view auto/unix @ 8398:82e174e47663

Changed keepalive_requests default to 1000 (ticket #2155). It turns out no browsers implement HTTP/2 GOAWAY handling properly, and large enough number of resources on a page results in failures to load some resources. In particular, Chrome seems to experience errors if loading of all resources requires more than 1 connection (while it is usually able to retry requests at least once, even with 2 connections there are occasional failures for some reason), Safari if loading requires more than 3 connections, and Firefox if loading requires more than 10 connections (can be configured with network.http.request.max-attempts, defaults to 10). It does not seem to be possible to resolve this on nginx side, even strict limiting of maximum concurrency does not help, and loading issues seems to be triggered by merely queueing of a request for a particular connection. The only available mitigation seems to use higher keepalive_requests value. The new default is 1000 and matches previously used default for http2_max_requests. It is expected to be enough for 99.98% of the pages (https://httparchive.org/reports/state-of-the-web?start=latest#reqTotal) even in Chrome.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 08 Apr 2021 00:16:30 +0300
parents e2e9e0fae747
children afebde21cb32
line wrap: on
line source


# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


NGX_USER=${NGX_USER:-nobody}

if [ -z "$NGX_GROUP" ]; then
    if [ $NGX_USER = nobody ]; then
        if grep nobody /etc/group 2>&1 >/dev/null; then
            echo "checking for nobody group ... found"
            NGX_GROUP=nobody
        else
            echo "checking for nobody group ... not found"

            if grep nogroup /etc/group 2>&1 >/dev/null; then
                echo "checking for nogroup group ... found"
                NGX_GROUP=nogroup
            else
                echo "checking for nogroup group ... not found"
                NGX_GROUP=nobody
            fi
        fi
    else
        NGX_GROUP=$NGX_USER
    fi
fi


ngx_feature="poll()"
ngx_feature_name=
ngx_feature_run=no
ngx_feature_incs="#include <poll.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int  n; struct pollfd  pl;
                  pl.fd = 0;
                  pl.events = 0;
                  pl.revents = 0;
                  n = poll(&pl, 1, 0);
                  if (n == -1) return 1"
. auto/feature

if [ $ngx_found = no ]; then
    EVENT_POLL=NONE
fi


ngx_feature="/dev/poll"
ngx_feature_name="NGX_HAVE_DEVPOLL"
ngx_feature_run=no
ngx_feature_incs="#include <sys/devpoll.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int  n, dp; struct dvpoll  dvp;
                  dp = 0;
                  dvp.dp_fds = NULL;
                  dvp.dp_nfds = 0;
                  dvp.dp_timeout = 0;
                  n = ioctl(dp, DP_POLL, &dvp);
                  if (n == -1) return 1"
. auto/feature

if [ $ngx_found = yes ]; then
    CORE_SRCS="$CORE_SRCS $DEVPOLL_SRCS"
    EVENT_MODULES="$EVENT_MODULES $DEVPOLL_MODULE"
    EVENT_FOUND=YES
fi


if test -z "$NGX_KQUEUE_CHECKED"; then
    ngx_feature="kqueue"
    ngx_feature_name="NGX_HAVE_KQUEUE"
    ngx_feature_run=no
    ngx_feature_incs="#include <sys/event.h>"
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test="(void) kqueue()"
    . auto/feature

    if [ $ngx_found = yes ]; then

        have=NGX_HAVE_CLEAR_EVENT . auto/have
        EVENT_MODULES="$EVENT_MODULES $KQUEUE_MODULE"
        CORE_SRCS="$CORE_SRCS $KQUEUE_SRCS"
        EVENT_FOUND=YES

        ngx_feature="kqueue's NOTE_LOWAT"
        ngx_feature_name="NGX_HAVE_LOWAT_EVENT"
        ngx_feature_run=no
        ngx_feature_incs="#include <sys/event.h>"
        ngx_feature_path=
        ngx_feature_libs=
        ngx_feature_test="struct kevent  kev;
                          kev.fflags = NOTE_LOWAT;
                          (void) kev"
        . auto/feature


        ngx_feature="kqueue's EVFILT_TIMER"
        ngx_feature_name="NGX_HAVE_TIMER_EVENT"
        ngx_feature_run=yes
        ngx_feature_incs="#include <sys/event.h>
                          #include <sys/time.h>"
        ngx_feature_path=
        ngx_feature_libs=
        ngx_feature_test="int      kq;
                  struct kevent    kev;
                  struct timespec  ts;

