FM-TOWNS AUDIO: fix thread lockups and cleanup

- fixed lockup situation in imuse destructor (only concerning the fm-towns driver)
- fixed lockup situation when AudioCDManager functions get called
(in both cases both the main thread and the mixer thread would get locked in different mutex belonging to the other thread)

1 files changed, 9 insertions, 2 deletions

diff --git a/audio/softsynth/fmtowns_pc98/towns_audio.h b/audio/softsynth/fmtowns_pc98/towns_audio.h
index 2c58d46d06..b00243f610 100644
--- a/audio/softsynth/fmtowns_pc98/towns_audio.h
+++ b/audio/softsynth/fmtowns_pc98/towns_audio.h
@@ -25,7 +25,7 @@
 
 #include "audio/mixer.h"
 
-class TownsAudioInterfaceIntern;
+class TownsAudioInterfaceInternal;
 
 class TownsAudioInterfacePluginDriver {
 public:
@@ -48,8 +48,15 @@ public:
 	// The first 6 bits are the 6 fm channels. The next 8 bits are pcm channels.
 	void setSoundEffectChanMask(int mask);
 
+	// These methods should not be needed in standard situations, since the mutex
+	// is handled internally. However, they may be required to avoid lockup situations
+	// if the code using this class has a mutex of its own (example for a lockup
+	// situation: imuse.cpp, line 78).
+	void lockInternal();
+	void unlockInternal();
+
 private:
-	TownsAudioInterfaceIntern *_intf;
+	TownsAudioInterfaceInternal *_intf;
 };
 
 #endif