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      1 /*
      2  * pthread_setcanceltype.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 (at) 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_setcanceltype (int type, int *oldtype)
     43      /*
     44       * ------------------------------------------------------
     45       * DOCPUBLIC
     46       *      This function atomically sets the calling thread's
     47       *      cancelability type to 'type' and returns the previous
     48       *      cancelability type at the location referenced by
     49       *      'oldtype'
     50       *
     51       * PARAMETERS
     52       *      type,
     53       *      oldtype
     54       *              PTHREAD_CANCEL_DEFERRED
     55       *                      only deferred cancelation is allowed,
     56       *
     57       *              PTHREAD_CANCEL_ASYNCHRONOUS
     58       *                      Asynchronous cancellation is allowed
     59       *
     60       *
     61       * DESCRIPTION
     62       *      This function atomically sets the calling thread's
     63       *      cancelability type to 'type' and returns the previous
     64       *      cancelability type at the location referenced by
     65       *      'oldtype'
     66       *
     67       *      NOTES:
     68       *      1)      Use with caution; most code is not safe for use
     69       *              with asynchronous cancelability.
     70       *
     71       * COMPATIBILITY ADDITIONS
     72       *      If 'oldtype' is NULL then the previous type is not returned
     73       *      but the function still succeeds. (Solaris)
     74       *
     75       * RESULTS
     76       *              0               successfully set cancelability type,
     77       *              EINVAL          'type' 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       || (type != PTHREAD_CANCEL_DEFERRED
     89 	  && type != PTHREAD_CANCEL_ASYNCHRONOUS))
     90     {
     91       return EINVAL;
     92     }
     93 
     94   /*
     95    * Lock for async-cancel safety.
     96    */
     97   ptw32_mcs_lock_acquire (&sp->stateLock, &stateLock);
     98 
     99   if (oldtype != NULL)
    100     {
    101       *oldtype = sp->cancelType;
    102     }
    103 
    104   sp->cancelType = type;
    105 
    106   /*
    107    * Check if there is a pending asynchronous cancel
    108    */
    109   if (sp->cancelState == PTHREAD_CANCEL_ENABLE
    110       && type == PTHREAD_CANCEL_ASYNCHRONOUS
    111       && WaitForSingleObject (sp->cancelEvent, 0) == WAIT_OBJECT_0)
    112     {
    113       sp->state = PThreadStateCanceling;
    114       sp->cancelState = PTHREAD_CANCEL_DISABLE;
    115       ResetEvent (sp->cancelEvent);
    116       ptw32_mcs_lock_release (&stateLock);
    117       ptw32_throw (PTW32_EPS_CANCEL);
    118 
    119       /* Never reached */
    120     }
    121 
    122   ptw32_mcs_lock_release (&stateLock);
    123 
    124   return (result);
    125 
    126 }				/* pthread_setcanceltype */
    127