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
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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>

#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_ */