netconf/sal-netconf-connector/src/main/java/org/opendaylight/netconf/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.netconf.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
  14 final class UncancellableFuture<V> extends AbstractFuture<V> {
  15     private volatile boolean uncancellable = false;
  16
  17     UncancellableFuture(final boolean uncancellable) {
  18         this.uncancellable = uncancellable;
  19     }
  20
  21     public boolean setUncancellable() {
  22         if (isCancelled()) {
  23             return false;
  24         }
  25
  26         uncancellable = true;
  27         return true;
  28     }
  29
  30     public boolean isUncancellable() {
  31         return uncancellable;
  32     }
  33
  34     @Override
  35     public boolean cancel(final boolean mayInterruptIfRunning) {
  36         return !uncancellable && super.cancel(mayInterruptIfRunning);
  37     }
  38
  39     @Override
  40     public boolean set(@Nullable final V value) {
  41         Preconditions.checkState(uncancellable);
  42         return super.set(value);
  43     }
  44
  45     @Override
  46     protected boolean setException(final Throwable throwable) {
  47         Preconditions.checkState(uncancellable);
  48         return super.setException(throwable);
  49     }
  50 }