1 /* Copyright (C) 2002-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include "pthreadP.h"
19 #include <tls.h>
20 #include <libc-lock.h>
21
22 void
__libc_cleanup_push_defer(struct _pthread_cleanup_buffer * buffer)23 __libc_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer)
24 {
25 struct pthread *self = THREAD_SELF;
26
27 buffer->__prev = THREAD_GETMEM (self, cleanup);
28
29 int cancelhandling = atomic_load_relaxed (&self->cancelhandling);
30
31 /* Disable asynchronous cancellation for now. */
32 if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
33 {
34 int newval;
35 do
36 {
37 newval = cancelhandling & ~CANCELTYPE_BITMASK;
38 }
39 while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
40 &cancelhandling,
41 newval));
42 }
43
44 buffer->__canceltype = (cancelhandling & CANCELTYPE_BITMASK
45 ? PTHREAD_CANCEL_ASYNCHRONOUS
46 : PTHREAD_CANCEL_DEFERRED);
47
48 THREAD_SETMEM (self, cleanup, buffer);
49 }
libc_hidden_def(__libc_cleanup_push_defer)50 libc_hidden_def (__libc_cleanup_push_defer)
51
52 void
53 __libc_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer)
54 {
55 struct pthread *self = THREAD_SELF;
56
57 THREAD_SETMEM (self, cleanup, buffer->__prev);
58
59 int cancelhandling = atomic_load_relaxed (&self->cancelhandling);
60 if (buffer->__canceltype != PTHREAD_CANCEL_DEFERRED
61 && (cancelhandling & CANCELTYPE_BITMASK) == 0)
62 {
63 int newval;
64 do
65 {
66 newval = cancelhandling | CANCELTYPE_BITMASK;
67 }
68 while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
69 &cancelhandling, newval));
70
71 if (cancel_enabled_and_canceled (cancelhandling))
72 {
73 self->result = PTHREAD_CANCELED;
74 __do_cancel ();
75 }
76 }
77 }
78 libc_hidden_def (__libc_cleanup_pop_restore)
79