Major BugFix: avoid default gst g_main_context

Do NOT update g_main_context at RenderingManager update. Do not use g_main_context for Dialogs. Do not rely on default g_main_context for Device discoverer (implemented a thread save g_main_loop dedicated).

DeviceSource.cpp

@@ -150,6 +150,9 @@ void Device::add(GstDevice *device)
     if (device==nullptr)
         return;
 
+    // lock before change
+    access_.lock();
+
     gchar *device_name = gst_device_get_display_name (device);
 
     if ( std::find(manager().src_name_.begin(), manager().src_name_.end(), device_name) == manager().src_name_.end())   {
@@ -171,6 +174,9 @@ void Device::add(GstDevice *device)
         list_uptodate_ = false;
     }
     g_free (device_name);
+
+    // unlock access
+    access_.unlock();
 }
 
 void Device::remove(GstDevice *device)
@@ -178,6 +184,9 @@ void Device::remove(GstDevice *device)
     if (device==nullptr)
         return;
 
+    // lock before change
+    access_.lock();
+
     gchar *device_name = gst_device_get_display_name (device);
 
     std::vector< std::string >::iterator nameit   = src_name_.begin();
@@ -204,47 +213,42 @@ void Device::remove(GstDevice *device)
         ++coit;
     }
     g_free (device_name);
+
+    // unlock access
+    access_.unlock();
 }
 
 
 Device::Device(): list_uptodate_(false)
 {
-
+    std::thread(launchMonitoring, this).detach();
 }
 
-void Device::init()
+void Device::launchMonitoring(Device *d)
 {
-    GstBus *bus;
-    GstCaps *caps;
+    d->monitor_ = gst_device_monitor_new ();
 
-    // create GStreamer device monitor to capture
-    // when a device is plugged in or out
-    monitor_ = gst_device_monitor_new ();
-
-    bus = gst_device_monitor_get_bus (monitor_);
-    gst_bus_add_watch (bus, callback_device_monitor, NULL);
-    gst_object_unref (bus);
-
-    caps = gst_caps_new_empty_simple ("video/x-raw");
-    gst_device_monitor_add_filter (monitor_, "Video/Source", caps);
+    GstCaps *caps = gst_caps_new_empty_simple ("video/x-raw");
+    gst_device_monitor_add_filter (d->monitor_, "Video/Source", caps);
     gst_caps_unref (caps);
 
-    gst_device_monitor_set_show_all_devices(monitor_, true);
-    gst_device_monitor_start (monitor_);
+    gst_device_monitor_set_show_all_devices(d->monitor_, true);
+    gst_device_monitor_start (d->monitor_);
 
-    // initial fill of the list
-    GList *devices = gst_device_monitor_get_devices(monitor_);
+    // Add configs for plugged devices
+    GList *devices = gst_device_monitor_get_devices(d->monitor_);
     GList *tmp;
     for (tmp = devices; tmp ; tmp = tmp->next ) {
         GstDevice *device = (GstDevice *) tmp->data;
-        add(device);
+        d->add(device);
         gst_object_unref (device);
     }
     g_list_free(devices);
 
     // Add config for plugged screen
-    src_name_.push_back("Screen capture");
-    src_description_.push_back(gst_plugin_vidcap);
+    d->access_.lock();
+    d->src_name_.push_back("Screen capture");
+    d->src_description_.push_back(gst_plugin_vidcap);
 
