process messages outside of step loop

src/lib.rs

@@ -101,6 +101,7 @@ pub fn init(
     verbose_println!("\n\n    Begin execution...\n");
     match options.step_by {
         Some(step_size) => loop {
+            process_messages(&receiver, &mut cpu);
             for _ in 0..step_size {
                 cycle_num += 1;
                 if options.cycle_count {
@@ -113,14 +114,7 @@ pub fn init(
             pause();
         },
         None => loop {
-            while let Ok(msg) = receiver.try_recv() {
+            process_messages(&receiver, &mut cpu);
-                match msg {
-                    EmulatorMessage::Stop => {
-                        cpu.memory.flush_rom();
-                        exit(0);
-                    }
-                }
-            }
             cycle_num += 1;
             if options.cycle_count {
                 print_cycles(&cycle_num);
@@ -130,6 +124,17 @@ pub fn init(
     }
 }
 
+fn process_messages(receiver: &Receiver<EmulatorMessage>, cpu: &mut Cpu) {
+    while let Ok(msg) = receiver.try_recv() {
+        match msg {
+            EmulatorMessage::Stop => {
+                cpu.memory.flush_rom();
+                exit(0);
+            }
+        }
+    }
+}
+
 fn run_cycle(cpu: &mut Cpu) {
     let will_pause = unsafe { PAUSE_QUEUED };
     let pause_enabled = unsafe { PAUSE_ENABLED };