// Proactor.cpp
// $Id: Proactor.cpp,v

#define ACE_BUILD_DLL
#include "ace/Proactor.h"

#if defined (ACE_WIN32)
// This only works on Win32 platforms

#include "ace/Task_T.h"
#include "ace/Log_Msg.h"
#include "ace/Object_Manager.h"

#if !defined (__ACE_INLINE__)
#include "ace/Proactor.i"
#endif /* __ACE_INLINE__ */

// Process-wide ACE_Proactor.
ACE_Proactor *ACE_Proactor::proactor_ = 0;

// Controls whether the Proactor is deleted when we shut down (we can
// only delete it safely if we created it!)
int ACE_Proactor::delete_proactor_ = 0;

// Terminate the eventloop.
sig_atomic_t ACE_Proactor::end_event_loop_ = 0;

class ACE_Export ACE_Proactor_Timer_Handler : public ACE_Task <ACE_NULL_SYNCH>
  //     
  // = TITLE
  //
  //     A Handler for timer. It helps in the management of timers
  //     registered with the Proactor. 
  //
  // = DESCRIPTION 
  //     
  //     This object has a thread that will wait on the earliest
  //     time in a list of timers and an event. When a timer
  //     expires, the thread will post a completion event on the
  //     port and go back to waiting on the timer queue and
  //     event. If the event is signaled, the thread will refresh
  //     the time it is currently waiting on (in case the earliest
  //     time has changed)
  // 
{
  friend class ACE_Proactor;
  // Proactor has special privileges
  // Access needed to: timer_event_
  
public:
  ACE_Proactor_Timer_Handler (ACE_Proactor &proactor);
  // Constructor
  
  ~ACE_Proactor_Timer_Handler (void);
  // Destructor
  
protected:
  virtual int svc (void);
  // Run by a daemon thread to handle deferred processing. In other
  // words, this method will do the waiting on the earliest timer
  // and event
  
  ACE_Auto_Event timer_event_;
  // Event to wait on
  
  ACE_Proactor &proactor_;
  // Proactor 

  int shutting_down_;
  // Flag used to indicate when we are shutting down.
};
  
ACE_Proactor_Timer_Handler::ACE_Proactor_Timer_Handler (ACE_Proactor &proactor)
  : ACE_Task <ACE_NULL_SYNCH> (&proactor.thr_mgr_),
    proactor_ (proactor),
    shutting_down_ (0)
{
}

ACE_Proactor_Timer_Handler::~ACE_Proactor_Timer_Handler (void)
{
  // Mark for closing down
  this->shutting_down_ = 1;

  // Signal timer event
  this->timer_event_.signal ();  

  // Don't bother to wait (since the thread may have already
  // gone). But make sure to close up the descriptor.  This may not be
  // necessary in the future when THR_DETACHED is correctly
  // implemented.
  this->thr_mgr ()->close (0);
}

int
ACE_Proactor_Timer_Handler::svc (void)
{
  u_long time;
  ACE_Time_Value absolute_time;

  for (; !this->shutting_down_;)
    {
      // default value
      time = INFINITE;

      // If the timer queue is not empty
      if (!this->proactor_.timer_queue ()->is_empty ())
	{
	  // Get the earliest absolute time
	  absolute_time 
	    = this->proactor_.timer_queue ()->earliest_time () 
	    - this->proactor_.timer_queue ()->gettimeofday ();
	  
	  // time to wait
	  time = absolute_time.msec ();
	  
	  // Make sure the time is positive
	  if (time < 0)
	    time = 0;
	}
      
      // Wait for event upto <time> milli seconds
      int result = ::WaitForSingleObject (this->timer_event_.handle (),
					  time);
      switch (result)
	{
	case WAIT_TIMEOUT:
	  // timeout: expire timers
	  this->proactor_.timer_queue ()->expire ();
	  break;
	case WAIT_FAILED:
	  // error 
	  ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "WaitForSingleObject"), -1);
	}
    }

  return 0;  
}

ACE_Proactor_Handle_Timeout_Upcall::ACE_Proactor_Handle_Timeout_Upcall (void)
  : proactor_ (0)
{
}

int
ACE_Proactor_Handle_Timeout_Upcall::timeout (TIMER_QUEUE &timer_queue,
					     ACE_Handler *handler,
					     const void *act,
					     const ACE_Time_Value &time)
{
  ACE_UNUSED_ARG (timer_queue);

  if (this->proactor_ == 0)
    ACE_ERROR_RETURN ((LM_ERROR, 
		       "(%t) No Proactor set in ACE_Proactor_Handle_Timeout_Upcall, no completion port to post timeout to?!@\n"),
		      -1);
  
