not
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* block, so may overlap with update operations (including {@code put}
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* and {@code remove}). Retrievals reflect the results of the most
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* recently <em>completed</em> update operations holding upon their
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* onset. (More formally, an update operation for a given key bears a
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* <em>happens-before</em> relation with any (non-null) retrieval for
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* that key reporting the updated value.) For aggregate operations
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* such as {@code putAll} and {@code clear}, concurrent retrievals may
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* reflect insertion or removal of only some entries. Similarly,
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* Iterators and Enumerations return elements reflecting the state of
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* the hash table at some point at or since the creation of the
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* iterator/enumeration. They do <em>not</em> throw {@link
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* ConcurrentModificationException}. However, iterators are designed
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* to be used by only one thread at a time. Bear in mind that the
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* results of aggregate status methods including {@code size}, {@code
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* isEmpty}, and {@code containsValue} are typically useful only when
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* a map is not undergoing concurrent updates in other threads.
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* Otherwise the results of these methods reflect transient states
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* that may be adequate for monitoring or estimation purposes, but not
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* for program control.
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*
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* <p>The table is dynamically expanded when there are too many
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* collisions (i.e., keys that have distinct hash codes but fall into
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* the same slot modulo the table size), with the expected average
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* effect of maintaining roughly two bins per mapping (corresponding
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* to a 0.75 load factor threshold for resizing). There may be much
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* variance around this average as mappings are added and removed, but
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* overall, this maintains a commonly accepted time/space tradeoff for
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* hash tables. However, resizing this or any other kind of hash
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* table may be a relatively slow operation. When possible, it is a
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* good idea to provide a size estimate as an optional {@code
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* initialCapacity} constructor argument. An additional optional
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* {@code loadFactor} constructor argument provides a further means of
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* customizing initial table capacity by specifying the table density
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* to be used in calculating the amount of space to allocate for the
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* given number of elements. Also, for compatibility with previous
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* versions of this class, constructors may optionally specify an
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* expected {@code concurrencyLevel} as an additional hint for
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* internal sizing. Note that using many keys with exactly the same
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* {@code hashCode()} is a sure way to slow down performance of any
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* hash table. To ameliorate impact, when keys are {@link Comparable},
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* this class may use comparison order among keys to help break ties.
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*
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* <p>A {@link Set} projection of a ConcurrentHashMapV8 may be created
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* (using {@link #newKeySet()} or {@link #newKeySet(int)}), or viewed
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* (using {@link #keySet(Object)} when only keys are of interest, and the
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* mapped values are (perhaps transiently) not used or all take the
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* same mapping value.
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*
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* <p>This class and its views and iterators implement all of the
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* <em>optional</em> methods of the {@link Map} and {@link Iterator}
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* interfaces.
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*
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* <p>Like {@link Hashtable} but unlike {@link HashMap}, this class
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* does <em>not</em> allow {@code null} to be used as a key or value.
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*
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* <p>ConcurrentHashMapV8s support a set of sequential and parallel bulk
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* operations that are designed
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* to be safely, and often sensibly, applied even with maps that are
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* being concurrently updated by other threads; for example, when
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* computing a snapshot summary of the values in a shared registry.
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* There are three kinds of operation, each with four forms, accepting
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* functions with Keys, Values, Entries, and (Key, Value) arguments
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* and/or return values. Because the elements of a ConcurrentHashMapV8
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* are not ordered in any particular way, and may be processed in
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* different orders in different parallel executions, the correctness
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* of supplied functions should not depend on any ordering, or on any
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* other objects or values that may transiently change while
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* computation is in progress; and except for forEach actions, should
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* ideally be side-effect-free. Bulk operations on {@link java.util.Map.Entry}
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* objects do not support method {@code setValue}.
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*
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* <ul>
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* <li> forEach: Perform a given action on each element.
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* A variant form applies a given transformation on each element
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* before performing the action.</li>
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*
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* <li> search: Return the first available non-null result of
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* applying a given function on each element; skipping further
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* search when a result is found.</li>
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*
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* <li> reduce: Accumulate each element. The supplied reduction
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* function cannot rely on ordering (more formally, it should be
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* both associative and commutative). There are five variants:
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*
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* <ul>
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*
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* <li> Plain reductions. (There is not a form of this method for
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* (key, value) function arguments since there is no corresponding
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* return type.)</li>
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*
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* <li> Mapped reductions that accumulate the results of a given
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* function applied to each element.</li>
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*
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* <li> Reductions to scalar doubles, longs, and ints, using a
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* given basis value.</li>
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*
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* </ul>
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* </li>
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* </ul>
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*
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* <p>These bulk operations accept a {@code parallelismThreshold}
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* argument. Methods proceed sequentially if the current map size is
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* estimated to be less than the given threshold. Using a value of
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* {@code Long.MAX_VALUE} suppresses all parallelism. Using a value
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* of {@code 1} results in maximal parallelism by partitioning into
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* enough subtasks to fully utilize the {@link
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* ForkJoinPool#commonPool()} that is used for all parallel
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* computations. Normally, you would initially choose one of these
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* extreme values, and then measure performance of using in-between
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* values that trade off overhead versus throughput.
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*
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* <p>The concurrency properties of bulk operations follow
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* from those of ConcurrentHashMapV8: Any non-null result returned
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* from {@code get(key)} and related access methods bears a
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* happens-before relation with the associated insertion or
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* update. The result of any bulk operation reflects the
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* composition of these per-element relations (but is not
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* necessarily atomic with respect to the map as a whole unless it
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* is somehow known to be quiescent). Conversely, because keys
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* and values in the map are never null, null serves as a reliable
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* atomic indicator of the current lack of any result. To
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* maintain this property, null serves as an implicit basis for
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* all non-scalar reduction operations. For the double, long, and
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* int versions, the basis should be one that, when combined with
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* any other value, returns that other value (more formally, it
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* should be the identity element for the reduction). Most common
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* reductions have these properties; for example, computing a sum
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* with basis 0 or a minimum with basis MAX_VALUE.
