Fix a potential race condition (leading to lockups) in IMuseDigital::refreshScripts

svn-id: r26254

2 files changed, 15 insertions, 11 deletions

diff --git a/engines/scumm/imuse_digi/dimuse_script.cpp b/engines/scumm/imuse_digi/dimuse_script.cpp
index 1a257c905f..ad976e3300 100644
--- a/engines/scumm/imuse_digi/dimuse_script.cpp
+++ b/engines/scumm/imuse_digi/dimuse_script.cpp
@@ -189,16 +189,20 @@ void IMuseDigital::flushTracks() {
 }
 
 void IMuseDigital::refreshScripts() {
-	Common::StackLock lock(_mutex, "IMuseDigital::refreshScripts()");
-	debug(5, "refreshScripts()");
-	bool found = false;
-	for (int l = 0; l < MAX_DIGITAL_TRACKS; l++) {
-		Track *track = _track[l];
-		if (track->used && !track->toBeRemoved && (track->volGroupId == IMUSE_VOLGRP_MUSIC)) {
-			found = true;
+	{
+		Common::StackLock lock(_mutex, "IMuseDigital::refreshScripts()");
+		debug(5, "refreshScripts()");
+		bool found = false;
+		for (int l = 0; l < MAX_DIGITAL_TRACKS; l++) {
+			Track *track = _track[l];
+			if (track->used && !track->toBeRemoved && (track->volGroupId == IMUSE_VOLGRP_MUSIC)) {
+				found = true;
+			}
 		}
 	}
-
+	
+	// Make sure parseScriptCmds is *not* called while the mutex is locked
+	// (else race conditions can occur).
 	if (!found && (_curMusicSeq != 0)) {
 		debug(5, "refreshScripts() Start Sequence");
 		parseScriptCmds(0x1001, 0, 0, 0, 0, 0, 0, 0);
diff --git a/engines/scumm/imuse_digi/dimuse_track.cpp b/engines/scumm/imuse_digi/dimuse_track.cpp
index b58d73c8d5..968f01c9e8 100644
--- a/engines/scumm/imuse_digi/dimuse_track.cpp
+++ b/engines/scumm/imuse_digi/dimuse_track.cpp
@@ -45,7 +45,7 @@ int IMuseDigital::allocSlot(int priority) {
 	}
 
 	if (trackId == -1) {
-		debug(5, "IMuseDigital::startSound(): All slots are full");
+		debug(5, "IMuseDigital::allocSlot(): All slots are full");
 		for (l = 0; l < MAX_DIGITAL_TRACKS; l++) {
 			Track *track = _track[l];
 			if (track->used && !track->toBeRemoved &&
@@ -57,9 +57,9 @@ int IMuseDigital::allocSlot(int priority) {
 		if (lowest_priority <= priority) {
 			assert(trackId != -1);
 			_track[trackId]->toBeRemoved = true;
-			debug(5, "IMuseDigital::startSound(): Removed sound %d from track %d", _track[trackId]->soundId, trackId);
+			debug(5, "IMuseDigital::allocSlot(): Removed sound %d from track %d", _track[trackId]->soundId, trackId);
 		} else {
-			debug(5, "IMuseDigital::startSound(): Priority sound too low");
+			debug(5, "IMuseDigital::allocSlot(): Priority sound too low");
 			return -1;
 		}
 	}