  // Grab the event associated with the Proactor
  HANDLE handle = this->proactor_->get_handle ();

  // Create the Asynch_Timer
  ACE_Proactor::Asynch_Timer *asynch_timer 
    = new ACE_Proactor::Asynch_Timer (*handler,
				      act,
				      time,
				      handle);
  // If Proactor event is valid, signal it
  if (handle != ACE_INVALID_HANDLE || 
      handle != 0)
    ACE_OS::event_signal (&handle);
  
  // Post a completion
  if (::PostQueuedCompletionStatus (this->proactor_->completion_port_, // completion port
				    0, // number of bytes tranferred 
				    0,	// completion key 
				    asynch_timer // overlapped
				    ) == FALSE)
    {
      delete asynch_timer;
      ACE_ERROR_RETURN ((LM_ERROR, "Failure in dealing with timers: PostQueuedCompletionStatus failed\n"), -1);
    }
  
  return 0;
}


int
ACE_Proactor_Handle_Timeout_Upcall::cancellation (TIMER_QUEUE &timer_queue,
						  ACE_Handler *handler)
{
  ACE_UNUSED_ARG (timer_queue);
  ACE_UNUSED_ARG (handler);

  // Do nothing
  return 0;
}

int 
ACE_Proactor_Handle_Timeout_Upcall::deletion (TIMER_QUEUE &timer_queue,
                                              ACE_Handler *handler,
                                              const void *arg)
{
  ACE_UNUSED_ARG (timer_queue);
  ACE_UNUSED_ARG (handler);
  ACE_UNUSED_ARG (arg);

  // Do nothing
  return 0;
}

int
ACE_Proactor_Handle_Timeout_Upcall::proactor (ACE_Proactor &proactor)
{
  if (this->proactor_ == 0)
    {
      this->proactor_ = &proactor;
      return 0;
    }
  else
    ACE_ERROR_RETURN ((LM_ERROR, 
		       "ACE_Proactor_Handle_Timeout_Upcall is only suppose to be used with ONE (and only one) Proactor\n"), 
		      -1);
}



ACE_Proactor::ACE_Proactor (size_t number_of_threads, 
			    Timer_Queue *tq,
			    int used_with_reactor_event_loop)
  : completion_port_ (0), // This *MUST* be 0, *NOT* ACE_INVALID_HANDLE!!!!
    number_of_threads_ (number_of_threads),
    timer_queue_ (0),
    delete_timer_queue_ (0),
    timer_handler_ (0),
    used_with_reactor_event_loop_ (used_with_reactor_event_loop)
{
  // create the completion port
  this->completion_port_ = ::CreateIoCompletionPort (INVALID_HANDLE_VALUE,						     
						     this->completion_port_,
						     0,
						     this->number_of_threads_);
  if (this->completion_port_ == 0)
    ACE_ERROR ((LM_ERROR, "%p\n", "CreateIoCompletionPort"));

  // set the timer queue
  this->timer_queue (tq);

  // Create the timer handler
  ACE_NEW (this->timer_handler_, ACE_Proactor_Timer_Handler (*this));

  // activate <timer_handler>
  if (this->timer_handler_->activate (THR_NEW_LWP | THR_DETACHED) == -1)
    ACE_ERROR ((LM_ERROR, "%p Could not create thread\n", "Task::activate"));

