make try_initialize_global_cpu_info thread safe

quink-black · quink-black · commit c6712ee2b29a · 2024-09-04T21:51:40.000+08:00
diff --git a/src/cpu.cpp b/src/cpu.cpp
@@ -1932,15 +1932,10 @@ static void initialize_global_cpu_info()
 #endif // defined __ANDROID__ || defined __linux__
 }
 
-static int g_cpu_info_initialized = 0;
-
 static inline void try_initialize_global_cpu_info()
 {
-    if (!g_cpu_info_initialized)
-    {
-        initialize_global_cpu_info();
-        g_cpu_info_initialized = 1;
-    }
+    static ncnn::OnceFlag flag = OnceFlagInit;
+    ncnn::CallOnce(flag, &initialize_global_cpu_info);
 }
 
 namespace ncnn {

Original file line number	Diff line number	Diff line change
`@@ -1932,15 +1932,10 @@ static void initialize_global_cpu_info()`
`1932`	`1932`	`#endif // defined __ANDROID__ \|\| defined __linux__`
`1933`	`1933`	`}`
`1934`	`1934`
`1935`		`-static int g_cpu_info_initialized = 0;`
`1936`		`-`
`1937`	`1935`	`static inline void try_initialize_global_cpu_info()`
`1938`	`1936`	`{`
`1939`		`- if (!g_cpu_info_initialized)`
`1940`		`- {`
`1941`		`- initialize_global_cpu_info();`
`1942`		`- g_cpu_info_initialized = 1;`
`1943`		`- }`
	`1937`	`+ static ncnn::OnceFlag flag = OnceFlagInit;`
	`1938`	`+ ncnn::CallOnce(flag, &initialize_global_cpu_info);`
`1944`	`1939`	`}`
`1945`	`1940`
`1946`	`1941`	`namespace ncnn {`