opendaylight/netconf/sal-netconf-connector/src/main/java/org/opendaylight/controller/sal/connect/netconf/listener/UncancellableFuture.java

   1 /*
   2  * Copyright (c) 2014 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.sal.connect.netconf.listener;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.util.concurrent.AbstractFuture;
  12 import javax.annotation.Nullable;
  13 import javax.annotation.concurrent.GuardedBy;
  14
  15 final class UncancellableFuture<V> extends AbstractFuture<V> {
  16     @GuardedBy("this")
  17     private boolean uncancellable = false;
  18
  19     public UncancellableFuture(final boolean uncancellable) {
  20         this.uncancellable = uncancellable;
  21     }
  22
  23     public synchronized boolean setUncancellable() {
  24         if (isCancelled()) {
  25             return false;
  26         }
  27
  28         uncancellable = true;
  29         return true;
  30     }
  31
  32     public synchronized boolean isUncancellable() {
  33         return uncancellable;
  34     }
  35
  36     @Override
  37     public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
  38         return uncancellable ? false : super.cancel(mayInterruptIfRunning);
  39     }
  40
  41     @Override
  42     public synchronized boolean set(@Nullable final V value) {
  43         Preconditions.checkState(uncancellable);
  44         return super.set(value);
  45     }
  46
  47     @Override
  48     protected boolean setException(final Throwable throwable) {
  49         Preconditions.checkState(uncancellable);
  50         return super.setException(throwable);
  51     }
  52 }