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@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
41int
42pthread_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