From fac4c7bdf53ee7d8fec6568f1e9fecefcde6feba Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Thu, 17 Oct 2019 16:02:19 +0300 Subject: Events: available bytes calculation via ioctl(FIONREAD). This makes it possible to avoid looping for a long time while working with a fast enough peer when data are added to the socket buffer faster than we are able to read and process them (ticket #1431). This is basically what we already do on FreeBSD with kqueue, where information about the number of bytes in the socket buffer is returned by the kevent() call. With other event methods rev->available is now set to -1 when the socket is ready for reading. Later in ngx_recv() and ngx_recv_chain(), if full buffer is received, real number of bytes in the socket buffer is retrieved using ioctl(FIONREAD). Reading more than this number of bytes ensures that even with edge-triggered event methods the event will be triggered again, so it is safe to stop processing of the socket and switch to other connections. Using ioctl(FIONREAD) only after reading a full buffer is an optimization. With this approach we only call ioctl(FIONREAD) when there are at least two recv()/readv() calls. --- src/event/modules/ngx_devpoll_module.c | 1 + src/event/modules/ngx_epoll_module.c | 3 +-- src/event/modules/ngx_eventport_module.c | 1 + src/event/modules/ngx_poll_module.c | 1 + src/event/modules/ngx_select_module.c | 1 + src/event/modules/ngx_win32_poll_module.c | 1 + src/event/modules/ngx_win32_select_module.c | 1 + 7 files changed, 7 insertions(+), 2 deletions(-) (limited to 'src/event/modules') diff --git a/src/event/modules/ngx_devpoll_module.c b/src/event/modules/ngx_devpoll_module.c index ee9f854b6..590eb28e1 100644 --- a/src/event/modules/ngx_devpoll_module.c +++ b/src/event/modules/ngx_devpoll_module.c @@ -495,6 +495,7 @@ ngx_devpoll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, if ((revents & POLLIN) && rev->active) { rev->ready = 1; + rev->available = -1; if (flags & NGX_POST_EVENTS) { queue = rev->accept ? &ngx_posted_accept_events diff --git a/src/event/modules/ngx_epoll_module.c b/src/event/modules/ngx_epoll_module.c index 76aee08c3..98e3ce7c8 100644 --- a/src/event/modules/ngx_epoll_module.c +++ b/src/event/modules/ngx_epoll_module.c @@ -886,11 +886,10 @@ ngx_epoll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags) if (revents & EPOLLRDHUP) { rev->pending_eof = 1; } - - rev->available = 1; #endif rev->ready = 1; + rev->available = -1; if (flags & NGX_POST_EVENTS) { queue = rev->accept ? &ngx_posted_accept_events diff --git a/src/event/modules/ngx_eventport_module.c b/src/event/modules/ngx_eventport_module.c index 11ad0934e..f67c70457 100644 --- a/src/event/modules/ngx_eventport_module.c +++ b/src/event/modules/ngx_eventport_module.c @@ -559,6 +559,7 @@ ngx_eventport_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, if (revents & POLLIN) { rev->ready = 1; + rev->available = -1; if (flags & NGX_POST_EVENTS) { queue = rev->accept ? &ngx_posted_accept_events diff --git a/src/event/modules/ngx_poll_module.c b/src/event/modules/ngx_poll_module.c index b46ab538a..c16f0242e 100644 --- a/src/event/modules/ngx_poll_module.c +++ b/src/event/modules/ngx_poll_module.c @@ -370,6 +370,7 @@ ngx_poll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags) ev = c->read; ev->ready = 1; + ev->available = -1; queue = ev->accept ? &ngx_posted_accept_events : &ngx_posted_events; diff --git a/src/event/modules/ngx_select_module.c b/src/event/modules/ngx_select_module.c index 06446219f..b9fceb3b6 100644 --- a/src/event/modules/ngx_select_module.c +++ b/src/event/modules/ngx_select_module.c @@ -330,6 +330,7 @@ ngx_select_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, if (found) { ev->ready = 1; + ev->available = -1; queue = ev->accept ? &ngx_posted_accept_events : &ngx_posted_events; diff --git a/src/event/modules/ngx_win32_poll_module.c b/src/event/modules/ngx_win32_poll_module.c index 9fe867f79..2fbc1b376 100644 --- a/src/event/modules/ngx_win32_poll_module.c +++ b/src/event/modules/ngx_win32_poll_module.c @@ -380,6 +380,7 @@ ngx_poll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags) ev = c->read; ev->ready = 1; + ev->available = -1; queue = ev->accept ? &ngx_posted_accept_events : &ngx_posted_events; diff --git a/src/event/modules/ngx_win32_select_module.c b/src/event/modules/ngx_win32_select_module.c index 8093a600b..962514a36 100644 --- a/src/event/modules/ngx_win32_select_module.c +++ b/src/event/modules/ngx_win32_select_module.c @@ -330,6 +330,7 @@ ngx_select_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, if (found) { ev->ready = 1; + ev->available = -1; queue = ev->accept ? &ngx_posted_accept_events : &ngx_posted_events; -- cgit