view auto/os/linux @ 8805:96ae8e57b3dd

Avoid sending "Connection: keep-alive" when shutting down. When a worker process is shutting down, keepalive is not used: this is checked before the ngx_http_set_keepalive() call in ngx_http_finalize_connection(). Yet the "Connection: keep-alive" header was still sent, even if we know that the worker process is shutting down, potentially resulting in additional requests being sent to the connection which is going to be closed anyway. While clients are expected to be able to handle asynchronous close events (see ticket #1022), it is certainly possible to send the "Connection: close" header instead, informing the client that the connection is going to be closed and potentially saving some unneeded work. With this change, we additionally check for worker process shutdown just before sending response headers, and disable keepalive accordingly.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 11 Jan 2022 02:23:49 +0300
parents e2e9e0fae747
children 7f95010f10b7 c0a432c0301b
line wrap: on
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# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


have=NGX_LINUX . auto/have_headers

CORE_INCS="$UNIX_INCS"
CORE_DEPS="$UNIX_DEPS $LINUX_DEPS"
CORE_SRCS="$UNIX_SRCS $LINUX_SRCS"

ngx_spacer='
'

cc_aux_flags="$CC_AUX_FLAGS"
CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"


# Linux kernel version

version=$((`uname -r \
    | sed -n -e 's/^\([0-9][0-9]*\)\.\([0-9][0-9]*\)\.\([0-9][0-9]*\).*/ \
                                                 \1*256*256+\2*256+\3/p' \
             -e 's/^\([0-9][0-9]*\)\.\([0-9][0-9]*\).*/\1*256*256+\2*256/p'`))

version=${version:-0}


# posix_fadvise64() had been implemented in 2.5.60

if [ $version -lt 132412 ]; then
    have=NGX_HAVE_POSIX_FADVISE . auto/nohave
fi

# epoll, EPOLLET version

ngx_feature="epoll"
ngx_feature_name="NGX_HAVE_EPOLL"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/epoll.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int efd = 0;
                  struct epoll_event ee;
                  ee.events = EPOLLIN|EPOLLOUT|EPOLLET;
                  ee.data.ptr = NULL;
                  (void) ee;
                  efd = epoll_create(100);
                  if (efd == -1) return 1;"
. auto/feature

if [ $ngx_found = yes ]; then
    have=NGX_HAVE_CLEAR_EVENT . auto/have
    CORE_SRCS="$CORE_SRCS $EPOLL_SRCS"
    EVENT_MODULES="$EVENT_MODULES $EPOLL_MODULE"
    EVENT_FOUND=YES


    # EPOLLRDHUP appeared in Linux 2.6.17, glibc 2.8

    ngx_feature="EPOLLRDHUP"
    ngx_feature_name="NGX_HAVE_EPOLLRDHUP"
    ngx_feature_run=no
    ngx_feature_incs="#include <sys/epoll.h>"
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test="int efd = 0, fd = 0;
                      struct epoll_event ee;
                      ee.events = EPOLLIN|EPOLLRDHUP|EPOLLET;
                      ee.data.ptr = NULL;
                      epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)"
    . auto/feature


    # EPOLLEXCLUSIVE appeared in Linux 4.5, glibc 2.24

    ngx_feature="EPOLLEXCLUSIVE"
    ngx_feature_name="NGX_HAVE_EPOLLEXCLUSIVE"
    ngx_feature_run=no
    ngx_feature_incs="#include <sys/epoll.h>"
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test="int efd = 0, fd = 0;
                      struct epoll_event ee;
                      ee.events = EPOLLIN|EPOLLEXCLUSIVE;
                      ee.data.ptr = NULL;
                      epoll_ctl(efd, EPOLL_CTL_ADD, fd, &ee)"
    . auto/feature


    # eventfd()

    ngx_feature="eventfd()"
    ngx_feature_name="NGX_HAVE_EVENTFD"
    ngx_feature_run=no
    ngx_feature_incs="#include <sys/eventfd.h>"
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test="(void) eventfd(0, 0)"
    . auto/feature

    if [ $ngx_found = yes ]; then
        have=NGX_HAVE_SYS_EVENTFD_H . auto/have
    fi


    if [ $ngx_found = no ]; then

        ngx_feature="eventfd() (SYS_eventfd)"
        ngx_feature_incs="#include <sys/syscall.h>"
        ngx_feature_test="(void) SYS_eventfd"
        . auto/feature
    fi
fi


# O_PATH and AT_EMPTY_PATH were introduced in 2.6.39, glibc 2.14

ngx_feature="O_PATH"
ngx_feature_name="NGX_HAVE_O_PATH"
ngx_feature_run=no
ngx_feature_incs="#include <sys/types.h>
                  #include <sys/stat.h>
                  #include <fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int fd; struct stat sb;
                  fd = openat(AT_FDCWD, \".\", O_PATH|O_DIRECTORY|O_NOFOLLOW);
                  if (fstatat(fd, \"\", &sb, AT_EMPTY_PATH) != 0) return 1"
. auto/feature


# sendfile()

CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE"
ngx_feature="sendfile()"
ngx_feature_name="NGX_HAVE_SENDFILE"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/sendfile.h>
                  #include <errno.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int s = 0, fd = 1;
                  ssize_t n; off_t off = 0;
                  n = sendfile(s, fd, &off, 1);
                  if (n == -1 && errno == ENOSYS) return 1"
. auto/feature

if [ $ngx_found = yes ]; then
    CORE_SRCS="$CORE_SRCS $LINUX_SENDFILE_SRCS"
fi


# sendfile64()

CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"
ngx_feature="sendfile64()"
ngx_feature_name="NGX_HAVE_SENDFILE64"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/sendfile.h>
                  #include <errno.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int s = 0, fd = 1;
                  ssize_t n; off_t off = 0;
                  n = sendfile(s, fd, &off, 1);
                  if (n == -1 && errno == ENOSYS) return 1"
. auto/feature


ngx_include="sys/prctl.h"; . auto/include

# prctl(PR_SET_DUMPABLE)

ngx_feature="prctl(PR_SET_DUMPABLE)"
ngx_feature_name="NGX_HAVE_PR_SET_DUMPABLE"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/prctl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) == -1) return 1"
. auto/feature


# prctl(PR_SET_KEEPCAPS)

ngx_feature="prctl(PR_SET_KEEPCAPS)"
ngx_feature_name="NGX_HAVE_PR_SET_KEEPCAPS"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/prctl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) == -1) return 1"
. auto/feature


# capabilities

ngx_feature="capabilities"
ngx_feature_name="NGX_HAVE_CAPABILITIES"
ngx_feature_run=no
ngx_feature_incs="#include <linux/capability.h>
                  #include <sys/syscall.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct __user_cap_data_struct    data;
                  struct __user_cap_header_struct  header;

                  header.version = _LINUX_CAPABILITY_VERSION_1;
                  data.effective = CAP_TO_MASK(CAP_NET_RAW);
                  data.permitted = 0;

                  (void) header;
                  (void) data;
                  (void) SYS_capset"
. auto/feature


# crypt_r()

ngx_feature="crypt_r()"
ngx_feature_name="NGX_HAVE_GNU_CRYPT_R"
ngx_feature_run=no
ngx_feature_incs="#include <crypt.h>"
ngx_feature_path=
ngx_feature_libs=-lcrypt
ngx_feature_test="struct crypt_data  cd;
                  crypt_r(\"key\", \"salt\", &cd);"
. auto/feature


ngx_include="sys/vfs.h";     . auto/include


CC_AUX_FLAGS="$cc_aux_flags -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64"