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*
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* <p>Search and transformation functions provided as arguments
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* should similarly return null to indicate the lack of any result
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* (in which case it is not used). In the case of mapped
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* reductions, this also enables transformations to serve as
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* filters, returning null (or, in the case of primitive
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* specializations, the identity basis) if the element should not
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* be combined. You can create compound transformations and
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* filterings by composing them yourself under this "null means
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* there is nothing there now" rule before using them in search or
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* reduce operations.
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*
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* <p>Methods accepting and/or returning Entry arguments maintain
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* key-value associations. They may be useful for example when
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* finding the key for the greatest value. Note that "plain" Entry
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* arguments can be supplied using {@code new
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* AbstractMap.SimpleEntry(k,v)}.
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*
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* <p>Bulk operations may complete abruptly, throwing an
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* exception encountered in the application of a supplied
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* function. Bear in mind when handling such exceptions that other
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* concurrently executing functions could also have thrown
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* exceptions, or would have done so if the first exception had
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* not occurred.
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*
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* <p>Speedups for parallel compared to sequential forms are common
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* but not guaranteed. Parallel operations involving brief functions
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* on small maps may execute more slowly than sequential forms if the
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* underlying work to parallelize the computation is more expensive
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* than the computation itself. Similarly, parallelization may not
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* lead to much actual parallelism if all processors are busy
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* performing unrelated tasks.
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*
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* <p>All arguments to all task methods must be non-null.
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*
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* <p><em>jsr166e note: During transition, this class
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* uses nested functional interfaces with different names but the
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* same forms as those expected for JDK8.</em>
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*
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* <p>This class is a member of the
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* <a href="{@docRoot}/../technotes/guides/collections/index.html">
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* Java Collections Framework</a>.
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*
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* @since 1.5
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* @author Doug Lea
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* @param <K> the type of keys maintained by this map
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* @param <V> the type of mapped values
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*/
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@SuppressWarnings("all")
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public class ConcurrentHashMapV8<K,V> extends AbstractMap<K,V>
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implements ConcurrentMap<K,V>, Serializable {
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private static final long serialVersionUID = 7249069246763182397L;
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/**
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* An object for traversing and partitioning elements of a source.
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* This interface provides a subset of the functionality of JDK8
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* java.util.Spliterator.
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*/
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public static interface ConcurrentHashMapSpliterator<T> {
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/**
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* If possible, returns a new spliterator covering
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* approximately one half of the elements, which will not be
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* covered by this spliterator. Returns null if cannot be
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* split.
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*/
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ConcurrentHashMapSpliterator<T> trySplit();
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/**
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* Returns an estimate of the number of elements covered by
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* this Spliterator.
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*/
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long estimateSize();
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/** Applies the action to each untraversed element */
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void forEachRemaining(Action<? super T> action);
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/** If an element remains, applies the action and returns true. */
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boolean tryAdvance(Action<? super T> action);
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}
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// Sams
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/** Interface describing a void action of one argument */
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public interface Action<A> { void apply(A a); }
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/** Interface describing a void action of two arguments */
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public interface BiAction<A,B> { void apply(A a, B b); }
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/** Interface describing a function of one argument */
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public interface Fun<A,T> { T apply(A a); }
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/** Interface describing a function of two arguments */
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public interface BiFun<A,B,T> { T apply(A a, B b); }
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/** Interface describing a function mapping its argument to a double */
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public interface ObjectToDouble<A> { double apply(A a); }
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/** Interface describing a function mapping its argument to a long */
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public interface ObjectToLong<A> { long apply(A a); }
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/** Interface describing a function mapping its argument to an int */
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public interface ObjectToInt<A> {int apply(A a); }
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/** Interface describing a function mapping two arguments to a double */
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public interface ObjectByObjectToDouble<A,B> { double apply(A a, B b); }
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/** Interface describing a function mapping two arguments to a long */
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public interface ObjectByObjectToLong<A,B> { long apply(A a, B b); }
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/** Interface describing a function mapping two arguments to an int */
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public interface ObjectByObjectToInt<A,B> {int apply(A a, B b); }
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/** Interface describing a function mapping two doubles to a double */
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public interface DoubleByDoubleToDouble { double apply(double a, double b); }
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/** Interface describing a function mapping two longs to a long */
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public interface LongByLongToLong { long apply(long a, long b); }
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/** Interface describing a function mapping two ints to an int */
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public interface IntByIntToInt { int apply(int a, int b); }
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/*
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* Overview:
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*
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* The primary design goal of this hash table is to maintain
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* concurrent readability (typically method get(), but also
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* iterators and related methods) while minimizing update
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* contention. Secondary goals are to keep space consumption about
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* the same or better than java.util.HashMap, and to support high
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* initial insertion rates on an empty table by many threads.
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*
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* This map usually acts as a binned (bucketed) hash table. Each
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* key-value mapping is held in a Node. Most nodes are instances
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* of the basic Node class with hash, key, value, and next
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* fields. However, various subclasses exist: TreeNodes are
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* arranged in balanced trees, not lists. TreeBins hold the roots
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* of sets of TreeNodes. ForwardingNodes are placed at the heads
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* of bins during resizing. ReservationNodes are used as
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* placeholders while establishing values in computeIfAbsent and
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* related methods. The types TreeBin, ForwardingNode, and
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* ReservationNode do not hold normal user keys, values, or
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* hashes, and are readily distinguishable during search etc
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* because they have negative hash fields and null key and value
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* fields. (These special nodes are either uncommon or transient,
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* so the impact of carrying around some unused fields is
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* insignificant.)
