diff options
Diffstat (limited to 'openjdk/java/lang/invoke/ConstantCallSite.java')
| -rw-r--r-- | openjdk/java/lang/invoke/ConstantCallSite.java | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/openjdk/java/lang/invoke/ConstantCallSite.java b/openjdk/java/lang/invoke/ConstantCallSite.java deleted file mode 100644 index 2d9fedec..00000000 --- a/openjdk/java/lang/invoke/ConstantCallSite.java +++ /dev/null @@ -1,120 +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 ConstantCallSite} is a {@link CallSite} whose target is permanent, and can never be changed. - * An {@code invokedynamic} instruction linked to a {@code ConstantCallSite} is permanently - * bound to the call site's target. - * @author John Rose, JSR 292 EG - */ -public class ConstantCallSite extends CallSite { - private final boolean isFrozen; - - /** - * Creates a call site with a permanent target. - * @param target the target to be permanently associated with this call site - * @throws NullPointerException if the proposed target is null - */ - public ConstantCallSite(MethodHandle target) { - super(target); - isFrozen = true; - } - - /** - * Creates a call site with a permanent target, possibly bound to the call site itself. - * <p> - * During construction of the call site, the {@code createTargetHook} is invoked to - * produce the actual target, as if by a call of the form - * {@code (MethodHandle) createTargetHook.invoke(this)}. - * <p> - * Note that user code cannot perform such an action directly in a subclass constructor, - * since the target must be fixed before the {@code ConstantCallSite} constructor returns. - * <p> - * The hook is said to bind the call site to a target method handle, - * and a typical action would be {@code someTarget.bindTo(this)}. - * However, the hook is free to take any action whatever, - * including ignoring the call site and returning a constant target. - * <p> - * The result returned by the hook must be a method handle of exactly - * the same type as the call site. - * <p> - * While the hook is being called, the new {@code ConstantCallSite} - * object is in a partially constructed state. - * In this state, - * a call to {@code getTarget}, or any other attempt to use the target, - * will result in an {@code IllegalStateException}. - * It is legal at all times to obtain the call site's type using the {@code type} method. - * - * @param targetType the type of the method handle to be permanently associated with this call site - * @param createTargetHook a method handle to invoke (on the call site) to produce the call site's target - * @throws WrongMethodTypeException if the hook cannot be invoked on the required arguments, - * or if the target returned by the hook is not of the given {@code targetType} - * @throws NullPointerException if the hook returns a null value - * @throws ClassCastException if the hook returns something other than a {@code MethodHandle} - * @throws Throwable anything else thrown by the the hook function - */ - protected ConstantCallSite(MethodType targetType, MethodHandle createTargetHook) throws Throwable { - super(targetType, createTargetHook); - isFrozen = true; - } - - /** - * Returns the target method of the call site, which behaves - * like a {@code final} field of the {@code ConstantCallSite}. - * That is, the the target is always the original value passed - * to the constructor call which created this instance. - * - * @return the immutable linkage state of this call site, a constant method handle - * @throws IllegalStateException if the {@code ConstantCallSite} constructor has not completed - */ - @Override public final MethodHandle getTarget() { - if (!isFrozen) throw new IllegalStateException(); - return target; - } - - /** - * Always throws an {@link UnsupportedOperationException}. - * This kind of call site cannot change its target. - * @param ignore a new target proposed for the call site, which is ignored - * @throws UnsupportedOperationException because this kind of call site cannot change its target - */ - @Override public final void setTarget(MethodHandle ignore) { - throw new UnsupportedOperationException(); - } - - /** - * Returns this call site's permanent target. - * Since that target will never change, this is a correct implementation - * of {@link CallSite#dynamicInvoker CallSite.dynamicInvoker}. - * @return the immutable linkage state of this call site, a constant method handle - * @throws IllegalStateException if the {@code ConstantCallSite} constructor has not completed - */ - @Override - public final MethodHandle dynamicInvoker() { - return getTarget(); - } -} |