[473862]: pthread_cancel.c Maximize Restore History

Download this file

pthread_cancel.c    190 lines (168 with data), 5.3 kB

  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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
/*
* pthread_cancel.c
*
* Description:
* POSIX thread functions related to thread cancellation.
*
* --------------------------------------------------------------------------
*
* Pthreads-win32 - POSIX Threads Library for Win32
* Copyright(C) 1998 John E. Bossom
* Copyright(C) 1999,2005 Pthreads-win32 contributors
*
* Contact Email: rpj@callisto.canberra.edu.au
*
* 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
*/
#include "pthread.h"
#include "implement.h"
#include "context.h"
static void
ptw32_cancel_self (void)
{
ptw32_throw (PTW32_EPS_CANCEL);
/* Never reached */
}
static void CALLBACK
ptw32_cancel_callback (ULONG_PTR unused)
{
ptw32_throw (PTW32_EPS_CANCEL);
/* Never reached */
}
/*
* ptw32_RegisterCancelation() -
* Must have args of same type as QueueUserAPCEx because this function
* is a substitute for QueueUserAPCEx if it's not available.
*/
DWORD
ptw32_RegisterCancelation (PAPCFUNC unused1, HANDLE threadH, DWORD unused2)
{
CONTEXT context;
context.ContextFlags = CONTEXT_CONTROL;
GetThreadContext (threadH, &context);
PTW32_PROGCTR (context) = (DWORD_PTR) ptw32_cancel_self;
SetThreadContext (threadH, &context);
return 0;
}
int
pthread_cancel (pthread_t thread)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function requests cancellation of 'thread'.
*
* PARAMETERS
* thread
* reference to an instance of pthread_t
*
*
* DESCRIPTION
* This function requests cancellation of 'thread'.
* NOTE: cancellation is asynchronous; use pthread_join to
* wait for termination of 'thread' if necessary.
*
* RESULTS
* 0 successfully requested cancellation,
* ESRCH no thread found corresponding to 'thread',
* ENOMEM implicit self thread create failed.
* ------------------------------------------------------
*/
{
int result;
int cancel_self;
pthread_t self;
ptw32_thread_t * tp;
ptw32_mcs_local_node_t stateLock;
result = pthread_kill (thread, 0);
if (0 != result)
{
return result;
}
if ((self = pthread_self ()).p == NULL)
{
return ENOMEM;
};
/*
* For self cancellation we need to ensure that a thread can't
* deadlock itself trying to cancel itself asynchronously
* (pthread_cancel is required to be an async-cancel
* safe function).
*/
cancel_self = pthread_equal (thread, self);
tp = (ptw32_thread_t *) thread.p;
/*
* Lock for async-cancel safety.
*/
ptw32_mcs_lock_acquire (&tp->stateLock, &stateLock);
if (tp->cancelType == PTHREAD_CANCEL_ASYNCHRONOUS
&& tp->cancelState == PTHREAD_CANCEL_ENABLE
&& tp->state < PThreadStateCanceling)
{
if (cancel_self)
{
tp->state = PThreadStateCanceling;
tp->cancelState = PTHREAD_CANCEL_DISABLE;
ptw32_mcs_lock_release (&stateLock);
ptw32_throw (PTW32_EPS_CANCEL);
/* Never reached */
}
else
{
HANDLE threadH = tp->threadH;
SuspendThread (threadH);
if (WaitForSingleObject (threadH, 0) == WAIT_TIMEOUT)
{
tp->state = PThreadStateCanceling;
tp->cancelState = PTHREAD_CANCEL_DISABLE;
/*
* If alertdrv and QueueUserAPCEx is available then the following
* will result in a call to QueueUserAPCEx with the args given, otherwise
* this will result in a call to ptw32_RegisterCancelation and only
* the threadH arg will be used.
*/
ptw32_register_cancelation ((PAPCFUNC)ptw32_cancel_callback, threadH, 0);
ptw32_mcs_lock_release (&stateLock);
ResumeThread (threadH);
}
}
}
else
{
/*
* Set for deferred cancellation.
*/
if (tp->state < PThreadStateCancelPending)
{
tp->state = PThreadStateCancelPending;
if (!SetEvent (tp->cancelEvent))
{
result = ESRCH;
}
}
else if (tp->state >= PThreadStateCanceling)
{
result = ESRCH;
}
ptw32_mcs_lock_release (&stateLock);
}
return (result);
}