Mercurial > hg > nginx-quic
view auto/os/freebsd @ 7281:bd6563e81cea
Limit req: improved handling of negative times.
Negative times can appear since workers only update time on an event
loop iteration start. If a worker was blocked for a long time during
an event loop iteration, it is possible that another worker already
updated the time stored in the node. As such, time since last update
of the node (ms) will be negative.
Previous code used ngx_abs(ms) in the calculations. That is, negative
times were effectively treated as positive ones. As a result, it was
not possible to maintain high request rates, where the same node can be
updated multiple times from during an event loop iteration.
In particular, this affected setups with many SSL handshakes, see
http://mailman.nginx.org/pipermail/nginx/2018-May/056291.html.
Fix is to only update the last update time stored in the node if the
new time is larger than previously stored one. If a future time is
stored in the node, we preserve this time as is.
To prevent breaking things on platforms without monotonic time available
if system time is updated backwards, a safety limit of 60 seconds is
used. If the time stored in the node is more than 60 seconds in the future,
we assume that the time was changed backwards and update lr->last
to the current time.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 30 May 2018 15:40:34 +0300 |
parents | 4dc8e7b62216 |
children | ec2e6893caaa |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. have=NGX_FREEBSD . auto/have_headers CORE_INCS="$UNIX_INCS" CORE_DEPS="$UNIX_DEPS $FREEBSD_DEPS" CORE_SRCS="$UNIX_SRCS $FREEBSD_SRCS" ngx_spacer=' ' # __FreeBSD_version and sysctl kern.osreldate are the best ways # to determine whether some capability exists and is safe to use. # __FreeBSD_version is used for the testing of the build environment. # sysctl kern.osreldate is used for the testing of the kernel capabilities. version=`grep "#define __FreeBSD_version" /usr/include/osreldate.h \ | sed -e 's/^.* \(.*\)$/\1/'` osreldate=`/sbin/sysctl -n kern.osreldate` # setproctitle() in libutil if [ \( $version -ge 500000 -a $version -lt 500012 \) \ -o $version -lt 410002 ] then echo " + setproctitle() in libutil" CORE_LIBS="$CORE_LIBS -lutil" NGX_SETPROCTITLE_LIB="-lutil" fi # sendfile if [ $osreldate -gt 300007 ]; then echo " + sendfile() found" have=NGX_HAVE_SENDFILE . auto/have CORE_SRCS="$CORE_SRCS $FREEBSD_SENDFILE_SRCS" fi if [ $NGX_FILE_AIO = YES ]; then if [ $osreldate -gt 502103 ]; then echo " + sendfile()'s SF_NODISKIO found" have=NGX_HAVE_AIO_SENDFILE . auto/have fi fi # POSIX semaphores # http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/127545 if [ $osreldate -ge 701106 ]; then echo " + POSIX semaphores should work" else have=NGX_HAVE_POSIX_SEM . auto/nohave fi # kqueue if [ \( $osreldate -lt 500000 -a $osreldate -ge 410000 \) \ -o $osreldate -ge 500011 ] then echo " + kqueue found" have=NGX_HAVE_KQUEUE . auto/have have=NGX_HAVE_CLEAR_EVENT . auto/have EVENT_MODULES="$EVENT_MODULES $KQUEUE_MODULE" CORE_SRCS="$CORE_SRCS $KQUEUE_SRCS" EVENT_FOUND=YES fi NGX_KQUEUE_CHECKED=YES # kqueue's NOTE_LOWAT if [ \( $version -lt 500000 -a $version -ge 430000 \) \ -o $version -ge 500018 ] then echo " + kqueue's NOTE_LOWAT found" have=NGX_HAVE_LOWAT_EVENT . auto/have fi # kqueue's EVFILT_TIMER if [ \( $version -lt 500000 -a $version -ge 440001 \) \ -o $version -ge 500023 ] then echo " + kqueue's EVFILT_TIMER found" have=NGX_HAVE_TIMER_EVENT . auto/have fi # cpuset_setaffinity() if [ $version -ge 701000 ]; then echo " + cpuset_setaffinity() found" have=NGX_HAVE_CPUSET_SETAFFINITY . auto/have fi