diff --git a/Dorkbox-Util/src/dorkbox/util/FastThreadLocal.java b/Dorkbox-Util/src/dorkbox/util/FastThreadLocal.java new file mode 100644 index 0000000..7950c3d --- /dev/null +++ b/Dorkbox-Util/src/dorkbox/util/FastThreadLocal.java @@ -0,0 +1,117 @@ +/* + * Copyright © 2012-2014 Lightweight Java Game Library Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, are + * permitted provided that the following conditions are met: + * + * - Redistributions of source code must retain the above copyright notice, this list + * of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above copyright notice, this + * list of conditions and the following disclaimer in the documentation and/or + * other materials provided with the distribution. + * - Neither the name of 'Light Weight Java Game Library' nor the names of its + * contributors may be used to endorse or promote products derived from this + * software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY + * OF SUCH DAMAGE. + */ +package dorkbox.util; + +import java.util.Arrays; + +/** + * Fast {@code ThreadLocal} implementation, adapted from the + * LibStruct library. + * + *
This implementation replaces the {@code ThreadLocalMap} lookup in {@link ThreadLocal} with a simple array access. The big advantage of this method is + * that thread-local accesses are identified as invariant by the JVM, which enables significant code-motion optimizations.
+ * + *The underlying array contains a slot for each thread that uses the {@link FastThreadLocal} instance. The slot is indexed by {@link Thread#getId()}. The + * array grows if necessary when the {@link #set} method is called.
+ * + *It is assumed that usages of this class will be read heavy, so any contention/false-sharing issues caused by the {@link #set} method are ignored.
+ * + * @param