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Diffstat (limited to 'pthreads/w32_CancelableWait.c')
| -rw-r--r-- | pthreads/w32_CancelableWait.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/pthreads/w32_CancelableWait.c b/pthreads/w32_CancelableWait.c new file mode 100644 index 000000000..97e15aa31 --- /dev/null +++ b/pthreads/w32_CancelableWait.c @@ -0,0 +1,160 @@ +/* + * w32_CancelableWait.c + * + * Description: + * This translation unit implements miscellaneous thread functions. + * + * -------------------------------------------------------------------------- + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2005 Pthreads-win32 contributors + * + * Contact Email: rpj@callisto.canberra.edu.au + * + * The current list of contributors is contained + * in the file CONTRIBUTORS included with the source + * code distribution. The list can also be seen at the + * following World Wide Web location: + * http://sources.redhat.com/pthreads-win32/contributors.html + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library in the file COPYING.LIB; + * if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include "pthread.h" +#include "implement.h" + + +static INLINE int +ptw32_cancelable_wait (HANDLE waitHandle, DWORD timeout) + /* + * ------------------------------------------------------------------- + * This provides an extra hook into the pthread_cancel + * mechanism that will allow you to wait on a Windows handle and make it a + * cancellation point. This function blocks until the given WIN32 handle is + * signaled or pthread_cancel has been called. It is implemented using + * WaitForMultipleObjects on 'waitHandle' and a manually reset WIN32 + * event used to implement pthread_cancel. + * + * Given this hook it would be possible to implement more of the cancellation + * points. + * ------------------------------------------------------------------- + */ +{ + int result; + pthread_t self; + ptw32_thread_t * sp; + HANDLE handles[2]; + DWORD nHandles = 1; + DWORD status; + + handles[0] = waitHandle; + + self = pthread_self(); + sp = (ptw32_thread_t *) self.p; + + if (sp != NULL) + { + /* + * Get cancelEvent handle + */ + if (sp->cancelState == PTHREAD_CANCEL_ENABLE) + { + + if ((handles[1] = sp->cancelEvent) != NULL) + { + nHandles++; + } + } + } + else + { + handles[1] = NULL; + } + + status = WaitForMultipleObjects (nHandles, handles, PTW32_FALSE, timeout); + + switch (status - WAIT_OBJECT_0) + { + case 0: + /* + * Got the handle. + * In the event that both handles are signalled, the smallest index + * value (us) is returned. As it has been arranged, this ensures that + * we don't drop a signal that we should act on (i.e. semaphore, + * mutex, or condition variable etc). + */ + result = 0; + break; + + case 1: + /* + * Got cancel request. + * In the event that both handles are signaled, the cancel will + * be ignored (see case 0 comment). + */ + ResetEvent (handles[1]); + + if (sp != NULL) + { + /* + * Should handle POSIX and implicit POSIX threads.. + * Make sure we haven't been async-canceled in the meantime. + */ + (void) pthread_mutex_lock (&sp->cancelLock); + if (sp->state < PThreadStateCanceling) + { + sp->state = PThreadStateCanceling; + sp->cancelState = PTHREAD_CANCEL_DISABLE; + (void) pthread_mutex_unlock (&sp->cancelLock); + ptw32_throw (PTW32_EPS_CANCEL); + + /* Never reached */ + } + (void) pthread_mutex_unlock (&sp->cancelLock); + } + + /* Should never get to here. */ + result = EINVAL; + break; + + default: + if (status == WAIT_TIMEOUT) + { + result = ETIMEDOUT; + } + else + { + result = EINVAL; + } + break; + } + + return (result); + +} /* CancelableWait */ + +int +pthreadCancelableWait (HANDLE waitHandle) +{ + return (ptw32_cancelable_wait (waitHandle, INFINITE)); +} + +int +pthreadCancelableTimedWait (HANDLE waitHandle, DWORD timeout) +{ + return (ptw32_cancelable_wait (waitHandle, timeout)); +} |