native_client_sdk/src/libraries/third_party/pthreads-win32/pthread_testcancel.c

   1 /*
   2  * pthread_testcancel.c
   3  *
   4  * Description:
   5  * POSIX thread functions related to thread cancellation.
   6  *
   7  * --------------------------------------------------------------------------
   8  *
   9  *      Pthreads-win32 - POSIX Threads Library for Win32
  10  *      Copyright(C) 1998 John E. Bossom
  11  *      Copyright(C) 1999,2005 Pthreads-win32 contributors
  12  *
  13  *      Contact Email: rpj@callisto.canberra.edu.au
  14  *
  15  *      The current list of contributors is contained
  16  *      in the file CONTRIBUTORS included with the source
  17  *      code distribution. The list can also be seen at the
  18  *      following World Wide Web location:
  19  *      http://sources.redhat.com/pthreads-win32/contributors.html
  20  *
  21  *      This library is free software; you can redistribute it and/or
  22  *      modify it under the terms of the GNU Lesser General Public
  23  *      License as published by the Free Software Foundation; either
  24  *      version 2 of the License, or (at your option) any later version.
  25  *
  26  *      This library is distributed in the hope that it will be useful,
  27  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  28  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  29  *      Lesser General Public License for more details.
  30  *
  31  *      You should have received a copy of the GNU Lesser General Public
  32  *      License along with this library in the file COPYING.LIB;
  33  *      if not, write to the Free Software Foundation, Inc.,
  34  *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  35  */
  36
  37 #include "pthread.h"
  38 #include "implement.h"
  39
  40
  41 void
  42 pthread_testcancel (void)
  43      /*
  44       * ------------------------------------------------------
  45       * DOCPUBLIC
  46       *      This function creates a deferred cancellation point
  47       *      in the calling thread. The call has no effect if the
  48       *      current cancelability state is
  49       *              PTHREAD_CANCEL_DISABLE
  50       *
  51       * PARAMETERS
  52       *      N/A
  53       *
  54       *
  55       * DESCRIPTION
  56       *      This function creates a deferred cancellation point
  57       *      in the calling thread. The call has no effect if the
  58       *      current cancelability state is
  59       *              PTHREAD_CANCEL_DISABLE
  60       *
  61       *      NOTES:
  62       *      1)      Cancellation is asynchronous. Use pthread_join
  63       *              to wait for termination of thread if necessary
  64       *
  65       * RESULTS
  66       *              N/A
  67       *
  68       * ------------------------------------------------------
  69       */
  70 {
  71   ptw32_mcs_local_node_t stateLock;
  72   pthread_t self = pthread_self ();
  73   ptw32_thread_t * sp = (ptw32_thread_t *) self.p;
  74
  75   if (sp == NULL)
  76     {
  77       return;
  78     }
  79
  80   /*
  81    * Pthread_cancel() will have set sp->state to PThreadStateCancelPending
  82    * and set an event, so no need to enter kernel space if
  83    * sp->state != PThreadStateCancelPending - that only slows us down.
  84    */
  85   if (sp->state != PThreadStateCancelPending)
  86     {
  87       return;
  88     }
  89
  90   ptw32_mcs_lock_acquire (&sp->stateLock, &stateLock);
  91
  92   if (sp->cancelState != PTHREAD_CANCEL_DISABLE)
  93     {
  94       ResetEvent(sp->cancelEvent);
  95       sp->state = PThreadStateCanceling;
  96       sp->cancelState = PTHREAD_CANCEL_DISABLE;
  97       ptw32_mcs_lock_release (&stateLock);
  98       ptw32_throw (PTW32_EPS_CANCEL);
  99       /* Never returns here */
 100     }
 101
 102   ptw32_mcs_lock_release (&stateLock);
 103 }                               /* pthread_testcancel */