
//=============================================================================
/**
 *  @file    Task_Test.cpp
 *
 *    This test program illustrates how the ACE barrier
 *    synchronization mechanisms work in conjunction with the
 *    <ACE_Task> and the <ACE_Thread_Manager>.  This also illustrates
 *    how the <ACE_Thread_Hook> mechanism works.
 *
 *  @author Prashant Jain <pjain@cs.wustl.edu> and Douglas C. Schmidt <d.schmidt@vanderbilt.edu>
 */
//=============================================================================


#include "test_config.h"
#include "ace/Task.h"
#include "ace/Thread_Hook.h"



#if defined (ACE_HAS_THREADS)
#include "ace/Atomic_Op.h"
#include "ace/Barrier.h"

// Make sure that only one thread sees the "time to clean up" condition
// in Barrier_Task::close()
static ACE_Atomic_Op<ACE_Thread_Mutex, int> close_cleanups (0);

class My_Thread_Hook : public ACE_Thread_Hook
{
public:
  virtual ACE_THR_FUNC_RETURN start (ACE_THR_FUNC func,
                                     void *arg);
};

class Barrier_Task : public ACE_Task<ACE_MT_SYNCH>
{
public:
  Barrier_Task (ACE_Thread_Manager *thr_mgr,
                int n_threads,
                int n_iterations);

  //FUZZ: disable check_for_lack_ACE_OS
  ///FUZZ: enable check_for_lack_ACE_OS
  virtual int close (u_long flags = 0);

  /// Iterate <n_iterations> time printing off a message and "waiting"
  /// for all other threads to complete this iteration.
  virtual int svc (void);

private:
  /// Reference to the tester barrier.  This controls each iteration of
  /// the tester function running in every thread.
  ACE_Barrier barrier_;

  /// Number of iterations to run.
  int n_iterations_;
};

ACE_THR_FUNC_RETURN
My_Thread_Hook::start (ACE_THR_FUNC func,
                       void *arg)
{
  ACE_DEBUG ((LM_DEBUG,
              ACE_TEXT ("(%t) starting the thread!\n")));
  return (func) (arg);
}

Barrier_Task::Barrier_Task (ACE_Thread_Manager *thr_mgr,
                            int n_threads,
                            int n_iterations)
  : ACE_Task<ACE_MT_SYNCH> (thr_mgr),
    barrier_ (n_threads),
    n_iterations_ (n_iterations)
{
  // Create worker threads.
  if (this->activate (THR_NEW_LWP, n_threads) == -1)
    ACE_ERROR ((LM_ERROR, ACE_TEXT ("%p\n"), ACE_TEXT ("activate failed")));
}

// Check to see if it's time to clean up by examining last_thread().
int
Barrier_Task::close (u_long)
{
  if (ACE_OS::thr_equal (ACE_Thread::self (),
                         this->last_thread ()))
    {
      ++close_cleanups;
    }
  return 0;
}

// Iterate <n_iterations> time printing off a message and "waiting"
// for all other threads to complete this iteration.
int
Barrier_Task::svc (void)
{
  for (int iterations = 1;
       iterations <= this->n_iterations_;
       iterations++)
    {
      ACE_DEBUG ((LM_DEBUG,
                  ACE_TEXT ("(%t) in iteration %d\n"),
                  iterations));

      // Block until all other threads have waited, then continue.
      this->barrier_.wait ();
    }

  // Note that the <ACE_Task::svc_run> method automatically removes us
  // from the Thread_Manager when the thread exits.

  return 0;
}

#endif /* ACE_HAS_THREADS */

int
run_main (int, ACE_TCHAR *[])
{
  ACE_START_TEST (ACE_TEXT ("Task_Test"));

#if defined (ACE_HAS_THREADS)
  // Set the thread hook!
  ACE_Thread_Hook::thread_hook (new My_Thread_Hook);

  int n_threads = ACE_MAX_THREADS;
  int n_iterations = ACE_MAX_ITERATIONS;

  Barrier_Task barrier_task (ACE_Thread_Manager::instance (),
                             n_threads,
                             n_iterations);

  ACE_Thread_Manager::instance ()->wait ();

  // Only one of the threads should see a cleanup...
  if (close_cleanups != 1)
    ACE_ERROR ((LM_ERROR,
                ACE_TEXT ("%d threads saw cleanup indication; ")
                ACE_TEXT ("should be 1\n"),
                close_cleanups.value ()));

  // Cleanup the thread hook so it doesn't leak.
  delete ACE_Thread_Hook::thread_hook ();
#else
  ACE_ERROR ((LM_INFO,
              ACE_TEXT ("threads not supported on this platform\n")));
#endif /* ACE_HAS_THREADS */
  ACE_END_TEST;
  return 0;
}