     // Try to auto find resolution
     DeviceConfigSet confs = getDeviceConfigs(gst_plugin_vidcap);
@@ -254,25 +258,48 @@ void Device::init()
         DeviceConfigSet confscreen;
         best.fps_numerator = 15;
         confscreen.insert(best);
-        src_config_.push_back(confscreen);
+        d->src_config_.push_back(confscreen);
+    }
+    d->access_.unlock();
+
+    d->list_uptodate_ = true;
+
+    // create a local g_main_context for this threaded monitor
+    GMainContext *_gcontext_device = g_main_context_new();
+    if (g_main_context_acquire(_gcontext_device))
+        g_printerr("Starting Device monitoring... \n");
+
+    // temporarily push as default the default g_main_context for add_watch
+    g_main_context_push_thread_default(_gcontext_device);
+
+    GstBus *bus = gst_device_monitor_get_bus (d->monitor_);
+    gst_bus_add_watch (bus, callback_device_monitor, NULL);
+    gst_object_unref (bus);
+
+    g_main_context_pop_thread_default(_gcontext_device);
+
+    // start main loop for this context (blocking infinitely)
+    g_main_loop_run( g_main_loop_new (_gcontext_device, true) );
+
 }
 
-    // TODO Use lib glfw to get monitors
-    // TODO Detect auto removal of monitors
-
-    list_uptodate_ = true;
-}
-
-
-int Device::numDevices() const
+int Device::numDevices()
 {
-    return src_name_.size();
+    access_.lock();
+    int ret = src_name_.size();
+    access_.unlock();
+
+    return ret;
 }
 
-bool Device::exists(const std::string &device) const
+bool Device::exists(const std::string &device)
 {
+    access_.lock();
     std::vector< std::string >::const_iterator d = std::find(src_name_.begin(), src_name_.end(), device);
-    return d != src_name_.end();
+    bool  ret = (d != src_name_.end());
+    access_.unlock();
+
+    return ret;
 }
 
 struct hasDevice: public std::unary_function<DeviceSource*, bool>
@@ -307,43 +334,57 @@ Source *Device::createSource(const std::string &device) const
     return s;
 }
 
-bool Device::unplugged(const std::string &device) const
+bool Device::unplugged(const std::string &device)
 {
     if (list_uptodate_)
         return false;
     return !exists(device);
 }
 
-std::string Device::name(int index) const
+std::string Device::name(int index)
 {
+    std::string ret = "";
+
+    access_.lock();
     if (index > -1 && index < (int) src_name_.size())
-        return src_name_[index];
-    else
-        return "";
+        ret = src_name_[index];
+    access_.unlock();
+
+    return ret;
 }
 
-std::string Device::description(int index) const
+std::string Device::description(int index)
 {
+    std::string ret = "";
+
+    access_.lock();
     if (index > -1 && index < (int) src_description_.size())
-        return src_description_[index];
-    else
-        return "";
+        ret = src_description_[index];
+    access_.unlock();
+
+    return ret;
 }
 
-DeviceConfigSet Device::config(int index) const
+DeviceConfigSet Device::config(int index)
 {
+    DeviceConfigSet ret;
+
+    access_.lock();
     if (index > -1 && index < (int) src_config_.size())
-        return src_config_[index];
-    else
-        return DeviceConfigSet();
+        ret = src_config_[index];
+    access_.unlock();
+
+    return ret;
 }
 
-int  Device::index(const std::string &device) const
+int  Device::index(const std::string &device)
 {
     int i = -1;
-    std::vector< std::string >::const_iterator p = std::find(src_name_.begin(), src_name_.end(), device);
+    access_.lock();
+    std::vector< std::string >::iterator p = std::find(src_name_.begin(), src_name_.end(), device);
     if (p != src_name_.end())
         i = std::distance(src_name_.begin(), p);
+    access_.unlock();
 
     return i;
 }

DeviceSource.h

@@ -100,15 +100,14 @@ public:
         return _instance;
     }
 
-    void init();
-    int numDevices () const;
-    std::string name (int index) const;
-    std::string description (int index) const;
-    DeviceConfigSet config (int index) const;
+    int numDevices () ;
+    std::string name (int index) ;
+    std::string description (int index) ;
+    DeviceConfigSet config (int index) ;
 
-    int  index  (const std::string &device) const;
-    bool exists (const std::string &device) const;
-    bool unplugged (const std::string &device) const;
+    int  index  (const std::string &device);
+    bool exists (const std::string &device) ;
+    bool unplugged (const std::string &device) ;
 
     Source *createSource(const std::string &device) const;
 
