Fix several race conditions

Signed-off-by: falkTX <falktx@falktx.com>

source/backend/engine/CarlaEngine.cpp

@@ -860,7 +860,10 @@ bool CarlaEngine::addPlugin(const BinaryType btype,
         const float oldVolume = oldPlugin->getInternalParameterValue(PARAMETER_VOLUME);
 
         oldPlugin->prepareForDeletion();
-        pData->pluginsToDelete.push_back(oldPlugin);
+        {
+            const CarlaMutexLocker cml(pData->pluginsToDeleteMutex);
+            pData->pluginsToDelete.push_back(oldPlugin);
+        }
 
         if (plugin->getHints() & PLUGIN_CAN_DRYWET)
             plugin->setDryWet(oldDryWet, true, true);
@@ -939,12 +942,15 @@ bool CarlaEngine::removePlugin(const uint id)
     */
 #else
     pData->curPluginCount = 0;
-    pData->plugins[0].plugin = nullptr;
+    pData->plugins[0].plugin.reset();
     carla_zeroStruct(pData->plugins[0].peaks);
 #endif
 
     plugin->prepareForDeletion();
-    pData->pluginsToDelete.push_back(plugin);
+    {
+        const CarlaMutexLocker cml(pData->pluginsToDeleteMutex);
+        pData->pluginsToDelete.push_back(plugin);
+    }
 
     callback(true, true, ENGINE_CALLBACK_PLUGIN_REMOVED, id, 0, 0, 0, 0.0f, nullptr);
     return true;
@@ -969,7 +975,7 @@ bool CarlaEngine::removeAllPlugins()
 
 #ifndef BUILD_BRIDGE_ALTERNATIVE_ARCH
     if (pData->options.processMode == ENGINE_PROCESS_MODE_PATCHBAY)
-        pData->graph.removeAllPlugins();
+        pData->graph.removeAllPlugins(pData->aboutToClose);
 #endif
 
     const ScopedActionLock sal(this, kEnginePostActionZeroCount, 0, 0);
@@ -982,7 +988,10 @@ bool CarlaEngine::removeAllPlugins()
         EnginePluginData& pluginData(pData->plugins[id]);
 
         pluginData.plugin->prepareForDeletion();
-        pData->pluginsToDelete.push_back(pluginData.plugin);
+        {
+            const CarlaMutexLocker cml(pData->pluginsToDeleteMutex);
+            pData->pluginsToDelete.push_back(pluginData.plugin);
+        }
 
         pluginData.plugin.reset();
         carla_zeroStruct(pluginData.peaks);

source/backend/engine/CarlaEngineGraph.cpp

@@ -1476,9 +1476,10 @@ public:
 
     void reconfigure() override
     {
-        CARLA_SAFE_ASSERT_RETURN(fPlugin.get() != nullptr,);
+        const CarlaPluginPtr plugin = fPlugin;
+        CARLA_SAFE_ASSERT_RETURN(plugin.get() != nullptr,);
 
-        CarlaEngineClient* const client = fPlugin->getEngineClient();
+        CarlaEngineClient* const client = plugin->getEngineClient();
         CARLA_SAFE_ASSERT_RETURN(client != nullptr,);
 
         carla_stdout("reconfigure called");
@@ -1501,7 +1502,10 @@ public:
 
     const String getName() const override
     {
-        return fPlugin->getName();
+        const CarlaPluginPtr plugin = fPlugin;
+        CARLA_SAFE_ASSERT_RETURN(plugin.get() != nullptr, String());
+
+        return plugin->getName();
     }
 
     void processBlockWithCV(AudioSampleBuffer& audio,
@@ -1509,7 +1513,9 @@ public:
                             AudioSampleBuffer& cvOut,
                             MidiBuffer& midi) override
     {
-        if (fPlugin.get() == nullptr || ! fPlugin->isEnabled() || ! fPlugin->tryLock(kEngine->isOffline()))
+        const CarlaPluginPtr plugin = fPlugin;
+
+        if (plugin.get() == nullptr || !plugin->isEnabled() || !plugin->tryLock(kEngine->isOffline()))
         {
             audio.clear();
             cvOut.clear();
@@ -1517,7 +1523,7 @@ public:
             return;
         }
 
-        if (CarlaEngineEventPort* const port = fPlugin->getDefaultEventInPort())
+        if (CarlaEngineEventPort* const port = plugin->getDefaultEventInPort())
         {
             EngineEvent* const engineEvents(port->fBuffer);
             CARLA_SAFE_ASSERT_RETURN(engineEvents != nullptr,);
@@ -1528,7 +1534,7 @@ public:
 
         midi.clear();
 
-        fPlugin->initBuffers();
+        plugin->initBuffers();
 
         const uint32_t numSamples   = audio.getNumSamples();
         const uint32_t numAudioChan = audio.getNumChannels();
@@ -1538,14 +1544,14 @@ public:
         if (numAudioChan+numCVInChan+numCVOutChan == 0)
         {
             // nothing to process
-            fPlugin->process(nullptr, nullptr, nullptr, nullptr, numSamples);
+            plugin->process(nullptr, nullptr, nullptr, nullptr, numSamples);
         }
         else if (numAudioChan != 0)
         {
             // processing audio, include code for peaks
             const uint32_t numChan2 = jmin(numAudioChan, 2U);
 
