Mercurial > hg > nginx
annotate src/core/ngx_rwlock.c @ 7981:0b5f12d5c531
PCRE2 library support.
The PCRE2 library is now used by default if found, instead of the
original PCRE library. If needed for some reason, this can be disabled
with the --without-pcre2 configure option.
To make it possible to specify paths to the library and include files
via --with-cc-opt / --with-ld-opt, the library is first tested without
any additional paths and options. If this fails, the pcre2-config script
is used.
Similarly to the original PCRE library, it is now possible to build PCRE2
from sources with nginx configure, by using the --with-pcre= option.
It automatically detects if PCRE or PCRE2 sources are provided.
Note that compiling PCRE2 10.33 and later requires inttypes.h. When
compiling on Windows with MSVC, inttypes.h is only available starting
with MSVC 2013. In older versions some replacement needs to be provided
("echo '#include <stdint.h>' > pcre2-10.xx/src/inttypes.h" is good enough
for MSVC 2010).
The interface on nginx side remains unchanged.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Sat, 25 Dec 2021 01:07:15 +0300 |
parents | d1816a2696de |
children | 7752d8523066 |
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) { | |
7037
12efcdcb8a4b
Added memory barrier semantics to ngx_rwlock_unlock().
Ruslan Ermilov <ru@nginx.com>
parents:
6270
diff
changeset
|
97 (void) ngx_atomic_cmp_set(lock, NGX_RWLOCK_WLOCK, 0); |
6101 | 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 | |
7038
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
112 void |
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
113 ngx_rwlock_downgrade(ngx_atomic_t *lock) |
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
114 { |
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
115 if (*lock == NGX_RWLOCK_WLOCK) { |
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
116 *lock = 1; |
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
117 } |
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
118 } |
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
119 |
d1816a2696de
Introduced ngx_rwlock_downgrade().
Ruslan Ermilov <ru@nginx.com>
parents:
7037
diff
changeset
|
120 |
6103
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
121 #else |
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
122 |
6270
e769cc88f996
Core: read/write locks are also required by the Stream module.
Piotr Sikora <piotrsikora@google.com>
parents:
6103
diff
changeset
|
123 #if (NGX_HTTP_UPSTREAM_ZONE || NGX_STREAM_UPSTREAM_ZONE) |
6103
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
124 |
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
125 #error ngx_atomic_cmp_set() is not defined! |
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
126 |
6101 | 127 #endif |
6103
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
128 |
79ddb0bdb273
Upstream: the "zone" directive.
Ruslan Ermilov <ru@nginx.com>
parents:
6101
diff
changeset
|
129 #endif |