@@ -117,9 +116,11 @@ public:
 
 private:
 
+    static void launchMonitoring(Device *d);
     void remove(GstDevice *device);
     void add(GstDevice *device);
 
+    std::mutex access_;
     std::vector< std::string > src_name_;
     std::vector< std::string > src_description_;
     std::vector< DeviceConfigSet > src_config_;

DialogToolkit.cpp

@@ -254,10 +254,11 @@ std::string saveSessionFileDialog(const std::string &label, const std::string &p
     if ( gtk_dialog_run( GTK_DIALOG(dialog) ) == GTK_RESPONSE_ACCEPT ) {
 
         char *save_file_name = gtk_file_chooser_get_filename( GTK_FILE_CHOOSER(dialog) );
-        if (save_file_name)
+        if (save_file_name) {
             filename = std::string(save_file_name);
             g_free( save_file_name );
         }
+    }
 
     // remember position
     gtk_window_get_position( GTK_WINDOW(dialog), &window_x, &window_y);
@@ -314,10 +315,11 @@ std::string openSessionFileDialog(const std::string &label, const std::string &p
     if ( gtk_dialog_run( GTK_DIALOG(dialog) ) == GTK_RESPONSE_ACCEPT ) {
 
         char *open_file_name = gtk_file_chooser_get_filename( GTK_FILE_CHOOSER(dialog) );
-        if (open_file_name)
+        if (open_file_name) {
             filename = std::string(open_file_name);
             g_free( open_file_name );
         }
+    }
 
     // remember position
     gtk_window_get_position( GTK_WINDOW(dialog), &window_x, &window_y);
@@ -371,10 +373,11 @@ std::string openMediaFileDialog(const std::string &label, const std::string &pat
     if ( gtk_dialog_run( GTK_DIALOG(dialog) ) == GTK_RESPONSE_ACCEPT ) {
 
         char *open_file_name = gtk_file_chooser_get_filename( GTK_FILE_CHOOSER(dialog) );
-        if (open_file_name)
+        if (open_file_name) {
             filename = std::string(open_file_name);
             g_free( open_file_name );
         }
+    }
 
     // remember position
     gtk_window_get_position( GTK_WINDOW(dialog), &window_x, &window_y);
@@ -428,10 +431,11 @@ std::string openImageFileDialog(const std::string &label, const std::string &pat
     if ( gtk_dialog_run( GTK_DIALOG(dialog) ) == GTK_RESPONSE_ACCEPT ) {
 
         char *open_file_name = gtk_file_chooser_get_filename( GTK_FILE_CHOOSER(dialog) );
-        if (open_file_name)
+        if (open_file_name) {
             filename = std::string(open_file_name);
             g_free( open_file_name );
         }
+    }
 
     // remember position
     gtk_window_get_position( GTK_WINDOW(dialog), &window_x, &window_y);
@@ -480,10 +484,11 @@ std::string openFolderDialog(const std::string &label, const std::string &path)
     if ( gtk_dialog_run( GTK_DIALOG(dialog) ) == GTK_RESPONSE_ACCEPT ) {
 
         char *open_folder_name = gtk_file_chooser_get_filename( GTK_FILE_CHOOSER(dialog) );
-        if (open_folder_name)
+        if (open_folder_name) {
             foldername = std::string(open_folder_name);
             g_free( open_folder_name );
         }
+    }
 
     // remember position
     gtk_window_get_position( GTK_WINDOW(dialog), &window_x, &window_y);

MediaPlayer.cpp

@@ -374,7 +374,6 @@ void MediaPlayer::execute_open()
     gst_app_sink_set_max_buffers( GST_APP_SINK(sink), 5);
     gst_app_sink_set_drop (GST_APP_SINK(sink), true);
 
