Fix race condition around postponed rt event data pool

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

.github/workflows/macos-latest.yml

@@ -1,4 +1,4 @@
-name: C/C++ CI
+name: macos latest
 
 on:
   push:

.github/workflows/ubuntu-latest.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Install extra dependencies
         run: |
           sudo apt-get update
-          sudo apt-get install libasound2-dev liblo-dev libfluidsynth-dev libgl1-mesa-dev libgtk2.0-dev libgtk-3-dev libmagic-dev libpulse-dev libx11-dev pkg-config pyqt5-dev-tools qtbase5-dev
+          sudo apt-get install libasound2-dev liblo-dev libfluidsynth-dev libgl1-mesa-dev libgtk2.0-dev libgtk-3-dev libmagic-dev libpulse-dev libsndfile1-dev libx11-dev pkg-config pyqt5-dev-tools qtbase5-dev
           sudo apt-get install mingw-w64 binutils-mingw-w64-x86-64 g++-mingw-w64-x86-64
       - name: make features
         run: make features

source/backend/engine/CarlaEngineRtAudio.cpp

@@ -1073,7 +1073,7 @@ private:
 
         RtMidiEvents()
             : mutex(),
-              dataPool(512, 512),
+              dataPool("RtMidiEvents", 512, 512),
               data(dataPool),
               dataPending(dataPool) {}
 

source/backend/plugin/CarlaPluginInternal.cpp

@@ -509,7 +509,7 @@ const MidiProgramData& PluginMidiProgramData::getCurrent() const noexcept
 
 CarlaPlugin::ProtectedData::ExternalNotes::ExternalNotes() noexcept
     : mutex(),
-      dataPool(32, 152),
+      dataPool("CarlaPlugin::ProtectedData::ExternalNotes", 32, 152),
       data(dataPool) {}
 
 CarlaPlugin::ProtectedData::ExternalNotes::~ExternalNotes() noexcept
@@ -633,28 +633,30 @@ void CarlaPlugin::ProtectedData::Latency::recreateBuffers(const uint32_t newChan
 // ProtectedData::PostRtEvents
 
 CarlaPlugin::ProtectedData::PostRtEvents::PostRtEvents() noexcept
-    : dataPool(512, 512),
+    : dataPool("CarlaPlugin::ProtectedData::PostRtEvents", 512, 512),
       data(dataPool),
       dataPendingRT(dataPool),
       dataMutex(),
-      dataPendingMutex() {}
+      dataPendingMutex(),
+      poolMutex() {}
 
 CarlaPlugin::ProtectedData::PostRtEvents::~PostRtEvents() noexcept
 {
-    dataMutex.lock();
-    dataPendingMutex.lock();
+    const CarlaMutexLocker cml1(dataMutex);
+    const CarlaMutexLocker cml2(dataPendingMutex);
+    const CarlaMutexLocker cml3(poolMutex);
 
     data.clear();
     dataPendingRT.clear();
-
-    dataMutex.unlock();
-    dataPendingMutex.unlock();
 }
 
 void CarlaPlugin::ProtectedData::PostRtEvents::appendRT(const PluginPostRtEvent& e) noexcept
 {
     CARLA_SAFE_ASSERT_INT_RETURN(dataPendingMutex.tryLock(), e.type,);
-    dataPendingRT.append(e);
+    {
+        const CarlaMutexLocker cml(poolMutex);
+        dataPendingRT.append(e);
+    }
     dataPendingMutex.unlock();
 }
 
@@ -664,7 +666,10 @@ void CarlaPlugin::ProtectedData::PostRtEvents::trySplice() noexcept
 
     if (cmtl.wasLocked() && dataPendingRT.isNotEmpty() && dataMutex.tryLock())
     {
-        dataPendingRT.moveTo(data, true);
+        {
+            const CarlaMutexLocker cml(poolMutex);
+            dataPendingRT.moveTo(data, true);
+        }
         dataMutex.unlock();
     }
 }

source/backend/plugin/CarlaPluginInternal.hpp

@@ -329,9 +329,11 @@ struct CarlaPlugin::ProtectedData {
 
         struct Access {
             Access(PostRtEvents& e)
-              : data2(e.dataPool)
+              : data2(e.dataPool),
+                poolMutex(e.poolMutex)
             {
-                const CarlaMutexLocker cml(e.dataMutex);
+                const CarlaMutexLocker cml1(e.dataMutex);
+                const CarlaMutexLocker cml2(e.poolMutex);
 
                 if (e.data.isNotEmpty())
                     e.data.moveTo(data2, true);
@@ -339,6 +341,8 @@ struct CarlaPlugin::ProtectedData {
 
             ~Access()
             {
+                const CarlaMutexLocker cml(poolMutex);
+
                 data2.clear();
             }
 
@@ -354,6 +358,7 @@ struct CarlaPlugin::ProtectedData {
 
         private:
             RtLinkedList<PluginPostRtEvent> data2;
+            CarlaMutex& poolMutex;
         };
 
     private:
@@ -361,6 +366,7 @@ struct CarlaPlugin::ProtectedData {
         RtLinkedList<PluginPostRtEvent> data, dataPendingRT;
         CarlaMutex dataMutex;
         CarlaMutex dataPendingMutex;
+        CarlaMutex poolMutex;
 
         CARLA_DECLARE_NON_COPY_CLASS(PostRtEvents)
 

source/utils/RtLinkedList.hpp

@@ -38,8 +38,9 @@ public:
     class Pool
     {
     public:
-        Pool(const std::size_t minPreallocated, const std::size_t maxPreallocated) noexcept
+        Pool(const char* const poolName, const std::size_t minPreallocated, const std::size_t maxPreallocated) noexcept
             : kDataSize(sizeof(typename AbstractLinkedList<T>::Data)),
+              kPoolName(carla_strdup_safe(poolName)),
               fHandle(nullptr)
         {
             rtsafe_memory_pool_create(&fHandle, nullptr, kDataSize, minPreallocated, maxPreallocated);
@@ -50,9 +51,11 @@ public:
         {
             if (fHandle != nullptr)
             {
+                carla_debug("Destroying %s", kPoolName);
                 rtsafe_memory_pool_destroy(fHandle);
                 fHandle = nullptr;
             }
+            delete[] kPoolName;
         }
 
         void* allocate_atomic() const noexcept
@@ -84,6 +87,7 @@ public:
 
     private:
         const std::size_t kDataSize;
+        const char* const kPoolName;
 
         mutable RtMemPool_Handle fHandle;