}

ACE_Proactor *
ACE_Proactor::instance (size_t threads)
{
  ACE_TRACE ("ACE_Proactor::instance");

  if (ACE_Proactor::proactor_ == 0)
    {
      // Perform Double-Checked Locking Optimization.
      ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon,
				*ACE_Static_Object_Lock::instance (), 0));

      if (ACE_Proactor::proactor_ == 0)
	{
	  ACE_NEW_RETURN (ACE_Proactor::proactor_, ACE_Proactor (threads), 0);
	  ACE_Proactor::delete_proactor_ = 1;
	}
    }
  return ACE_Proactor::proactor_;
}

ACE_Proactor *
ACE_Proactor::instance (ACE_Proactor *r)
{
  ACE_TRACE ("ACE_Proactor::instance");

  ACE_MT (ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon,
			    *ACE_Static_Object_Lock::instance (), 0));

  ACE_Proactor *t = ACE_Proactor::proactor_;
  // We can't safely delete it since we don't know who created it!
  ACE_Proactor::delete_proactor_ = 0;

  ACE_Proactor::proactor_ = r;
  return t;
}

void
ACE_Proactor::close_singleton (void)
{
  ACE_TRACE ("ACE_Proactor::close_singleton");

  ACE_MT (ACE_GUARD (ACE_Recursive_Thread_Mutex, ace_mon,
		     *ACE_Static_Object_Lock::instance ()));

  if (ACE_Proactor::delete_proactor_)
    {
      delete ACE_Proactor::proactor_;
      ACE_Proactor::proactor_ = 0;
      ACE_Proactor::delete_proactor_ = 0;
    }
}

int
ACE_Proactor::run_event_loop (void)
{
  ACE_TRACE ("ACE_Proactor::run_event_loop");

  while (ACE_Proactor::end_event_loop_ == 0)
    {
      int result = ACE_Proactor::instance ()->handle_events ();

      if (ACE_Service_Config::reconfig_occurred ())
	ACE_Service_Config::reconfigure ();

      else if (result == -1)
	return -1;
    }
  /* NOTREACHED */
  return 0;
}

// Handle events for -tv- time.  handle_events updates -tv- to reflect
// time elapsed, so do not return until -tv- == 0, or an error occurs.
int
ACE_Proactor::run_event_loop (ACE_Time_Value &tv)
{
  ACE_TRACE ("ACE_Proactor::run_event_loop");

  while (ACE_Proactor::end_event_loop_ == 0 && tv != ACE_Time_Value::zero)
    {
      int result = ACE_Proactor::instance ()->handle_events (tv);
      if (ACE_Service_Config::reconfig_occurred ())
	ACE_Service_Config::reconfigure ();
      
      // An error has occurred.
      else if (result == -1)
	return result;
    }
  
  /* NOTREACHED */
  return 0;
}

int
ACE_Proactor::end_event_loop (void)
{
  ACE_TRACE ("ACE_Proactor::end_event_loop");
  ACE_Proactor::end_event_loop_ = 1;
  //  ACE_Proactor::instance()->notify ();
  return 0;
}

/* static */
int
ACE_Proactor::event_loop_done (void)
{
  ACE_TRACE ("ACE_Proactor::event_loop_done");
  return ACE_Proactor::end_event_loop_ != 0;
}

ACE_Proactor::~ACE_Proactor (void)
{
  this->close ();
}

int 
ACE_Proactor::close (void)
{
  // Take care of the timer handler
  if (this->timer_handler_)
    {
      delete this->timer_handler_;
      this->timer_handler_ = 0;
    }

  // Take care of the timer queue
  if (this->delete_timer_queue_)
    {
      delete this->timer_queue_;
      this->timer_queue_ = 0;
      this->delete_timer_queue_ = 0;
    }

