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

   1 /*
   2  * pthread_setcancelstate.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 int
  42 pthread_setcancelstate (int state, int *oldstate)
  43      /*
  44       * ------------------------------------------------------
  45       * DOCPUBLIC
  46       *      This function atomically sets the calling thread's
  47       *      cancelability state to 'state' and returns the previous
  48       *      cancelability state at the location referenced by
  49       *      'oldstate'
  50       *
  51       * PARAMETERS
  52       *      state,
  53       *      oldstate
  54       *              PTHREAD_CANCEL_ENABLE
  55       *                      cancellation is enabled,
  56       *
  57       *              PTHREAD_CANCEL_DISABLE
  58       *                      cancellation is disabled
  59       *
  60       *
  61       * DESCRIPTION
  62       *      This function atomically sets the calling thread's
  63       *      cancelability state to 'state' and returns the previous
  64       *      cancelability state at the location referenced by
  65       *      'oldstate'.
  66       *
  67       *      NOTES:
  68       *      1)      Use to disable cancellation around 'atomic' code that
  69       *              includes cancellation points
  70       *
  71       * COMPATIBILITY ADDITIONS
  72       *      If 'oldstate' is NULL then the previous state is not returned
  73       *      but the function still succeeds. (Solaris)
  74       *
  75       * RESULTS
  76       *              0               successfully set cancelability type,
  77       *              EINVAL          'state' is invalid
  78       *
  79       * ------------------------------------------------------
  80       */
  81 {
  82   ptw32_mcs_local_node_t stateLock;
  83   int result = 0;
  84   pthread_t self = pthread_self ();
  85   ptw32_thread_t * sp = (ptw32_thread_t *) self.p;
  86
  87   if (sp == NULL
  88       || (state != PTHREAD_CANCEL_ENABLE && state != PTHREAD_CANCEL_DISABLE))
  89     {
  90       return EINVAL;
  91     }
  92
  93   /*
  94    * Lock for async-cancel safety.
  95    */
  96   ptw32_mcs_lock_acquire (&sp->stateLock, &stateLock);
  97
  98   if (oldstate != NULL)
  99     {
 100       *oldstate = sp->cancelState;
 101     }
 102
 103   sp->cancelState = state;
 104
 105   /*
 106    * Check if there is a pending asynchronous cancel
 107    */
 108   if (state == PTHREAD_CANCEL_ENABLE
 109       && sp->cancelType == PTHREAD_CANCEL_ASYNCHRONOUS
 110       && WaitForSingleObject (sp->cancelEvent, 0) == WAIT_OBJECT_0)
 111     {
 112       sp->state = PThreadStateCanceling;
 113       sp->cancelState = PTHREAD_CANCEL_DISABLE;
 114       ResetEvent (sp->cancelEvent);
 115       ptw32_mcs_lock_release (&stateLock);
 116       ptw32_throw (PTW32_EPS_CANCEL);
 117
 118       /* Never reached */
 119     }
 120
 121   ptw32_mcs_lock_release (&stateLock);
 122
 123   return (result);
 124
 125 }                               /* pthread_setcancelstate */