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
|
/* Copyright (C) 2002 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C 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 2.1 of the License, or (at your option) any later version.
The GNU C 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 the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include "pthreadP.h"
#include <atomic.h>
int
__pthread_setcanceltype (type, oldtype)
int type;
int *oldtype;
{
volatile struct pthread *self;
if (type < PTHREAD_CANCEL_DEFERRED || type > PTHREAD_CANCEL_ASYNCHRONOUS)
return EINVAL;
self = THREAD_SELF;
while (1)
{
int oldval = THREAD_GETMEM (self, cancelhandling);
int newval = (type == PTHREAD_CANCEL_ASYNCHRONOUS
? oldval | CANCELTYPE_BITMASK
: oldval & ~CANCELTYPE_BITMASK);
/* Store the old value. */
if (oldtype != NULL)
*oldtype = ((oldval & CANCELTYPE_BITMASK)
? PTHREAD_CANCEL_ASYNCHRONOUS : PTHREAD_CANCEL_DEFERRED);
/* Avoid doing unnecessary work. The atomic operation can
potentially be expensive if the memory has to be locked and
remote cache lines have to be invalidated. */
if (oldval == newval)
break;
/* Update the cancel handling word. This has to be done
atomically since other bits could be modified as well. */
if (atomic_compare_and_exchange_acq (&self->cancelhandling, newval,
oldval) == 0)
{
if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval))
{
THREAD_SETMEM (self, result, PTHREAD_CANCELED);
__do_cancel ();
}
break;
}
}
return 0;
}
strong_alias (__pthread_setcanceltype, pthread_setcanceltype)
|
