Mercurial > hg > nginx-quic
view src/os/unix/ngx_process.h @ 8867:5119c8150478
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 | 8b84d60ef13d |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_PROCESS_H_INCLUDED_ #define _NGX_PROCESS_H_INCLUDED_ #include <ngx_setaffinity.h> #include <ngx_setproctitle.h> typedef pid_t ngx_pid_t; #define NGX_INVALID_PID -1 typedef void (*ngx_spawn_proc_pt) (ngx_cycle_t *cycle, void *data); typedef struct { ngx_pid_t pid; int status; ngx_socket_t channel[2]; ngx_spawn_proc_pt proc; void *data; char *name; unsigned respawn:1; unsigned just_spawn:1; unsigned detached:1; unsigned exiting:1; unsigned exited:1; } ngx_process_t; typedef struct { char *path; char *name; char *const *argv; char *const *envp; } ngx_exec_ctx_t; #define NGX_MAX_PROCESSES 1024 #define NGX_PROCESS_NORESPAWN -1 #define NGX_PROCESS_JUST_SPAWN -2 #define NGX_PROCESS_RESPAWN -3 #define NGX_PROCESS_JUST_RESPAWN -4 #define NGX_PROCESS_DETACHED -5 #define ngx_getpid getpid #define ngx_getppid getppid #ifndef ngx_log_pid #define ngx_log_pid ngx_pid #endif ngx_pid_t ngx_spawn_process(ngx_cycle_t *cycle, ngx_spawn_proc_pt proc, void *data, char *name, ngx_int_t respawn); ngx_pid_t ngx_execute(ngx_cycle_t *cycle, ngx_exec_ctx_t *ctx); ngx_int_t ngx_init_signals(ngx_log_t *log); void ngx_debug_point(void); #if (NGX_HAVE_SCHED_YIELD) #define ngx_sched_yield() sched_yield() #else #define ngx_sched_yield() usleep(1) #endif extern int ngx_argc; extern char **ngx_argv; extern char **ngx_os_argv; extern ngx_pid_t ngx_pid; extern ngx_pid_t ngx_parent; extern ngx_socket_t ngx_channel; extern ngx_int_t ngx_process_slot; extern ngx_int_t ngx_last_process; extern ngx_process_t ngx_processes[NGX_MAX_PROCESSES]; #endif /* _NGX_PROCESS_H_INCLUDED_ */