tlibbe.cxx

基于VXWORKS H323通信技术源代码

 /*
 * tlibbe.cxx
 *
 * Thread library implementation for BeOS
 *
 * Portable Windows Library
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * The Original Code is Portable Windows Library.
 *
 * The Initial Developer of the Original Code is Equivalence Pty. Ltd.
 *
 * Portions are Copyright (c) 1993-1998 Equivalence Pty. Ltd.
 *
 * Portions are Copyright (C) 1993 Free Software Foundation, Inc.
 * All Rights Reserved.
 *
 * Contributor(s): Yuri Kiryanov, BeVox Group, [e-mail].
 */

class PProcess;
class PSemaphore;

#include <ptlib.h>

///////////////////////////////////////////////////////////////////////////////
// Threads
static int const priorities[] = {
  1, // Lowest priority is 1. 0 is not
  B_LOW_PRIORITY,
  B_NORMAL_PRIORITY,
  B_DISPLAY_PRIORITY,
  B_URGENT_DISPLAY_PRIORITY,
};

int32 PThread::ThreadFunction(void * threadPtr)
{
  PThread * thread = (PThread *)PAssertNULL(threadPtr);

  PProcess & process = PProcess::Current();

  process.activeThreadMutex.Wait();
  process.activeThreads.SetAt(thread->threadId, thread);
  process.activeThreadMutex.Signal();

  process.SignalTimerChange();

  thread->Main();

  return 0;
}

PThread::PThread()
 : threadId(B_BAD_THREAD_ID),
   priority(B_NORMAL_PRIORITY),
   originalStackSize(0)
{
}

PThread::PThread(PINDEX stackSize,
                 AutoDeleteFlag deletion,
                 Priority priorityLevel)
{
  PAssert(stackSize > 0, PInvalidParameter);
  autoDelete = deletion == AutoDeleteThread;
  originalStackSize = stackSize;

  priority = priorities[priorityLevel];

  threadId =  ::spawn_thread(ThreadFunction, // Function 
         "PWLT", // Name
         priority, // Priority 
         (void *) this); // Pass this as cookie

  PAssertOS(threadId >= B_NO_ERROR);

  if (autoDelete) {
    PProcess & process = PProcess::Current();
    process.deleteThreadMutex.Wait();
    process.autoDeleteThreads.Append(this);
    process.deleteThreadMutex.Signal();
  }
}


PThread::~PThread()
{
  if (originalStackSize <= 0)
    return;

  PProcess & process = PProcess::Current();
  process.activeThreadMutex.Wait();
  process.activeThreads.SetAt(threadId, NULL);
  process.activeThreadMutex.Signal();
  
  if (!IsTerminated())
    Terminate();
}


void PThread::Restart()
{
  PAssert(IsTerminated(), "Cannot restart running thread");

  threadId =  ::spawn_thread(ThreadFunction, // Function 
         "PWLT", // Name
           priority, 
         (void *) this); // Pass this as cookie
         
  PAssertOS(threadId >= B_NO_ERROR);
}


void PThread::Terminate()
{
	PAssert(!IsTerminated(), "Operation on terminated thread");
	PAssert(originalStackSize > 0, PLogicError);
	
	if (Current() == this)
	{
		sem_id semId = ::create_sem( 1, "PWST" );
		if ( ::acquire_sem(semId) == B_NO_ERROR )
		{
			// Invalidate the thread
			threadId = B_BAD_THREAD_ID;
			::release_sem(semId);
			::delete_sem(semId);
			
			::exit_thread(0);
		}
	}
	else 
	{
		sem_id semId = ::create_sem( 1, "PWTS" );
		if ( ::acquire_sem(semId) == B_NO_ERROR )
		{
			thread_id tId(B_BAD_THREAD_ID);
			
			// Invalidate the thread
			tId = threadId;
			threadId = B_BAD_THREAD_ID;
			
			// Kill it
			if (tId != B_BAD_THREAD_ID)
			{
				::release_sem(semId);
				::delete_sem(semId);
				::kill_thread(tId);
			}
			
		}
	}
	PAssert(threadId == B_BAD_THREAD_ID, "Can't acquire semaphore to terminate thread");
}


BOOL PThread::IsTerminated() const
{
  return threadId == B_BAD_THREAD_ID;
}


void PThread::WaitForTermination() const
{
  WaitForTermination(PMaxTimeInterval);
}


BOOL PThread::WaitForTermination(const PTimeInterval & /*maxWait*/) const // Fix timeout
{
  if (threadId == 0)
    return TRUE;

  status_t result, exit_value;
  PINDEX retries = 10;
  
  while ((result = ::wait_for_thread(threadId, &exit_value) != B_NO_ERROR)) {

    if ( result == B_INTERRUPTED ) { // thread was killed.
      return TRUE;
    }

    if (retries > 0)
      return TRUE;

    retries--;
  }

  return FALSE;
}


void PThread::Suspend(BOOL susp)
{
  PAssert(!IsTerminated(), "Operation on terminated thread");
  if (susp)
  {
    status_t result = ::suspend_thread(threadId);

