Mercurial > hg > nginx-quic
view src/os/unix/ngx_posix_init.c @ 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 | 057adb2a9d23 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <nginx.h> ngx_int_t ngx_ncpu; ngx_int_t ngx_max_sockets; ngx_uint_t ngx_inherited_nonblocking; ngx_uint_t ngx_tcp_nodelay_and_tcp_nopush; struct rlimit rlmt; ngx_os_io_t ngx_os_io = { ngx_unix_recv, ngx_readv_chain, ngx_udp_unix_recv, ngx_unix_send, ngx_udp_unix_send, ngx_udp_unix_sendmsg_chain, ngx_writev_chain, 0 }; ngx_int_t ngx_os_init(ngx_log_t *log) { ngx_time_t *tp; ngx_uint_t n; #if (NGX_HAVE_LEVEL1_DCACHE_LINESIZE) long size; #endif #if (NGX_HAVE_OS_SPECIFIC_INIT) if (ngx_os_specific_init(log) != NGX_OK) { return NGX_ERROR; } #endif if (ngx_init_setproctitle(log) != NGX_OK) { return NGX_ERROR; } ngx_pagesize = getpagesize(); ngx_cacheline_size = NGX_CPU_CACHE_LINE; for (n = ngx_pagesize; n >>= 1; ngx_pagesize_shift++) { /* void */ } #if (NGX_HAVE_SC_NPROCESSORS_ONLN) if (ngx_ncpu == 0) { ngx_ncpu = sysconf(_SC_NPROCESSORS_ONLN); } #endif if (ngx_ncpu < 1) { ngx_ncpu = 1; } #if (NGX_HAVE_LEVEL1_DCACHE_LINESIZE) size = sysconf(_SC_LEVEL1_DCACHE_LINESIZE); if (size > 0) { ngx_cacheline_size = size; } #endif ngx_cpuinfo(); if (getrlimit(RLIMIT_NOFILE, &rlmt) == -1) { ngx_log_error(NGX_LOG_ALERT, log, errno, "getrlimit(RLIMIT_NOFILE) failed"); return NGX_ERROR; } ngx_max_sockets = (ngx_int_t) rlmt.rlim_cur; #if (NGX_HAVE_INHERITED_NONBLOCK || NGX_HAVE_ACCEPT4) ngx_inherited_nonblocking = 1; #else ngx_inherited_nonblocking = 0; #endif tp = ngx_timeofday(); srandom(((unsigned) ngx_pid << 16) ^ tp->sec ^ tp->msec); return NGX_OK; } void ngx_os_status(ngx_log_t *log) { ngx_log_error(NGX_LOG_NOTICE, log, 0, NGINX_VER_BUILD); #ifdef NGX_COMPILER ngx_log_error(NGX_LOG_NOTICE, log, 0, "built by " NGX_COMPILER); #endif #if (NGX_HAVE_OS_SPECIFIC_INIT) ngx_os_specific_status(log); #endif ngx_log_error(NGX_LOG_NOTICE, log, 0, "getrlimit(RLIMIT_NOFILE): %r:%r", rlmt.rlim_cur, rlmt.rlim_max); } #if 0 ngx_int_t ngx_posix_post_conf_init(ngx_log_t *log) { ngx_fd_t pp[2]; if (pipe(pp) == -1) { ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "pipe() failed"); return NGX_ERROR; } if (dup2(pp[1], STDERR_FILENO) == -1) { ngx_log_error(NGX_LOG_EMERG, log, errno, "dup2(STDERR) failed"); return NGX_ERROR; } if (pp[1] > STDERR_FILENO) { if (close(pp[1]) == -1) { ngx_log_error(NGX_LOG_EMERG, log, errno, "close() failed"); return NGX_ERROR; } } return NGX_OK; } #endif