Adding upstream version 1.7.5.upstream/1.7.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 9 insertions, 8 deletions

diff --git a/include/arch/win32/apr_arch_misc.h b/include/arch/win32/apr_arch_misc.h
index 4dbe899..3cc91b0 100644
--- a/include/arch/win32/apr_arch_misc.h
+++ b/include/arch/win32/apr_arch_misc.h
@@ -198,15 +198,16 @@ FARPROC apr_load_dll_func(apr_dlltoken_e fnLib, char *fnName, int ordinal);
  */
 #define APR_DECLARE_LATE_DLL_FUNC(lib, rettype, calltype, fn, ord, args, names) \
     typedef rettype (calltype *apr_winapi_fpt_##fn) args; \
-    static apr_winapi_fpt_##fn apr_winapi_pfn_##fn = NULL; \
-    static int apr_winapi_chk_##fn = 0; \
+    static volatile apr_winapi_fpt_##fn apr_winapi_pfn_##fn = (apr_winapi_fpt_##fn) (ULONG_PTR) (-1); \
     static APR_INLINE int apr_winapi_ld_##fn(void) \
-    {   if (apr_winapi_pfn_##fn) return 1; \
-        if (apr_winapi_chk_##fn ++) return 0; \
-        if (!apr_winapi_pfn_##fn) \
-            apr_winapi_pfn_##fn = (apr_winapi_fpt_##fn) \
-                                      apr_load_dll_func(lib, #fn, ord); \
-        if (apr_winapi_pfn_##fn) return 1; else return 0; }; \
+    {   \
+        apr_winapi_fpt_##fn cached_func = apr_winapi_pfn_##fn; \
+        if (cached_func == (apr_winapi_fpt_##fn) (ULONG_PTR) (-1)) { \
+            cached_func = (apr_winapi_fpt_##fn) apr_load_dll_func(lib, #fn, ord); \
+            /* Pointer-sized writes are atomic on Windows. */ \
+            apr_winapi_pfn_##fn = cached_func; \
+        } \
+        if (cached_func) return 1; else return 0; }; \
     static APR_INLINE rettype apr_winapi_##fn args \
     {   if (apr_winapi_ld_##fn()) \
             return (*(apr_winapi_pfn_##fn)) names; \