view auto/os/freebsd @ 7969:84c60a3cd12a stable-1.20

Changed ngx_chain_update_chains() to test tag first (ticket #2248). Without this change, aio used with HTTP/2 can result in connection hang, as observed with "aio threads; aio_write on;" and proxying (ticket #2248). The problem is that HTTP/2 updates buffers outside of the output filters (notably, marks them as sent), and then posts a write event to call output filters. If a filter does not call the next one for some reason (for example, because of an AIO operation in progress), this might result in a state when the owner of a buffer already called ngx_chain_update_chains() and can reuse the buffer, while the same buffer is still sitting in the busy chain of some other filter. In the particular case a buffer was sitting in output chain's ctx->busy, and was reused by event pipe. Output chain's ctx->busy was permanently blocked by it, and this resulted in connection hang. Fix is to change ngx_chain_update_chains() to skip buffers from other modules unconditionally, without trying to wait for these buffers to become empty.
author Maxim Dounin <mdounin@mdounin.ru>
date Sat, 30 Oct 2021 02:39:19 +0300
parents 4dc8e7b62216
children ec2e6893caaa
line wrap: on
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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