                  if ((kq = kqueue()) == -1) return 1;

                  kev.ident = 0;
                  kev.filter = EVFILT_TIMER;
                  kev.flags = EV_ADD|EV_ENABLE;
                  kev.fflags = 0;
                  kev.data = 1000;
                  kev.udata = 0;

                  ts.tv_sec = 0;
                  ts.tv_nsec = 0;

                  if (kevent(kq, &kev, 1, &kev, 1, &ts) == -1) return 1;

                  if (kev.flags & EV_ERROR) return 1;"

        . auto/feature
    fi
fi


if [ "$NGX_SYSTEM" = "NetBSD" ]; then

    # NetBSD 2.0 incompatibly defines kevent.udata as "intptr_t"

    cat << END >> $NGX_AUTO_CONFIG_H

#define NGX_KQUEUE_UDATA_T

END

else
    cat << END >> $NGX_AUTO_CONFIG_H

#define NGX_KQUEUE_UDATA_T  (void *)

END

fi


ngx_feature="crypt()"
ngx_feature_name=
ngx_feature_run=no
ngx_feature_incs=
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="crypt(\"test\", \"salt\");"
. auto/feature


if [ $ngx_found = no ]; then

    ngx_feature="crypt() in libcrypt"
    ngx_feature_name=
    ngx_feature_run=no
    ngx_feature_incs=
    ngx_feature_path=
    ngx_feature_libs=-lcrypt
    . auto/feature

    if [ $ngx_found = yes ]; then
        CRYPT_LIB="-lcrypt"
    fi
fi


ngx_feature="F_READAHEAD"
ngx_feature_name="NGX_HAVE_F_READAHEAD"
ngx_feature_run=no
ngx_feature_incs="#include <fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="fcntl(0, F_READAHEAD, 1);"
. auto/feature


ngx_feature="posix_fadvise()"
ngx_feature_name="NGX_HAVE_POSIX_FADVISE"
ngx_feature_run=no
ngx_feature_incs="#include <fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="posix_fadvise(0, 0, 0, POSIX_FADV_SEQUENTIAL);"
. auto/feature


ngx_feature="O_DIRECT"
ngx_feature_name="NGX_HAVE_O_DIRECT"
ngx_feature_run=no
ngx_feature_incs="#include <fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="fcntl(0, F_SETFL, O_DIRECT);"
. auto/feature


if [ $ngx_found = yes -a "$NGX_SYSTEM" = "Linux" ]; then
    have=NGX_HAVE_ALIGNED_DIRECTIO . auto/have
fi

ngx_feature="F_NOCACHE"
ngx_feature_name="NGX_HAVE_F_NOCACHE"
ngx_feature_run=no
ngx_feature_incs="#include <fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="fcntl(0, F_NOCACHE, 1);"
. auto/feature


ngx_feature="directio()"
ngx_feature_name="NGX_HAVE_DIRECTIO"
ngx_feature_run=no
ngx_feature_incs="#include <sys/types.h>
                  #include <sys/fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="directio(0, DIRECTIO_ON);"
. auto/feature


ngx_feature="statfs()"
ngx_feature_name="NGX_HAVE_STATFS"
ngx_feature_run=no
ngx_feature_incs="$NGX_INCLUDE_SYS_PARAM_H
                  $NGX_INCLUDE_SYS_MOUNT_H
                  $NGX_INCLUDE_SYS_VFS_H"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct statfs  fs;
                  statfs(\".\", &fs);"
. auto/feature


ngx_feature="statvfs()"
ngx_feature_name="NGX_HAVE_STATVFS"
ngx_feature_run=no
ngx_feature_incs="#include <sys/types.h>
                  #include <sys/statvfs.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct statvfs  fs;
                  statvfs(\".\", &fs);"
. auto/feature


ngx_feature="dlopen()"
ngx_feature_name="NGX_HAVE_DLOPEN"
ngx_feature_run=no
ngx_feature_incs="#include <dlfcn.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="dlopen(NULL, RTLD_NOW | RTLD_GLOBAL); dlsym(NULL, \"\")"
. auto/feature


