Mercurial > hg > nginx
view src/event/ngx_event_connect.h @ 7969:84c60a3cd12a stable-1.20
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 | 570d8c626eea |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_EVENT_CONNECT_H_INCLUDED_ #define _NGX_EVENT_CONNECT_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #define NGX_PEER_KEEPALIVE 1 #define NGX_PEER_NEXT 2 #define NGX_PEER_FAILED 4 typedef struct ngx_peer_connection_s ngx_peer_connection_t; typedef ngx_int_t (*ngx_event_get_peer_pt)(ngx_peer_connection_t *pc, void *data); typedef void (*ngx_event_free_peer_pt)(ngx_peer_connection_t *pc, void *data, ngx_uint_t state); typedef void (*ngx_event_notify_peer_pt)(ngx_peer_connection_t *pc, void *data, ngx_uint_t type); typedef ngx_int_t (*ngx_event_set_peer_session_pt)(ngx_peer_connection_t *pc, void *data); typedef void (*ngx_event_save_peer_session_pt)(ngx_peer_connection_t *pc, void *data); struct ngx_peer_connection_s { ngx_connection_t *connection; struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t *name; ngx_uint_t tries; ngx_msec_t start_time; ngx_event_get_peer_pt get; ngx_event_free_peer_pt free; ngx_event_notify_peer_pt notify; void *data; #if (NGX_SSL || NGX_COMPAT) ngx_event_set_peer_session_pt set_session; ngx_event_save_peer_session_pt save_session; #endif ngx_addr_t *local; int type; int rcvbuf; ngx_log_t *log; unsigned cached:1; unsigned transparent:1; unsigned so_keepalive:1; unsigned down:1; /* ngx_connection_log_error_e */ unsigned log_error:2; NGX_COMPAT_BEGIN(2) NGX_COMPAT_END }; ngx_int_t ngx_event_connect_peer(ngx_peer_connection_t *pc); ngx_int_t ngx_event_get_peer(ngx_peer_connection_t *pc, void *data); #endif /* _NGX_EVENT_CONNECT_H_INCLUDED_ */