1/* Copyright (C) 2002-2021 Free Software Foundation, Inc.
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
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <stdlib.h>
20#include "pthreadP.h"
21
22
23void
24__cleanup_fct_attribute
25__pthread_register_cancel_defer (__pthread_unwind_buf_t *buf)
26{
27 struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf;
28 struct pthread *self = THREAD_SELF;
29
30 /* Store old info. */
31 ibuf->priv.data.prev = THREAD_GETMEM (self, cleanup_jmp_buf);
32 ibuf->priv.data.cleanup = THREAD_GETMEM (self, cleanup);
33
34 int cancelhandling = THREAD_GETMEM (self, cancelhandling);
35
36 /* Disable asynchronous cancellation for now. */
37 if (__glibc_unlikely (cancelhandling & CANCELTYPE_BITMASK))
38 while (1)
39 {
40 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
41 cancelhandling
42 & ~CANCELTYPE_BITMASK,
43 cancelhandling);
44 if (__glibc_likely (curval == cancelhandling))
45 /* Successfully replaced the value. */
46 break;
47
48 /* Prepare for the next round. */
49 cancelhandling = curval;
50 }
51
52 ibuf->priv.data.canceltype = (cancelhandling & CANCELTYPE_BITMASK
53 ? PTHREAD_CANCEL_ASYNCHRONOUS
54 : PTHREAD_CANCEL_DEFERRED);
55
56 /* Store the new cleanup handler info. */
57 THREAD_SETMEM (self, cleanup_jmp_buf, (struct pthread_unwind_buf *) buf);
58}
59
60
61void
62__cleanup_fct_attribute
63__pthread_unregister_cancel_restore (__pthread_unwind_buf_t *buf)
64{
65 struct pthread *self = THREAD_SELF;
66 struct pthread_unwind_buf *ibuf = (struct pthread_unwind_buf *) buf;
67
68 THREAD_SETMEM (self, cleanup_jmp_buf, ibuf->priv.data.prev);
69
70 int cancelhandling;
71 if (ibuf->priv.data.canceltype != PTHREAD_CANCEL_DEFERRED
72 && ((cancelhandling = THREAD_GETMEM (self, cancelhandling))
73 & CANCELTYPE_BITMASK) == 0)
74 {
75 while (1)
76 {
77 int curval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
78 cancelhandling
79 | CANCELTYPE_BITMASK,
80 cancelhandling);
81 if (__glibc_likely (curval == cancelhandling))
82 /* Successfully replaced the value. */
83 break;
84
85 /* Prepare for the next round. */
86 cancelhandling = curval;
87 }
88
89 CANCELLATION_P (self);
90 }
91}
92