1 files changed, 128 insertions, 0 deletions
diff --git a/simple/simple-common/src/main/java/org/simpleframework/common/thread/ExecutorQueue.java b/simple/simple-common/src/main/java/org/simpleframework/common/thread/ExecutorQueue.java
new file mode 100644
index 0000000..99e8fb2
--- /dev/null
+++ b/simple/simple-common/src/main/java/org/simpleframework/common/thread/ExecutorQueue.java
@@ -0,0 +1,128 @@
+/*
+ * ExecutorQueue.java February 2007
+ *
+ * Copyright (C) 2007, Niall Gallagher <niallg@users.sf.net>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 
+ * implied. See the License for the specific language governing 
+ * permissions and limitations under the License.
+ */
+
+package org.simpleframework.common.thread;
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * The <code>ExecutorQueue</code> object is used to queue tasks in 
+ * a thread pool. This creates a thread pool with no limit to the 
+ * number of tasks that can be enqueued, which ensures that any 
+ * system requesting a task to be executed will not block when 
+ * handing it over, it also means the user must use caution.
+ * 
+ * @author Niall Gallagher
+ * 
+ * @see org.simpleframework.common.thread.ConcurrentExecutor
+ */
+class ExecutorQueue {
+   
+   /**
+    * This is the task queue that contains tasks due to execute.
+    */
+   private final BlockingQueue<Runnable> queue;
+   
+   /**
+    * This is the actual thread pool implementation used.
+    */
+   private final ThreadPoolExecutor executor;
+   
+   /**
+    * This is used to create the pool worker threads.
+    */
+   private final ThreadFactory factory;
+   
+   /**
+    * Constructor for the <code>ExecutorQueue</code> object. This is
+    * used to create a pool of threads that can be used to execute
+    * arbitrary <code>Runnable</code> tasks. If the threads are
+    * busy this will simply enqueue the tasks and return.
+    * 
+    * @param type this is the type of runnable that this accepts
+    * @param rest this is the number of threads to use in the pool    
+    * @param active this is the maximum size the pool can grow to 
+    */    
+   public ExecutorQueue(Class type, int rest, int active) {
+      this(type, rest, active, 120, TimeUnit.SECONDS);
+   }
+  
+   /**
+    * Constructor for the <code>ExecutorQueue</code> object. This is
+    * used to create a pool of threads that can be used to execute
+    * arbitrary <code>Runnable</code> tasks. If the threads are
+    * busy this will simply enqueue the tasks and return.
+    *
+    * @param type this is the type of runnable that this accepts
+    * @param rest this is the number of threads to use in the pool    
+    * @param active this is the maximum size the pool can grow to
+    * @param duration the duration active threads remain idle for
+    * @param unit this is the time unit used for the duration 
+    */    
+   public ExecutorQueue(Class type, int rest, int active, long duration, TimeUnit unit) {
+      this.queue = new LinkedBlockingQueue<Runnable>();
+      this.factory = new DaemonFactory(type);
+      this.executor = new ThreadPoolExecutor(rest, active, duration, unit, queue, factory);
+   }
+   
+   /**
+    * The <code>execute</code> method is used to queue the task for
+    * execution. If all threads are busy the provided task is queued
+    * and waits until all current and outstanding tasks are finished.
+    * 
+    * @param task this is the task to be queued for execution
+    */
+   public void execute(Runnable task) {
+      executor.execute(task);
+   }
+   
+   /**
+    * This is used to stop the executor by interrupting all running
+    * tasks and shutting down the threads within the pool. This will
+    * return once it has been stopped, and no further tasks will be 
+    * accepted by this pool for execution.
+    */   
+   public void stop() {
+      stop(60000);
+   }
+   
+   /**
+    * This is used to stop the executor by interrupting all running
+    * tasks and shutting down the threads within the pool. This will
+    * return once it has been stopped, and no further tasks will be 
+    * accepted by this pool for execution.
+    * 
+    * @param wait the number of milliseconds to wait for it to stop
+    */   
+   public void stop(long wait) {
+      if(!executor.isTerminated()) {
+         try {
+            executor.shutdown();
+            executor.awaitTermination(wait, MILLISECONDS);
+         } catch(Exception e) {
+            throw new IllegalStateException("Could not stop pool", e);
+         }         
+      }
+   }
+}