#5231: Remove wxWidgets dependency from ModuleRegistry.

include/imodule.h

@@ -290,7 +290,7 @@ class IModuleRegistry
     /**
      * Invoked when all modules have been initialised.
      */
-    virtual sigc::signal<void> signal_allModulesInitialised() const = 0;
+    virtual sigc::signal<void>& signal_allModulesInitialised() = 0;
 
 	/**
 	 * Progress function called during module loading and intialisation.
@@ -299,12 +299,18 @@ class IModuleRegistry
 	 * will be in the range [0.0f..1.0f].
 	 */
 	typedef sigc::signal<void, const std::string&, float> ProgressSignal;
-	virtual ProgressSignal signal_moduleInitialisationProgress() const = 0;
+	virtual ProgressSignal& signal_moduleInitialisationProgress() = 0;
 
     /**
     * Invoked when all modules have been shut down (i.e. after shutdownModule()).
     */
-    virtual sigc::signal<void> signal_allModulesUninitialised() const = 0;
+    virtual sigc::signal<void>& signal_allModulesUninitialised() = 0;
+
+	/**
+	* Invoked right before the module binaries will be unloaded, which will
+	* trigger the destruction of any static instances in them.
+	*/
+	virtual sigc::signal<void>& signal_modulesUnloading() = 0;
 
 	// The compatibility level this Registry instance was compiled against.
 	// Old module registrations will be rejected by the registry anyway,

radiant/RadiantApp.cpp

@@ -152,8 +152,25 @@ void RadiantApp::onStartupEvent(wxCommandEvent& ev)
 	// Pick up all the statically defined modules and register them
 	module::internal::StaticModuleList::RegisterModules();
 
+	// Register to the modules unloading event, we need to get notified
+	// before the DLLs/SOs are relased to give wxWidgets a chance to clean up
+	_modulesUnloadingHandler = _coreModule->get()->getModuleRegistry().signal_modulesUnloading()
+		.connect(sigc::mem_fun(this, &RadiantApp::onModulesUnloading));
+
 	// Startup the application
 	_coreModule->get()->startup();
 
 	// Scope ends here, PIDFile is deleted by its destructor
 }
+
+void RadiantApp::onModulesUnloading()
+{
+	// We need to delete all pending objects before unloading modules
+	// wxWidgets needs a chance to delete them before memory access is denied
+	if (wxTheApp != nullptr)
+	{
+		wxTheApp->ProcessIdle();
+	}
+
+	_modulesUnloadingHandler.disconnect();
+}

radiant/RadiantApp.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <wx/app.h>
+#include <sigc++/connection.h>
 #include "modulesystem/ApplicationContextImpl.h"
 #include "module/CoreModule.h"
 
@@ -19,11 +20,13 @@ class RadiantApp :
 	public wxApp
 {
 	// The RadiantApp owns the ApplicationContext which is then passed to the
-	// ModuleRegistry as a refernce.
+	// ModuleRegistry as a reference.
 	radiant::ApplicationContextImpl _context;
 
 	std::unique_ptr<module::CoreModule> _coreModule;
 
+	sigc::connection _modulesUnloadingHandler;
+
 public:
 	bool OnInit() override;
 	int OnExit() override;
@@ -35,4 +38,5 @@ class RadiantApp :
 
 private:
 	void onStartupEvent(wxCommandEvent& ev);
+	void onModulesUnloading();
 };

radiantcore/modulesystem/ModuleRegistry.cpp

@@ -7,7 +7,6 @@
 #include <iostream>
 #include "ModuleLoader.h"
 
-#include <wx/app.h>
 #include <fmt/format.h>
 
 namespace module
@@ -47,12 +46,8 @@ void ModuleRegistry::unloadModules()
 
 	tempMap.clear();
 
-    // We need to delete all pending objects before unloading modules
-    // wxWidgets needs a chance to delete them before memory access is denied
-    if (wxTheApp != NULL)
-    {
-        wxTheApp->ProcessIdle();
-    }
+	// Send out the signal that the DLLs/SOs will be unloaded
+	signal_modulesUnloading().emit();
 
 	_loader->unloadModules();
 }
@@ -131,7 +126,7 @@ void ModuleRegistry::initialiseModuleRecursive(const std::string& name)
 		_progress);
 
 	// Initialise the module itself, now that the dependencies are ready
-    wxASSERT(_context);
+    assert(_context);
 	module->initialiseModule(*_context);
 }
 
@@ -244,7 +239,7 @@ RegisterableModulePtr ModuleRegistry::getModule(const std::string& name) const {
 
 const ApplicationContext& ModuleRegistry::getApplicationContext() const
 {
-    wxASSERT(_context);
+    assert(_context);
 	return *_context;
 }
 
@@ -263,21 +258,26 @@ applog::ILogWriter& ModuleRegistry::getApplicationLogWriter()
 	return coreModule->getLogWriter();
 }
 
-sigc::signal<void> ModuleRegistry::signal_allModulesInitialised() const
+sigc::signal<void>& ModuleRegistry::signal_allModulesInitialised()
 {
     return _sigAllModulesInitialised;
 }
 
-ModuleRegistry::ProgressSignal ModuleRegistry::signal_moduleInitialisationProgress() const
+ModuleRegistry::ProgressSignal& ModuleRegistry::signal_moduleInitialisationProgress()
 {
 	return _sigModuleInitialisationProgress;
 }
 
-sigc::signal<void> ModuleRegistry::signal_allModulesUninitialised() const
+sigc::signal<void>& ModuleRegistry::signal_allModulesUninitialised()
 {
     return _sigAllModulesUninitialised;
 }
 
+sigc::signal<void>& ModuleRegistry::signal_modulesUnloading()
+{
+    return _sigModulesUnloading;
+}
+
 std::size_t ModuleRegistry::getCompatibilityLevel() const
 {
 	return MODULE_COMPATIBILITY_LEVEL;

radiantcore/modulesystem/ModuleRegistry.h

@@ -43,6 +43,7 @@ class ModuleRegistry :
     // Signals fired after ALL modules have been initialised or shut down.
     sigc::signal<void> _sigAllModulesInitialised;
 	sigc::signal<void> _sigAllModulesUninitialised;
+	sigc::signal<void> _sigModulesUnloading;
 	ProgressSignal _sigModuleInitialisationProgress;
 
 	// Dynamic library loader
@@ -73,9 +74,10 @@ class ModuleRegistry :
 
 	applog::ILogWriter& getApplicationLogWriter() override;
 
-    sigc::signal<void> signal_allModulesInitialised() const override;
-	ProgressSignal signal_moduleInitialisationProgress() const override;
-    sigc::signal<void> signal_allModulesUninitialised() const override;
+    sigc::signal<void>& signal_allModulesInitialised() override;
+	ProgressSignal& signal_moduleInitialisationProgress() override;
+    sigc::signal<void>& signal_allModulesUninitialised() override;
+    sigc::signal<void>& signal_modulesUnloading() override;
 
 	std::size_t getCompatibilityLevel() const override;