Mercurial > hg > nginx
view src/core/ngx_queue.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 | d620f497c50f |
children | 3038bd4d7816 |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #ifndef _NGX_QUEUE_H_INCLUDED_ #define _NGX_QUEUE_H_INCLUDED_ typedef struct ngx_queue_s ngx_queue_t; struct ngx_queue_s { ngx_queue_t *prev; ngx_queue_t *next; }; #define ngx_queue_init(q) \ (q)->prev = q; \ (q)->next = q #define ngx_queue_empty(h) \ (h == (h)->prev) #define ngx_queue_insert_head(h, x) \ (x)->next = (h)->next; \ (x)->next->prev = x; \ (x)->prev = h; \ (h)->next = x #define ngx_queue_insert_after ngx_queue_insert_head #define ngx_queue_insert_tail(h, x) \ (x)->prev = (h)->prev; \ (x)->prev->next = x; \ (x)->next = h; \ (h)->prev = x #define ngx_queue_head(h) \ (h)->next #define ngx_queue_last(h) \ (h)->prev #define ngx_queue_sentinel(h) \ (h) #define ngx_queue_next(q) \ (q)->next #define ngx_queue_prev(q) \ (q)->prev #if (NGX_DEBUG) #define ngx_queue_remove(x) \ (x)->next->prev = (x)->prev; \ (x)->prev->next = (x)->next; \ (x)->prev = NULL; \ (x)->next = NULL #else #define ngx_queue_remove(x) \ (x)->next->prev = (x)->prev; \ (x)->prev->next = (x)->next #endif #define ngx_queue_split(h, q, n) \ (n)->prev = (h)->prev; \ (n)->prev->next = n; \ (n)->next = q; \ (h)->prev = (q)->prev; \ (h)->prev->next = h; \ (q)->prev = n; #define ngx_queue_add(h, n) \ (h)->prev->next = (n)->next; \ (n)->next->prev = (h)->prev; \ (h)->prev = (n)->prev; \ (h)->prev->next = h; #define ngx_queue_data(q, type, link) \ (type *) ((u_char *) q - offsetof(type, link)) ngx_queue_t *ngx_queue_middle(ngx_queue_t *queue); void ngx_queue_sort(ngx_queue_t *queue, ngx_int_t (*cmp)(const ngx_queue_t *, const ngx_queue_t *)); #endif /* _NGX_QUEUE_H_INCLUDED_ */