plugins/svn4idea/src/org/jetbrains/idea/svn/ReentranceDefence.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.jetbrains.idea.svn;
  17
  18 public class ReentranceDefence {
  19   protected final ThreadLocal<Boolean> myThreadLocal;
  20
  21   protected ReentranceDefence() {
  22     myThreadLocal = new ThreadLocal<Boolean>() {
  23       @Override
  24       protected Boolean initialValue() {
  25         return Boolean.TRUE;
  26       }
  27     };
  28   }
  29
  30   public static <T> T executeReentrant(final ReentranceDefence defence, final MyControlled<T> controlled) {
  31     if (defence.isInside()) {
  32       return controlled.executeMeSimple();
  33     }
  34     return controlled.executeMe();
  35   }
  36
  37   public boolean isInside() {
  38     return ! Boolean.TRUE.equals(myThreadLocal.get());
  39   }
  40
  41   public boolean isOutside() {
  42     return ! isInside();
  43   }
  44
  45   public void executeOtherDefended(final Runnable runnable) {
  46     try {
  47       myThreadLocal.set(Boolean.FALSE);
  48       runnable.run();
  49     } finally {
  50       myThreadLocal.set(Boolean.TRUE);
  51     }
  52   }
  53
  54   public interface MyControlled<T> {
  55     T executeMe();
  56     T executeMeSimple();
  57   }
  58 }