obs-studio/w32-pthreads/pthread_setcanceltype.c

127 lines
4.0 KiB
C

/*
* pthread_setcanceltype.c
*
* Description:
* POSIX thread functions related to thread cancellation.
*
* --------------------------------------------------------------------------
*
* 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"
int
pthread_setcanceltype (int type, int *oldtype)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function atomically sets the calling thread's
* cancelability type to 'type' and returns the previous
* cancelability type at the location referenced by
* 'oldtype'
*
* PARAMETERS
* type,
* oldtype
* PTHREAD_CANCEL_DEFERRED
* only deferred cancelation is allowed,
*
* PTHREAD_CANCEL_ASYNCHRONOUS
* Asynchronous cancellation is allowed
*
*
* DESCRIPTION
* This function atomically sets the calling thread's
* cancelability type to 'type' and returns the previous
* cancelability type at the location referenced by
* 'oldtype'
*
* NOTES:
* 1) Use with caution; most code is not safe for use
* with asynchronous cancelability.
*
* COMPATIBILITY ADDITIONS
* If 'oldtype' is NULL then the previous type is not returned
* but the function still succeeds. (Solaris)
*
* RESULTS
* 0 successfully set cancelability type,
* EINVAL 'type' is invalid
*
* ------------------------------------------------------
*/
{
ptw32_mcs_local_node_t stateLock;
int result = 0;
pthread_t self = pthread_self ();
ptw32_thread_t * sp = (ptw32_thread_t *) self.p;
if (sp == NULL
|| (type != PTHREAD_CANCEL_DEFERRED
&& type != PTHREAD_CANCEL_ASYNCHRONOUS))
{
return EINVAL;
}
/*
* Lock for async-cancel safety.
*/
ptw32_mcs_lock_acquire (&sp->stateLock, &stateLock);
if (oldtype != NULL)
{
*oldtype = sp->cancelType;
}
sp->cancelType = type;
/*
* Check if there is a pending asynchronous cancel
*/
if (sp->cancelState == PTHREAD_CANCEL_ENABLE
&& type == PTHREAD_CANCEL_ASYNCHRONOUS
&& WaitForSingleObject (sp->cancelEvent, 0) == WAIT_OBJECT_0)
{
sp->state = PThreadStateCanceling;
sp->cancelState = PTHREAD_CANCEL_DISABLE;
ResetEvent (sp->cancelEvent);
ptw32_mcs_lock_release (&stateLock);
ptw32_throw (PTW32_EPS_CANCEL);
/* Never reached */
}
ptw32_mcs_lock_release (&stateLock);
return (result);
} /* pthread_setcanceltype */