aboutsummaryrefslogtreecommitdiff
path: root/pthreads/pthread_setcancelstate.c
blob: 152682577c7be02d8498c10afb745605824f787e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*
 * pthread_setcancelstate.c
 *
 * Description:
 * POSIX thread functions related to thread cancellation.
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2012 Pthreads-win32 contributors
 *
 *      Homepage1: http://sourceware.org/pthreads-win32/
 *      Homepage2: http://sourceforge.net/projects/pthreads4w/
 *
 *      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
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include "pthread.h"
#include "implement.h"


int
pthread_setcancelstate (int state, int *oldstate)
     /*
      * ------------------------------------------------------
      * DOCPUBLIC
      *      This function atomically sets the calling thread's
      *      cancelability state to 'state' and returns the previous
      *      cancelability state at the location referenced by
      *      'oldstate'
      *
      * PARAMETERS
      *      state,
      *      oldstate
      *              PTHREAD_CANCEL_ENABLE
      *                      cancellation is enabled,
      *
      *              PTHREAD_CANCEL_DISABLE
      *                      cancellation is disabled
      *
      *
      * DESCRIPTION
      *      This function atomically sets the calling thread's
      *      cancelability state to 'state' and returns the previous
      *      cancelability state at the location referenced by
      *      'oldstate'.
      *
      *      NOTES:
      *      1)      Use to disable cancellation around 'atomic' code that
      *              includes cancellation points
      *
      * COMPATIBILITY ADDITIONS
      *      If 'oldstate' is NULL then the previous state is not returned
      *      but the function still succeeds. (Solaris)
      *
      * RESULTS
      *              0               successfully set cancelability type,
      *              EINVAL          'state' 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
      || (state != PTHREAD_CANCEL_ENABLE && state != PTHREAD_CANCEL_DISABLE))
    {
      return EINVAL;
    }

  /*
   * Lock for async-cancel safety.
   */
  ptw32_mcs_lock_acquire (&sp->stateLock, &stateLock);

  if (oldstate != NULL)
    {
      *oldstate = sp->cancelState;
    }

  sp->cancelState = state;

  /*
   * Check if there is a pending asynchronous cancel
   */
  if (state == PTHREAD_CANCEL_ENABLE
      && sp->cancelType == 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_setcancelstate */