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*
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* The table is lazily initialized to a power-of-two size upon the
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* first insertion. Each bin in the table normally contains a
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* list of Nodes (most often, the list has only zero or one Node).
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* Table accesses require volatile/atomic reads, writes, and
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* CASes. Because there is no other way to arrange this without
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* adding further indirections, we use intrinsics
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* (sun.misc.Unsafe) operations.
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*
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* We use the top (sign) bit of Node hash fields for control
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* purposes -- it is available anyway because of addressing
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* constraints. Nodes with negative hash fields are specially
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* handled or ignored in map methods.
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*
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* Insertion (via put or its variants) of the first node in an
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* empty bin is performed by just CASing it to the bin. This is
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* by far the most common case for put operations under most
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* key/hash distributions. Other update operations (insert,
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* delete, and replace) require locks. We do not want to waste
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* the space required to associate a distinct lock object with
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* each bin, so instead use the first node of a bin list itself as
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* a lock. Locking support for these locks relies on builtin
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* "synchronized" monitors.
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*
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* Using the first node of a list as a lock does not by itself
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* suffice though: When a node is locked, any update must first
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* validate that it is still the first node after locking it, and
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* retry if not. Because new nodes are always appended to lists,
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* once a node is first in a bin, it remains first until deleted
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* or the bin becomes invalidated (upon resizing).
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*
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* The main disadvantage of per-bin locks is that other update
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* operations on other nodes in a bin list protected by the same
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* lock can stall, for example when user equals() or mapping
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* functions take a long time. However, statistically, under
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* random hash codes, this is not a common problem. Ideally, the
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* frequency of nodes in bins follows a Poisson distribution
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* (http://en.wikipedia.org/wiki/Poisson_distribution) with a
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* parameter of about 0.5 on average, given the resizing threshold
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* of 0.75, although with a large variance because of resizing
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* granularity. Ignoring variance, the expected occurrences of
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* list size k are (exp(-0.5) * pow(0.5, k) / factorial(k)). The
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* first values are:
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*
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* 0: 0.60653066
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* 1: 0.30326533
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* 2: 0.07581633
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* 3: 0.01263606
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* 4: 0.00157952
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* 5: 0.00015795
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* 6: 0.00001316
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* 7: 0.00000094
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* 8: 0.00000006
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* more: less than 1 in ten million
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*
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* Lock contention probability for two threads accessing distinct
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* elements is roughly 1 / (8 * #elements) under random hashes.
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*
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* Actual hash code distributions encountered in practice
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* sometimes deviate significantly from uniform randomness. This
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* includes the case when N > (1<<30), so some keys MUST collide.
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* Similarly for dumb or hostile usages in which multiple keys are
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* designed to have identical hash codes or ones that differs only
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* in masked-out high bits. So we use a secondary strategy that
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* applies when the number of nodes in a bin exceeds a
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* threshold. These TreeBins use a balanced tree to hold nodes (a
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* specialized form of red-black trees), bounding search time to
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* O(log N). Each search step in a TreeBin is at least twice as
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* slow as in a regular list, but given that N cannot exceed
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* (1<<64) (before running out of addresses) this bounds search
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* steps, lock hold times, etc, to reasonable constants (roughly
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* 100 nodes inspected per operation worst case) so long as keys
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* are Comparable (which is very common -- String, Long, etc).
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* TreeBin nodes (TreeNodes) also maintain the same "next"
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* traversal pointers as regular nodes, so can be traversed in
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* iterators in the same way.
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*
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* The table is resized when occupancy exceeds a percentage
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* threshold (nominally, 0.75, but see below). Any thread
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* noticing an overfull bin may assist in resizing after the
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* initiating thread allocates and sets up the replacement
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* array. However, rather than stalling, these other threads may
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* proceed with insertions etc. The use of TreeBins shields us
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* from the worst case effects of overfilling while resizes are in
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* progress. Resizing proceeds by transferring bins, one by one,
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* from the table to the next table. To enable concurrency, the
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* next table must be (incrementally) prefilled with place-holders
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* serving as reverse forwarders to the old table. Because we are
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* using power-of-two expansion, the elements from each bin must
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* either stay at same index, or move with a power of two
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* offset. We eliminate unnecessary node creation by catching
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* cases where old nodes can be reused because their next fields
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* won't change. On average, only about one-sixth of them need
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* cloning when a table doubles. The nodes they replace will be
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* garbage collectable as soon as they are no longer referenced by
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* any reader thread that may be in the midst of concurrently
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* traversing table. Upon transfer, the old table bin contains
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* only a special forwarding node (with hash field "MOVED") that
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* contains the next table as its key. On encountering a
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* forwarding node, access and update operations restart, using
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* the new table.
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*
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* Each bin transfer requires its bin lock, which can stall
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* waiting for locks while resizing. However, because other
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* threads can join in and help resize rather than contend for
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* locks, average aggregate waits become shorter as resizing
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* progresses. The transfer operation must also ensure that all
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* accessible bins in both the old and new table are usable by any
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* traversal. This is arranged by proceeding from the last bin
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* (table.length - 1) up towards the first. Upon seeing a
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* forwarding node, traversals (see class Traverser) arrange to
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* move to the new table without revisiting nodes. However, to
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* ensure that no intervening nodes are skipped, bin splitting can
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* only begin after the associated reverse-forwarders are in
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* place.
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*
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* The traversal scheme also applies to partial traversals of
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* ranges of bins (via an alternate Traverser constructor)
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* to support partitioned aggregate operations. Also, read-only
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* operations give up if ever forwarded to a null table, which
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* provides support for shutdown-style clearing, which is also not
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* currently implemented.
