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 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
35 */
36
37 #include "pthread.h"
38 #include "implement.h"
39
40
41 int
pthread_setcancelstate(int state,int * oldstate)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 */
126