view auto/cc/clang @ 7951:c7a8bdf5af55

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 ceab908790c4
children
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# Copyright (C) Nginx, Inc.


# clang


NGX_CLANG_VER=`$CC -v 2>&1 | grep 'version' 2>&1 \
                           | sed -n -e 's/^.*clang version \(.*\)/\1/p' \
                                    -e 's/^.*LLVM version \(.*\)/\1/p'`

echo " + clang version: $NGX_CLANG_VER"

have=NGX_COMPILER value="\"clang $NGX_CLANG_VER\"" . auto/define


CC_TEST_FLAGS="-pipe"


# optimizations

#NGX_CLANG_OPT="-O2"
#NGX_CLANG_OPT="-Oz"
NGX_CLANG_OPT="-O"

case $CPU in
    pentium)
        # optimize for Pentium
        CPU_OPT="-march=pentium"
        NGX_CPU_CACHE_LINE=32
    ;;

    pentiumpro | pentium3)
        # optimize for Pentium Pro, Pentium II and Pentium III
        CPU_OPT="-march=pentiumpro"
        NGX_CPU_CACHE_LINE=32
    ;;

    pentium4)
        # optimize for Pentium 4
        CPU_OPT="-march=pentium4"
        NGX_CPU_CACHE_LINE=128
    ;;

    athlon)
        # optimize for Athlon
        CPU_OPT="-march=athlon"
        NGX_CPU_CACHE_LINE=64
    ;;

    opteron)
        # optimize for Opteron
        CPU_OPT="-march=opteron"
        NGX_CPU_CACHE_LINE=64
    ;;

esac

CC_AUX_FLAGS="$CC_AUX_FLAGS $CPU_OPT"


CFLAGS="$CFLAGS -pipe $CPU_OPT"

if [ ".$PCRE_OPT" = "." ]; then
    PCRE_OPT="-O2 -pipe $CPU_OPT"
else
    PCRE_OPT="$PCRE_OPT -pipe"
fi

if [ ".$ZLIB_OPT" = "." ]; then
    ZLIB_OPT="-O2 -pipe $CPU_OPT"
else
    ZLIB_OPT="$ZLIB_OPT -pipe"
fi


# warnings

CFLAGS="$CFLAGS $NGX_CLANG_OPT -Wall -Wextra -Wpointer-arith"
CFLAGS="$CFLAGS -Wconditional-uninitialized"
#CFLAGS="$CFLAGS -Wmissing-prototypes"

# we have a lot of unused function arguments
CFLAGS="$CFLAGS -Wno-unused-parameter"

# deprecated system OpenSSL library on OS X
if [ "$NGX_SYSTEM" = "Darwin" ]; then
    CFLAGS="$CFLAGS -Wno-deprecated-declarations"
fi

# stop on warning
CFLAGS="$CFLAGS -Werror"

# debug
CFLAGS="$CFLAGS -g"

if [ ".$CPP" = "." ]; then
    CPP="$CC -E"
fi