-            if (fPlugin->getAudioInCount() == 0)
+            if (plugin->getAudioInCount() == 0)
                 audio.clear();
 
             float* audioBuffers[numAudioChan];
@@ -1562,17 +1568,17 @@ public:
             float inPeaks[2] = { 0.0f };
             float outPeaks[2] = { 0.0f };
 
-            for (uint32_t i=0, count=jmin(fPlugin->getAudioInCount(), numChan2); i<count; ++i)
+            for (uint32_t i=0, count=jmin(plugin->getAudioInCount(), numChan2); i<count; ++i)
                 inPeaks[i] = carla_findMaxNormalizedFloat(audioBuffers[i], numSamples);
 
-            fPlugin->process(const_cast<const float**>(audioBuffers), audioBuffers,
-                             cvInBuffers, cvOutBuffers,
-                             numSamples);
+            plugin->process(const_cast<const float**>(audioBuffers), audioBuffers,
+                            cvInBuffers, cvOutBuffers,
+                            numSamples);
 
-            for (uint32_t i=0, count=jmin(fPlugin->getAudioOutCount(), numChan2); i<count; ++i)
+            for (uint32_t i=0, count=jmin(plugin->getAudioOutCount(), numChan2); i<count; ++i)
                 outPeaks[i] = carla_findMaxNormalizedFloat(audioBuffers[i], numSamples);
 
-            kEngine->setPluginPeaksRT(fPlugin->getId(), inPeaks, outPeaks);
+            kEngine->setPluginPeaksRT(plugin->getId(), inPeaks, outPeaks);
         }
         else
         {
@@ -1585,14 +1591,14 @@ public:
             for (uint32_t i=0; i<numCVInChan; ++i)
                 cvInBuffers[i] = cvIn.getReadPointer(i);
 
-            fPlugin->process(nullptr, nullptr,
-                             cvInBuffers, cvOutBuffers,
-                             numSamples);
+            plugin->process(nullptr, nullptr,
+                            cvInBuffers, cvOutBuffers,
+                            numSamples);
         }
 
         midi.clear();
 
-        if (CarlaEngineEventPort* const port = fPlugin->getDefaultEventOutPort())
+        if (CarlaEngineEventPort* const port = plugin->getDefaultEventOutPort())
         {
             /*const*/ EngineEvent* const engineEvents(port->fBuffer);
             CARLA_SAFE_ASSERT_RETURN(engineEvents != nullptr,);
@@ -1601,12 +1607,15 @@ public:
             carla_zeroStructs(engineEvents, kMaxEngineEventInternalCount);
         }
 
-        fPlugin->unlock();
+        plugin->unlock();
     }
 
     const String getInputChannelName(ChannelType t, uint i) const override
     {
-        CarlaEngineClient* const client = fPlugin->getEngineClient();
+        const CarlaPluginPtr plugin = fPlugin;
+        CARLA_SAFE_ASSERT_RETURN(plugin.get() != nullptr, String());
+
+        CarlaEngineClient* const client = plugin->getEngineClient();
 
         switch (t)
         {
@@ -1623,7 +1632,10 @@ public:
 
     const String getOutputChannelName(ChannelType t, uint i) const override
     {
-        CarlaEngineClient* const client(fPlugin->getEngineClient());
+        const CarlaPluginPtr plugin = fPlugin;
+        CARLA_SAFE_ASSERT_RETURN(plugin.get() != nullptr, String());
+
+        CarlaEngineClient* const client(plugin->getEngineClient());
 
         switch (t)
         {
@@ -1641,8 +1653,21 @@ public:
     void prepareToPlay(double, int) override {}
     void releaseResources() override {}
 
-    bool acceptsMidi()  const override { return fPlugin->getDefaultEventInPort() != nullptr; }
-    bool producesMidi() const override { return fPlugin->getDefaultEventOutPort() != nullptr; }
+    bool acceptsMidi()  const override
+    {
+        const CarlaPluginPtr plugin = fPlugin;
+        CARLA_SAFE_ASSERT_RETURN(plugin.get() != nullptr, false);
+
+        return plugin->getDefaultEventInPort() != nullptr;
+    }
+
+    bool producesMidi() const override
+    {
+        const CarlaPluginPtr plugin = fPlugin;
+        CARLA_SAFE_ASSERT_RETURN(plugin.get() != nullptr, false);
+
+        return plugin->getDefaultEventOutPort() != nullptr;
+    }
 
 private:
     CarlaEngine* const kEngine;
@@ -2040,10 +2065,12 @@ void PatchbayGraph::removePlugin(const CarlaPluginPtr plugin)
     CARLA_SAFE_ASSERT_RETURN(graph.removeNode(node->nodeId),);
 }
 
