1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <errno.h>
30
31 #include "pthread_accessor.h"
32
pthread_join(pthread_t t,void ** ret_val)33 int pthread_join(pthread_t t, void ** ret_val) {
34 if (t == pthread_self()) {
35 return EDEADLK;
36 }
37
38 pthread_accessor thread(t);
39 if (thread.get() == NULL) {
40 return ESRCH;
41 }
42
43 if (thread->attr.flags & PTHREAD_ATTR_FLAG_DETACHED) {
44 return EINVAL;
45 }
46
47 // Wait for thread death when needed.
48
49 // If the 'join_count' is negative, this is a 'zombie' thread that
50 // is already dead and without stack/TLS. Otherwise, we need to increment 'join-count'
51 // and wait to be signaled
52 int count = thread->join_count;
53 if (count >= 0) {
54 thread->join_count += 1;
55 pthread_cond_wait(&thread->join_cond, &gThreadListLock);
56 count = --thread->join_count;
57 }
58 if (ret_val) {
59 *ret_val = thread->return_value;
60 }
61
62 // Remove thread from thread list when we're the last joiner or when the
63 // thread was already a zombie.
64 if (count <= 0) {
65 _pthread_internal_remove_locked(thread.get());
66 }
67 return 0;
68 }
69