if [ $ngx_found = no ]; then

    ngx_feature="dlopen() in libdl"
    ngx_feature_libs="-ldl"
    . auto/feature

    if [ $ngx_found = yes ]; then
        CORE_LIBS="$CORE_LIBS -ldl"
        NGX_LIBDL="-ldl"
    fi
fi


ngx_feature="sched_yield()"
ngx_feature_name="NGX_HAVE_SCHED_YIELD"
ngx_feature_run=no
ngx_feature_incs="#include <sched.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="sched_yield()"
. auto/feature


if [ $ngx_found = no ]; then

    ngx_feature="sched_yield() in librt"
    ngx_feature_libs="-lrt"
    . auto/feature

    if [ $ngx_found = yes ]; then
        CORE_LIBS="$CORE_LIBS -lrt"
    fi
fi


ngx_feature="sched_setaffinity()"
ngx_feature_name="NGX_HAVE_SCHED_SETAFFINITY"
ngx_feature_run=no
ngx_feature_incs="#include <sched.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="cpu_set_t mask;
                  CPU_ZERO(&mask);
                  sched_setaffinity(0, sizeof(cpu_set_t), &mask)"
. auto/feature


ngx_feature="SO_SETFIB"
ngx_feature_name="NGX_HAVE_SETFIB"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, SOL_SOCKET, SO_SETFIB, NULL, 0)"
. auto/feature


ngx_feature="SO_REUSEPORT"
ngx_feature_name="NGX_HAVE_REUSEPORT"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, SOL_SOCKET, SO_REUSEPORT, NULL, 0)"
. auto/feature


ngx_feature="SO_ACCEPTFILTER"
ngx_feature_name="NGX_HAVE_DEFERRED_ACCEPT"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, SOL_SOCKET, SO_ACCEPTFILTER, NULL, 0)"
. auto/feature


# OpenBSD bind to any address for transparent proxying

ngx_feature="SO_BINDANY"
ngx_feature_name="NGX_HAVE_TRANSPARENT_PROXY"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, SOL_SOCKET, SO_BINDANY, NULL, 0)"
. auto/feature


# Linux transparent proxying

ngx_feature="IP_TRANSPARENT"
ngx_feature_name="NGX_HAVE_TRANSPARENT_PROXY"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_IP, IP_TRANSPARENT, NULL, 0)"
. auto/feature


# FreeBSD bind to any address for transparent proxying

ngx_feature="IP_BINDANY"
ngx_feature_name="NGX_HAVE_TRANSPARENT_PROXY"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_IP, IP_BINDANY, NULL, 0)"
. auto/feature


# Linux IP_BIND_ADDRESS_NO_PORT

ngx_feature="IP_BIND_ADDRESS_NO_PORT"
ngx_feature_name="NGX_HAVE_IP_BIND_ADDRESS_NO_PORT"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_IP, IP_BIND_ADDRESS_NO_PORT, NULL, 0)"
. auto/feature


# BSD way to get IPv4 datagram destination address

ngx_feature="IP_RECVDSTADDR"
ngx_feature_name="NGX_HAVE_IP_RECVDSTADDR"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_IP, IP_RECVDSTADDR, NULL, 0)"
. auto/feature


# BSD way to set IPv4 datagram source address

ngx_feature="IP_SENDSRCADDR"
ngx_feature_name="NGX_HAVE_IP_SENDSRCADDR"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_IP, IP_SENDSRCADDR, NULL, 0)"
. auto/feature


# Linux way to get IPv4 datagram destination address

ngx_feature="IP_PKTINFO"
ngx_feature_name="NGX_HAVE_IP_PKTINFO"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct in_pktinfo  pkt;
                  pkt.ipi_spec_dst.s_addr = INADDR_ANY;
                  (void) pkt;
                  setsockopt(0, IPPROTO_IP, IP_PKTINFO, NULL, 0)"
. auto/feature