    PAssert(result == B_OK, "Thread don't want to be suspended");
  }
  else
    Resume();
}


void PThread::Resume()
{
  PAssert(!IsTerminated(), "Operation on terminated thread");
  status_t result = ::resume_thread(threadId);

  PAssert(result == B_NO_ERROR, "Thread doesn't want to resume");
}


BOOL PThread::IsSuspended() const
{
  PAssert(!IsTerminated(), "Operation on terminated thread");

  thread_info info;
  status_t result = ::get_thread_info(threadId, &info);

  PAssert(result == B_OK && threadId == info.thread, "Thread info inaccessible");
  return info.state == B_THREAD_SUSPENDED;
}

void PThread::SetPriority(Priority priorityLevel)
{
  PAssert(!IsTerminated(), "Operation on terminated thread");

  priority = priorities[priorityLevel];
  status_t result = ::set_thread_priority(threadId, priority );

  PAssert(result == B_OK, "Thread priority change error");
}


PThread::Priority PThread::GetPriority() const
{
  PAssert(!IsTerminated(), "Operation on terminated thread");

  switch (priority) {
    case 0 :
      return LowestPriority;
    case B_LOW_PRIORITY :
      return LowPriority;
    case B_NORMAL_PRIORITY :
      return NormalPriority;
    case B_DISPLAY_PRIORITY :
      return HighPriority;
    case B_URGENT_DISPLAY_PRIORITY :
      return HighestPriority;
  }
  PAssertAlways(POperatingSystemError);
  return LowestPriority;
}

void PThread::Yield()
{
  // we just sleep for long enough to cause a reschedule (100 microsec)
  ::snooze(100);
}

void PThread::Sleep( const PTimeInterval & delay ) // Time interval to sleep for.
{
	bigtime_t microseconds = 
		delay == PMaxTimeInterval ? B_INFINITE_TIMEOUT : (delay.GetMilliSeconds() * 1000 );
 
  status_t result = ::snooze( microseconds ) ; // delay in ms, snooze in microsec
  PAssert(result == B_OK, "Thread has insomnia");
}

void PThread::InitialiseProcessThread()
{
  originalStackSize = 0;
  autoDelete = FALSE;
  
  threadId = ::find_thread(NULL);
  PAssertOS(threadId >= B_NO_ERROR);

  ((PProcess *)this)->activeThreads.DisallowDeleteObjects();
  ((PProcess *)this)->activeThreads.SetAt(threadId, this);
}


PThread * PThread::Current()
{
  PProcess & process = PProcess::Current();
  process.activeThreadMutex.Wait();
  
  thread_id tId = ::find_thread(NULL);
  PAssertOS(tId >= B_NO_ERROR);

  PThread * thread = process.activeThreads.GetAt( tId );

  process.activeThreadMutex.Signal();
  return thread;
}

int PThread::PXBlockOnChildTerminate(int pid, const PTimeInterval & /*timeout*/) // Fix timeout
{
  status_t result, exit_value;

  while ((result = ::wait_for_thread(pid, &exit_value) != B_NO_ERROR));
  return exit_value;
}

int PThread::PXBlockOnIO(int handle, int type, const PTimeInterval & timeout)
{
  // make sure we flush the buffer before doing a write
  fd_set tmp_rfd, tmp_wfd, tmp_efd;
  fd_set * read_fds      = &tmp_rfd;
  fd_set * write_fds     = &tmp_wfd;
  fd_set * exception_fds = &tmp_efd;

  FD_ZERO (read_fds);
  FD_ZERO (write_fds);
  FD_ZERO (exception_fds);

  switch (type) {
    case PChannel::PXReadBlock:
    case PChannel::PXAcceptBlock:
      FD_SET (handle, read_fds);
      break;
    case PChannel::PXWriteBlock:
      FD_SET (handle, write_fds);
      break;
    case PChannel::PXConnectBlock:
      FD_SET (handle, write_fds);
      FD_SET (handle, exception_fds);
      break;
    default:
      PAssertAlways(PLogicError);
      return 0;
  }

  struct timeval * tptr = NULL;
  struct timeval   timeout_val;
  if (timeout != PMaxTimeInterval) { // Clean up for infinite timeout
    static const PTimeInterval oneDay(0, 0, 0, 0, 1);
    if (timeout < oneDay) {
    
      timeout_val.tv_usec = (timeout.GetMilliSeconds() % 1000) * 1000;
      timeout_val.tv_sec  = timeout.GetSeconds();
      tptr                = &timeout_val;
    }
  }

  int retval = ::select(handle+1, read_fds, write_fds, exception_fds, tptr);
  //YK PProcess::Current().PXCheckSignals();