Restart engine workers when setting real-time priority.

include/system.hpp

@@ -28,7 +28,7 @@ int getLogicalCoreCount();
 /** Sets a name of the current thread for debuggers and OS-specific process viewers. */
 void setThreadName(const std::string &name);
 /** Sets the current thread to be high-priority. */
-void setThreadRealTime();
+void setThreadRealTime(bool realTime);
 /** Returns the caller's human-readable stack trace with "\n"-separated lines. */
 std::string getStackTrace();
 /** Opens a URL, also happens to work with PDFs and folders.

src/audio.cpp

@@ -211,7 +211,7 @@ static int rtCallback(void *outputBuffer, void *inputBuffer, unsigned int nFrame
 	// Exploit the stream time to run code on startup of the audio thread
 	if (streamTime == 0.0) {
 		system::setThreadName("Audio");
-		system::setThreadRealTime();
+		// system::setThreadRealTime();
 	}
 	port->processStream((const float *) inputBuffer, (float *) outputBuffer, nFrames);
 	return 0;

src/engine/Engine.cpp

@@ -116,15 +116,7 @@ struct EngineWorker {
 		thread.join();
 	}
 
-	void run() {
-		system::setThreadName("Engine worker");
-		// system::setThreadRealTime();
-		disableDenormals();
-		while (running) {
-			step();
-		}
-	}
-
+	void run();
 	void step();
 };
 
@@ -168,6 +160,8 @@ Engine::Engine() {
 
 	internal->sampleRate = 44100.f;
 	internal->sampleTime = 1 / internal->sampleRate;
+
+	system::setThreadRealTime(false);
 }
 
 Engine::~Engine() {
@@ -300,22 +294,31 @@ static void Engine_relaunchWorkers(Engine *that) {
 	assert(1 <= internal->threadCount);
 
 	// Stop all workers
+	DEBUG("1");
 	for (EngineWorker &worker : internal->workers) {
 		worker.stop();
 	}
+	DEBUG("2");
 	internal->engineBarrier.wait();
 
 	// Destroy all workers
+	DEBUG("3");
 	for (EngineWorker &worker : internal->workers) {
 		worker.join();
 	}
+	DEBUG("4");
 	internal->workers.resize(0);
+	DEBUG("5");
+
+	// Configure main thread
+	system::setThreadRealTime(internal->realTime);
 
 	// Set barrier counts
 	internal->engineBarrier.total = internal->threadCount;
 	internal->workerBarrier.total = internal->threadCount;
 
 	// Create workers
+	DEBUG("6");
 	internal->workers.resize(internal->threadCount - 1);
 	for (int id = 1; id < internal->threadCount; id++) {
 		EngineWorker &worker = internal->workers[id - 1];
@@ -323,6 +326,7 @@ static void Engine_relaunchWorkers(Engine *that) {
 		worker.engine = that;
 		worker.start();
 	}
+	DEBUG("7");
 }
 
 static void Engine_run(Engine *that) {
@@ -351,8 +355,9 @@ static void Engine_run(Engine *that) {
 		}
 
 		// Launch workers
-		if (internal->threadCount != settings::threadCount) {
+		if (internal->threadCount != settings::threadCount || internal->realTime != settings::realTime) {
 			internal->threadCount = settings::threadCount;
+			internal->realTime = settings::realTime;
 			Engine_relaunchWorkers(that);
 		}
 
@@ -696,6 +701,15 @@ void Engine::updateParamHandle(ParamHandle *paramHandle, int moduleId, int param
 }
 
 
+void EngineWorker::run() {
+	system::setThreadName("Engine worker");
+	system::setThreadRealTime(engine->internal->realTime);
+	disableDenormals();
+	while (running) {
+		step();
+	}
+}
+
 void EngineWorker::step() {
 	engine->internal->engineBarrier.wait();
 	if (!running)

src/system.cpp

@@ -105,17 +105,37 @@ void setThreadName(const std::string &name) {
 #endif
 }
 
-void setThreadRealTime() {
+void setThreadRealTime(bool realTime) {
 #if defined ARCH_LIN || defined ARCH_MAC
-	// Round-robin scheduler policy
-	int policy = SCHED_RR;
+	int err;
+	int policy;
 	struct sched_param param;
-	param.sched_priority = sched_get_priority_max(policy);
-	pthread_setschedparam(pthread_self(), policy, &param);
+	if (realTime) {
+		// Round-robin scheduler policy
+		policy = SCHED_RR;
+		param.sched_priority = sched_get_priority_max(policy);
+	}
+	else {
+		// Default scheduler policy
+		policy = 0;
+		param.sched_priority = 0;
+	}
+	err = pthread_setschedparam(pthread_self(), policy, &param);
+	assert(!err);
+
+	// pthread_getschedparam(pthread_self(), &policy, &param);
+	// DEBUG("policy %d priority %d", policy, param.sched_priority);
+
 #elif defined ARCH_WIN
 	// Set process class first
-	SetPriorityClass(GetCurrentProcess(), HIGH_PRIORITY_CLASS);
-	SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
+	if (realTime) {
+		SetPriorityClass(GetCurrentProcess(), HIGH_PRIORITY_CLASS);
+		SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);
+	}
+	else {
+		SetPriorityClass(GetCurrentProcess(), NORMAL_PRIORITY_CLASS);
+		SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_NORMAL);
+	}
 #endif
 }