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
|
/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <errno.h>
#include "private/bionic_futex.h"
#include "pthread_internal.h"
int pthread_join(pthread_t t, void** return_value) {
if (t == pthread_self()) {
return EDEADLK;
}
pthread_internal_t* thread = __pthread_internal_find(t);
if (thread == NULL) {
return ESRCH;
}
ThreadJoinState old_state = THREAD_NOT_JOINED;
while ((old_state == THREAD_NOT_JOINED || old_state == THREAD_EXITED_NOT_JOINED) &&
!atomic_compare_exchange_weak(&thread->join_state, &old_state, THREAD_JOINED)) {
}
if (old_state == THREAD_DETACHED || old_state == THREAD_JOINED) {
return EINVAL;
}
pid_t tid = thread->tid;
volatile int* tid_ptr = &thread->tid;
// We set thread->join_state to THREAD_JOINED with atomic operation,
// so no one is going to remove this thread except us.
// Wait for the thread to actually exit, if it hasn't already.
while (*tid_ptr != 0) {
__futex_wait(tid_ptr, tid, NULL);
}
if (return_value) {
*return_value = thread->return_value;
}
__pthread_internal_remove_and_free(thread);
return 0;
}
|