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*
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* Lazy table initialization minimizes footprint until first use,
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* and also avoids resizings when the first operation is from a
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|
* 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<K,V> implements Map.Entry<K,V> {
|
|
final int hash;
|
|
final K key;
|
|
volatile V val;
|
|
volatile Node<K,V> next;
|
|
|
|
Node(int hash, K key, V val, Node<K,V> 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<K,V> find(int h, Object k) {
|
|
Node<K,V> 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<C>", 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 <K,V> Node<K,V> tabAt(Node<K,V>[] tab, int i) {
|
|
return (Node<K,V>)U.getObjectVolatile(tab, ((long)i << ASHIFT) + ABASE);
|
|
}
|
|
|
|
static final <K,V> boolean casTabAt(Node<K,V>[] tab, int i,
|
|
Node<K,V> c, Node<K,V> v) {
|
|
return U.compareAndSwapObject(tab, ((long)i << ASHIFT) + ABASE, c, v);
|
|
}
|
|
|
|
static final <K,V> void setTabAt(Node<K,V>[] tab, int i, Node<K,V> 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<K,V>[] table;
|
|
|
|
/**
|
|
* The next table to use; non-null only while resizing.
|
|
*/
|
|
private transient volatile Node<K,V>[] 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<K,V> keySet;
|
|
private transient ValuesView<K,V> values;
|
|
private transient EntrySetView<K,V> 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<? extends K, ? extends V> 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.
|
|
*
|
|
* <p>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<K,V>[] tab; Node<K,V> 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<K,V>[] t;
|
|
if ((t = this.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> 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.
|
|
*
|
|
* <p>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<K,V>[] tab = this.table;;) {
|
|
Node<K,V> 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<K,V>(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<K,V> 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<K,V> pred = e;
|
|
if ((e = e.next) == null) {
|
|
pred.next = new Node<K,V>(hash, key,
|
|
value, null);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else if (f instanceof TreeBin) {
|
|
Node<K,V> p;
|
|
binCount = 2;
|
|
if ((p = ((TreeBin<K,V>)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<? extends K, ? extends V> m) {
|
|
tryPresize(m.size());
|
|
for (Map.Entry<? extends K, ? extends V> 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<K,V>[] tab = this.table;;) {
|
|
Node<K,V> 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<K,V> 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<K,V> t = (TreeBin<K,V>)f;
|
|
TreeNode<K,V> 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<K,V>[] tab = this.table;
|
|
while (tab != null && i < tab.length) {
|
|
int fh;
|
|
Node<K,V> 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<K,V> p = fh >= 0 ? f :
|
|
f instanceof TreeBin ?
|
|
((TreeBin<K,V>)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.
|
|
*
|
|
* <p>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<K,V> keySet() {
|
|
KeySetView<K,V> ks;
|
|
return (ks = this.keySet) != null ? ks : (this.keySet = new KeySetView<K,V>(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.
|
|
*
|
|
* <p>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<V> values() {
|
|
ValuesView<K,V> vs;
|
|
return (vs = this.values) != null ? vs : (this.values = new ValuesView<K,V>(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.
|
|
*
|
|
* <p>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<Map.Entry<K,V>> entrySet() {
|
|
EntrySetView<K,V> es;
|
|
return (es = this.entrySet) != null ? es : (this.entrySet = new EntrySetView<K,V>(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<K,V>[] t;
|
|
if ((t = this.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> 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<K,V>[] t;
|
|
int f = (t = this.table) == null ? 0 : t.length;
|
|
Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
|
|
StringBuilder sb = new StringBuilder();
|
|
sb.append('{');
|
|
Node<K,V> 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<K,V>[] t;
|
|
int f = (t = this.table) == null ? 0 : t.length;
|
|
Traverser<K,V> it = new Traverser<K,V>(t, f, 0, f);
|
|
for (Node<K,V> 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<K,V> 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<K,V>[] segments = (Segment<K,V>[])
|
|
new Segment<?,?>[DEFAULT_CONCURRENCY_LEVEL];
|
|
for (int i = 0; i < segments.length; ++i) {
|
|
segments[i] = new Segment<K,V>(LOAD_FACTOR);
|
|
}
|
|
s.putFields().put("segments", segments);
|
|
s.putFields().put("segmentShift", segmentShift);
|
|
s.putFields().put("segmentMask", segmentMask);
|
|
s.writeFields();
|
|
|
|
Node<K,V>[] t;
|
|
if ((t = this.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> 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<K,V> 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<K,V>(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<K,V>[] tab = new Node[n];
|
|
int mask = n - 1;
|
|
long added = 0L;
|
|
while (p != null) {
|
|
boolean insertAtFront;
|
|
Node<K,V> 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<K,V> t = (TreeBin<K,V>)first;
|
|
if (t.putTreeVal(h, k, p.val) == null) {
|
|
++added;
|
|
}
|
|
insertAtFront = false;
|
|
}
|
|
else {
|
|
int binCount = 0;
|
|
insertAtFront = true;
|
|
Node<K,V> 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<K,V> hd = null, tl = null;
|
|
for (q = p; q != null; q = q.next) {
|
|
TreeNode<K,V> t = new TreeNode<K,V>
|
|
(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<K,V>(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<? super K, ? super V> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
Node<K,V>[] t;
|
|
if ((t = this.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> p; (p = it.advance()) != null; ) {
|
|
action.apply(p.key, p.val);
|
|
}
|
|
}
|
|
}
|
|
|
|
public void replaceAll(BiFun<? super K, ? super V, ? extends V> function) {
|
|
if (function == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
Node<K,V>[] t;
|
|
if ((t = this.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> 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<? super K, ? extends V> mappingFunction) {
|
|
if (key == null || mappingFunction == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
int h = spread(key.hashCode());
|
|
V val = null;
|
|
int binCount = 0;
|
|
for (Node<K,V>[] tab = this.table;;) {
|
|
Node<K,V> 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<K,V> r = new ReservationNode<K,V>();
