Fix Windows crash on exit with upcoming NDI video output plugin (#510)

### Fix Windows crash on exit with upcoming NDI video output plugin

### Linked issues
NA

### Summarize your change.

This commit makes sure that the allocated video modules are released
when RV exits.
To do so, the TwkApp::VideoModules container which previously contained
raw pointers (std::vector<VideoModule*>) which were never released on
exit, has been converted to std::vector<std::shared_ptr<VideoModule>>

### Describe the reason for the change.

This missing TwkApp::VideoModules cleanup on exit, was causing a crash
on Windows when the upcoming NDI video output plugin was unloaded.
More specifically: The NDI crash was caused when trying to unload the
NDI dll without having called the NDIlib_destroy().
Note that NDIlib_initialize() is called when allocating an NDI video
module while the NDIlib_destroy() is called when releasing the NDI video
module. So it became essential to fix this TwkApp::VideoModules cleanup
on exit to prevent a crash on Windows.

### Describe what you have tested and on which operating system.
Successfully tested on macOS and Windows.

### Add a list of changes, and note any that might need special
attention during the review.

### If possible, provide screenshots.

Signed-off-by: Bernard Laberge <[email protected]>

Author: bernie-laberge

src/lib/app/RvCommon/RvApplication.cpp

@@ -1787,7 +1787,7 @@ RvApplication::findPresentationDevice(const std::string& dpath) const
 
         if (mindex >= 0)
         {
-            VideoModule* m = videoModules()[mindex];
+            VideoModule* m = videoModules()[mindex].get();
             openVideoModule(m);
             const VideoModule::VideoDevices& devs = m->devices();
             string dname = parts[1].toUtf8().constData();

src/lib/app/RvCommon/RvPreferences.cpp

@@ -3249,7 +3249,7 @@ RvPreferences::updateVideo()
 
             if (m_currentVideoDevice < 0 && m_currentVideoModule >= 0)
             {
-                VideoModule* m = vmods[m_currentVideoModule];
+                const auto m = vmods[m_currentVideoModule];
                 const VideoModule::VideoDevices& devs = m->devices();
                 string dname = parts[1].toUtf8().constData();
 
@@ -3277,12 +3277,12 @@ RvPreferences::updateVideo()
 
     for (size_t i = 0; i < vmods.size(); i++)
     {
-        TwkApp::VideoModule* mod = vmods[i];
+        auto mod = vmods[i];
         m_ui.videoModuleCombo->addItem(QString::fromUtf8(mod->name().c_str()));
 
         if (i == m_currentVideoModule)
         {
-            if (!mod->isOpen()) RvApp()->openVideoModule(mod);
+            if (!mod->isOpen()) RvApp()->openVideoModule(mod.get());
             m_ui.videoModuleCombo->setCurrentIndex(i);
             m_ui.videoDeviceCombo->clear();
             m_ui.videoDeviceCombo->hide();
@@ -3810,7 +3810,7 @@ RvPreferences::currentVideoDevice() const
         m_currentVideoModule == -1) return 0;
 
     const IPCore::Application::VideoModules& vmods = RvApp()->videoModules();
-    VideoModule* mod = vmods[m_currentVideoModule];
+    const auto mod = vmods[m_currentVideoModule];
     const VideoModule::VideoDevices& devs = mod->devices();
     return devs[m_currentVideoDevice];
 }

src/lib/app/RvCommon/RvTopViewToolBar.cpp

@@ -485,20 +485,12 @@ RvTopViewToolBar::receiveEvent(const Event& event)
                     const string deviceName = contents.substr(p+1);
                     const string moduleName = contents.substr(0, p);
 
-                    const IPCore::Application::VideoModules& modules = RvApp()->videoModules();
-
-                    for (size_t i = 0; i < modules.size(); i++)
+                    for (const auto module : RvApp()->videoModules())
                     {
-                        const VideoModule* module = modules[i];
-
                         if (module->name() == moduleName)
                         {
-                            const VideoModule::VideoDevices& devices = module->devices();
-                        
-                            for (size_t q = 0; q < devices.size(); q++)
+                            for (const auto device : module->devices())
                             {
-                                const VideoDevice* device = devices[q];
-
                                 if (device->name() == deviceName)
                                 {
                                     m_outputDevice = device;
@@ -1025,17 +1017,10 @@ RvTopViewToolBar::monitorMenuUpdate()
 
