Use a blocking queue instead of lock free to massively reduce CPU usage

Source/PluginProcessor.cpp

@@ -444,8 +444,11 @@ void OscirenderAudioProcessor::processBlock(juce::AudioBuffer<float>& buffer, ju
     }
     
     prevMidiEnabled = usingMidi;
+
+    const double EPSILON = 0.00001;
     
-    {
+    
+    if (volume > EPSILON) {
         juce::SpinLock::ScopedLockType lock1(parsersLock);
         juce::SpinLock::ScopedLockType lock2(effectsLock);
         synth.renderNextBlock(buffer, midiMessages, 0, buffer.getNumSamples());
@@ -460,9 +463,11 @@ void OscirenderAudioProcessor::processBlock(juce::AudioBuffer<float>& buffer, ju
         {
             juce::SpinLock::ScopedLockType lock1(parsersLock);
             juce::SpinLock::ScopedLockType lock2(effectsLock);
-            for (auto& effect : toggleableEffects) {
-                if (effect->enabled->getValue()) {
-                    channels = effect->apply(sample, channels);
+            if (volume > EPSILON) {
+                for (auto& effect : toggleableEffects) {
+                    if (effect->enabled->getValue()) {
+                        channels = effect->apply(sample, channels);
+                    }
                 }
             }
             for (auto& effect : permanentEffects) {

Source/audio/ShapeSound.cpp

@@ -9,6 +9,11 @@ ShapeSound::ShapeSound(std::shared_ptr<FileParser> parser) : parser(parser) {
     producer->startThread();
 }
 
+ShapeSound::~ShapeSound() {
+    frames.kill();
+    producer->stopThread(1000);
+}
+
 bool ShapeSound::appliesToNote(int note) {
     return true;
 }
@@ -18,36 +23,12 @@ bool ShapeSound::appliesToChannel(int channel) {
 }
 
 void ShapeSound::addFrame(std::vector<std::unique_ptr<Shape>>& frame) {
-    const auto scope = frameFifo.write(1);
-
-    if (scope.blockSize1 > 0) {
-        frameBuffer[scope.startIndex1].clear();
-        for (auto& shape : frame) {
-            frameBuffer[scope.startIndex1].push_back(std::move(shape));
-        }
-    }
-
-    if (scope.blockSize2 > 0) {
-        frameBuffer[scope.startIndex2].clear();
-        for (auto& shape : frame) {
-            frameBuffer[scope.startIndex2].push_back(std::move(shape));
-        }
-    }
+    frames.push(std::move(frame));
 }
 
 double ShapeSound::updateFrame(std::vector<std::unique_ptr<Shape>>& frame) {
-    if (frameFifo.getNumReady() > 0) {
-        {
-            const auto scope = frameFifo.read(1);
-
-            if (scope.blockSize1 > 0) {
-                frame.swap(frameBuffer[scope.startIndex1]);
-            } else if (scope.blockSize2 > 0) {
-                frame.swap(frameBuffer[scope.startIndex2]);
-            }
-
-            frameLength = Shape::totalLength(frame);
-        }
+    if (frames.try_pop(frame)) {
+        frameLength = Shape::totalLength(frame);
     }
 
     return frameLength;

Source/audio/ShapeSound.h

@@ -3,10 +3,12 @@
 #include "../parser/FileParser.h"
 #include "../parser/FrameProducer.h"
 #include "../parser/FrameConsumer.h"
+#include "../concurrency/BlockingQueue.h"
 
 class ShapeSound : public juce::SynthesiserSound, public FrameConsumer {
 public:
 	ShapeSound(std::shared_ptr<FileParser> parser);
+	~ShapeSound() override;
 
 	bool appliesToNote(int note) override;
 	bool appliesToChannel(int channel) override;
@@ -19,8 +21,7 @@ public:
 
 private:
 	
-	juce::AbstractFifo frameFifo{ 10 };
-	std::vector<std::unique_ptr<Shape>> frameBuffer[10];
+	BlockingQueue frames{10};
 	std::unique_ptr<FrameProducer> producer;
 	double frameLength = 0.0;
 };

Source/concurrency/BlockingQueue.h

@@ -0,0 +1,81 @@
+#pragma once
+
+#include <mutex>
+#include <condition_variable>
+#include <queue>
+
+typedef std::vector<std::unique_ptr<Shape>> Frame;
+class BlockingQueue {
+    std::vector<Frame> content;
+    std::atomic<int> size = 0;
+    int head = 0;
+    std::atomic<bool> killed = false;
+
+    std::mutex mutex;
+    std::condition_variable not_empty;
+    std::condition_variable not_full;
+
+    BlockingQueue(const BlockingQueue &) = delete;
+    BlockingQueue(BlockingQueue &&) = delete;
+    BlockingQueue &operator = (const BlockingQueue &) = delete;
+    BlockingQueue &operator = (BlockingQueue &&) = delete;
+
+public:
+    BlockingQueue(size_t capacity) {
+        content = std::vector<Frame>(capacity);
+    }
+
+    void kill() {
+        killed = true;
+        not_empty.notify_all();
+        not_full.notify_all();
+    }
+
+    void push(Frame &&item) {
+        {
+            std::unique_lock<std::mutex> lk(mutex);
+            not_full.wait(lk, [this]() { return size < content.size() || killed; });
+            content[head] = std::move(item);
+            size++;
+        }
+        not_empty.notify_one();
+    }
+
+    bool try_push(Frame &&item) {
+        {
+            std::unique_lock<std::mutex> lk(mutex);
+            if (size == content.size()) {
+                return false;
+            }
+            content[head] = std::move(item);
+            size++;
+        }
+        not_empty.notify_one();
+        return true;
+    }
+
+    void pop(Frame &item) {
+        {
+            std::unique_lock<std::mutex> lk(mutex);
+            not_empty.wait(lk, [this]() { return size > 0 || killed; });
+            content[head].swap(item);
+            head = (head + 1) % content.size();
+            size--;
+        }
+        not_full.notify_one();
+    }
+
+    bool try_pop(Frame &item) {
+        {
+            std::unique_lock<std::mutex> lk(mutex);
+            if (size == 0) {
+                return false;
+            }
+            content[head].swap(item);
+            head = (head + 1) % content.size();
+            size--;
+        }
+        not_full.notify_one();
+        return true;
+    }
+};

Source/parser/FrameProducer.cpp

@@ -2,10 +2,7 @@
 
 FrameProducer::FrameProducer(FrameConsumer& fc, std::shared_ptr<FileParser> fs) : frameConsumer(fc), frameSource(fs), juce::Thread("producer", 0) {}
 
-FrameProducer::~FrameProducer() {
-	frameSource->disable();
-	stopThread(-1);
-}
+FrameProducer::~FrameProducer() {}
 
 void FrameProducer::run() {
 	while (!threadShouldExit()) {

osci-render.jucer

@@ -135,6 +135,7 @@
               file="Source/components/VolumeComponent.h"/>
       </GROUP>
       <GROUP id="{9F5970A9-8094-E7F3-7AC1-812AE5589B9F}" name="concurrency">
+        <FILE id="F5kUMH" name="BlockingQueue.h" compile="0" resource="0" file="Source/concurrency/BlockingQueue.h"/>
         <FILE id="WQ2W15" name="BufferConsumer.h" compile="0" resource="0"
               file="Source/concurrency/BufferConsumer.h"/>
       </GROUP>