|
|
synchronized (r) {
|
|
if (casTabAt(tab, i, null, r)) {
|
|
binCount = 1;
|
|
Node<K,V> node = null;
|
|
try {
|
|
if ((val = mappingFunction.apply(key)) != null) {
|
|
node = new Node<K,V>(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<K,V> 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<K,V> pred = e;
|
|
if ((e = e.next) == null) {
|
|
if ((val = mappingFunction.apply(key)) != null) {
|
|
added = true;
|
|
pred.next = new Node<K,V>(h, key, val, null);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else if (f instanceof TreeBin) {
|
|
binCount = 2;
|
|
TreeBin<K,V> t = (TreeBin<K,V>)f;
|
|
TreeNode<K,V> 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<? super K, ? super V, ? extends V> 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<K,V>[] tab = this.table;;) {
|
|
Node<K,V> 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<K,V> 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<K,V> 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<K,V> t = (TreeBin<K,V>)f;
|
|
TreeNode<K,V> 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<? super K, ? super V, ? extends V> 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<K,V>[] tab = this.table;;) {
|
|
Node<K,V> 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<K,V> r = new ReservationNode<K,V>();
|
|
synchronized (r) {
|
|
if (casTabAt(tab, i, null, r)) {
|
|
binCount = 1;
|
|
Node<K,V> node = null;
|
|
try {
|
|
if ((val = remappingFunction.apply(key, null)) != null) {
|
|
delta = 1;
|
|
node = new Node<K,V>(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<K,V> 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<K,V> 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<K,V>(h, key, val, null);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else if (f instanceof TreeBin) {
|
|
binCount = 1;
|
|
TreeBin<K,V> t = (TreeBin<K,V>)f;
|
|
TreeNode<K,V> 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<? super V, ? super V, ? extends V> 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<K,V>[] tab = this.table;;) {
|
|
Node<K,V> 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<K,V>(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<K,V> 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<K,V> 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<K,V>(h, key, val, null);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else if (f instanceof TreeBin) {
|
|
binCount = 2;
|
|
TreeBin<K,V> t = (TreeBin<K,V>)f;
|
|
TreeNode<K,V> r = t.root;
|
|
TreeNode<K,V> 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<K> keys() {
|
|
Node<K,V>[] t;
|
|
int f = (t = this.table) == null ? 0 : t.length;
|
|
return new KeyIterator<K,V>(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<V> elements() {
|
|
Node<K,V>[] t;
|
|
int f = (t = this.table) == null ? 0 : t.length;
|
|
return new ValueIterator<K,V>(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 <K> KeySetView<K,Boolean> newKeySet() {
|
|
return new KeySetView<K,Boolean>
|
|
(new ConcurrentHashMapV8<K,Boolean>(), 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 <K> KeySetView<K,Boolean> newKeySet(int initialCapacity) {
|
|
return new KeySetView<K,Boolean>
|
|
(new ConcurrentHashMapV8<K,Boolean>(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<K,V> keySet(V mappedValue) {
|
|
if (mappedValue == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
return new KeySetView<K,V>(this, mappedValue);
|
|
}
|
|
|
|
/* ---------------- Special Nodes -------------- */
|
|
|
|
/**
|
|
* A node inserted at head of bins during transfer operations.
|
|
*/
|
|
static final class ForwardingNode<K,V> extends Node<K,V> {
|
|
final Node<K,V>[] nextTable;
|
|
ForwardingNode(Node<K,V>[] tab) {
|
|
super(MOVED, null, null, null);
|
|
this.nextTable = tab;
|
|
}
|
|
|
|
@Override
|
|
Node<K,V> find(int h, Object k) {
|
|
// loop to avoid arbitrarily deep recursion on forwarding nodes
|
|
outer: for (Node<K,V>[] tab = this.nextTable;;) {
|
|
Node<K,V> 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<K,V>)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<K,V> extends Node<K,V> {
|
|
ReservationNode() {
|
|
super(RESERVED, null, null, null);
|
|
}
|
|
|
|
@Override
|
|
Node<K,V> find(int h, Object k) {
|
|
return null;
|
|
}
|
|
}
|
|
|
|
/* ---------------- Table Initialization and Resizing -------------- */
|
|
|
|
/**
|
|
* Initializes table, using the size recorded in sizeCtl.
|
|
*/
|
|
private final Node<K,V>[] initTable() {
|
|
Node<K,V>[] 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<K,V>[] 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<K,V>[] 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<K,V>[] helpTransfer(Node<K,V>[] tab, Node<K,V> f) {
|
|
Node<K,V>[] nextTab; int sc;
|
|
if (f instanceof ForwardingNode &&
|
|
(nextTab = ((ForwardingNode<K,V>)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<K,V>[] 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<K,V>[] 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<K,V>[] tab, Node<K,V>[] 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<K,V>[] 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<K,V> rev = new ForwardingNode<K,V>(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<K,V> fwd = new ForwardingNode<K,V>(nextTab);
|
|
boolean advance = true;
|
|
boolean finishing = false; // to ensure sweep before committing nextTab
|
|
for (int i = 0, bound = 0;;) {
|
|
int nextIndex, nextBound, fh; Node<K,V> 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<K,V> ln, hn;
|
|
if (fh >= 0) {
|
|
int runBit = fh & n;
|
|
Node<K,V> lastRun = f;
|
|
for (Node<K,V> 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<K,V> 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<K,V>(ph, pk, pv, ln);
|
|
} else {
|
|
hn = new Node<K,V>(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<K,V> t = (TreeBin<K,V>)f;
|
|
TreeNode<K,V> lo = null, loTail = null;
|
|
TreeNode<K,V> hi = null, hiTail = null;
|
|
int lc = 0, hc = 0;
|
|
for (Node<K,V> e = t.first; e != null; e = e.next) {
|
|
int h = e.hash;
|
|
TreeNode<K,V> p = new TreeNode<K,V>
|
|
(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<K,V>(lo) : t;
|
|
hn = hc <= UNTREEIFY_THRESHOLD ? untreeify(hi) :
|
|
lc != 0 ? new TreeBin<K,V>(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<K,V>[] tab, int index) {
|
|
Node<K,V> 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<K,V> hd = null, tl = null;
|
|
for (Node<K,V> e = b; e != null; e = e.next) {
|
|
TreeNode<K,V> p =
|
|
new TreeNode<K,V>(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<K,V>(hd));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Returns a list on non-TreeNodes replacing those in given list.
