]>
Commit | Line | Data |
---|---|---|
dff8da6b | 1 | /* Copyright (C) 2002-2024 Free Software Foundation, Inc. |
76a50749 | 2 | This file is part of the GNU C Library. |
76a50749 UD |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or | |
5 | modify it under the terms of the GNU Lesser General Public | |
6 | License as published by the Free Software Foundation; either | |
7 | version 2.1 of the License, or (at your option) any later version. | |
8 | ||
9 | The GNU C Library is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | Lesser General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU Lesser General Public | |
59ba27a6 | 15 | License along with the GNU C Library; if not, see |
5a82c748 | 16 | <https://www.gnu.org/licenses/>. */ |
76a50749 UD |
17 | |
18 | #include <setjmp.h> | |
19 | #include <stdlib.h> | |
20 | #include "pthreadP.h" | |
a2f0363f | 21 | #include <futex-internal.h> |
76a50749 UD |
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(). | |
676b2f20 CD |
26 | They do not need to check parameters etc. These functions must be |
27 | AS-safe, with the exception of the actual cancellation, because they | |
28 | are called by wrappers around AS-safe functions like write().*/ | |
bdb04f92 | 29 | int |
bdb04f92 UD |
30 | __pthread_enable_asynccancel (void) |
31 | { | |
32 | struct pthread *self = THREAD_SELF; | |
40465600 | 33 | int oldval = atomic_load_relaxed (&self->cancelhandling); |
bdb04f92 | 34 | |
40465600 AZ |
35 | while (1) |
36 | { | |
37 | int newval = oldval | CANCELTYPE_BITMASK; | |
bdb04f92 | 38 | |
40465600 AZ |
39 | if (newval == oldval) |
40 | break; | |
b22d701b | 41 | |
40465600 AZ |
42 | if (atomic_compare_exchange_weak_acquire (&self->cancelhandling, |
43 | &oldval, newval)) | |
44 | { | |
45 | if (cancel_enabled_and_canceled_and_async (newval)) | |
46 | { | |
47 | self->result = PTHREAD_CANCELED; | |
48 | __do_cancel (); | |
49 | } | |
50 | ||
51 | break; | |
52 | } | |
bdb04f92 UD |
53 | } |
54 | ||
55 | return oldval; | |
56 | } | |
ce0b7961 | 57 | libc_hidden_def (__pthread_enable_asynccancel) |
bdb04f92 | 58 | |
676b2f20 CD |
59 | /* See the comment for __pthread_enable_asynccancel regarding |
60 | the AS-safety of this function. */ | |
bdb04f92 | 61 | void |
bdb04f92 UD |
62 | __pthread_disable_asynccancel (int oldtype) |
63 | { | |
64 | /* If asynchronous cancellation was enabled before we do not have | |
65 | anything to do. */ | |
40465600 | 66 | if (oldtype & CANCELTYPE_BITMASK) |
bdb04f92 UD |
67 | return; |
68 | ||
69 | struct pthread *self = THREAD_SELF; | |
40465600 AZ |
70 | int newval; |
71 | int oldval = atomic_load_relaxed (&self->cancelhandling); | |
72 | do | |
73 | { | |
74 | newval = oldval & ~CANCELTYPE_BITMASK; | |
75 | } | |
76 | while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling, | |
77 | &oldval, newval)); | |
78 | ||
79 | /* We cannot return when we are being canceled. Upon return the | |
80 | thread might be things which would have to be undone. The | |
81 | following loop should loop until the cancellation signal is | |
82 | delivered. */ | |
83 | while (__glibc_unlikely ((newval & (CANCELING_BITMASK | CANCELED_BITMASK)) | |
84 | == CANCELING_BITMASK)) | |
85 | { | |
86 | futex_wait_simple ((unsigned int *) &self->cancelhandling, newval, | |
87 | FUTEX_PRIVATE); | |
88 | newval = atomic_load_relaxed (&self->cancelhandling); | |
89 | } | |
bdb04f92 | 90 | } |
ce0b7961 | 91 | libc_hidden_def (__pthread_disable_asynccancel) |