Mercurial > hg > nginx
view auto/module @ 8045:aa28c802409f
Resolver: make TCP write timer event cancelable.
Similar to 70e65bf8dfd7, the change is made to ensure that the ability to
cancel resolver tasks is fully controlled by the caller. As mentioned in the
referenced commit, it is safe to make this timer cancelable because resolve
tasks can have their own timeouts that are not cancelable.
The scenario where this may become a problem is a periodic background resolve
task (not tied to a specific request or a client connection), which receives a
response with short TTL, large enough to warrant fallback to a TCP query.
With each event loop wakeup, we either have a previously set write timer
instance or schedule a new one. The non-cancelable write timer can delay or
block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable
flag is set by the API user, and there are no other tasks or connections.
We use the resolver API in this way to maintain the list of upstream server
addresses specified with the 'resolve' parameter, and there could be third-party
modules implementing similar logic.
author | Aleksei Bavshin <a.bavshin@f5.com> |
---|---|
date | Wed, 01 Jun 2022 20:17:23 -0700 |
parents | 4b1299b1856a |
children |
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# Copyright (C) Ruslan Ermilov # Copyright (C) Nginx, Inc. case $ngx_module_type in HTTP_*) ngx_var=HTTP ;; *) ngx_var=$ngx_module_type ;; esac if [ "$ngx_module_link" = DYNAMIC ]; then for ngx_module in $ngx_module_name; do # extract the first name break done DYNAMIC_MODULES="$DYNAMIC_MODULES $ngx_module" eval ${ngx_module}_MODULES=\"$ngx_module_name\" if [ -z "$ngx_module_order" -a \ \( "$ngx_module_type" = "HTTP_FILTER" \ -o "$ngx_module_type" = "HTTP_AUX_FILTER" \) ] then eval ${ngx_module}_ORDER=\"$ngx_module_name \ ngx_http_copy_filter_module\" else eval ${ngx_module}_ORDER=\"$ngx_module_order\" fi srcs= shrd= for src in $ngx_module_srcs do found=no for old in $DYNAMIC_MODULES_SRCS do if [ $src = $old ]; then found=yes break fi done if [ $found = no ]; then srcs="$srcs $src" else shrd="$shrd $src" fi done eval ${ngx_module}_SRCS=\"$srcs\" eval ${ngx_module}_SHRD=\"$shrd\" DYNAMIC_MODULES_SRCS="$DYNAMIC_MODULES_SRCS $srcs" if test -n "$ngx_module_incs"; then CORE_INCS="$CORE_INCS $ngx_module_incs" fi if test -n "$ngx_module_deps"; then NGX_ADDON_DEPS="$NGX_ADDON_DEPS $ngx_module_deps" fi libs= for lib in $ngx_module_libs do case $lib in LIBXSLT | LIBGD | GEOIP | PERL) libs="$libs \$NGX_LIB_$lib" if eval [ "\$USE_${lib}" = NO ] ; then eval USE_${lib}=DYNAMIC fi ;; PCRE | OPENSSL | ZLIB) eval USE_${lib}=YES ;; MD5 | SHA1) # obsolete ;; *) libs="$libs $lib" ;; esac done eval ${ngx_module}_LIBS=\'$libs\' elif [ "$ngx_module_link" = YES ]; then eval ${ngx_module_type}_MODULES=\"\$${ngx_module_type}_MODULES \ $ngx_module_name\" eval ${ngx_var}_SRCS=\"\$${ngx_var}_SRCS $ngx_module_srcs\" if test -n "$ngx_module_incs"; then eval ${ngx_var}_INCS=\"\$${ngx_var}_INCS $ngx_module_incs\" fi if test -n "$ngx_module_deps"; then eval ${ngx_var}_DEPS=\"\$${ngx_var}_DEPS $ngx_module_deps\" fi for lib in $ngx_module_libs do case $lib in PCRE | OPENSSL | ZLIB | LIBXSLT | LIBGD | PERL | GEOIP) eval USE_${lib}=YES ;; MD5 | SHA1) # obsolete ;; *) CORE_LIBS="$CORE_LIBS $lib" ;; esac done elif [ "$ngx_module_link" = ADDON ]; then eval ${ngx_module_type}_MODULES=\"\$${ngx_module_type}_MODULES \ $ngx_module_name\" srcs= for src in $ngx_module_srcs do found=no for old in $NGX_ADDON_SRCS do if [ $src = $old ]; then found=yes break fi done if [ $found = no ]; then srcs="$srcs $src" fi done NGX_ADDON_SRCS="$NGX_ADDON_SRCS $srcs" if test -n "$ngx_module_incs"; then eval ${ngx_var}_INCS=\"\$${ngx_var}_INCS $ngx_module_incs\" fi if test -n "$ngx_module_deps"; then NGX_ADDON_DEPS="$NGX_ADDON_DEPS $ngx_module_deps" fi for lib in $ngx_module_libs do case $lib in PCRE | OPENSSL | ZLIB | LIBXSLT | LIBGD | PERL | GEOIP) eval USE_${lib}=YES ;; MD5 | SHA1) # obsolete ;; *) CORE_LIBS="$CORE_LIBS $lib" ;; esac done fi