|
|
*/
|
|
static <K,V> Node<K,V> untreeify(Node<K,V> b) {
|
|
Node<K,V> hd = null, tl = null;
|
|
for (Node<K,V> q = b; q != null; q = q.next) {
|
|
Node<K,V> p = new Node<K,V>(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<K,V> extends Node<K,V> {
|
|
TreeNode<K,V> parent; // red-black tree links
|
|
TreeNode<K,V> left;
|
|
TreeNode<K,V> right;
|
|
TreeNode<K,V> prev; // needed to unlink next upon deletion
|
|
boolean red;
|
|
|
|
TreeNode(int hash, K key, V val, Node<K,V> next,
|
|
TreeNode<K,V> parent) {
|
|
super(hash, key, val, next);
|
|
this.parent = parent;
|
|
}
|
|
|
|
@Override
|
|
Node<K,V> 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<K,V> findTreeNode(int h, Object k, Class<?> kc) {
|
|
if (k != null) {
|
|
TreeNode<K,V> p = this;
|
|
do {
|
|
int ph, dir; K pk; TreeNode<K,V> q;
|
|
TreeNode<K,V> 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<K,V> extends Node<K,V> {
|
|
TreeNode<K,V> root;
|
|
volatile TreeNode<K,V> 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<K,V> b) {
|
|
super(TREEBIN, null, null, null);
|
|
this.first = b;
|
|
TreeNode<K,V> r = null;
|
|
for (TreeNode<K,V> x = b, next; x != null; x = next) {
|
|
next = (TreeNode<K,V>)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<K,V> 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<K,V> 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<K,V> find(int h, Object k) {
|
|
if (k != null) {
|
|
for (Node<K,V> 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<K,V> 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<K,V> putTreeVal(int h, K k, V v) {
|
|
Class<?> kc = null;
|
|
boolean searched = false;
|
|
for (TreeNode<K,V> p = this.root;;) {
|
|
int dir, ph; K pk;
|
|
if (p == null) {
|
|
this.first = this.root = new TreeNode<K,V>(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<K,V> 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<K,V> xp = p;
|
|
if ((p = dir <= 0 ? p.left : p.right) == null) {
|
|
TreeNode<K,V> x, f = this.first;
|
|
this.first = x = new TreeNode<K,V>(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<K,V> p) {
|
|
TreeNode<K,V> next = (TreeNode<K,V>)p.next;
|
|
TreeNode<K,V> pred = p.prev; // unlink traversal pointers
|
|
TreeNode<K,V> 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<K,V> replacement;
|
|
TreeNode<K,V> pl = p.left;
|
|
TreeNode<K,V> pr = p.right;
|
|
if (pl != null && pr != null) {
|
|
TreeNode<K,V> s = pr, sl;
|
|
while ((sl = s.left) != null) {
|
|
s = sl;
|
|
}
|
|
boolean c = s.red; s.red = p.red; p.red = c; // swap colors
|
|
TreeNode<K,V> sr = s.right;
|
|
TreeNode<K,V> pp = p.parent;
|
|
if (s == pr) { // p was s's direct parent
|
|
p.parent = s;
|
|
s.right = p;
|
|
}
|
|
else {
|
|
TreeNode<K,V> 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<K,V> 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<K,V> 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 <K,V> TreeNode<K,V> rotateLeft(TreeNode<K,V> root,
|
|
TreeNode<K,V> p) {
|
|
TreeNode<K,V> 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 <K,V> TreeNode<K,V> rotateRight(TreeNode<K,V> root,
|
|
TreeNode<K,V> p) {
|
|
TreeNode<K,V> 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 <K,V> TreeNode<K,V> balanceInsertion(TreeNode<K,V> root,
|
|
TreeNode<K,V> x) {
|
|
x.red = true;
|
|
for (TreeNode<K,V> 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 <K,V> TreeNode<K,V> balanceDeletion(TreeNode<K,V> root,
|
|
TreeNode<K,V> x) {
|
|
for (TreeNode<K,V> 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<K,V> 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<K,V> 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 <K,V> boolean checkInvariants(TreeNode<K,V> t) {
|
|
TreeNode<K,V> tp = t.parent, tl = t.left, tr = t.right,
|
|
tb = t.prev, tn = (TreeNode<K,V>)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<K,V> {
|
|
Node<K,V>[] tab; // current table; updated if resized
|
|
Node<K,V> 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<K,V>[] 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<K,V> advance() {
|
|
Node<K,V> e;
|
|
if ((e = this.next) != null) {
|
|
e = e.next;
|
|
}
|
|
for (;;) {
|
|
Node<K,V>[] 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<K,V>)e).nextTable;
|
|
e = null;
|
|
continue;
|
|
}
|
|
else if (e instanceof TreeBin) {
|
|
e = ((TreeBin<K,V>)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<K,V> extends Traverser<K,V> {
|
|
final ConcurrentHashMapV8<K,V> map;
|
|
Node<K,V> lastReturned;
|
|
BaseIterator(Node<K,V>[] tab, int size, int index, int limit,
|
|
ConcurrentHashMapV8<K,V> 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<K,V> p;
|
|
if ((p = this.lastReturned) == null) {
|
|
throw new IllegalStateException();
|
|
}
|
|
this.lastReturned = null;
|
|
this.map.replaceNode(p.key, null, null);
|
|
}
|
|
}
|
|
|
|
static final class KeyIterator<K,V> extends BaseIterator<K,V>
|
|
implements Iterator<K>, Enumeration<K> {
|
|
