streamlined multithreading a bit

notes

@@ -45,9 +45,6 @@ project data {
 
 TODO {
     immediate frontburner {
-        ( - can eliminate the moodycamel queue) and atomic lock on nodes now that the main queue is deduplicated
-        buffer underruns are being caused by some sync wonkiness between multiple workers
-        
         make the audio engine thread itself act as a worker during tick
         
         give node helper functions to move ports (index-wise) and collapse them (eliminate numbering holes)
@@ -55,8 +52,14 @@ TODO {
         
     }
     
+    return the latency/buffer size to 100ms once multithreading is streamlined
     # fix how qt5.12 broke header text (removed elide for now)
     
+    bugs to fix {
+        graph connections sometimes spawn in duplicated :|
+        buffer underruns are being caused by some sync wonkiness between multiple workers
+    }
+    
     misc features needed before proper release {
         song metadata (title, artist, comment, default bpm)
         

xybrid/audio/audioengine.cpp

@@ -94,6 +94,7 @@ void AudioEngine::initAudio(bool startNow) {
         output->setCategory("Xybrid");
         output->setObjectName("Xybrid"); // if Qt ever implements naming the stream this way, WE'LL BE READY
         output->setBufferSize(static_cast<int>(sampleRate*4*100.0/1000.0)); // 100ms
+        output->setBufferSize(static_cast<int>(sampleRate*4* 110.0 /1000.0)); // a bit more if acting up
     }
 
     if (startNow) output->start();
@@ -233,9 +234,6 @@ void AudioEngine::buildQueue() {
         }
     }
 
-    // set queue size
-    //wqueue = moodycamel::ConcurrentQueue<std::shared_ptr<Node>>(queue.size());
-
     /*/{
         auto dbg = qDebug() << "Queue:";
         for (auto n : queue) {
@@ -498,9 +496,7 @@ void AudioEngine::processNodes() {
     if (workers.empty()) {
         for (auto n : queue) if (!n->try_process()) qWarning() << "Dependency check failed in single threaded mode!";
     } else {
-        //for (auto n : queue) wqueue.enqueue(n);
-        //wqueue.enqueue_bulk(queue.begin(), queue.size());
-        queueIndex.store(0);
+        queueIndex.store(0); // reset sync index
         auto wc = static_cast<int>(workers.size());
         wsem.release(wc);
         for (auto w : workers) w->invoke();

xybrid/audio/audioengine.h

@@ -12,8 +12,6 @@
 #include <QSemaphore>
 #include <QWaitCondition>
 
-#include "inclib/concurrentqueue.h"
-
 class QThread;
 namespace Xybrid::Data {
     class Project;
@@ -62,7 +60,6 @@ namespace Xybrid::Audio {
         std::shared_ptr<Data::Project> project;
 
         std::vector<AudioWorker*> workers;
-        //moodycamel::ConcurrentQueue<std::shared_ptr<Data::Node>> wqueue;
         QSemaphore wsem;
 
         std::vector<std::shared_ptr<Data::Node>> queue;

xybrid/data/node.cpp

@@ -24,9 +24,7 @@ Port::~Port() {
     }
 }
 
-Port::Port(const Port &) : std::enable_shared_from_this<Port>() {
-    procLock = false;
-}
+Port::Port(const Port &) : std::enable_shared_from_this<Port>() { }
 
 bool Port::canConnectTo(DataType d) const {
     return d == dataType();
@@ -137,12 +135,6 @@ bool Node::try_process(bool checkDependencies) {
     size_t tick_this = audioEngine->curTickId();
     if (tick_last == tick_this) return true; // already processed
 
-    bool lock = false;
-    if (!procLock.compare_exchange_strong(lock, true)) {
-        qDebug() << "node order dupe!!";
-        return true; // another worker is using this, advance to the next
-    }
-
     if (checkDependencies) { // check if dependencies are done
         auto checkInput = Util::yCombinator([tick_this](auto checkInput, std::shared_ptr<Port> p) -> bool {
             for (auto c : p->connections) { // check each connection; if node valid...
@@ -161,7 +153,7 @@ bool Node::try_process(bool checkDependencies) {
             return true;
         });
 
-        for (auto t : inputs) for (auto p : t.second) if (!checkInput(p.second)) { procLock.store(false); return false; }
+        for (auto t : inputs) for (auto p : t.second) if (!checkInput(p.second)) return false;
 
         /*for (auto& t : inputs) {
             for (auto& p : t.second) {
@@ -181,14 +173,9 @@ bool Node::try_process(bool checkDependencies) {
 
     }
 
-
-    /*auto qd = qDebug() << "processing" << QString::fromStdString(pluginName());
-    if (!name.empty()) qd << "named" << QString::fromStdString(name);
-    if (auto p = parent.lock(); p && !p->name.empty()) qd << "within" << QString::fromStdString(p->name);*/
     process();
 
     tick_last = tick_this;
-    procLock.store(false);
     return true;
 }
 

xybrid/data/node.h

@@ -7,6 +7,7 @@
 #include <string>
 #include <atomic>
 
+#include <QMutex>
 #include <QPointer>
 #include <QObject>
 
@@ -49,7 +50,7 @@ namespace Xybrid::Data {
         std::weak_ptr<Port> passthroughTo;
         Type type;
         uint8_t index;
-        std::atomic_bool procLock = false;
+        QMutex lock;
         size_t tickUpdatedOn = static_cast<size_t>(-1);
 
         QPointer<UI::PortObject> obj;
@@ -76,7 +77,6 @@ namespace Xybrid::Data {
         friend class Audio::AudioEngine;
         friend class Audio::AudioWorker;
         size_t tick_last = 0;
-        std::atomic_bool procLock = false;
         bool try_process(bool checkDependencies = true);
     public:
         Project* project;
@@ -117,7 +117,6 @@ namespace Xybrid::Data {
         virtual void onParent(std::shared_ptr<Graph>) { }
 
         virtual void onDoubleClick() { }
-        // something something customChrome?
     };
 
 }

xybrid/data/porttypes.cpp

@@ -9,12 +9,8 @@ using namespace Xybrid::Audio;
 void AudioPort::pull() {
     auto t = audioEngine->curTickId();
     if (tickUpdatedOn == t) return;
-    bool lock = false;
-    if (!procLock.compare_exchange_strong(lock, true)) {
-        while (procLock.load()) ; // spinlock; this is a very fast operation
-        return; // and done
-    }
-    //qDebug() << "just locked";
+    lock.lock();
+    if (tickUpdatedOn == t) { lock.unlock(); return; } // someone else got here before us
 
     size_t ts = audioEngine->curTickSize();
     size_t s = sizeof(float) * ts;
@@ -54,17 +50,14 @@ void AudioPort::pull() {
     }
 done:
     tickUpdatedOn = t;
-    procLock.store(false);
+    lock.unlock();
 }
 
 void CommandPort::pull() {
     auto t = audioEngine->curTickId();
     if (tickUpdatedOn == t) return;
-    bool lock = false;
-    if (!procLock.compare_exchange_strong(lock, true)) {
-        while (procLock.load()) ; // spinlock; this is a very fast operation
-        return; // and done
-    }
+    lock.lock();
+    if (tickUpdatedOn == t) { lock.unlock(); return; } // someone else got here before us
 
     dataSize = 0;
     if (type == Input) {
@@ -84,7 +77,7 @@ void CommandPort::pull() {
     } // don't need an else case, size is already zero
 
     tickUpdatedOn = t;
-    procLock.store(false);
+    lock.unlock();
 }
 
 void CommandPort::push(std::vector<uint8_t> v) {