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b168057a | 1 | /* Copyright (C) 2002-2015 Free Software Foundation, Inc. |
76a50749 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. | |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
76a50749 UD |
18 | |
19 | #include <setjmp.h> | |
20 | #include <stdlib.h> | |
21 | #include "pthreadP.h" | |
22 | ||
23 | ||
bdb04f92 UD |
24 | /* The next two functions are similar to pthread_setcanceltype() but |
25 | more specialized for the use in the cancelable functions like write(). | |
26 | They do not need to check parameters etc. */ | |
27 | int | |
28 | attribute_hidden | |
29 | __pthread_enable_asynccancel (void) | |
30 | { | |
31 | struct pthread *self = THREAD_SELF; | |
b22d701b | 32 | int oldval = THREAD_GETMEM (self, cancelhandling); |
bdb04f92 UD |
33 | |
34 | while (1) | |
35 | { | |
bdb04f92 UD |
36 | int newval = oldval | CANCELTYPE_BITMASK; |
37 | ||
38 | if (newval == oldval) | |
39 | break; | |
40 | ||
b22d701b UD |
41 | int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, |
42 | oldval); | |
a1ffb40e | 43 | if (__glibc_likely (curval == oldval)) |
bdb04f92 UD |
44 | { |
45 | if (CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS (newval)) | |
46 | { | |
47 | THREAD_SETMEM (self, result, PTHREAD_CANCELED); | |
9ae0909b | 48 | __do_cancel (); |
bdb04f92 UD |
49 | } |
50 | ||
51 | break; | |
52 | } | |
b22d701b UD |
53 | |
54 | /* Prepare the next round. */ | |
55 | oldval = curval; | |
bdb04f92 UD |
56 | } |
57 | ||
58 | return oldval; | |
59 | } | |
60 | ||
61 | ||
62 | void | |
9ae0909b | 63 | internal_function attribute_hidden |
bdb04f92 UD |
64 | __pthread_disable_asynccancel (int oldtype) |
65 | { | |
66 | /* If asynchronous cancellation was enabled before we do not have | |
67 | anything to do. */ | |
68 | if (oldtype & CANCELTYPE_BITMASK) | |
69 | return; | |
70 | ||
71 | struct pthread *self = THREAD_SELF; | |
1a7f254b | 72 | int newval; |
d5c157a9 | 73 | |
b22d701b | 74 | int oldval = THREAD_GETMEM (self, cancelhandling); |
bdb04f92 UD |
75 | |
76 | while (1) | |
77 | { | |
1a7f254b | 78 | newval = oldval & ~CANCELTYPE_BITMASK; |
bdb04f92 | 79 | |
b22d701b UD |
80 | int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling, newval, |
81 | oldval); | |
a1ffb40e | 82 | if (__glibc_likely (curval == oldval)) |
bdb04f92 | 83 | break; |
b22d701b UD |
84 | |
85 | /* Prepare the next round. */ | |
86 | oldval = curval; | |
bdb04f92 | 87 | } |
1a7f254b UD |
88 | |
89 | /* We cannot return when we are being canceled. Upon return the | |
90 | thread might be things which would have to be undone. The | |
91 | following loop should loop until the cancellation signal is | |
92 | delivered. */ | |
9437b427 UD |
93 | while (__builtin_expect ((newval & (CANCELING_BITMASK | CANCELED_BITMASK)) |
94 | == CANCELING_BITMASK, 0)) | |
1a7f254b UD |
95 | { |
96 | lll_futex_wait (&self->cancelhandling, newval, LLL_PRIVATE); | |
97 | newval = THREAD_GETMEM (self, cancelhandling); | |
98 | } | |
bdb04f92 | 99 | } |