KeyIterator(Node<K,V>[] tab, int index, int size, int limit,
|
|
ConcurrentHashMapV8<K,V> map) {
|
|
super(tab, index, size, limit, map);
|
|
}
|
|
|
|
@Override
|
|
public final K next() {
|
|
Node<K,V> 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<K,V> extends BaseIterator<K,V>
|
|
implements Iterator<V>, Enumeration<V> {
|
|
ValueIterator(Node<K,V>[] tab, int index, int size, int limit,
|
|
ConcurrentHashMapV8<K,V> map) {
|
|
super(tab, index, size, limit, map);
|
|
}
|
|
|
|
@Override
|
|
public final V next() {
|
|
Node<K,V> 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<K,V> extends BaseIterator<K,V>
|
|
implements Iterator<Map.Entry<K,V>> {
|
|
EntryIterator(Node<K,V>[] tab, int index, int size, int limit,
|
|
ConcurrentHashMapV8<K,V> map) {
|
|
super(tab, index, size, limit, map);
|
|
}
|
|
|
|
@Override
|
|
public final Map.Entry<K,V> next() {
|
|
Node<K,V> 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>(k, v, this.map);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Exported Entry for EntryIterator
|
|
*/
|
|
static final class MapEntry<K,V> implements Map.Entry<K,V> {
|
|
final K key; // non-null
|
|
V val; // non-null
|
|
final ConcurrentHashMapV8<K,V> map;
|
|
MapEntry(K key, V val, ConcurrentHashMapV8<K,V> 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<K,V> extends Traverser<K,V>
|
|
implements ConcurrentHashMapSpliterator<K> {
|
|
long est; // size estimate
|
|
KeySpliterator(Node<K,V>[] tab, int size, int index, int limit,
|
|
long est) {
|
|
super(tab, size, index, limit);
|
|
this.est = est;
|
|
}
|
|
|
|
@Override
|
|
public ConcurrentHashMapSpliterator<K> trySplit() {
|
|
int i, f, h;
|
|
return (h = (i = this.baseIndex) + (f = this.baseLimit) >>> 1) <= i ? null :
|
|
new KeySpliterator<K,V>(this.tab, this.baseSize, this.baseLimit = h,
|
|
f, this.est >>>= 1);
|
|
}
|
|
|
|
@Override
|
|
public void forEachRemaining(Action<? super K> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
for (Node<K,V> p; (p = advance()) != null;) {
|
|
action.apply(p.key);
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public boolean tryAdvance(Action<? super K> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
Node<K,V> p;
|
|
if ((p = advance()) == null) {
|
|
return false;
|
|
}
|
|
action.apply(p.key);
|
|
return true;
|
|
}
|
|
|
|
@Override
|
|
public long estimateSize() { return this.est; }
|
|
|
|
}
|
|
|
|
static final class ValueSpliterator<K,V> extends Traverser<K,V>
|
|
implements ConcurrentHashMapSpliterator<V> {
|
|
long est; // size estimate
|
|
ValueSpliterator(Node<K,V>[] tab, int size, int index, int limit,
|
|
long est) {
|
|
super(tab, size, index, limit);
|
|
this.est = est;
|
|
}
|
|
|
|
@Override
|
|
public ConcurrentHashMapSpliterator<V> trySplit() {
|
|
int i, f, h;
|
|
return (h = (i = this.baseIndex) + (f = this.baseLimit) >>> 1) <= i ? null :
|
|
new ValueSpliterator<K,V>(this.tab, this.baseSize, this.baseLimit = h,
|
|
f, this.est >>>= 1);
|
|
}
|
|
|
|
@Override
|
|
public void forEachRemaining(Action<? super V> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
for (Node<K,V> p; (p = advance()) != null;) {
|
|
action.apply(p.val);
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public boolean tryAdvance(Action<? super V> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
Node<K,V> p;
|
|
if ((p = advance()) == null) {
|
|
return false;
|
|
}
|
|
action.apply(p.val);
|
|
return true;
|
|
}
|
|
|
|
@Override
|
|
public long estimateSize() { return this.est; }
|
|
|
|
}
|
|
|
|
static final class EntrySpliterator<K,V> extends Traverser<K,V>
|
|
implements ConcurrentHashMapSpliterator<Map.Entry<K,V>> {
|
|
final ConcurrentHashMapV8<K,V> map; // To export MapEntry
|
|
long est; // size estimate
|
|
EntrySpliterator(Node<K,V>[] tab, int size, int index, int limit,
|
|
long est, ConcurrentHashMapV8<K,V> map) {
|
|
super(tab, size, index, limit);
|
|
this.map = map;
|
|
this.est = est;
|
|
}
|
|
|
|
@Override
|
|
public ConcurrentHashMapSpliterator<Map.Entry<K,V>> trySplit() {
|
|
int i, f, h;
|
|
return (h = (i = this.baseIndex) + (f = this.baseLimit) >>> 1) <= i ? null :
|
|
new EntrySpliterator<K,V>(this.tab, this.baseSize, this.baseLimit = h,
|
|
f, this.est >>>= 1, this.map);
|
|
}
|
|
|
|
@Override
|
|
public void forEachRemaining(Action<? super Map.Entry<K,V>> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
for (Node<K,V> p; (p = advance()) != null; ) {
|
|
action.apply(new MapEntry<K,V>(p.key, p.val, this.map));
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public boolean tryAdvance(Action<? super Map.Entry<K,V>> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
Node<K,V> p;
|
|
if ((p = advance()) == null) {
|
|
return false;
|
|
}
|
|
action.apply(new MapEntry<K,V>(p.key, p.val, this.map));
|
|
return true;
|
|
}
|
|
|
|
@Override
|
|
public long estimateSize() { return this.est; }
|
|
|
|
}
|
|
|
|
/* ----------------Views -------------- */
|
|
|
|
/**
|
|
* Base class for views.
