Mercurial > hg > nginx
view src/core/ngx_regex.h @ 8045:aa28c802409f
Resolver: make TCP write timer event cancelable.
Similar to 70e65bf8dfd7, the change is made to ensure that the ability to
cancel resolver tasks is fully controlled by the caller. As mentioned in the
referenced commit, it is safe to make this timer cancelable because resolve
tasks can have their own timeouts that are not cancelable.
The scenario where this may become a problem is a periodic background resolve
task (not tied to a specific request or a client connection), which receives a
response with short TTL, large enough to warrant fallback to a TCP query.
With each event loop wakeup, we either have a previously set write timer
instance or schedule a new one. The non-cancelable write timer can delay or
block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable
flag is set by the API user, and there are no other tasks or connections.
We use the resolver API in this way to maintain the list of upstream server
addresses specified with the 'resolve' parameter, and there could be third-party
modules implementing similar logic.
author | Aleksei Bavshin <a.bavshin@f5.com> |
---|---|
date | Wed, 01 Jun 2022 20:17:23 -0700 |
parents | d07456044b61 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_REGEX_H_INCLUDED_ #define _NGX_REGEX_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_PCRE2) #define PCRE2_CODE_UNIT_WIDTH 8 #include <pcre2.h> #define NGX_REGEX_NO_MATCHED PCRE2_ERROR_NOMATCH /* -1 */ typedef pcre2_code ngx_regex_t; #else #include <pcre.h> #define NGX_REGEX_NO_MATCHED PCRE_ERROR_NOMATCH /* -1 */ typedef struct { pcre *code; pcre_extra *extra; } ngx_regex_t; #endif #define NGX_REGEX_CASELESS 0x00000001 #define NGX_REGEX_MULTILINE 0x00000002 typedef struct { ngx_str_t pattern; ngx_pool_t *pool; ngx_uint_t options; ngx_regex_t *regex; int captures; int named_captures; int name_size; u_char *names; ngx_str_t err; } ngx_regex_compile_t; typedef struct { ngx_regex_t *regex; u_char *name; } ngx_regex_elt_t; void ngx_regex_init(void); ngx_int_t ngx_regex_compile(ngx_regex_compile_t *rc); ngx_int_t ngx_regex_exec(ngx_regex_t *re, ngx_str_t *s, int *captures, ngx_uint_t size); #if (NGX_PCRE2) #define ngx_regex_exec_n "pcre2_match()" #else #define ngx_regex_exec_n "pcre_exec()" #endif ngx_int_t ngx_regex_exec_array(ngx_array_t *a, ngx_str_t *s, ngx_log_t *log); #endif /* _NGX_REGEX_H_INCLUDED_ */