Mercurial > hg > nginx
view src/core/ngx_regex.h @ 7951:c7a8bdf5af55
Changed ngx_chain_update_chains() to test tag first (ticket #2248).
Without this change, aio used with HTTP/2 can result in connection hang,
as observed with "aio threads; aio_write on;" and proxying (ticket #2248).
The problem is that HTTP/2 updates buffers outside of the output filters
(notably, marks them as sent), and then posts a write event to call
output filters. If a filter does not call the next one for some reason
(for example, because of an AIO operation in progress), this might
result in a state when the owner of a buffer already called
ngx_chain_update_chains() and can reuse the buffer, while the same buffer
is still sitting in the busy chain of some other filter.
In the particular case a buffer was sitting in output chain's ctx->busy,
and was reused by event pipe. Output chain's ctx->busy was permanently
blocked by it, and this resulted in connection hang.
Fix is to change ngx_chain_update_chains() to skip buffers from other
modules unconditionally, without trying to wait for these buffers to
become empty.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Sat, 30 Oct 2021 02:39:19 +0300 |
parents | 6e1a48bcf915 |
children | 0b5f12d5c531 |
line wrap: on
line source
/* * 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> #include <pcre.h> #define NGX_REGEX_NO_MATCHED PCRE_ERROR_NOMATCH /* -1 */ #define NGX_REGEX_CASELESS PCRE_CASELESS typedef struct { pcre *code; pcre_extra *extra; } ngx_regex_t; typedef struct { ngx_str_t pattern; ngx_pool_t *pool; ngx_int_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); #define ngx_regex_exec(re, s, captures, size) \ pcre_exec(re->code, re->extra, (const char *) (s)->data, (s)->len, 0, 0, \ captures, size) #define ngx_regex_exec_n "pcre_exec()" ngx_int_t ngx_regex_exec_array(ngx_array_t *a, ngx_str_t *s, ngx_log_t *log); #endif /* _NGX_REGEX_H_INCLUDED_ */