Fixed bug 4391 - hid_enumerate() sometimes causes game to freeze for a few seconds

Daniel Gibson

Even though my game (dhewm3) doesn't use SDL_INIT_JOYSTICK, SDL_PumpEvent() calls SDL_JoystickUpdate() which ends up calling hid_enumerate() every three seconds, and sometimes on my Win7 box hid_enumerate() takes about 5 seconds, which causes the whole game to freeze for that time.

include/SDL_bits.h

@@ -101,6 +101,15 @@ SDL_MostSignificantBitIndex32(Uint32 x)
 #endif
 }
 
+SDL_FORCE_INLINE SDL_bool
+SDL_HasExactlyOneBitSet32(Uint32 x)
+{
+    if (x && !(x & (x - 1))) {
+        return SDL_TRUE;
+    }
+    return SDL_FALSE;
+}
+
 /* Ends C function definitions when using C++ */
 #ifdef __cplusplus
 }