Fix exit behaviour

We can't rely on atexit, handlers registered with it are in a hard to establish ordering relationship with destructors of static and thread-local objects.

src/PowderToy.cpp

@@ -123,7 +123,7 @@ void BlueScreen(String detailMessage)
 	{
 		while (SDL_PollEvent(&event))
 			if(event.type == SDL_QUIT)
-				exit(-1);
+				exit(-1); // Don't use Platform::Exit, we're practically zombies at this point anyway.
 		blit(engine.g->vid);
 	}
 }
@@ -181,21 +181,9 @@ static std::unique_ptr<ExplicitSingletons> explicitSingletons;
 int main(int argc, char * argv[])
 {
 	Platform::SetupCrt();
-	atexit([]() {
-		ui::Engine::Ref().CloseWindow();
+	Platform::Atexit([]() {
+		SDLClose();
 		explicitSingletons.reset();
-		if (SDL_GetWindowFlags(sdl_window) & SDL_WINDOW_OPENGL)
-		{
-			// * nvidia-460 egl registers callbacks with x11 that end up being called
-			//   after egl is unloaded unless we grab it here and release it after
-			//   sdl closes the display. this is an nvidia driver weirdness but
-			//   technically an sdl bug. glfw has this fixed:
-			//   https://github.com/glfw/glfw/commit/9e6c0c747be838d1f3dc38c2924a47a42416c081
-			SDL_GL_LoadLibrary(NULL);
-			SDL_QuitSubSystem(SDL_INIT_VIDEO);
-			SDL_GL_UnloadLibrary();
-		}
-		SDL_Quit();
 	});
 	explicitSingletons = std::make_unique<ExplicitSingletons>();
 
@@ -318,7 +306,7 @@ int main(int argc, char * argv[])
 		FILE *new_stderr = freopen("stderr.log", "w", stderr);
 		if (!new_stdout || !new_stderr)
 		{
-			exit(42);
+			Platform::Exit(42);
 		}
 	}
 
@@ -522,5 +510,6 @@ int main(int argc, char * argv[])
 	{
 		wrapWithBluescreen();
 	}
+	Platform::Exit(0);
 	return 0;
 }

src/PowderToyFontEditor.cpp

@@ -36,21 +36,9 @@ static std::unique_ptr<ExplicitSingletons> explicitSingletons;
 int main(int argc, char * argv[])
 {
 	Platform::SetupCrt();
-	atexit([]() {
-		ui::Engine::Ref().CloseWindow();
+	Platform::Atexit([]() {
+		SDLClose();
 		explicitSingletons.reset();
-		if (SDL_GetWindowFlags(sdl_window) & SDL_WINDOW_OPENGL)
-		{
-			// * nvidia-460 egl registers callbacks with x11 that end up being called
-			//   after egl is unloaded unless we grab it here and release it after
-			//   sdl closes the display. this is an nvidia driver weirdness but
-			//   technically an sdl bug. glfw has this fixed:
-			//   https://github.com/glfw/glfw/commit/9e6c0c747be838d1f3dc38c2924a47a42416c081
-			SDL_GL_LoadLibrary(NULL);
-			SDL_QuitSubSystem(SDL_INIT_VIDEO);
-			SDL_GL_UnloadLibrary();
-		}
-		SDL_Quit();
 	});
 	explicitSingletons = std::make_unique<ExplicitSingletons>();
 	
@@ -99,9 +87,10 @@ int main(int argc, char * argv[])
 	else
 	{
 		std::cerr << "path to font.cpp not supplied" << std::endl;
-		exit(1);
+		Platform::Exit(1);
 	}
 
 	EngineProcess();
+	Platform::Exit(0);
 	return 0;
 }

src/PowderToySDL.cpp

@@ -4,6 +4,7 @@
 #include "Config.h"
 #include "gui/interface/Engine.h"
 #include "graphics/Graphics.h"
+#include "common/Platform.h"
 #include <iostream>
 
 int desktopWidth = 1280;
@@ -96,13 +97,13 @@ void SDLOpen()
 	if (SDL_InitSubSystem(SDL_INIT_VIDEO) < 0)
 	{
 		fprintf(stderr, "Initializing SDL (video subsystem): %s\n", SDL_GetError());
-		exit(-1);
+		Platform::Exit(-1);
 	}
 
 	if (!RecreateWindow())
 	{
 		fprintf(stderr, "Creating SDL window: %s\n", SDL_GetError());
-		exit(-1);
+		Platform::Exit(-1);
 	}
 
 	int displayIndex = SDL_GetWindowDisplayIndex(sdl_window);
@@ -122,6 +123,22 @@ void SDLOpen()
 	}
 }
 
