plugins/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 static com.google.common.base.Preconditions.checkState;
  11
  12 import com.google.common.util.concurrent.AbstractFuture;
  13 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  14
  15 final class UncancellableFuture<V> extends AbstractFuture<V> {
  16     private volatile boolean uncancellable = false;
  17
  18     UncancellableFuture(final boolean uncancellable) {
  19         this.uncancellable = uncancellable;
  20     }
  21
  22     public boolean setUncancellable() {
  23         if (isCancelled()) {
  24             return false;
  25         }
  26
  27         uncancellable = true;
  28         return true;
  29     }
  30
  31     public boolean isUncancellable() {
  32         return uncancellable;
  33     }
  34
  35     @Override
  36     public boolean cancel(final boolean mayInterruptIfRunning) {
  37         return !uncancellable && super.cancel(mayInterruptIfRunning);
  38     }
  39
  40     @SuppressFBWarnings(value = "NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE",
  41             justification = "Unrecognised NullableDecl")
  42     @Override
  43     public boolean set(final V value) {
  44         checkState(uncancellable);
  45         return super.set(value);
  46     }
  47
  48     @Override
  49     protected boolean setException(final Throwable throwable) {
  50         checkState(uncancellable);
  51         return super.setException(throwable);
  52     }
  53 }