opendaylight/md-sal/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 javax.annotation.Nullable;
  11 import javax.annotation.concurrent.GuardedBy;
  12
  13 import com.google.common.base.Preconditions;
  14 import com.google.common.util.concurrent.AbstractFuture;
  15
  16 final class UncancellableFuture<V> extends AbstractFuture<V> {
  17     @GuardedBy("this")
  18     private boolean uncancellable = false;
  19
  20     public UncancellableFuture(final boolean uncancellable) {
  21         this.uncancellable = uncancellable;
  22     }
  23
  24     public synchronized boolean setUncancellable() {
  25         if (isCancelled()) {
  26             return false;
  27         }
  28
  29         uncancellable = true;
  30         return true;
  31     }
  32
  33     public synchronized boolean isUncancellable() {
  34         return uncancellable;
  35     }
  36
  37     @Override
  38     public synchronized boolean cancel(final boolean mayInterruptIfRunning) {
  39         return uncancellable ? false : super.cancel(mayInterruptIfRunning);
  40     }
  41
  42     @Override
  43     public synchronized boolean set(@Nullable final V value) {
  44         Preconditions.checkState(uncancellable);
  45         return super.set(value);
  46     }
  47
  48     @Override
  49     protected boolean setException(final Throwable throwable) {
  50         Preconditions.checkState(uncancellable);
  51         return super.setException(throwable);
  52     }
  53 }