Move processMutex from RtAudioDevice to audio::Device.

include/audio.hpp

@@ -1,6 +1,7 @@
 #pragma once
 #include <vector>
 #include <set>
+#include <mutex>
 
 #include <jansson.h>
 
@@ -72,6 +73,9 @@ Methods throw `rack::Exception` if the driver API has an exception.
 */
 struct Device {
 	std::set<Port*> subscribed;
+	/** Ensures that ports do not subscribe/unsubscribe while processBuffer() is called. */
+	std::mutex processMutex;
+
 	virtual ~Device() {}
 
 	virtual std::string getName() {

src/audio.cpp

@@ -19,10 +19,12 @@ static std::vector<std::pair<int, Driver*>> drivers;
 ////////////////////
 
 void Device::subscribe(Port* port) {
+	std::lock_guard<std::mutex> lock(processMutex);
 	subscribed.insert(port);
 }
 
 void Device::unsubscribe(Port* port) {
+	std::lock_guard<std::mutex> lock(processMutex);
 	auto it = subscribed.find(port);
 	if (it != subscribed.end())
 		subscribed.erase(it);
@@ -32,6 +34,7 @@ void Device::processBuffer(const float* input, int inputStride, float* output, i
 	// Zero output in case no Port writes values to it.
 	std::memset(output, 0, frames * outputStride * sizeof(float));
 
+	std::lock_guard<std::mutex> lock(processMutex);
 	for (Port* port : subscribed) {
 		// Setting the thread context should probably be the responsibility of Port, but because processInput() etc are overridden, this is the only good place for it.
 		contextSet(port->context);

src/rtaudio.cpp

@@ -1,6 +1,5 @@
 #include <map>
 #include <algorithm>
-#include <mutex>
 
 #pragma GCC diagnostic push
 #ifndef __clang__
@@ -43,8 +42,6 @@ struct RtAudioDevice : audio::Device {
 	RtAudio::StreamOptions options;
 	int blockSize = 0;
 	float sampleRate = 0;
-	/** Ensures that ports do not subscribe/unsubscribe while processBuffer() is called. */
-	std::mutex processMutex;
 
 	RtAudioDevice(RtAudio::Api api, int deviceId) {
 		this->api = api;
@@ -212,16 +209,6 @@ struct RtAudioDevice : audio::Device {
 		openStream();
 	}
 
-	void subscribe(audio::Port* port) override {
-		std::lock_guard<std::mutex> lock(processMutex);
-		Device::subscribe(port);
-	}
-
-	void unsubscribe(audio::Port* port) override {
-		std::lock_guard<std::mutex> lock(processMutex);
-		Device::unsubscribe(port);
-	}
-
 	static int rtAudioCallback(void* outputBuffer, void* inputBuffer, unsigned int nFrames, double streamTime, RtAudioStreamStatus status, void* userData) {
 		// fprintf(stderr, ".");
 		// fflush(stderr);
@@ -229,8 +216,6 @@ struct RtAudioDevice : audio::Device {
 		RtAudioDevice* that = (RtAudioDevice*) userData;
 		assert(that);
 
-		std::lock_guard<std::mutex> lock(that->processMutex);
-
 		system::setThreadName("RtAudio");
 
 		int inputStride = that->getNumInputs();