+void SDLClose()
+{
+	if (SDL_GetWindowFlags(sdl_window) & SDL_WINDOW_OPENGL)
+	{
+		// * nvidia-460 egl registers callbacks with x11 that end up being called
+		//   after egl is unloaded unless we grab it here and release it after
+		//   sdl closes the display. this is an nvidia driver weirdness but
+		//   technically an sdl bug. glfw has this fixed:
+		//   https://github.com/glfw/glfw/commit/9e6c0c747be838d1f3dc38c2924a47a42416c081
+		SDL_GL_LoadLibrary(NULL);
+		SDL_QuitSubSystem(SDL_INIT_VIDEO);
+		SDL_GL_UnloadLibrary();
+	}
+	SDL_Quit();
+}
+
 void SDLSetScreen(int scale_, bool resizable_, bool fullscreen_, bool altFullscreen_, bool forceIntegerScaling_)
 {
 //	bool changingScale = scale != scale_;

src/PowderToySDL.h

@@ -37,6 +37,7 @@ unsigned int GetTicks();
 void CalculateMousePosition(int *x, int *y);
 void blit(pixel *vid);
 void SDLOpen();
+void SDLClose();
 void SDLSetScreen(int scale_, bool resizable_, bool fullscreen_, bool altFullscreen_, bool forceIntegerScaling_);
 bool RecreateWindow();
 void LoadWindowPosition();

src/bson/BSON.cpp

@@ -975,7 +975,7 @@ void bson_fatal_msg( int ok , const char *msg ) {
 	}
 
 	bson_errprintf( "error: %s\n" , msg );
-	exit( -5 );
+	abort();
 }
 
 

src/common/Platform.cpp

@@ -3,6 +3,7 @@
 #include "tpt-rand.h"
 #include "Config.h"
 #include <memory>
+#include <list>
 #include <cstring>
 #include <fstream>
 #include <iostream>
@@ -106,4 +107,20 @@ bool WriteFile(const std::vector<char> &fileData, ByteString filename)
 	}
 	return true;
 }
+
+std::list<ExitFunc> exitFuncs;
+
+void Atexit(ExitFunc exitFunc)
+{
+	exitFuncs.push_front(exitFunc);
+}
+
+void Exit(int code)
+{
+	for (auto exitFunc : exitFuncs)
+	{
+		exitFunc();
+	}
+	exit(code);
+}
 }

src/common/Platform.h

@@ -55,4 +55,8 @@ namespace Platform
 	void UpdateCleanup();
 
 	void SetupCrt();
+
+	using ExitFunc = void (*)();
+	void Atexit(ExitFunc exitFunc);
+	void Exit(int code);
 }

src/common/PlatformPosix.cpp

@@ -149,7 +149,7 @@ void DoRestart()
 	{
 		fprintf(stderr, "cannot restart: no executable name???\n");
 	}
-	exit(-1);
+	Exit(-1);
 }
 
 bool UpdateStart(const std::vector<char> &data)

src/common/PlatformWindows.cpp

@@ -209,14 +209,14 @@ void DoRestart()
 		}
 		else
 		{
-			exit(0);
+			Exit(0);
 		}
 	}
 	else
 	{
 		fprintf(stderr, "cannot restart: no executable name???\n");
 	}
-	exit(-1);
+	Exit(-1);
 }
 
 bool CanUpdate()

src/lua/LuaScriptInterface.cpp

@@ -212,6 +212,14 @@ LuaScriptInterface::LuaScriptInterface(GameController * c, GameModel * m):
 	initHttpAPI();
 	initSocketAPI();
 
+	lua_getglobal(l, "os");
+	lua_pushcfunction(l, [](lua_State *l) -> int {
+		Platform::Exit(luaL_optinteger(l, 1, 0));
+		return 0;
+	});
+	lua_setfield(l, -2, "exit");
+	lua_pop(l, 1);
+
 	initBZ2API(l);
 
 	//Old TPT API