     QString html = "<style type=\"text/css\"> td { padding: 4px; } </style><table>";
 
-    const IPCore::Application::VideoModules& modules = RvApp()->videoModules();
-
-    for (size_t i = 0; i < modules.size(); i++)
+    for (const auto module : RvApp()->videoModules())
     {
-        const VideoModule* module = modules[i];
-        const VideoModule::VideoDevices& devices = module->devices();
-
-        for (size_t q = 0; q < devices.size(); q++)
+        for (const auto device : module->devices())
         {
-            const VideoDevice* device = devices[q];
-
             VideoDevice::VideoFormat format = device->videoFormatAtIndex(device->currentVideoFormat());
             VideoDevice::DataFormat data = device->dataFormatAtIndex(device->currentDataFormat());
 

src/lib/app/TwkApp/Application.cpp

@@ -26,6 +26,9 @@ Application::Application() : TwkUtil::Notifier()
 Application::~Application()
 {
     m_app = 0;
+
+    // Make sure to release all the video modules before we unload the plugins
+    m_videoModules.clear();
 }
 
 void
@@ -58,7 +61,7 @@ Application::receive(Notifier* originator,
 VideoModule* 
 Application::primaryVideoModule() const
 {
-    return m_videoModules.empty() ? 0 : m_videoModules.front();
+    return m_videoModules.empty() ? 0 : m_videoModules.front().get();
 }
 
 void

src/lib/app/TwkApp/TwkApp/Application.h

@@ -10,9 +10,9 @@
 #include <TwkUtil/Notifier.h>
 #include <TwkApp/Document.h>
 #include <TwkApp/OutputPlugins.h>
+#include <TwkApp/VideoModule.h>
 
 namespace TwkApp {
-class VideoModule;
 
 //
 //  class Application
@@ -38,7 +38,7 @@ class Application : public TwkUtil::Notifier
     //
 
     typedef std::vector<Document*>    Documents;
-    typedef std::vector<VideoModule*> VideoModules;
+    typedef std::vector<std::shared_ptr<VideoModule>> VideoModules;
     typedef TwkUtil::Notifier         Notifier;
 
     //
@@ -59,7 +59,7 @@ class Application : public TwkUtil::Notifier
 
     void loadOutputPlugins(const std::string& envvar);
     void unloadOutputPlugins();
-    void addVideoModule(VideoModule* m) { m_videoModules.push_back(m); }
+    void addVideoModule(VideoModule* m) { m_videoModules.push_back(std::shared_ptr<VideoModule>(m)); }
     virtual VideoModule* primaryVideoModule() const;
     const VideoModules& videoModules() const { return m_videoModules; }
 

src/lib/ip/IPCore/IPCore/Application.h

@@ -44,7 +44,7 @@ class Application : public TwkApp::Application
     typedef std::vector<std::string>                    StringVector;
     typedef std::map<std::string,std::string>           PropEnvMap;
     typedef TwkApp::VideoModule                         VideoModule;
-    typedef std::vector<VideoModule*>                   VideoModules;
+    typedef std::vector<std::shared_ptr<VideoModule>>   VideoModules;
     typedef size_t                                      DispatchID;
     typedef std::function<void(DispatchID)>             DispatchCallback;
 

src/lib/ip/IPCore/IPCore/IPGraph.h

@@ -126,7 +126,7 @@ class IPGraph : public TwkApp::EventNode
     typedef IPNode::IPNodes                     IPNodes;
     typedef TwkApp::VideoModule                 VideoModule;
     typedef TwkApp::VideoDevice                 VideoDevice;
-    typedef std::vector<VideoModule*>           VideoModules;
+    typedef std::vector<std::shared_ptr<VideoModule>> VideoModules;
     typedef std::vector<DisplayGroupIPNode*>    DisplayGroups;
     typedef IPImage::InternalGLMatricesContext  InternalGLMatricesContext;
     typedef int                                 WorkItemID;

src/lib/ip/IPCore/IPGraph.cpp

@@ -712,7 +712,7 @@ IPGraph::setPhysicalDevicesInternal(const VideoModules& modules)
     {
         for (size_t i = 0; i < modules.size(); i++)
         {
-            const VideoModule* module = modules[i];
+            const VideoModule* module = modules[i].get();
             const TwkApp::VideoModule::VideoDevices& devices = module->devices();
 
             for (size_t j = 0; j < devices.size(); j++)