Mercurial > hg > nginx-quic
view auto/cc/conf @ 7281:bd6563e81cea
Limit req: improved handling of negative times.
Negative times can appear since workers only update time on an event
loop iteration start. If a worker was blocked for a long time during
an event loop iteration, it is possible that another worker already
updated the time stored in the node. As such, time since last update
of the node (ms) will be negative.
Previous code used ngx_abs(ms) in the calculations. That is, negative
times were effectively treated as positive ones. As a result, it was
not possible to maintain high request rates, where the same node can be
updated multiple times from during an event loop iteration.
In particular, this affected setups with many SSL handshakes, see
http://mailman.nginx.org/pipermail/nginx/2018-May/056291.html.
Fix is to only update the last update time stored in the node if the
new time is larger than previously stored one. If a future time is
stored in the node, we preserve this time as is.
To prevent breaking things on platforms without monotonic time available
if system time is updated backwards, a safety limit of 60 seconds is
used. If the time stored in the node is more than 60 seconds in the future,
we assume that the time was changed backwards and update lr->last
to the current time.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 30 May 2018 15:40:34 +0300 |
parents | 4925a6d13746 |
children | 9bcc5cc94ff4 |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. LINK="\$(CC)" MAIN_LINK= MODULE_LINK="-shared" ngx_include_opt="-I " ngx_compile_opt="-c" ngx_pic_opt="-fPIC" ngx_objout="-o " ngx_binout="-o " ngx_objext="o" ngx_binext= ngx_modext=".so" ngx_long_start= ngx_long_end= ngx_regex_dirsep="\/" ngx_dirsep='/' ngx_regex_cont=' \\\ ' ngx_cont=' \ ' ngx_tab=' \ ' ngx_spacer= ngx_long_regex_cont=$ngx_regex_cont ngx_long_cont=$ngx_cont . auto/cc/name if test -n "$CFLAGS"; then CC_TEST_FLAGS="$CFLAGS $NGX_CC_OPT" case $NGX_CC_NAME in ccc) # Compaq C V6.5-207 ngx_include_opt="-I" ;; sunc) MAIN_LINK= MODULE_LINK="-G" case "$NGX_MACHINE" in i86pc) NGX_AUX=" src/os/unix/ngx_sunpro_x86.il" ;; sun4u | sun4v) NGX_AUX=" src/os/unix/ngx_sunpro_sparc64.il" ;; esac case $CPU in amd64) NGX_AUX=" src/os/unix/ngx_sunpro_amd64.il" ;; esac ;; esac else case $NGX_CC_NAME in gcc) # gcc 2.7.2.3, 2.8.1, 2.95.4, egcs-1.1.2 # 3.0.4, 3.1.1, 3.2.3, 3.3.2, 3.3.3, 3.3.4, 3.4.0, 3.4.2 # 4.0.0, 4.0.1, 4.1.0 . auto/cc/gcc ;; clang) # Clang C compiler . auto/cc/clang ;; icc) # Intel C++ compiler 7.1, 8.0, 8.1 . auto/cc/icc ;; sunc) # Sun C 5.7 Patch 117837-04 2005/05/11 . auto/cc/sunc ;; ccc) # Compaq C V6.5-207 . auto/cc/ccc ;; acc) # aCC: HP ANSI C++ B3910B A.03.55.02 . auto/cc/acc ;; msvc*) # MSVC++ 6.0 SP2, MSVC++ Toolkit 2003 . auto/cc/msvc ;; owc) # Open Watcom C 1.0, 1.2 . auto/cc/owc ;; bcc) # Borland C++ 5.5 . auto/cc/bcc ;; esac CC_TEST_FLAGS="$CC_TEST_FLAGS $NGX_CC_OPT" fi CFLAGS="$CFLAGS $NGX_CC_OPT" NGX_TEST_LD_OPT="$NGX_LD_OPT" if [ "$NGX_PLATFORM" != win32 ]; then if test -n "$NGX_LD_OPT"; then ngx_feature=--with-ld-opt=\"$NGX_LD_OPT\" ngx_feature_name= ngx_feature_run=no ngx_feature_incs= ngx_feature_path= ngx_feature_libs= ngx_feature_test= . auto/feature if [ $ngx_found = no ]; then echo $0: error: the invalid value in --with-ld-opt=\"$NGX_LD_OPT\" echo exit 1 fi fi ngx_feature="-Wl,-E switch" ngx_feature_name= ngx_feature_run=no ngx_feature_incs= ngx_feature_path= ngx_feature_libs=-Wl,-E ngx_feature_test= . auto/feature if [ $ngx_found = yes ]; then MAIN_LINK="-Wl,-E" fi if [ "$NGX_CC_NAME" = "sunc" ]; then echo "checking for gcc builtin atomic operations ... disabled" else ngx_feature="gcc builtin atomic operations" ngx_feature_name=NGX_HAVE_GCC_ATOMIC ngx_feature_run=yes ngx_feature_incs= ngx_feature_path= ngx_feature_libs= ngx_feature_test="long n = 0; if (!__sync_bool_compare_and_swap(&n, 0, 1)) return 1; if (__sync_fetch_and_add(&n, 1) != 1) return 1; if (n != 2) return 1; __sync_synchronize();" . auto/feature fi if [ "$NGX_CC_NAME" = "ccc" ]; then echo "checking for C99 variadic macros ... disabled" else ngx_feature="C99 variadic macros" ngx_feature_name="NGX_HAVE_C99_VARIADIC_MACROS" ngx_feature_run=yes ngx_feature_incs="#include <stdio.h> #define var(dummy, ...) sprintf(__VA_ARGS__)" ngx_feature_path= ngx_feature_libs= ngx_feature_test="char buf[30]; buf[0] = '0'; var(0, buf, \"%d\", 1); if (buf[0] != '1') return 1" . auto/feature fi ngx_feature="gcc variadic macros" ngx_feature_name="NGX_HAVE_GCC_VARIADIC_MACROS" ngx_feature_run=yes ngx_feature_incs="#include <stdio.h> #define var(dummy, args...) sprintf(args)" ngx_feature_path= ngx_feature_libs= ngx_feature_test="char buf[30]; buf[0] = '0'; var(0, buf, \"%d\", 1); if (buf[0] != '1') return 1" . auto/feature ngx_feature="gcc builtin 64 bit byteswap" ngx_feature_name="NGX_HAVE_GCC_BSWAP64" ngx_feature_run=no ngx_feature_incs= ngx_feature_path= ngx_feature_libs= ngx_feature_test="if (__builtin_bswap64(0)) return 1" . auto/feature # ngx_feature="inline" # ngx_feature_name= # ngx_feature_run=no # ngx_feature_incs="int inline f(void) { return 1 }" # ngx_feature_path= # ngx_feature_libs= # ngx_feature_test= # . auto/feature # # if [ $ngx_found = yes ]; then # fi fi