Imported MaNGOS revision 6767 from http://mangos.svn.sourceforge.net/svnroot/mangos/trunk/

dep/include/zthread/PoolExecutor.h

@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2005, Eric Crahen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is furnished
+ * to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#ifndef __ZTPOOLEXECUTOR_H__
+#define __ZTPOOLEXECUTOR_H__
+
+#include "zthread/Executor.h"
+#include "zthread/CountedPtr.h"
+#include "zthread/Thread.h"
+
+namespace ZThread {
+  
+  namespace { class ExecutorImpl; }
+
+  /**
+   * @class PoolExecutor
+   *
+   * @author Eric Crahen <http://www.code-foo.com>
+   * @date <2003-07-16T22:41:07-0400>
+   * @version 2.3.0
+   *
+   * A PoolExecutor spawns a set of threads that are used to run tasks 
+   * that are submitted in parallel. A PoolExecutor supports the following
+   * optional operations,
+   *
+   * - <em>cancel</em>()ing a PoolExecutor will cause it to stop accepting 
+   *   new tasks. 
+   *
+   * - <em>interrupt</em>()ing a PoolExecutor will cause the any thread running 
+   *   a task which was submitted prior to the invocation of this function to 
+   *   be interrupted during the execution of that task.
+   *
+   * - <em>wait</em>()ing on a PoolExecutor will block the calling thread 
+   *   until all tasks that were submitted prior to the invocation of this function
+   *   have completed.
+   * 
+   * @see Executor.
+   */
+  class PoolExecutor : public Executor {
+
+    //! Reference to the internal implementation 
+    CountedPtr< ExecutorImpl > _impl;
+    
+    //! Cancellation task
+    Task _shutdown;
+
+  public:
+    
+    /**
+     * Create a PoolExecutor
+     *
+     * @param n number of threads to service tasks with
+     */
+    PoolExecutor(size_t n);
+
+    //! Destroy a PoolExecutor
+    virtual ~PoolExecutor();
+
+    /**
+     * Invoking this function causes each task that had been submitted prior to
+     * this function to be interrupted. Tasks submitted after the invocation of 
+     * this function are unaffected.
+     *
+     * @post Any task submitted prior to the invocation of this function will be
+     *       run in the context of an interrupted thread. 
+     * @post Any thread already executing a task which was submitted prior to the 
+     *       invocation of this function will be interrupted.        
+     */
+    virtual void interrupt();
+
+    /**
+     * Alter the number of threads being used to execute submitted tasks.
+     * 
+     * @param n number of worker threads.
+     *
+     * @pre  <i>n</i> must be greater than 0.
+     * @post <i>n</i> threads will be executing tasks submitted to this executor.
+     *
+     * @exception InvalidOp_Exception thrown if the new number of threads
+     *            <i>n</i> is less than 1.
+     */
+    void size(size_t n);
+        
+    /**
+     * Get the current number of threads being used to execute submitted tasks.
+     *
+     * @return n number of worker threads.
+     */
+    size_t size();
+    
+    /**
+     * Submit a task to this Executor. 
+     *
+     * This will not block the calling thread very long. The submitted task will
+     * be executed at some later point by another thread.
+     * 
+     * @param task Task to be run by a thread managed by this executor 
+     *
+     * @pre  The Executor should have been canceled prior to this invocation.
+     * @post The submitted task will be run at some point in the future by this Executor.
+     *
+     * @exception Cancellation_Exception thrown if the Executor was canceled prior to
+     *            the invocation of this function.
+     *
+     * @see PoolExecutor::cancel()
+     * @see Executor::execute(const Task& task)
+     */
+    virtual void execute(const Task& task);
+
+    /**
+     * @see Cancelable::cancel()
+     */
+    virtual void cancel();
+
+    /**
+     * @see Cancelable::isCanceled()
+     */
+    virtual bool isCanceled();
+ 
+    /**
+     * Block the calling thread until all tasks submitted prior to this invocation
+     * complete.
+     *
+     * @exception Interrupted_Exception thrown if the calling thread is interrupted
+     *            before the set of tasks being wait for can complete.
+     *
+     * @see Waitable::wait()
+     */
+    virtual void wait();
+
+    /**
+     * Block the calling thread until all tasks submitted prior to this invocation
+     * complete or until the calling thread is interrupted.
+     *
+     * @param timeout maximum amount of time, in milliseconds, to wait for the 
+     *                currently submitted set of Tasks to complete.
+     *
+     * @exception Interrupted_Exception thrown if the calling thread is interrupted
+     *            before the set of tasks being wait for can complete.
+     *
+     * @return 
+     *   - <em>true</em> if the set of tasks being wait for complete before 
+     *                   <i>timeout</i> milliseconds elapse.
+     *   - <em>false</em> otherwise.
+     *
+     * @see Waitable::wait(unsigned long timeout)
+     */
+    virtual bool wait(unsigned long timeout);
+      
+  }; /* PoolExecutor */
+
+
+} // namespace ZThread
+
+#endif // __ZTPOOLEXECUTOR_H__
+
+
+
+