  // Close the completion port
  if (this->completion_port_ != 0)
    {
      int result = ACE_OS::close (this->completion_port_);
      this->completion_port_ = 0;
      return result;
    }
  else
    return 0;
}

int 
ACE_Proactor::register_handle (ACE_HANDLE handle, 
			       const void *completion_key)
{
  // No locking is needed here as no state changes
  ACE_HANDLE cp = ::CreateIoCompletionPort (handle,
					    this->completion_port_,
					    (u_long) completion_key,
					    this->number_of_threads_);
  if (cp == 0)
    {
      errno = ::GetLastError ();
      // If errno == ERROR_INVALID_PARAMETER, then this handle was
      // already registered.
      if (errno != ERROR_INVALID_PARAMETER)
	ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "CreateIoCompletionPort"), -1);
    }
  return 0;
}

long
ACE_Proactor::schedule_timer (ACE_Handler &handler, 
			      const void *act,
			      const ACE_Time_Value &time)
{
  return this->schedule_timer (handler, act, time, ACE_Time_Value::zero);
}

long
ACE_Proactor::schedule_repeating_timer (ACE_Handler &handler, 
					const void *act,
					const ACE_Time_Value &interval)
{
  return this->schedule_timer (handler, act, interval, interval);
}

long
ACE_Proactor::schedule_timer (ACE_Handler &handler, 
			      const void *act,
			      const ACE_Time_Value &time,
			      const ACE_Time_Value &interval)
{
  // absolute time
  ACE_Time_Value absolute_time = this->timer_queue_->gettimeofday () + time;
  
  // Only one guy goes in here at a time
  ACE_GUARD_RETURN (ACE_Recursive_Thread_Mutex, ace_mon, this->timer_queue_->mutex (), -1);  

  // Schedule the timer
  long result = this->timer_queue_->schedule (&handler, 
					      act,
					      absolute_time,
					      interval);
  if (result != -1)
    {
      // no failures: check to see if we are the earliest time
      if (this->timer_queue_->earliest_time () == absolute_time)
	
	// wake up the timer thread
	if (this->timer_handler_->timer_event_.signal () == -1)
	  {
	    // Cancel timer
	    this->timer_queue_->cancel (result);
	    result = -1;
	  }
    }
  return result;
}

int
ACE_Proactor::cancel_timer (long timer_id, 
			    const void **arg,
			    int dont_call_handle_close)
{
  // No need to singal timer event here. Even if the cancel timer was
  // the earliest, we will have an extra wakeup.
  return this->timer_queue_->cancel (timer_id, arg, dont_call_handle_close);
}

int 
ACE_Proactor::cancel_timer (ACE_Handler &handler,
			    int dont_call_handle_close)
{
  // No need to singal timer event here. Even if the cancel timer was
  // the earliest, we will have an extra wakeup.
  return this->timer_queue_->cancel (&handler, dont_call_handle_close);
}

int
ACE_Proactor::handle_signal (int, siginfo_t *, ucontext_t *)
{
  // Perform a non-blocking "poll" for all the I/O events that have
  // completed in the I/O completion queue.

  ACE_Time_Value timeout (0, 0);
  int result;

  while ((result = this->handle_events (timeout)) == 1)
    continue;
  
  // If our handle_events failed, we'll report a failure to the
  // Reactor.
  return result == -1 ? -1 : 0;
}

int 
ACE_Proactor::handle_close (ACE_HANDLE handle,
			    ACE_Reactor_Mask close_mask)
{
  ACE_UNUSED_ARG (close_mask);
  ACE_UNUSED_ARG (handle);

  return this->close ();
}

ACE_HANDLE 
ACE_Proactor::get_handle (void) const
{
  if (this->used_with_reactor_event_loop_)
    return this->event_.handle ();
  else
    return 0;
}
  
int 
ACE_Proactor::handle_events (ACE_Time_Value &wait_time)
{
  // Decrement <wait_time> with the amount of time spent in the method
  ACE_Countdown_Time countdown (&wait_time);
  return this->handle_events (wait_time.msec ());
}

int 
ACE_Proactor::handle_events (void)
{
  return this->handle_events (INFINITE);
}

int 
ACE_Proactor::handle_events (unsigned long milli_seconds)
{
  OVERLAPPED *overlapped = 0;
  u_long bytes_transferred = 0;
  u_long completion_key = 0;

  // Get the next asynchronous operation that completes
  BOOL result = ::GetQueuedCompletionStatus (this->completion_port_,
					     &bytes_transferred,
					     &completion_key,
					     &overlapped,
					     milli_seconds);

  if (result == FALSE && overlapped == 0)
    {
      errno = ::GetLastError ();

