Mercurial > hg > nginx
view src/http/ngx_http_upstream_round_robin.h @ 8018:5119c8150478
Fixed runtime handling of systems without EPOLLRDHUP support.
In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the
ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP
support in the kernel (but with EPOLLRDHUP in headers) was broken.
Before the change, rev->available was never set to 0 unless
ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP
introduced in 6536:f7849bfb6d21 succeeded). After the change,
rev->available might reach 0 on systems without runtime EPOLLRDHUP
support, stopping further reading in ngx_readv_chain() and ngx_unix_recv().
And, if EOF happened to be already reported along with the last event,
it is not reported again by epoll_wait(), leading to connection hangs
and timeouts on such systems.
This affects Linux kernels before 2.6.17 if nginx was compiled
with newer headers, and, more importantly, emulation layers, such as
DigitalOcean's App Platform's / gVisor's epoll emulation layer.
Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding
rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author | Marcus Ball <marcus.ball@live.com> |
---|---|
date | Mon, 30 May 2022 02:38:07 +0300 |
parents | 90cc7194e993 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ #define _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct ngx_http_upstream_rr_peer_s ngx_http_upstream_rr_peer_t; struct ngx_http_upstream_rr_peer_s { struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t name; ngx_str_t server; ngx_int_t current_weight; ngx_int_t effective_weight; ngx_int_t weight; ngx_uint_t conns; ngx_uint_t max_conns; ngx_uint_t fails; time_t accessed; time_t checked; ngx_uint_t max_fails; time_t fail_timeout; ngx_msec_t slow_start; ngx_msec_t start_time; ngx_uint_t down; #if (NGX_HTTP_SSL || NGX_COMPAT) void *ssl_session; int ssl_session_len; #endif #if (NGX_HTTP_UPSTREAM_ZONE) ngx_atomic_t lock; #endif ngx_http_upstream_rr_peer_t *next; NGX_COMPAT_BEGIN(32) NGX_COMPAT_END }; typedef struct ngx_http_upstream_rr_peers_s ngx_http_upstream_rr_peers_t; struct ngx_http_upstream_rr_peers_s { ngx_uint_t number; #if (NGX_HTTP_UPSTREAM_ZONE) ngx_slab_pool_t *shpool; ngx_atomic_t rwlock; ngx_http_upstream_rr_peers_t *zone_next; #endif ngx_uint_t total_weight; ngx_uint_t tries; unsigned single:1; unsigned weighted:1; ngx_str_t *name; ngx_http_upstream_rr_peers_t *next; ngx_http_upstream_rr_peer_t *peer; }; #if (NGX_HTTP_UPSTREAM_ZONE) #define ngx_http_upstream_rr_peers_rlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_rlock(&peers->rwlock); \ } #define ngx_http_upstream_rr_peers_wlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_wlock(&peers->rwlock); \ } #define ngx_http_upstream_rr_peers_unlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_unlock(&peers->rwlock); \ } #define ngx_http_upstream_rr_peer_lock(peers, peer) \ \ if (peers->shpool) { \ ngx_rwlock_wlock(&peer->lock); \ } #define ngx_http_upstream_rr_peer_unlock(peers, peer) \ \ if (peers->shpool) { \ ngx_rwlock_unlock(&peer->lock); \ } #else #define ngx_http_upstream_rr_peers_rlock(peers) #define ngx_http_upstream_rr_peers_wlock(peers) #define ngx_http_upstream_rr_peers_unlock(peers) #define ngx_http_upstream_rr_peer_lock(peers, peer) #define ngx_http_upstream_rr_peer_unlock(peers, peer) #endif typedef struct { ngx_uint_t config; ngx_http_upstream_rr_peers_t *peers; ngx_http_upstream_rr_peer_t *current; uintptr_t *tried; uintptr_t data; } ngx_http_upstream_rr_peer_data_t; ngx_int_t ngx_http_upstream_init_round_robin(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us); ngx_int_t ngx_http_upstream_init_round_robin_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us); ngx_int_t ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r, ngx_http_upstream_resolved_t *ur); ngx_int_t ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data); void ngx_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t state); #if (NGX_HTTP_SSL) ngx_int_t ngx_http_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc, void *data); void ngx_http_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc, void *data); #endif #endif /* _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ */