1 files changed, 94 insertions, 0 deletions
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/PausableThreadPoolExecutor.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/PausableThreadPoolExecutor.java
new file mode 100644
index 000000000..5ec915810
--- /dev/null
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/PausableThreadPoolExecutor.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2013 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.util;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * Example from
+ * http://docs.oracle.com/javase/1.5.0/docs/api/java/util/concurrent/ThreadPoolExecutor.html
+ */
+public class PausableThreadPoolExecutor extends ThreadPoolExecutor {
+
+    public PausableThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime,
+                                      TimeUnit unit, BlockingQueue<Runnable> workQueue,
+                                      RejectedExecutionHandler handler) {
+        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, handler);
+    }
+
+    public PausableThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime,
+                                      TimeUnit unit, BlockingQueue<Runnable> workQueue,
+                                      ThreadFactory threadFactory,
+                                      RejectedExecutionHandler handler) {
+        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory, handler);
+    }
+
+    public PausableThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime,
+                                      TimeUnit unit, BlockingQueue<Runnable> workQueue,
+                                      ThreadFactory threadFactory) {
+        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue, threadFactory);
+    }
+
+    public PausableThreadPoolExecutor(int corePoolSize, int maximumPoolSize, long keepAliveTime,
+                                      TimeUnit unit, BlockingQueue<Runnable> workQueue) {
+        super(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue);
+    }
+
+    private boolean mIsPaused;
+    private ReentrantLock mPauseLock = new ReentrantLock();
+    private Condition mUnPaused = mPauseLock.newCondition();
+
+    protected void beforeExecute(Thread t, Runnable r) {
+        super.beforeExecute(t, r);
+        mPauseLock.lock();
+        try {
+            while (mIsPaused) {
+                mUnPaused.await();
+            }
+        } catch (InterruptedException ie) {
+            t.interrupt();
+        } finally {
+            mPauseLock.unlock();
+        }
+    }
+
+    public void pause() {
+        mPauseLock.lock();
+        try {
+            mIsPaused = true;
+        } finally {
+            mPauseLock.unlock();
+        }
+    }
+
+    public void resume() {
+        mPauseLock.lock();
+        try {
+            mIsPaused = false;
+            mUnPaused.signalAll();
+        } finally {
+            mPauseLock.unlock();
+        }
+    }
+}