      // @@  What's the WIN32 constant for timeout (258)?!?!?!
      if (errno == 258)
	{
	  errno = ETIME;
	  return 0;
	}
      else
	ACE_ERROR_RETURN ((LM_ERROR, "%p\n", "GetQueuedCompletionStatus"), -1);
    }
  else
    {
      // Narrow the result.
      ACE_Asynch_Result *asynch_result = (ACE_Asynch_Result *) overlapped;

      // If errors happen, grab the error.
      if (result == FALSE)
	errno = ::GetLastError ();
      
      this->application_specific_code (asynch_result,
				       bytes_transferred,
				       result,
				       (void *) completion_key,
				       errno);
    }
  return 0;
}

void
ACE_Proactor::application_specific_code (ACE_Asynch_Result *asynch_result,
					 u_long bytes_transferred,
					 int success,
					 const void *completion_key,
					 u_long error)
{
  ACE_SEH_TRY
    {
      // Call completion hook
      asynch_result->complete (bytes_transferred,
			       success,
			       (void *) completion_key,
			       error);
    }
  ACE_SEH_FINALLY
    {
      // This is crucial to prevent memory leaks
      delete asynch_result;
    }
}

int 
ACE_Proactor::wake_up_dispatch_threads (void)
{
  return 0;
}

int 
ACE_Proactor::close_dispatch_threads (int)
{
  return 0;
}

size_t 
ACE_Proactor::number_of_threads (void) const
{
  return this->number_of_threads_;
}

void 
ACE_Proactor::number_of_threads (size_t threads)
{
  this->number_of_threads_ = threads;
}

ACE_Proactor::Timer_Queue *
ACE_Proactor::timer_queue (void) const
{
  return this->timer_queue_;
}

void 
ACE_Proactor::timer_queue (Timer_Queue *tq)
{
  // cleanup old timer queue
  if (this->delete_timer_queue_)
    {
      delete this->timer_queue_;
      this->delete_timer_queue_ = 0;
    }

  // new timer queue
  if (tq == 0)
    {
      this->timer_queue_ = new Timer_Heap;
      this->delete_timer_queue_ = 1;
    }
  else
    {
      this->timer_queue_ = tq;
      this->delete_timer_queue_ = 0;
    }

  // Set the proactor in the timer queue's functor
  this->timer_queue_->upcall_functor ().proactor (*this);
}

ACE_Proactor::Asynch_Timer::Asynch_Timer (ACE_Handler &handler,
					  const void *act,
					  const ACE_Time_Value &tv,
					  ACE_HANDLE event)
  : ACE_Asynch_Result (handler, act, event),
    time_ (tv)
{
}

void
ACE_Proactor::Asynch_Timer::complete (u_long bytes_transferred,
				      int success,
				      const void *completion_key,
				      u_long error)
{
  ACE_UNUSED_ARG (error);
  ACE_UNUSED_ARG (completion_key);
  ACE_UNUSED_ARG (success);
  ACE_UNUSED_ARG (bytes_transferred);

  this->handler_.handle_time_out (this->time_, this->act ());
}

#else /* ACE_WIN32 */

ACE_Proactor *
ACE_Proactor::instance (size_t threads)
{
  ACE_UNUSED_ARG (threads);
  return 0;
}

ACE_Proactor *
ACE_Proactor::instance (ACE_Proactor *)
{
  return 0;
}

void
ACE_Proactor::close_singleton (void)
{
}

int 
ACE_Proactor::run_event_loop (void)
{
  // not implemented
  return -1;
}

int 
ACE_Proactor::run_event_loop (ACE_Time_Value &tv)
{
  // not implemented
  ACE_UNUSED_ARG (tv);
  return -1;
}

int 
ACE_Proactor::end_event_loop (void)
{
  // not implemented
  return -1;
}

sig_atomic_t 
ACE_Proactor::event_loop_done (void)
{
  return sig_atomic_t (1);
}
#endif /* ACE_WIN32 */