# RFC 3542 way to get IPv6 datagram destination address

ngx_feature="IPV6_RECVPKTINFO"
ngx_feature_name="NGX_HAVE_IPV6_RECVPKTINFO"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_IPV6, IPV6_RECVPKTINFO, NULL, 0)"
. auto/feature


ngx_feature="TCP_DEFER_ACCEPT"
ngx_feature_name="NGX_HAVE_DEFERRED_ACCEPT"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>
                  #include <netinet/tcp.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_TCP, TCP_DEFER_ACCEPT, NULL, 0)"
. auto/feature


ngx_feature="TCP_KEEPIDLE"
ngx_feature_name="NGX_HAVE_KEEPALIVE_TUNABLE"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>
                  #include <netinet/tcp.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_TCP, TCP_KEEPIDLE, NULL, 0);
                  setsockopt(0, IPPROTO_TCP, TCP_KEEPINTVL, NULL, 0);
                  setsockopt(0, IPPROTO_TCP, TCP_KEEPCNT, NULL, 0)"
. auto/feature


ngx_feature="TCP_FASTOPEN"
ngx_feature_name="NGX_HAVE_TCP_FASTOPEN"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>
                  #include <netinet/tcp.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="setsockopt(0, IPPROTO_TCP, TCP_FASTOPEN, NULL, 0)"
. auto/feature


ngx_feature="TCP_INFO"
ngx_feature_name="NGX_HAVE_TCP_INFO"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>
                  #include <netinet/tcp.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="socklen_t optlen = sizeof(struct tcp_info);
                  struct tcp_info ti;
                  ti.tcpi_rtt = 0;
                  ti.tcpi_rttvar = 0;
                  ti.tcpi_snd_cwnd = 0;
                  ti.tcpi_rcv_space = 0;
                  getsockopt(0, IPPROTO_TCP, TCP_INFO, &ti, &optlen)"
. auto/feature


ngx_feature="accept4()"
ngx_feature_name="NGX_HAVE_ACCEPT4"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="accept4(0, NULL, NULL, SOCK_NONBLOCK)"
. auto/feature

if [ $NGX_FILE_AIO = YES ]; then

    ngx_feature="kqueue AIO support"
    ngx_feature_name="NGX_HAVE_FILE_AIO"
    ngx_feature_run=no
    ngx_feature_incs="#include <aio.h>"
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test="struct aiocb  iocb;
                      iocb.aio_sigevent.sigev_notify = SIGEV_KEVENT;
                      (void) aio_read(&iocb)"
    . auto/feature

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

    if [ $ngx_found = no ]; then

        ngx_feature="Linux AIO support"
        ngx_feature_name="NGX_HAVE_FILE_AIO"
        ngx_feature_run=no
        ngx_feature_incs="#include <linux/aio_abi.h>
                          #include <sys/eventfd.h>"
        ngx_feature_path=
        ngx_feature_libs=
        ngx_feature_test="struct iocb  iocb;
                          iocb.aio_lio_opcode = IOCB_CMD_PREAD;
                          iocb.aio_flags = IOCB_FLAG_RESFD;
                          iocb.aio_resfd = -1;
                          (void) iocb;
                          (void) eventfd(0, 0)"
        . auto/feature

        if [ $ngx_found = yes ]; then
            have=NGX_HAVE_EVENTFD . auto/have
            have=NGX_HAVE_SYS_EVENTFD_H . auto/have
            CORE_SRCS="$CORE_SRCS $LINUX_AIO_SRCS"
        fi
    fi

    if [ $ngx_found = no ]; then

        ngx_feature="Linux AIO support (SYS_eventfd)"
        ngx_feature_incs="#include <linux/aio_abi.h>
                          #include <sys/syscall.h>"
        ngx_feature_test="struct iocb  iocb;
                          iocb.aio_lio_opcode = IOCB_CMD_PREAD;
                          iocb.aio_flags = IOCB_FLAG_RESFD;
                          iocb.aio_resfd = -1;
                          (void) iocb;
                          (void) SYS_eventfd"
        . auto/feature

        if [ $ngx_found = yes ]; then
            have=NGX_HAVE_EVENTFD . auto/have
            CORE_SRCS="$CORE_SRCS $LINUX_AIO_SRCS"
        fi
    fi

    if [ $ngx_found = no ]; then
        cat << END

$0: no supported file AIO was found
Currently file AIO is supported on FreeBSD 4.3+ and Linux 2.6.22+ only

