Mercurial > hg > nginx
annotate src/core/ngx_rwlock.c @ 6520:9070ba416284
HTTP/2: send the output queue after emitting WINDOW_UPDATE.
The WINDOW_UPDATE frame could be left in the output queue for an indefinite
period of time resulting in the request timeout.
This might happen if reading of the body was triggered by an event unrelated
to client connection, e.g. by the limit_req timer.
| author | Valentin Bartenev <vbart@nginx.com> |
|---|---|
| date | Tue, 19 Apr 2016 17:38:49 +0300 |
| parents | e769cc88f996 |
| children | 12efcdcb8a4b |
| rev | line source |
|---|---|
| 6101 | 1 |
| 2 /* | |
| 3 * Copyright (C) Ruslan Ermilov | |
| 4 * Copyright (C) Nginx, Inc. | |
| 5 */ | |
| 6 | |
| 7 | |
| 8 #include <ngx_config.h> | |
| 9 #include <ngx_core.h> | |
| 10 | |
| 11 | |
| 12 #if (NGX_HAVE_ATOMIC_OPS) | |
| 13 | |
| 14 | |
| 15 #define NGX_RWLOCK_SPIN 2048 | |
| 16 #define NGX_RWLOCK_WLOCK ((ngx_atomic_uint_t) -1) | |
| 17 | |
| 18 | |
| 19 void | |
| 20 ngx_rwlock_wlock(ngx_atomic_t *lock) | |
| 21 { | |
| 22 ngx_uint_t i, n; | |
| 23 | |
| 24 for ( ;; ) { | |
| 25 | |
| 26 if (*lock == 0 && ngx_atomic_cmp_set(lock, 0, NGX_RWLOCK_WLOCK)) { | |
| 27 return; | |
| 28 } | |
| 29 | |
| 30 if (ngx_ncpu > 1) { | |
| 31 | |
| 32 for (n = 1; n < NGX_RWLOCK_SPIN; n <<= 1) { | |
| 33 | |
| 34 for (i = 0; i < n; i++) { | |
| 35 ngx_cpu_pause(); | |
| 36 } | |
| 37 | |
| 38 if (*lock == 0 | |
| 39 && ngx_atomic_cmp_set(lock, 0, NGX_RWLOCK_WLOCK)) | |
| 40 { | |
| 41 return; | |
| 42 } | |
| 43 } | |
| 44 } | |
| 45 | |
| 46 ngx_sched_yield(); | |
| 47 } | |
| 48 } | |
| 49 | |
| 50 | |
| 51 void | |
| 52 ngx_rwlock_rlock(ngx_atomic_t *lock) | |
| 53 { | |
| 54 ngx_uint_t i, n; | |
| 55 ngx_atomic_uint_t readers; | |
| 56 | |
| 57 for ( ;; ) { | |
| 58 readers = *lock; | |
| 59 | |
| 60 if (readers != NGX_RWLOCK_WLOCK | |
| 61 && ngx_atomic_cmp_set(lock, readers, readers + 1)) | |
| 62 { | |
| 63 return; | |
| 64 } | |
| 65 | |
| 66 if (ngx_ncpu > 1) { | |
| 67 | |
| 68 for (n = 1; n < NGX_RWLOCK_SPIN; n <<= 1) { | |
| 69 | |
| 70 for (i = 0; i < n; i++) { | |
| 71 ngx_cpu_pause(); | |
| 72 } | |
| 73 | |
| 74 readers = *lock; | |
| 75 | |
| 76 if (readers != NGX_RWLOCK_WLOCK | |
| 77 && ngx_atomic_cmp_set(lock, readers, readers + 1)) | |
| 78 { | |
| 79 return; | |
| 80 } | |
| 81 } | |
| 82 } | |
| 83 | |
| 84 ngx_sched_yield(); | |
| 85 } | |
| 86 } | |
| 87 | |
| 88 | |
| 89 void | |
| 90 ngx_rwlock_unlock(ngx_atomic_t *lock) | |
| 91 { | |
| 92 ngx_atomic_uint_t readers; | |
| 93 | |
| 94 readers = *lock; | |
| 95 | |
| 96 if (readers == NGX_RWLOCK_WLOCK) { | |
| 97 *lock = 0; | |
| 98 return; | |
| 99 } | |
| 100 | |
| 101 for ( ;; ) { | |
| 102 | |
| 103 if (ngx_atomic_cmp_set(lock, readers, readers - 1)) { | |
| 104 return; | |
| 105 } | |
| 106 | |
| 107 readers = *lock; | |
| 108 } | |
| 109 } | |
| 110 | |
| 111 | |
|
6103
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
112 #else |
|
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
113 |
|
6270
e769cc88f996
Core: read/write locks are also required by the Stream module.
Piotr Sikora <piotrsikora@google.com>
parents:
6103
diff
changeset
|
114 #if (NGX_HTTP_UPSTREAM_ZONE || NGX_STREAM_UPSTREAM_ZONE) |
|
6103
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
115 |
|
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
116 #error ngx_atomic_cmp_set() is not defined! |
|
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
117 |
| 6101 | 118 #endif |
|
6103
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
119 |
|
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
120 #endif |