Fixes #45025 - Protects _last_mix_time and _last_frame_time with the AudioDriver lock() and unlock() methods

(cherry picked from commit 17ac0127284145d366a4611960525ecbdac8ab10)

servers/audio_server.cpp

@@ -71,15 +71,20 @@ void AudioDriver::update_mix_time(int p_frames) {
 		_last_mix_time = OS::get_singleton()->get_ticks_usec();
 }
 
-double AudioDriver::get_time_since_last_mix() const {
-
-	return (OS::get_singleton()->get_ticks_usec() - _last_mix_time) / 1000000.0;
+double AudioDriver::get_time_since_last_mix() {
+	lock();
+	uint64_t last_mix_time = _last_mix_time;
+	unlock();
+	return (OS::get_singleton()->get_ticks_usec() - last_mix_time) / 1000000.0;
 }
 
-double AudioDriver::get_time_to_next_mix() const {
-
-	double total = (OS::get_singleton()->get_ticks_usec() - _last_mix_time) / 1000000.0;
-	double mix_buffer = _last_mix_frames / (double)get_mix_rate();
+double AudioDriver::get_time_to_next_mix() {
+	lock();
+	uint64_t last_mix_time = _last_mix_time;
+	uint64_t last_mix_frames = _last_mix_frames;
+	unlock();
+	double total = (OS::get_singleton()->get_ticks_usec() - last_mix_time) / 1000000.0;
+	double mix_buffer = last_mix_frames / (double)get_mix_rate();
 	return mix_buffer - total;
 }
 

servers/audio_server.h

@@ -71,8 +71,8 @@ protected:
 #endif
 
 public:
-	double get_time_since_last_mix() const; //useful for video -> audio sync
-	double get_time_to_next_mix() const;
+	double get_time_since_last_mix(); //useful for video -> audio sync
+	double get_time_to_next_mix();
 
 	enum SpeakerMode {
 		SPEAKER_MODE_STEREO,