END
        exit 1
    fi
fi


have=NGX_HAVE_UNIX_DOMAIN . auto/have

ngx_feature_libs=


# C types

ngx_type="int"; . auto/types/sizeof

ngx_type="long"; . auto/types/sizeof

ngx_type="long long"; . auto/types/sizeof

ngx_type="void *"; . auto/types/sizeof; ngx_ptr_size=$ngx_size
ngx_param=NGX_PTR_SIZE; ngx_value=$ngx_size; . auto/types/value


# POSIX types

NGX_INCLUDE_AUTO_CONFIG_H="#include \"ngx_auto_config.h\""

ngx_type="uint32_t"; ngx_types="u_int32_t"; . auto/types/typedef
ngx_type="uint64_t"; ngx_types="u_int64_t"; . auto/types/typedef

ngx_type="sig_atomic_t"; ngx_types="int"; . auto/types/typedef
. auto/types/sizeof
ngx_param=NGX_SIG_ATOMIC_T_SIZE; ngx_value=$ngx_size; . auto/types/value

ngx_type="socklen_t"; ngx_types="int"; . auto/types/typedef

ngx_type="in_addr_t"; ngx_types="uint32_t u_int32_t"; . auto/types/typedef

ngx_type="in_port_t"; ngx_types="u_short"; . auto/types/typedef

ngx_type="rlim_t"; ngx_types="int"; . auto/types/typedef

. auto/types/uintptr_t

. auto/endianness

ngx_type="size_t"; . auto/types/sizeof
ngx_param=NGX_MAX_SIZE_T_VALUE; ngx_value=$ngx_max_value; . auto/types/value
ngx_param=NGX_SIZE_T_LEN; ngx_value=$ngx_max_len; . auto/types/value

ngx_type="off_t"; . auto/types/sizeof
ngx_param=NGX_MAX_OFF_T_VALUE; ngx_value=$ngx_max_value; . auto/types/value
ngx_param=NGX_OFF_T_LEN; ngx_value=$ngx_max_len; . auto/types/value

ngx_type="time_t"; . auto/types/sizeof
ngx_param=NGX_TIME_T_SIZE; ngx_value=$ngx_size; . auto/types/value
ngx_param=NGX_TIME_T_LEN; ngx_value=$ngx_max_len; . auto/types/value
ngx_param=NGX_MAX_TIME_T_VALUE; ngx_value=$ngx_max_value; . auto/types/value


# syscalls, libc calls and some features


ngx_feature="AF_INET6"
ngx_feature_name="NGX_HAVE_INET6"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <netinet/in.h>
                  #include <arpa/inet.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct sockaddr_in6  sin6;
                  sin6.sin6_family = AF_INET6;
                  (void) sin6"
. auto/feature


ngx_feature="setproctitle()"
ngx_feature_name="NGX_HAVE_SETPROCTITLE"
ngx_feature_run=no
ngx_feature_incs="#include <stdlib.h>"
ngx_feature_path=
ngx_feature_libs=$NGX_SETPROCTITLE_LIB
ngx_feature_test="setproctitle(\"test\");"
. auto/feature


ngx_feature="pread()"
ngx_feature_name="NGX_HAVE_PREAD"
ngx_feature_run=no
ngx_feature_incs=
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="char buf[1]; ssize_t n; n = pread(0, buf, 1, 0);
                  if (n == -1) return 1"
. auto/feature


ngx_feature="pwrite()"
ngx_feature_name="NGX_HAVE_PWRITE"
ngx_feature_run=no
ngx_feature_incs=
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="char buf[1]; ssize_t n; n = pwrite(1, buf, 1, 0);
                  if (n == -1) return 1"
. auto/feature


# pwritev() was introduced in FreeBSD 6 and Linux 2.6.30, glibc 2.10

ngx_feature="pwritev()"
ngx_feature_name="NGX_HAVE_PWRITEV"
ngx_feature_run=no
ngx_feature_incs='#include <sys/uio.h>'
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="char buf[1]; struct iovec vec[1]; ssize_t n;
                  vec[0].iov_base = buf;
                  vec[0].iov_len = 1;
                  n = pwritev(1, vec, 1, 0);
                  if (n == -1) return 1"
. auto/feature