-#ifdef USE_GST_APPSINK_CALLBACKS
     // set the callbacks
     GstAppSinkCallbacks callbacks;
     callbacks.new_preroll = callback_new_preroll;
@@ -388,15 +387,6 @@ void MediaPlayer::execute_open()
     }
     gst_app_sink_set_callbacks (GST_APP_SINK(sink), &callbacks, this, NULL);
     gst_app_sink_set_emit_signals (GST_APP_SINK(sink), false);
-#else
-    // connect signals callbacks
-    g_signal_connect(G_OBJECT(sink), "new-preroll", G_CALLBACK (callback_new_preroll), this);
-    if (!media_.isimage) {
-        g_signal_connect(G_OBJECT(sink), "new-sample", G_CALLBACK (callback_new_sample), this);
-        g_signal_connect(G_OBJECT(sink), "eos", G_CALLBACK (callback_end_of_stream), this);
-    }
-    gst_app_sink_set_emit_signals (GST_APP_SINK(sink), true);
-#endif
 
     // done with ref to sink
     gst_object_unref (sink);

RenderingManager.cpp

@@ -368,9 +368,6 @@ void Rendering::draw()
     // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
     glfwPollEvents();
 
-    // no g_main_loop_run(loop) : update global GMainContext
-    g_main_context_iteration(NULL, FALSE);
-
 }
 
 void Rendering::terminate()

Stream.cpp

@@ -241,7 +241,6 @@ void Stream::execute_open()
     gst_app_sink_set_max_buffers( GST_APP_SINK(sink), 30);
     gst_app_sink_set_drop (GST_APP_SINK(sink), true);
 
-#ifdef USE_GST_APPSINK_CALLBACKS
     // set the callbacks
     GstAppSinkCallbacks callbacks;
     callbacks.new_preroll = callback_new_preroll;
@@ -256,15 +255,6 @@ void Stream::execute_open()
     }
     gst_app_sink_set_callbacks (GST_APP_SINK(sink), &callbacks, this, NULL);
     gst_app_sink_set_emit_signals (GST_APP_SINK(sink), false);
-#else
-    // connect signals callbacks
-    g_signal_connect(G_OBJECT(sink), "new-preroll", G_CALLBACK (callback_new_preroll), this);
-    if (!single_frame_) {
-        g_signal_connect(G_OBJECT(sink), "new-sample", G_CALLBACK (callback_new_sample), this);
-        g_signal_connect(G_OBJECT(sink), "eos", G_CALLBACK (callback_end_of_stream), this);
-    }
-    gst_app_sink_set_emit_signals (GST_APP_SINK(sink), true);
-#endif
 
     // set to desired state (PLAY or PAUSE)
     live_ = false;

defines.h

@@ -104,8 +104,6 @@
 #define COLOR_SLIDER_CIRCLE 0.11f, 0.11f, 0.11f
 #define COLOR_STASH_CIRCLE 0.06f, 0.06f, 0.06f
 
-#define USE_GST_APPSINK_CALLBACKS
-
 #define OSC_PORT_RECV_DEFAULT 7000
 #define OSC_PORT_SEND_DEFAULT 7001
 #define OSC_CONFIG_FILE "osc.xml"

main.cpp

@@ -30,7 +30,6 @@
 #include "ControlManager.h"
 #include "Connection.h"
 #include "Metronome.h"
-#include "DeviceSource.h"
 
 #if defined(APPLE)
 extern "C"{
@@ -105,29 +104,24 @@ int main(int argc, char *argv[])
         return 1;
 
     ///
-    /// CONTROLLER INIT
+    /// CONTROLLER INIT (OSC)
     ///
     Control::manager().init();
 
     ///
-    /// METRONOME INIT
+    /// METRONOME INIT (Ableton Link)
     ///
     if ( !Metronome::manager().init() )
         return 1;
 
     ///
-    /// RENDERING INIT
+    /// RENDERING & GST INIT
     ///
     if ( !Rendering::manager().init() )
         return 1;
 
     ///
-    /// DEVICES INIT
-    ///
-    Device::manager().init();
-
-    ///
-    /// UI INIT
+    /// IMGUI INIT
     ///
     if ( !UserInterface::manager().Init() )
         return 1;