|
|
*/
|
|
abstract static class CollectionView<K,V,E>
|
|
implements Collection<E>, java.io.Serializable {
|
|
private static final long serialVersionUID = 7249069246763182397L;
|
|
final ConcurrentHashMapV8<K,V> map;
|
|
CollectionView(ConcurrentHashMapV8<K,V> map) { this.map = map; }
|
|
|
|
/**
|
|
* Returns the map backing this view.
|
|
*
|
|
* @return the map backing this view
|
|
*/
|
|
public ConcurrentHashMapV8<K,V> 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<E> 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> 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<E> 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<E> 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<E> 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<K,V> extends CollectionView<K,V,K>
|
|
implements Set<K>, java.io.Serializable {
|
|
private static final long serialVersionUID = 7249069246763182397L;
|
|
private final V value;
|
|
KeySetView(ConcurrentHashMapV8<K,V> 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<K> iterator() {
|
|
Node<K,V>[] t;
|
|
ConcurrentHashMapV8<K,V> m = this.map;
|
|
int f = (t = m.table) == null ? 0 : t.length;
|
|
return new KeyIterator<K,V>(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<? extends K> 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<K> spliterator() {
|
|
Node<K,V>[] t;
|
|
ConcurrentHashMapV8<K,V> m = this.map;
|
|
long n = m.sumCount();
|
|
int f = (t = m.table) == null ? 0 : t.length;
|
|
return new KeySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
|
|
}
|
|
|
|
public void forEach(Action<? super K> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
Node<K,V>[] t;
|
|
if ((t = this.map.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> 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<K,V> extends CollectionView<K,V,V>
|
|
implements Collection<V>, java.io.Serializable {
|
|
private static final long serialVersionUID = 2249069246763182397L;
|
|
ValuesView(ConcurrentHashMapV8<K,V> 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<V> it = iterator(); it.hasNext();) {
|
|
if (o.equals(it.next())) {
|
|
it.remove();
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
@Override
|
|
public final Iterator<V> iterator() {
|
|
ConcurrentHashMapV8<K,V> m = this.map;
|
|
Node<K,V>[] t;
|
|
int f = (t = m.table) == null ? 0 : t.length;
|
|
return new ValueIterator<K,V>(t, f, 0, f, m);
|
|
}
|
|
|
|
@Override
|
|
public final boolean add(V e) {
|
|
throw new UnsupportedOperationException();
|
|
}
|
|
@Override
|
|
public final boolean addAll(Collection<? extends V> c) {
|
|
throw new UnsupportedOperationException();
|
|
}
|
|
|
|
public ConcurrentHashMapSpliterator<V> spliterator() {
|
|
Node<K,V>[] t;
|
|
ConcurrentHashMapV8<K,V> m = this.map;
|
|
long n = m.sumCount();
|
|
int f = (t = m.table) == null ? 0 : t.length;
|
|
return new ValueSpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n);
|
|
}
|
|
|
|
public void forEach(Action<? super V> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
Node<K,V>[] t;
|
|
if ((t = this.map.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> 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<K,V> extends CollectionView<K,V,Map.Entry<K,V>>
|
|
implements Set<Map.Entry<K,V>>, java.io.Serializable {
|
|
private static final long serialVersionUID = 2249069246763182397L;
|
|
EntrySetView(ConcurrentHashMapV8<K,V> 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<Map.Entry<K,V>> iterator() {
|
|
ConcurrentHashMapV8<K,V> m = this.map;
|
|
Node<K,V>[] t;
|
|
int f = (t = m.table) == null ? 0 : t.length;
|
|
return new EntryIterator<K,V>(t, f, 0, f, m);
|
|
}
|
|
|
|
@Override
|
|
public boolean add(Entry<K,V> e) {
|
|
return this.map.putVal(e.getKey(), e.getValue(), false) == null;
|
|
}
|
|
|
|
@Override
|
|
public boolean addAll(Collection<? extends Entry<K,V>> c) {
|
|
boolean added = false;
|
|
for (Entry<K,V> e : c) {
|
|
if (add(e)) {
|
|
added = true;
|
|
}
|
|
}
|
|
return added;
|
|
}
|
|
|
|
@Override
|
|
public final int hashCode() {
|
|
int h = 0;
|
|
Node<K,V>[] t;
|
|
if ((t = this.map.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> 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<Map.Entry<K,V>> spliterator() {
|
|
Node<K,V>[] t;
|
|
ConcurrentHashMapV8<K,V> m = this.map;
|
|
long n = m.sumCount();
|
|
int f = (t = m.table) == null ? 0 : t.length;
|
|
return new EntrySpliterator<K,V>(t, f, 0, f, n < 0L ? 0L : n, m);
|
|
}
|
|
|
|
public void forEach(Action<? super Map.Entry<K,V>> action) {
|
|
if (action == null) {
|
|
throw new NullPointerException();
|
|
}
|
|
Node<K,V>[] t;
|
|
if ((t = this.map.table) != null) {
|
|
Traverser<K,V> it = new Traverser<K,V>(t, t.length, 0, t.length);
|
|
for (Node<K,V> p; (p = it.advance()) != null; ) {
|
|
action.apply(new MapEntry<K,V>(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<CounterHashCode> threadCounterHashCode =
|
|
new ThreadLocal<CounterHashCode>();
|
|
|
|
|
|
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<sun.misc.Unsafe>() {
|
|
@Override
|
|
public sun.misc.Unsafe run() throws Exception {
|
|
Class<sun.misc.Unsafe> 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());
|
|
}
|
|
}
|
|
}
|