From a84fd58f48fa332b1c5a545d9b7e2440b8784656 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Marek=20Ol=C5=A1=C3=A1k?= Date: Wed, 5 Sep 2018 19:15:56 -0400 Subject: [PATCH] gallium/u_cpu_detect: fix a race condition on initialization Reviewed-by: Brian Paul --- src/gallium/auxiliary/util/u_cpu_detect.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/src/gallium/auxiliary/util/u_cpu_detect.c b/src/gallium/auxiliary/util/u_cpu_detect.c index 14003aa7692..93cf58011db 100644 --- a/src/gallium/auxiliary/util/u_cpu_detect.c +++ b/src/gallium/auxiliary/util/u_cpu_detect.c @@ -36,6 +36,7 @@ #include "u_debug.h" #include "u_cpu_detect.h" +#include "c11/threads.h" #if defined(PIPE_ARCH_PPC) #if defined(PIPE_OS_APPLE) @@ -366,14 +367,9 @@ check_os_arm_support(void) } #endif /* PIPE_ARCH_ARM */ -void -util_cpu_detect(void) +static void +util_cpu_detect_once(void) { - static boolean util_cpu_detect_initialized = FALSE; - - if(util_cpu_detect_initialized) - return; - memset(&util_cpu_caps, 0, sizeof util_cpu_caps); /* Count the number of CPUs in system */ @@ -561,6 +557,12 @@ util_cpu_detect(void) debug_printf("util_cpu_caps.has_avx512vbmi = %u\n", util_cpu_caps.has_avx512vbmi); } #endif +} + +static once_flag cpu_once_flag = ONCE_FLAG_INIT; - util_cpu_detect_initialized = TRUE; +void +util_cpu_detect(void) +{ + call_once(&cpu_once_flag, util_cpu_detect_once); } -- 2.30.2