Mercurial > hg > nginx
view src/os/unix/ngx_time.c @ 7583:efd71d49bde0
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.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 17 Oct 2019 16:02:19 +0300 |
parents | d620f497c50f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> /* * FreeBSD does not test /etc/localtime change, however, we can workaround it * by calling tzset() with TZ and then without TZ to update timezone. * The trick should work since FreeBSD 2.1.0. * * Linux does not test /etc/localtime change in localtime(), * but may stat("/etc/localtime") several times in every strftime(), * therefore we use it to update timezone. * * Solaris does not test /etc/TIMEZONE change too and no workaround available. */ void ngx_timezone_update(void) { #if (NGX_FREEBSD) if (getenv("TZ")) { return; } putenv("TZ=UTC"); tzset(); unsetenv("TZ"); tzset(); #elif (NGX_LINUX) time_t s; struct tm *t; char buf[4]; s = time(0); t = localtime(&s); strftime(buf, 4, "%H", t); #endif } void ngx_localtime(time_t s, ngx_tm_t *tm) { #if (NGX_HAVE_LOCALTIME_R) (void) localtime_r(&s, tm); #else ngx_tm_t *t; t = localtime(&s); *tm = *t; #endif tm->ngx_tm_mon++; tm->ngx_tm_year += 1900; } void ngx_libc_localtime(time_t s, struct tm *tm) { #if (NGX_HAVE_LOCALTIME_R) (void) localtime_r(&s, tm); #else struct tm *t; t = localtime(&s); *tm = *t; #endif } void ngx_libc_gmtime(time_t s, struct tm *tm) { #if (NGX_HAVE_LOCALTIME_R) (void) gmtime_r(&s, tm); #else struct tm *t; t = gmtime(&s); *tm = *t; #endif }