1 | /* Wait for thread termination. |
2 | Copyright (C) 2000-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
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 <errno.h> |
20 | #include <pthread.h> |
21 | #include <stddef.h> |
22 | |
23 | #include <pt-internal.h> |
24 | |
25 | /* Make calling thread wait for termination of thread THREAD. Return |
26 | the exit status of the thread in *STATUS. */ |
27 | static int |
28 | __pthread_join_common (pthread_t thread, void **status, int try, |
29 | clockid_t clockid, |
30 | const struct timespec *abstime) |
31 | { |
32 | struct __pthread *pthread; |
33 | int err = 0; |
34 | |
35 | /* Lookup the thread structure for THREAD. */ |
36 | pthread = __pthread_getid (thread); |
37 | if (pthread == NULL) |
38 | return ESRCH; |
39 | |
40 | if (pthread == _pthread_self ()) |
41 | return EDEADLK; |
42 | |
43 | __pthread_mutex_lock (&pthread->state_lock); |
44 | |
45 | if (try == 0) |
46 | { |
47 | pthread_cleanup_push ((void (*)(void *)) __pthread_mutex_unlock, |
48 | &pthread->state_lock); |
49 | |
50 | /* Rely on pthread_cond_wait being a cancellation point to make |
51 | pthread_join one too. */ |
52 | while (pthread->state == PTHREAD_JOINABLE && err != ETIMEDOUT) |
53 | err = __pthread_cond_clockwait (&pthread->state_cond, |
54 | &pthread->state_lock, |
55 | clockid, abstime); |
56 | |
57 | pthread_cleanup_pop (0); |
58 | } |
59 | |
60 | switch (pthread->state) |
61 | { |
62 | case PTHREAD_JOINABLE: |
63 | __pthread_mutex_unlock (&pthread->state_lock); |
64 | if (err != ETIMEDOUT) |
65 | err = EBUSY; |
66 | break; |
67 | |
68 | case PTHREAD_EXITED: |
69 | /* THREAD has already exited. Salvage its exit status. */ |
70 | if (status != NULL) |
71 | *status = pthread->status; |
72 | |
73 | __pthread_mutex_unlock (&pthread->state_lock); |
74 | |
75 | __pthread_dealloc (thread: pthread); |
76 | break; |
77 | |
78 | default: |
79 | /* Thou shalt not join non-joinable threads! */ |
80 | __pthread_mutex_unlock (&pthread->state_lock); |
81 | err = EINVAL; |
82 | break; |
83 | } |
84 | |
85 | return err; |
86 | } |
87 | |
88 | int |
89 | __pthread_join (pthread_t thread, void **status) |
90 | { |
91 | return __pthread_join_common (thread, status, try: 0, CLOCK_REALTIME, NULL); |
92 | } |
93 | weak_alias (__pthread_join, pthread_join); |
94 | |
95 | int |
96 | __pthread_tryjoin_np (pthread_t thread, void **status) |
97 | { |
98 | return __pthread_join_common (thread, status, try: 1, CLOCK_REALTIME, NULL); |
99 | } |
100 | weak_alias (__pthread_tryjoin_np, pthread_tryjoin_np); |
101 | |
102 | int |
103 | __pthread_timedjoin_np (pthread_t thread, void **status, |
104 | const struct timespec *abstime) |
105 | { |
106 | return __pthread_join_common (thread, status, try: 0, CLOCK_REALTIME, abstime); |
107 | } |
108 | weak_alias (__pthread_timedjoin_np, pthread_timedjoin_np); |
109 | |
110 | int |
111 | __pthread_clockjoin_np (pthread_t thread, void **status, |
112 | clockid_t clockid, |
113 | const struct timespec *abstime) |
114 | { |
115 | return __pthread_join_common (thread, status, try: 0, clockid, abstime); |
116 | } |
117 | weak_alias (__pthread_clockjoin_np, pthread_clockjoin_np); |
118 | |