pvr: render timeout when using ggpo or !threaded

will cause ggpo desyncs with previous versions

core/emulator.cpp

@@ -679,8 +679,11 @@ void EventManager::broadcastEvent(Event event) {
 		callback(event);
 }
 
-void Emulator::run() {
+void Emulator::run()
+{
 	verify(state == Running);
+	startTime = sh4_sched_now64();
+	renderTimeout = false;
 	try {
 		runInternal();
 		if (ggpo::active())
@@ -724,6 +727,8 @@ void Emulator::start()
 				try {
 					while (state == Running)
 					{
+						startTime = sh4_sched_now64();
+						renderTimeout = false;
 						runInternal();
 						if (!ggpo::nextFrame())
 							break;
@@ -744,7 +749,8 @@ void Emulator::start()
 	}
 }
 
-bool Emulator::checkStatus() {
+bool Emulator::checkStatus()
+{
 	try {
 		if (threadResult.wait_for(std::chrono::seconds(0)) == std::future_status::timeout)
 			return true;
@@ -756,19 +762,30 @@ bool Emulator::checkStatus() {
 	}
 }
 
-bool Emulator::render() {
+bool Emulator::render()
+{
 	if (!config::ThreadedRendering)
 	{
 		if (state != Running)
 			return false;
-		// FIXME used to timeout in retro_rend_vblank()
-		//startTime = sh4_sched_now64();
 		run();
-		return true; // FIXME need something like is_dupe
+		// TODO if stopping due to a user request, no frame has been rendered
+		return !renderTimeout;
 	}
 	if (!checkStatus())
 		return false;
 	return rend_single_frame(true); // FIXME stop flag?
 }
 
+void Emulator::vblank()
+{
+	// Time out if a frame hasn't been rendered for 50 ms
+	if (sh4_sched_now64() - startTime <= 10000000)
+		return;
+	renderTimeout = true;
+	if (ggpo::active())
+		ggpo::endOfFrame();
+	else if (!config::ThreadedRendering)
+		sh4_cpu.Stop();
+}
 Emulator emu;

core/emulator.h

@@ -19,10 +19,12 @@
     along with flycast.  If not, see <https://www.gnu.org/licenses/>.
  */
 #pragma once
+#include "types.h"
 #include <atomic>
 #include <map>
 #include <vector>
 #include <future>
+#include <string>
 
 void loadGameSpecificSettings();
 void SaveSettings();
@@ -37,7 +39,7 @@ void dc_savestate(int index = 0);
 void dc_loadstate(int index = 0);
 bool dc_loadstate(const void **data, unsigned size);
 
-void dc_load_game(const char *path);
+void dc_load_game(const std::string& path);
 bool dc_is_load_done();
 void dc_cancel_load();
 void dc_get_load_status();
@@ -137,6 +139,10 @@ public:
 	 * Called internally to reset the emulator.
 	 */
 	void requestReset();
+	/**
+	 * Called internally on vblank.
+	 */
+	void vblank();
 
 private:
 	bool checkStatus();
@@ -154,5 +160,7 @@ private:
 	std::shared_future<void> threadResult;
 	bool resetRequested = false;
 	bool singleStep = false;
+	u64 startTime = 0;
+	bool renderTimeout = false;
 };
 extern Emulator emu;

core/hw/pvr/Renderer_if.cpp

@@ -6,19 +6,18 @@
 #include "rend/TexCache.h"
 #include "cfg/option.h"
 #include "network/ggpo.h"
+#include "emulator.h"
 
 #include <mutex>
 #include <zlib.h>
 
 void retro_rend_present();
-void retro_rend_vblank();
 #ifndef LIBRETRO
 void retro_rend_present()
 {
 	if (!config::ThreadedRendering)
 		sh4_cpu.Stop();
 }
-void retro_rend_vblank() {}
 #endif
 
 u32 VertexCount=0;
@@ -407,7 +406,7 @@ void rend_vblank()
 	render_called = false;
 	check_framebuffer_write();
 	cheatManager.apply();
-	retro_rend_vblank();
+	emu.vblank();
 }
 
 void check_framebuffer_write()

core/nullDC.cpp

@@ -215,12 +215,12 @@ void dc_loadstate(int index)
     INFO_LOG(SAVESTATE, "Loaded state from %s size %d", filename.c_str(), total_size) ;
 }
 
-void dc_load_game(const char *path)
+void dc_load_game(const std::string& path)
 {
 	loading_canceled = false;
 
 	loadingDone = std::async(std::launch::async, [path] {
-		emu.loadGame(path);
+		emu.loadGame(path.c_str());
 	});
 }
 

core/rend/gui.cpp

@@ -427,10 +427,7 @@ void gui_start_game(const std::string& path)
 
 	scanner.stop();
 	gui_state = GuiState::Loading;
-	static std::string path_copy;
-	path_copy = path;	// path may be a local var
-
-	dc_load_game(path.empty() ? NULL : path_copy.c_str());
+	dc_load_game(path);
 }
 
 void gui_stop_game(const std::string& message)
@@ -447,6 +444,8 @@ void gui_stop_game(const std::string& message)
 	}
 	else
 	{
+		if (!message.empty())
+			ERROR_LOG(COMMON, "Flycast has stopped: %s", message.c_str());
 		// Exit emulator
 		dc_exit();
 	}

shell/libretro/libretro.cpp

@@ -1922,13 +1922,6 @@ void retro_rend_present()
 	}
 }
 
-void retro_rend_vblank()
-{
-	// Time out if a frame hasn't been rendered for 50 ms
-	if (!config::ThreadedRendering && is_dupe && sh4_sched_now64() - startTime > 10000000)
-		sh4_cpu.Stop();
-}
-
 static uint32_t get_time_ms()
 {
    return (uint32_t)(os_GetSeconds() * 1000.0);