# strerrordesc_np(), introduced in glibc 2.32

ngx_feature="strerrordesc_np()"
ngx_feature_name="NGX_HAVE_STRERRORDESC_NP"
ngx_feature_run=no
ngx_feature_incs='#include <string.h>'
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="char *p; p = strerrordesc_np(0);
                  if (p == NULL) return 1"
. auto/feature


if [ $ngx_found = no ]; then

    ngx_feature="sys_nerr"
    ngx_feature_name="NGX_SYS_NERR"
    ngx_feature_run=value
    ngx_feature_incs='#include <errno.h>
                      #include <stdio.h>'
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test='printf("%d", sys_nerr);'
    . auto/feature
fi


if [ $ngx_found = no ]; then

    # Cygiwn defines _sys_nerr
    ngx_feature="_sys_nerr"
    ngx_feature_name="NGX_SYS_NERR"
    ngx_feature_run=value
    ngx_feature_incs='#include <errno.h>
                      #include <stdio.h>'
    ngx_feature_path=
    ngx_feature_libs=
    ngx_feature_test='printf("%d", _sys_nerr);'
    . auto/feature
fi


ngx_feature="localtime_r()"
ngx_feature_name="NGX_HAVE_LOCALTIME_R"
ngx_feature_run=no
ngx_feature_incs="#include <time.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct tm t; time_t c=0; localtime_r(&c, &t)"
. auto/feature


ngx_feature="clock_gettime(CLOCK_MONOTONIC)"
ngx_feature_name="NGX_HAVE_CLOCK_MONOTONIC"
ngx_feature_run=no
ngx_feature_incs="#include <time.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct timespec ts; clock_gettime(CLOCK_MONOTONIC, &ts)"
. auto/feature


if [ $ngx_found = no ]; then

    # Linux before glibc 2.17, notably CentOS 6

    ngx_feature="clock_gettime(CLOCK_MONOTONIC) in librt"
    ngx_feature_libs="-lrt"
    . auto/feature

    if [ $ngx_found = yes ]; then
        CORE_LIBS="$CORE_LIBS -lrt"
    fi
fi


ngx_feature="posix_memalign()"
ngx_feature_name="NGX_HAVE_POSIX_MEMALIGN"
ngx_feature_run=no
ngx_feature_incs="#include <stdlib.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="void *p; int n; n = posix_memalign(&p, 4096, 4096);
                  if (n != 0) return 1"
. auto/feature


ngx_feature="memalign()"
ngx_feature_name="NGX_HAVE_MEMALIGN"
ngx_feature_run=no
ngx_feature_incs="#include <stdlib.h>
                  #include <malloc.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="void *p; p = memalign(4096, 4096);
                  if (p == NULL) return 1"
. auto/feature


ngx_feature="mmap(MAP_ANON|MAP_SHARED)"
ngx_feature_name="NGX_HAVE_MAP_ANON"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/mman.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="void *p;
                  p = mmap(NULL, 4096, PROT_READ|PROT_WRITE,
                           MAP_ANON|MAP_SHARED, -1, 0);
                  if (p == MAP_FAILED) return 1;"
. auto/feature


ngx_feature='mmap("/dev/zero", MAP_SHARED)'
ngx_feature_name="NGX_HAVE_MAP_DEVZERO"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/mman.h>
                  #include <sys/stat.h>
                  #include <fcntl.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test='void *p; int  fd;
                  fd = open("/dev/zero", O_RDWR);
                  p = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
                  if (p == MAP_FAILED) return 1;'
. auto/feature


ngx_feature="System V shared memory"
ngx_feature_name="NGX_HAVE_SYSVSHM"
ngx_feature_run=yes
ngx_feature_incs="#include <sys/ipc.h>
                  #include <sys/shm.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int  id;
                  id = shmget(IPC_PRIVATE, 4096, (SHM_R|SHM_W|IPC_CREAT));
                  if (id == -1) return 1;
                  shmctl(id, IPC_RMID, NULL);"
. auto/feature


ngx_feature="POSIX semaphores"
ngx_feature_name="NGX_HAVE_POSIX_SEM"
ngx_feature_run=yes
ngx_feature_incs="#include <semaphore.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="sem_t  sem;
                  if (sem_init(&sem, 1, 0) == -1) return 1;
                  sem_destroy(&sem);"
. auto/feature


if [ $ngx_found = no ]; then

    # Linux has POSIX semaphores in libpthread
    ngx_feature="POSIX semaphores in libpthread"
    ngx_feature_libs=-lpthread
    . auto/feature

