view auto/lib/libatomic/conf @ 8844:011f5ebdb928

HTTP/2: fixed closed_nodes overflow (ticket #1708). With large http2_max_concurrent_streams or http2_max_concurrent_pushes, more than 255 ngx_http_v2_node_t structures might be allocated, eventually leading to h2c->closed_nodes overflow when closing corresponding streams. This will in turn result in additional allocations in ngx_http_v2_get_node_by_id(). While mostly harmless, it can result in excessive memory usage by a HTTP/2 connection, notably in configurations with many keepalive_requests allowed. Fix is to use ngx_uint_t for h2c->closed_nodes instead of unsigned:8.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 03 Feb 2022 22:46:01 +0300
parents d620f497c50f
children
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# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


if [ $NGX_LIBATOMIC != YES ]; then

    have=NGX_HAVE_LIBATOMIC . auto/have
    CORE_INCS="$CORE_INCS $NGX_LIBATOMIC/src"
    LINK_DEPS="$LINK_DEPS $NGX_LIBATOMIC/src/libatomic_ops.a"
    CORE_LIBS="$CORE_LIBS $NGX_LIBATOMIC/src/libatomic_ops.a"

else

    ngx_feature="atomic_ops library"
    ngx_feature_name=NGX_HAVE_LIBATOMIC
    ngx_feature_run=yes
    ngx_feature_incs="#define AO_REQUIRE_CAS
                      #include <atomic_ops.h>"
    ngx_feature_path=
    ngx_feature_libs="-latomic_ops"
    ngx_feature_test="long  n = 0;
                      if (!AO_compare_and_swap(&n, 0, 1))
                          return 1;
                      if (AO_fetch_and_add(&n, 1) != 1)
                          return 1;
                      if (n != 2)
                          return 1;
                      AO_nop();"
    . auto/feature

    if [ $ngx_found = yes ]; then
        CORE_LIBS="$CORE_LIBS $ngx_feature_libs"
    else

cat << END

$0: error: libatomic_ops library was not found.

END
        exit 1
    fi
fi