Use std::atomic enum for SFXStatus

src/audio/sfx_base.hpp

@@ -43,7 +43,7 @@ class SFXBase : public NoCopy
 {
 public:
     /** Status of a sound effect. */
-    enum SFXStatus
+    enum SFXStatus : int
     {
         SFX_UNKNOWN = -1, SFX_STOPPED = 0, SFX_PAUSED = 1, SFX_PLAYING = 2,
         SFX_NOT_INITIALISED = 3

src/audio/sfx_openal.hpp

@@ -22,6 +22,7 @@
 #ifdef ENABLE_SOUND
 
 #include <assert.h>
+#include <atomic>
 #ifdef __APPLE__
 #  define OPENAL_DEPRECATED
 #  include <OpenAL/al.h>
@@ -48,7 +49,7 @@ private:
     ALuint       m_sound_source;
 
     /** The status of this SFX. */
-    SFXStatus    m_status;
+    std::atomic<SFXStatus> m_status;
 
     /** If the sfx is positional. */
     bool         m_positional;