/*
 * 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 __ZTCONCURRENTEXECUTOR_H__
#define __ZTCONCURRENTEXECUTOR_H__

#include "zthread/PoolExecutor.h"

namespace ZThread {

  /**
   * @class ConcurrentExecutor
   *
   * @author Eric Crahen <http://www.code-foo.com>
   * @date <2003-07-16T22:36:11-0400>
   * @version 2.3.0
   *
   * A ConcurrentExecutor spawns a single thread to service a series of Tasks.
   * 
   * @see PoolExecutor.
   */
  class ConcurrentExecutor : public Executor {

    PoolExecutor _executor;

  public:
    
    //! Create a ConcurrentExecutor
    ConcurrentExecutor(); 

    /**
     * Interrupting a ConcurrentExecutor will cause the thread running the tasks to be
     * be interrupted once during the execution of each task that has been submitted 
     * at the time this function is called.
     *  
     * Tasks that are submitted after this function is called will 
     * not be interrupt()ed; unless this function is invoked again().
     *
     * @code
     * 
     * void aFunction() {
     *
     *   ConcurrentExecutor executor;
     *
     *   // Submit p Tasks
     *   for(size_t n = 0; n < p; n++)
     *     executor.execute(new aRunnable);
     *
     *   // Tasks [m, p) may be interrupted, where m is the first task that has 
     *   // not completed at the time the interrupt() is invoked. 
     *   executor.interrupt();
     *
     *   // Submit (q - p) Tasks
     *   for(size_t n = p; n < q; n++)
     *     executor.execute(new Chore);
     * 
     *   // Tasks [p, q) are not interrupted 
     *
     * }
     *
     * @endcode
     */
    virtual void interrupt();
    
    /**
     * Submit a Task to this Executor. This will not block the current thread 
     * for very long. The task will be enqueued internally and eventually run 
     * in the context of the single thread driving all the Tasks submitted to this 
     * Executor.
     * 
     * @exception Cancellation_Exception thrown if this Executor has been canceled.
     * The Task being submitted will not be executed by this Executor.
     *
     * @exception Synchronization_Exception thrown only in the event of an error 
     * in the implementation of the library.
     *
     * @see Executor::execute(const Task&)
     */
    virtual void execute(const Task&);
    
    /**
     * @see Cancelable::cancel()
     */
    virtual void cancel();
    
    /**
     * @see Cancelable::isCanceled()
     */
    virtual bool isCanceled();
    
    /**
     * @see PoolExecutor::wait()
     */
    virtual void wait();
    
    /**
     * @see PoolExecutor::wait(unsigned long timeout)
     */
    virtual bool wait(unsigned long timeout);
    
  }; /* ConcurrentExecutor */
  
} // namespace ZThread

#endif // __ZTCONCURRENTEXECUTOR_H__