Mercurial > hg > nginx
comparison 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 |
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4308:39982fa69482 | 4309:3f6040cd731e |
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11 #include <ngx_config.h> | 11 #include <ngx_config.h> |
12 #include <ngx_core.h> | 12 #include <ngx_core.h> |
13 | 13 |
14 | 14 |
15 typedef struct { | 15 typedef struct { |
16 ngx_atomic_t lock; | |
17 #if (NGX_HAVE_POSIX_SEM) | |
18 ngx_atomic_t wait; | |
19 #endif | |
20 } ngx_shmtx_sh_t; | |
21 | |
22 | |
23 typedef struct { | |
16 #if (NGX_HAVE_ATOMIC_OPS) | 24 #if (NGX_HAVE_ATOMIC_OPS) |
17 ngx_atomic_t *lock; | 25 ngx_atomic_t *lock; |
18 #if (NGX_HAVE_POSIX_SEM) | 26 #if (NGX_HAVE_POSIX_SEM) |
27 ngx_atomic_t *wait; | |
19 ngx_uint_t semaphore; | 28 ngx_uint_t semaphore; |
20 sem_t sem; | 29 sem_t sem; |
21 #endif | 30 #endif |
22 #else | 31 #else |
23 ngx_fd_t fd; | 32 ngx_fd_t fd; |
25 #endif | 34 #endif |
26 ngx_uint_t spin; | 35 ngx_uint_t spin; |
27 } ngx_shmtx_t; | 36 } ngx_shmtx_t; |
28 | 37 |
29 | 38 |
30 ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, void *addr, u_char *name); | 39 ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, ngx_shmtx_sh_t *addr, |
40 u_char *name); | |
31 void ngx_shmtx_destory(ngx_shmtx_t *mtx); | 41 void ngx_shmtx_destory(ngx_shmtx_t *mtx); |
32 ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx); | 42 ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx); |
33 void ngx_shmtx_lock(ngx_shmtx_t *mtx); | 43 void ngx_shmtx_lock(ngx_shmtx_t *mtx); |
34 void ngx_shmtx_unlock(ngx_shmtx_t *mtx); | 44 void ngx_shmtx_unlock(ngx_shmtx_t *mtx); |
45 ngx_uint_t ngx_shmtx_force_unlock(ngx_shmtx_t *mtx, ngx_pid_t pid); | |
35 | 46 |
36 | 47 |
37 #endif /* _NGX_SHMTX_H_INCLUDED_ */ | 48 #endif /* _NGX_SHMTX_H_INCLUDED_ */ |