-void PatchbayGraph::removeAllPlugins()
+void PatchbayGraph::removeAllPlugins(const bool aboutToClose)
 {
     carla_debug("PatchbayGraph::removeAllPlugins()");
 
+    stopRunner();
+
     const bool sendHost = !usingExternalHost;
     const bool sendOSC  = !usingExternalOSC;
 
@@ -2062,6 +2089,9 @@ void PatchbayGraph::removeAllPlugins()
 
         graph.removeNode(node->nodeId);
     }
+
+    if (!aboutToClose)
+        startRunner(100);
 }
 
 bool PatchbayGraph::connect(const bool external,
@@ -2764,10 +2794,10 @@ void EngineInternalGraph::removePlugin(const CarlaPluginPtr plugin)
     fPatchbay->removePlugin(plugin);
 }
 
-void EngineInternalGraph::removeAllPlugins()
+void EngineInternalGraph::removeAllPlugins(const bool aboutToClose)
 {
     CARLA_SAFE_ASSERT_RETURN(fPatchbay != nullptr,);
-    fPatchbay->removeAllPlugins();
+    fPatchbay->removeAllPlugins(aboutToClose);
 }
 
 bool EngineInternalGraph::isUsingExternalHost() const noexcept

source/backend/engine/CarlaEngineGraph.hpp

@@ -197,7 +197,7 @@ public:
     void reconfigureForCV(CarlaPluginPtr plugin, const uint portIndex, bool added);
     void reconfigurePlugin(CarlaPluginPtr plugin, bool portsAdded);
     void removePlugin(CarlaPluginPtr plugin);
-    void removeAllPlugins();
+    void removeAllPlugins(bool aboutToClose);
 
     bool connect(bool external, uint groupA, uint portA, uint groupB, uint portB);
     bool disconnect(bool external, uint connectionId);

source/backend/engine/CarlaEngineInternal.cpp

@@ -409,6 +409,7 @@ CarlaEngine::ProtectedData::ProtectedData(CarlaEngine* const engine)
       xruns(0),
       dspLoad(0.0f),
 #endif
+      pluginsToDeleteMutex(),
       pluginsToDelete(),
       events(),
 #ifndef BUILD_BRIDGE_ALTERNATIVE_ARCH
@@ -433,6 +434,8 @@ CarlaEngine::ProtectedData::~ProtectedData()
     CARLA_SAFE_ASSERT(plugins == nullptr);
 #endif
 
+    const CarlaMutexLocker cml(pluginsToDeleteMutex);
+
     if (pluginsToDelete.size() != 0)
     {
         for (std::vector<CarlaPluginPtr>::iterator it = pluginsToDelete.begin(); it != pluginsToDelete.end(); ++it)
@@ -571,22 +574,27 @@ void CarlaEngine::ProtectedData::initTime(const char* const features)
 
 void CarlaEngine::ProtectedData::deletePluginsAsNeeded()
 {
-    for (bool stop;;)
+    std::vector<CarlaPluginPtr> safePluginListToDelete;
+
+    if (const size_t size = pluginsToDelete.size())
+        safePluginListToDelete.reserve(size);
+
     {
-        stop = true;
+        const CarlaMutexLocker cml(pluginsToDeleteMutex);
 
-        for (std::vector<CarlaPluginPtr>::iterator it = pluginsToDelete.begin(); it != pluginsToDelete.end(); ++it)
+        for (std::vector<CarlaPluginPtr>::iterator it = pluginsToDelete.begin(); it != pluginsToDelete.end();)
         {
             if (it->use_count() == 1)
             {
-                stop = false;
+                const CarlaPluginPtr plugin = *it;
+                safePluginListToDelete.push_back(plugin);
                 pluginsToDelete.erase(it);
-                break;
+            }
+            else
+            {
+                 ++it;
             }
         }
-
-        if (stop)
-            break;
     }
 }
 
@@ -614,7 +622,7 @@ void CarlaEngine::ProtectedData::doPluginRemove(const uint pluginId) noexcept
     const uint id = curPluginCount;
 
     // reset last plugin (now removed)
-    plugins[id].plugin.reset();
+    plugins[id].plugin = nullptr;
     carla_zeroFloats(plugins[id].peaks, 4);
 }
 

source/backend/engine/CarlaEngineInternal.hpp

@@ -117,7 +117,7 @@ public:
     void renamePlugin(CarlaPluginPtr plugin, const char* newName);
     void switchPlugins(CarlaPluginPtr pluginA, CarlaPluginPtr pluginB);
     void removePlugin(CarlaPluginPtr plugin);
-    void removeAllPlugins();
+    void removeAllPlugins(bool aboutToClose);
 
     bool isUsingExternalHost() const noexcept;
     bool isUsingExternalOSC() const noexcept;
@@ -288,6 +288,8 @@ struct CarlaEngine::ProtectedData {
     float dspLoad;
 #endif
     float peaks[4];
+
+    CarlaMutex pluginsToDeleteMutex;
     std::vector<CarlaPluginPtr> pluginsToDelete;
 
     EngineInternalEvents events;