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

dep/include/zthread/CountingSemaphore.h

@@ -0,0 +1,138 @@
+/*
+ * 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 __ZTCOUNTINGSEMAPHORE_H__
+#define __ZTCOUNTINGSEMAPHORE_H__
+
+#include "zthread/Lockable.h"
+#include "zthread/NonCopyable.h"
+
+namespace ZThread {
+  
+  class FifoSemaphoreImpl;
+  
+  /**
+   * @class CountingSemaphore
+   * @author Eric Crahen <http://www.code-foo.com>
+   * @date <2003-07-16T15:26:18-0400>
+   * @version 2.2.1
+   *
+   * A CountingSemaphore is an owner-less Lockable object. 
+   * 
+   * It differs from a normal Semaphore in that there is no upper bound on the count
+   * and it will not throw an exception because a maximum value has been exceeded.
+   *
+   * @see Semaphore
+   *
+   * Threads blocked on a CountingSemaphore are resumed in FIFO order.
+   */
+  class ZTHREAD_API CountingSemaphore : public Lockable, private NonCopyable {
+  
+    FifoSemaphoreImpl* _impl;  
+
+  public:
+
+    /**
+     * Create a new CountingSemaphore. 
+     *
+     * @param count - initial count
+     */
+    CountingSemaphore(int initialCount = 0); 
+
+    //! Destroy the CountingSemaphore
+    virtual ~CountingSemaphore();
+
+    /**
+     * <i>Provided to reflect the traditional Semaphore semantics</i>
+     *
+     * @see acquire()
+     */ 
+    void wait(); 
+
+
+    /**
+     * <i>Provided to reflect the traditional Semaphore semantics</i>
+     *
+     * @see tryAcquire(unsigned long timeout)
+     */
+    bool tryWait(unsigned long timeout); 
+
+    /**
+     * <i>Provided to reflect the traditional Semaphore semantics</i>
+     *
+     * @see release()
+     */
+    void post(); 
+
+  
+    /**
+     * Get the current count of the semaphore. 
+     *
+     * This value may change immediately after this function returns to the calling thread.
+     *
+     * @return <em>int</em> count
+     */
+    virtual int count(); 
+  
+    /**
+     * Decrement the count, blocking that calling thread if the count becomes 0 or 
+     * less than 0. The calling thread will remain blocked until the count is 
+     * raised above 0, an exception is thrown or the given amount of time expires.
+     * 
+     * @param timeout maximum amount of time (milliseconds) this method could block
+     * 
+     * @return 
+     *   - <em>true</em> if the Semaphore was acquired before <i>timeout</i> milliseconds elapse.
+     *   - <em>false</em> otherwise.
+     *
+     * @exception Interrupted_Exception thrown when the calling thread is interrupted.
+     *            A thread may be interrupted at any time, prematurely ending any wait.
+     * 
+     * @see Lockable::tryAcquire(unsigned long timeout)
+     */
+    virtual bool tryAcquire(unsigned long timeout);
+
+    /**
+     * Decrement the count, blocking that calling thread if the count becomes 0 or 
+     * less than 0. The calling thread will remain blocked until the count is 
+     * raised above 0 or if an exception is thrown.
+     * 
+     * @exception Interrupted_Exception thrown when the calling thread is interrupted.
+     *            A thread may be interrupted at any time, prematurely ending any wait.
+     * 
+     * @see Lockable::acquire()
+     */
+    virtual void acquire();
+
+    /**
+     * Increment the count, unblocking one thread if count is positive.
+     *
+     * @see Lockable::release()
+     */
+    virtual void release();
+  
+  }; 
+
+
+} // namespace ZThread
+
+#endif // __ZTCOUNTINGSEMAPHORE_H__