    if [ $ngx_found = yes ]; then
        CORE_LIBS="$CORE_LIBS -lpthread"
        NGX_LIBPTHREAD="-lpthread"
    fi
fi


if [ $ngx_found = no ]; then

    # Solaris has POSIX semaphores in librt
    ngx_feature="POSIX semaphores in librt"
    ngx_feature_libs=-lrt
    . auto/feature

    if [ $ngx_found = yes ]; then
        CORE_LIBS="$CORE_LIBS -lrt"
    fi
fi


ngx_feature="struct msghdr.msg_control"
ngx_feature_name="NGX_HAVE_MSGHDR_MSG_CONTROL"
ngx_feature_run=no
ngx_feature_incs="#include <sys/socket.h>
                  #include <stdio.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct msghdr  msg;
                  printf(\"%d\", (int) sizeof(msg.msg_control))"
. auto/feature


ngx_feature="ioctl(FIONBIO)"
ngx_feature_name="NGX_HAVE_FIONBIO"
ngx_feature_run=no
ngx_feature_incs="#include <sys/ioctl.h>
                  #include <stdio.h>
                  $NGX_INCLUDE_SYS_FILIO_H"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int i = FIONBIO; printf(\"%d\", i)"
. auto/feature


ngx_feature="ioctl(FIONREAD)"
ngx_feature_name="NGX_HAVE_FIONREAD"
ngx_feature_run=no
ngx_feature_incs="#include <sys/ioctl.h>
                  #include <stdio.h>
                  $NGX_INCLUDE_SYS_FILIO_H"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="int i = FIONREAD; printf(\"%d\", i)"
. auto/feature


ngx_feature="struct tm.tm_gmtoff"
ngx_feature_name="NGX_HAVE_GMTOFF"
ngx_feature_run=no
ngx_feature_incs="#include <time.h>
                  #include <stdio.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct tm  tm; tm.tm_gmtoff = 0;
                  printf(\"%d\", (int) tm.tm_gmtoff)"
. auto/feature


ngx_feature="struct dirent.d_namlen"
ngx_feature_name="NGX_HAVE_D_NAMLEN"
ngx_feature_run=no
ngx_feature_incs="#include <dirent.h>
                  #include <stdio.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct dirent  dir; dir.d_namlen = 0;
                  printf(\"%d\", (int) dir.d_namlen)"
. auto/feature


ngx_feature="struct dirent.d_type"
ngx_feature_name="NGX_HAVE_D_TYPE"
ngx_feature_run=no
ngx_feature_incs="#include <dirent.h>
                  #include <stdio.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="struct dirent  dir; dir.d_type = DT_REG;
                  printf(\"%d\", (int) dir.d_type)"
. auto/feature


ngx_feature="sysconf(_SC_NPROCESSORS_ONLN)"
ngx_feature_name="NGX_HAVE_SC_NPROCESSORS_ONLN"
ngx_feature_run=no
ngx_feature_incs=
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="sysconf(_SC_NPROCESSORS_ONLN)"
. auto/feature


ngx_feature="sysconf(_SC_LEVEL1_DCACHE_LINESIZE)"
ngx_feature_name="NGX_HAVE_LEVEL1_DCACHE_LINESIZE"
ngx_feature_run=no
ngx_feature_incs=
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test="sysconf(_SC_LEVEL1_DCACHE_LINESIZE)"
. auto/feature


ngx_feature="openat(), fstatat()"
ngx_feature_name="NGX_HAVE_OPENAT"
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="struct stat sb;
                  openat(AT_FDCWD, \".\", O_RDONLY|O_NOFOLLOW);
                  fstatat(AT_FDCWD, \".\", &sb, AT_SYMLINK_NOFOLLOW);"
. auto/feature


ngx_feature="getaddrinfo()"
ngx_feature_name="NGX_HAVE_GETADDRINFO"
ngx_feature_run=no
ngx_feature_incs="#include <sys/types.h>
                  #include <sys/socket.h>
                  #include <netdb.h>"
ngx_feature_path=
ngx_feature_libs=
ngx_feature_test='struct addrinfo *res;
                  if (getaddrinfo("localhost", NULL, NULL, &res) != 0) return 1;
                  freeaddrinfo(res)'
. auto/feature