Mercurial > hg > nginx
annotate src/core/ngx_shmtx.h @ 4309:3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
It is currently used from master process on abnormal worker termination to
unlock accept mutex (unlocking of accept mutex was broken in 1.0.2). It is
expected to be used in the future to unlock other mutexes as well.
Shared mutex code was rewritten to make this possible in a safe way, i.e.
with a check if lock was actually held by the exited process. We again use
pid to lock mutex, and use separate atomic variable for a count of processes
waiting in sem_wait().
author | Maxim Dounin <mdounin@mdounin.ru> |
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date | Wed, 23 Nov 2011 13:55:38 +0000 |
parents | 0daede16d68b |
children | d620f497c50f |
rev | line source |
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611 | 1 |
2 /* | |
3 * Copyright (C) Igor Sysoev | |
4 */ | |
5 | |
6 | |
7 #ifndef _NGX_SHMTX_H_INCLUDED_ | |
8 #define _NGX_SHMTX_H_INCLUDED_ | |
9 | |
10 | |
11 #include <ngx_config.h> | |
12 #include <ngx_core.h> | |
13 | |
14 | |
15 typedef struct { | |
4309
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
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16 ngx_atomic_t lock; |
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
17 #if (NGX_HAVE_POSIX_SEM) |
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
18 ngx_atomic_t wait; |
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
19 #endif |
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
20 } ngx_shmtx_sh_t; |
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
21 |
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
22 |
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
23 typedef struct { |
611 | 24 #if (NGX_HAVE_ATOMIC_OPS) |
25 ngx_atomic_t *lock; | |
3909
0daede16d68b
use POSIX semaphores in shmtx instead of sched_yield()
Igor Sysoev <igor@sysoev.ru>
parents:
2563
diff
changeset
|
26 #if (NGX_HAVE_POSIX_SEM) |
4309
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
27 ngx_atomic_t *wait; |
3909
0daede16d68b
use POSIX semaphores in shmtx instead of sched_yield()
Igor Sysoev <igor@sysoev.ru>
parents:
2563
diff
changeset
|
28 ngx_uint_t semaphore; |
0daede16d68b
use POSIX semaphores in shmtx instead of sched_yield()
Igor Sysoev <igor@sysoev.ru>
parents:
2563
diff
changeset
|
29 sem_t sem; |
0daede16d68b
use POSIX semaphores in shmtx instead of sched_yield()
Igor Sysoev <igor@sysoev.ru>
parents:
2563
diff
changeset
|
30 #endif |
611 | 31 #else |
32 ngx_fd_t fd; | |
33 u_char *name; | |
34 #endif | |
3909
0daede16d68b
use POSIX semaphores in shmtx instead of sched_yield()
Igor Sysoev <igor@sysoev.ru>
parents:
2563
diff
changeset
|
35 ngx_uint_t spin; |
611 | 36 } ngx_shmtx_t; |
37 | |
38 | |
4309
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
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39 ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, ngx_shmtx_sh_t *addr, |
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
40 u_char *name); |
611 | 41 void ngx_shmtx_destory(ngx_shmtx_t *mtx); |
3909
0daede16d68b
use POSIX semaphores in shmtx instead of sched_yield()
Igor Sysoev <igor@sysoev.ru>
parents:
2563
diff
changeset
|
42 ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx); |
0daede16d68b
use POSIX semaphores in shmtx instead of sched_yield()
Igor Sysoev <igor@sysoev.ru>
parents:
2563
diff
changeset
|
43 void ngx_shmtx_lock(ngx_shmtx_t *mtx); |
0daede16d68b
use POSIX semaphores in shmtx instead of sched_yield()
Igor Sysoev <igor@sysoev.ru>
parents:
2563
diff
changeset
|
44 void ngx_shmtx_unlock(ngx_shmtx_t *mtx); |
4309
3f6040cd731e
Added shmtx interface to forcibly unlock mutexes.
Maxim Dounin <mdounin@mdounin.ru>
parents:
3909
diff
changeset
|
45 ngx_uint_t ngx_shmtx_force_unlock(ngx_shmtx_t *mtx, ngx_pid_t pid); |
611 | 46 |
47 | |
48 #endif /* _NGX_SHMTX_H_INCLUDED_ */ |