diff -r eca8e9c3ec3e -r cd50c1894ce5 rt/emul/compact/src/main/java/java/lang/invoke/VolatileCallSite.java --- a/rt/emul/compact/src/main/java/java/lang/invoke/VolatileCallSite.java Sun Aug 17 20:09:05 2014 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,109 +0,0 @@ -/* - * Copyright (c) 2010, 2011, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. Oracle designates this - * particular file as subject to the "Classpath" exception as provided - * by Oracle in the LICENSE file that accompanied this code. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - */ - -package java.lang.invoke; - -/** - * A {@code VolatileCallSite} is a {@link CallSite} whose target acts like a volatile variable. - * An {@code invokedynamic} instruction linked to a {@code VolatileCallSite} sees updates - * to its call site target immediately, even if the update occurs in another thread. - * There may be a performance penalty for such tight coupling between threads. - *

- * Unlike {@code MutableCallSite}, there is no - * {@linkplain MutableCallSite#syncAll syncAll operation} on volatile - * call sites, since every write to a volatile variable is implicitly - * synchronized with reader threads. - *

- * In other respects, a {@code VolatileCallSite} is interchangeable - * with {@code MutableCallSite}. - * @see MutableCallSite - * @author John Rose, JSR 292 EG - */ -public class VolatileCallSite extends CallSite { - /** - * Creates a call site with a volatile binding to its target. - * The initial target is set to a method handle - * of the given type which will throw an {@code IllegalStateException} if called. - * @param type the method type that this call site will have - * @throws NullPointerException if the proposed type is null - */ - public VolatileCallSite(MethodType type) { - super(type); - } - - /** - * Creates a call site with a volatile binding to its target. - * The target is set to the given value. - * @param target the method handle that will be the initial target of the call site - * @throws NullPointerException if the proposed target is null - */ - public VolatileCallSite(MethodHandle target) { - super(target); - } - - /** - * Returns the target method of the call site, which behaves - * like a {@code volatile} field of the {@code VolatileCallSite}. - *

- * The interactions of {@code getTarget} with memory are the same - * as of a read from a {@code volatile} field. - *

- * In particular, the current thread is required to issue a fresh - * read of the target from memory, and must not fail to see - * a recent update to the target by another thread. - * - * @return the linkage state of this call site, a method handle which can change over time - * @see #setTarget - */ - @Override public final MethodHandle getTarget() { - return getTargetVolatile(); - } - - /** - * Updates the target method of this call site, as a volatile variable. - * The type of the new target must agree with the type of the old target. - *

- * The interactions with memory are the same as of a write to a volatile field. - * In particular, any threads is guaranteed to see the updated target - * the next time it calls {@code getTarget}. - * @param newTarget the new target - * @throws NullPointerException if the proposed new target is null - * @throws WrongMethodTypeException if the proposed new target - * has a method type that differs from the previous target - * @see #getTarget - */ - @Override public void setTarget(MethodHandle newTarget) { - checkTargetChange(getTargetVolatile(), newTarget); - setTargetVolatile(newTarget); - } - - /** - * {@inheritDoc} - */ - @Override - public final MethodHandle dynamicInvoker() { - return makeDynamicInvoker(); - } -}