aboutsummaryrefslogtreecommitdiff
blob: a6a0ecaa5a109784d8016e5d1299252edd5b0d60 (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
131
/* Linuxthreads - a simple clone()-based implementation of Posix        */
/* threads for Linux.                                                   */
/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
/*                                                                      */
/* This program is free software; you can redistribute it and/or        */
/* modify it under the terms of the GNU Library General Public License  */
/* as published by the Free Software Foundation; either version 2       */
/* of the License, or (at your option) any later version.               */
/*                                                                      */
/* This program 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 Library General Public License for more details.                 */

/* Thread cancellation */

#include <errno.h>
#include "pthread.h"
#include "internals.h"
#include "spinlock.h"
#include "restart.h"

int pthread_setcancelstate(int state, int * oldstate)
{
  pthread_descr self = thread_self();
  if (state < PTHREAD_CANCEL_ENABLE || state > PTHREAD_CANCEL_DISABLE)
    return EINVAL;
  if (oldstate != NULL) *oldstate = self->p_cancelstate;
  self->p_cancelstate = state;
  if (self->p_canceled &&
      self->p_cancelstate == PTHREAD_CANCEL_ENABLE &&
      self->p_canceltype == PTHREAD_CANCEL_ASYNCHRONOUS)
    pthread_exit(PTHREAD_CANCELED);
  return 0;
}

int pthread_setcanceltype(int type, int * oldtype)
{
  pthread_descr self = thread_self();
  if (type < PTHREAD_CANCEL_DEFERRED || type > PTHREAD_CANCEL_ASYNCHRONOUS)
    return EINVAL;
  if (oldtype != NULL) *oldtype = self->p_canceltype;
  self->p_canceltype = type;
  if (self->p_canceled &&
      self->p_cancelstate == PTHREAD_CANCEL_ENABLE &&
      self->p_canceltype == PTHREAD_CANCEL_ASYNCHRONOUS)
    pthread_exit(PTHREAD_CANCELED);
  return 0;
}

int pthread_cancel(pthread_t thread)
{
  pthread_handle handle = thread_handle(thread);
  int pid;

  acquire(&handle->h_spinlock);
  if (invalid_handle(handle, thread)) {
    release(&handle->h_spinlock);
    return ESRCH;
  }
  handle->h_descr->p_canceled = 1;
  pid = handle->h_descr->p_pid;
  release(&handle->h_spinlock);
  kill(pid, PTHREAD_SIG_CANCEL);
  return 0;
}

void pthread_testcancel(void)
{
  pthread_descr self = thread_self();
  if (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE)
    pthread_exit(PTHREAD_CANCELED);
}

void _pthread_cleanup_push(struct _pthread_cleanup_buffer * buffer,
			   void (*routine)(void *), void * arg)
{
  pthread_descr self = thread_self();
  buffer->routine = routine;
  buffer->arg = arg;
  buffer->prev = self->p_cleanup;
  self->p_cleanup = buffer;
}

void _pthread_cleanup_pop(struct _pthread_cleanup_buffer * buffer,
			  int execute)
{
  pthread_descr self = thread_self();
  if (execute) buffer->routine(buffer->arg);
  self->p_cleanup = buffer->prev;
}

void _pthread_cleanup_push_defer(struct _pthread_cleanup_buffer * buffer,
				 void (*routine)(void *), void * arg)
{
  pthread_descr self = thread_self();
  buffer->routine = routine;
  buffer->arg = arg;
  buffer->canceltype = self->p_canceltype;
  buffer->prev = self->p_cleanup;
  self->p_canceltype = PTHREAD_CANCEL_DEFERRED;
  self->p_cleanup = buffer;
}

void _pthread_cleanup_pop_restore(struct _pthread_cleanup_buffer * buffer,
				  int execute)
{
  pthread_descr self = thread_self();
  if (execute) buffer->routine(buffer->arg);
  self->p_cleanup = buffer->prev;
  self->p_canceltype = buffer->canceltype;
  if (self->p_canceled &&
      self->p_cancelstate == PTHREAD_CANCEL_ENABLE &&
      self->p_canceltype == PTHREAD_CANCEL_ASYNCHRONOUS)
    pthread_exit(PTHREAD_CANCELED);
}

void __pthread_perform_cleanup(void)
{
  pthread_descr self = thread_self();
  struct _pthread_cleanup_buffer * c;
  for (c = self->p_cleanup; c != NULL; c = c->prev) c->routine(c->arg);
}

#ifndef PIC
/* We need a hook to force the cancelation wrappers to be linked in when
   static libpthread is used.  */
extern const int __pthread_provide_wrappers;
static const int * const __pthread_require_wrappers =
  &__pthread_provide_wrappers;
#endif