Mercurial > hg > nginx-quic
view auto/os/freebsd @ 8896:aa28c802409f
Resolver: make TCP write timer event cancelable.
Similar to 70e65bf8dfd7, the change is made to ensure that the ability to
cancel resolver tasks is fully controlled by the caller. As mentioned in the
referenced commit, it is safe to make this timer cancelable because resolve
tasks can have their own timeouts that are not cancelable.
The scenario where this may become a problem is a periodic background resolve
task (not tied to a specific request or a client connection), which receives a
response with short TTL, large enough to warrant fallback to a TCP query.
With each event loop wakeup, we either have a previously set write timer
instance or schedule a new one. The non-cancelable write timer can delay or
block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable
flag is set by the API user, and there are no other tasks or connections.
We use the resolver API in this way to maintain the list of upstream server
addresses specified with the 'resolve' parameter, and there could be third-party
modules implementing similar logic.
author | Aleksei Bavshin <a.bavshin@f5.com> |
---|---|
date | Wed, 01 Jun 2022 20:17:23 -0700 |
parents | ec2e6893caaa |
children |
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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 [ $osreldate -gt 1100093 ]; then echo " + sendfile()'s SF_NODISKIO found" have=NGX_HAVE_SENDFILE_NODISKIO . auto/have 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