X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavutil%2Fcpu.c;h=16e0c9278fd04b1446f4bc2ae0ade951cf38e116;hb=2d7aadf3d95c96848433955b537ced415fb6ae20;hp=f5785fc13fb86355d46f8f5bba0e11fb9a22fda0;hpb=82c4d57553d474505ae2df26503598b4e0303a80;p=ffmpeg

diff --git a/libavutil/cpu.c b/libavutil/cpu.c
index f5785fc13fb..16e0c9278fd 100644
--- a/libavutil/cpu.c
+++ b/libavutil/cpu.c
@@ -17,6 +17,7 @@
  */
 
 #include <stdint.h>
+#include <stdatomic.h>
 
 #include "cpu.h"
 #include "cpu_internal.h"
@@ -44,7 +45,20 @@
 #include <unistd.h>
 #endif
 
-static int flags, checked;
+static atomic_int cpu_flags = ATOMIC_VAR_INIT(-1);
+
+static int get_cpu_flags(void)
+{
+    if (ARCH_AARCH64)
+        return ff_get_cpu_flags_aarch64();
+    if (ARCH_ARM)
+        return ff_get_cpu_flags_arm();
+    if (ARCH_PPC)
+        return ff_get_cpu_flags_ppc();
+    if (ARCH_X86)
+        return ff_get_cpu_flags_x86();
+    return 0;
+}
 
 void av_force_cpu_flags(int arg){
     if (   (arg & ( AV_CPU_FLAG_3DNOW    |
@@ -69,33 +83,23 @@ void av_force_cpu_flags(int arg){
         arg |= AV_CPU_FLAG_MMX;
     }
 
-    flags   = arg;
-    checked = arg != -1;
+    atomic_store_explicit(&cpu_flags, arg, memory_order_relaxed);
 }
 
 int av_get_cpu_flags(void)
 {
-    if (checked)
-        return flags;
-
-    if (ARCH_AARCH64)
-        flags = ff_get_cpu_flags_aarch64();
-    if (ARCH_ARM)
-        flags = ff_get_cpu_flags_arm();
-    if (ARCH_PPC)
-        flags = ff_get_cpu_flags_ppc();
-    if (ARCH_X86)
-        flags = ff_get_cpu_flags_x86();
-
-    checked = 1;
+    int flags = atomic_load_explicit(&cpu_flags, memory_order_relaxed);
+    if (flags == -1) {
+        flags = get_cpu_flags();
+        atomic_store_explicit(&cpu_flags, flags, memory_order_relaxed);
+    }
     return flags;
 }
 
 void av_set_cpu_flags_mask(int mask)
 {
-    checked       = 0;
-    flags         = av_get_cpu_flags() & mask;
-    checked       = 1;
+    atomic_store_explicit(&cpu_flags, get_cpu_flags() & mask,
+                          memory_order_relaxed);
 }
 
 int av_parse_cpu_flags(const char *s)