Save and load SRAM at all the right times

src/app.rs

@@ -1,4 +1,4 @@
-use std::{collections::HashSet, num::NonZero, sync::Arc, thread};
+use std::{collections::HashSet, num::NonZero, sync::Arc, thread, time::Duration};
 
 use egui::{
     ahash::{HashMap, HashMapExt},
@@ -15,7 +15,7 @@ use winit::{
 
 use crate::{
     controller::ControllerManager,
-    emulator::{EmulatorClient, SimId},
+    emulator::{EmulatorClient, EmulatorCommand, SimId},
     input::MappingProvider,
     window::{AppWindow, GameWindow, InputWindow},
 };
@@ -170,6 +170,15 @@ impl ApplicationHandler<UserEvent> for Application {
             viewport.window.request_redraw();
         }
     }
+
+    fn exiting(&mut self, _event_loop: &ActiveEventLoop) {
+        let (sender, receiver) = oneshot::channel();
+        if self.client.send_command(EmulatorCommand::Exit(sender)) {
+            if let Err(err) = receiver.recv_timeout(Duration::from_secs(5)) {
+                eprintln!("could not gracefully exit: {}", err);
+            }
+        }
+    }
 }
 
 struct Viewport {

src/emulator.rs

@@ -186,6 +186,8 @@ impl Emulator {
     }
 
     fn reset_sim(&mut self, sim_id: SimId, new_cart: Option<Cart>) -> Result<()> {
+        self.save_sram(sim_id)?;
+
         let index = sim_id.to_index();
         while self.sims.len() <= index {
             self.sims.push(Sim::new());
@@ -226,6 +228,10 @@ impl Emulator {
 
     pub fn pause_sim(&mut self, sim_id: SimId) -> Result<()> {
         self.running[sim_id.to_index()].store(false, Ordering::Release);
+        self.save_sram(sim_id)
+    }
+
+    fn save_sram(&mut self, sim_id: SimId) -> Result<()> {
         let sim = self.sims.get_mut(sim_id.to_index());
         let cart = self.carts[sim_id.to_index()].as_mut();
         if let (Some(sim), Some(cart)) = (sim, cart) {
@@ -236,13 +242,15 @@ impl Emulator {
         Ok(())
     }
 
-    pub fn stop_second_sim(&mut self) {
+    pub fn stop_second_sim(&mut self) -> Result<()> {
+        self.save_sram(SimId::Player2)?;
         self.renderers.remove(&SimId::Player2);
         self.sims.truncate(1);
         self.sim_count.store(self.sims.len(), Ordering::Relaxed);
         self.running[SimId::Player2.to_index()].store(false, Ordering::Release);
         self.has_game[SimId::Player2.to_index()].store(false, Ordering::Release);
         self.linked.store(false, Ordering::Release);
+        Ok(())
     }
 
     pub fn run(&mut self) {
@@ -336,7 +344,9 @@ impl Emulator {
                 }
             }
             EmulatorCommand::StopSecondSim => {
-                self.stop_second_sim();
+                if let Err(error) = self.stop_second_sim() {
+                    eprintln!("error stopping second sim: {}", error);
+                }
             }
             EmulatorCommand::Pause => {
                 for sim_id in SimId::values() {
@@ -373,6 +383,14 @@ impl Emulator {
                     sim.set_keys(keys);
                 }
             }
+            EmulatorCommand::Exit(done) => {
+                for sim_id in SimId::values() {
+                    if let Err(error) = self.save_sram(sim_id) {
+                        eprintln!("error saving sram on exit: {}", error);
+                    }
+                }
+                let _ = done.send(());
+            }
         }
     }
 }
@@ -390,6 +408,7 @@ pub enum EmulatorCommand {
     Unlink,
     Reset(SimId),
     SetKeys(SimId, VBKey),
+    Exit(oneshot::Sender<()>),
 }
 
 #[derive(Clone)]
@@ -418,12 +437,16 @@ impl EmulatorClient {
     pub fn is_audio_enabled(&self, sim_id: SimId) -> bool {
         self.audio_on[sim_id.to_index()].load(Ordering::Acquire)
     }
-    pub fn send_command(&self, command: EmulatorCommand) {
-        if let Err(err) = self.queue.send(command) {
-            eprintln!(
-                "could not send command {:?} as emulator is shut down",
-                err.0
-            );
+    pub fn send_command(&self, command: EmulatorCommand) -> bool {
+        match self.queue.send(command) {
+            Ok(()) => true,
+            Err(err) => {
+                eprintln!(
+                    "could not send command {:?} as emulator is shut down",
+                    err.0
+                );
+                false
+            }
         }
     }
 }