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   * 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
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   *
   * 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
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   */
  
  package java.lang.invoke;
  
  // Android-changed: Removed references to MutableCallSite.syncAll().
  /**
   * 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.
   * <p>
   * 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}.
       * <p>
       * The interactions of {@code getTarget} with memory are the same
       * as of a read from a {@code volatile} field.
       * <p>
       * 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.
       * <p>
       * 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();
      }
  }
  