fix race condition on relinquish focus v result return for dynamic and progress modals

There's a race condition between the return of a blocking scalar
and when focus is relinquished.

This causes chained graphics operations to get dropped sometimes.

Move the return result to after the focus switch; this allows us
to elimate some dead waits.

Author: bunnie

services/modals/src/lib.rs

@@ -334,12 +334,15 @@ impl Modals {
         Ok(())
     }
 
-    /// close the progress bar, regardless of the current state
+    /// Close the progress bar, regardless of the current state
+    /// This is a blocking call, because you want the GAM to revert focus back to your context before you
+    /// continue with any drawing operations. Otherwise, they could be missed as the modal is still covering
+    /// your window.
     pub fn finish_progress(&self) -> Result<(), xous::Error> {
         self.lock();
         send_message(
             self.conn,
-            Message::new_scalar(
+            Message::new_blocking_scalar(
                 Opcode::StopProgress.to_usize().unwrap(),
                 self.token[0] as usize,
                 self.token[1] as usize,

services/modals/src/main.rs

@@ -331,15 +331,15 @@ fn wrapped_main() -> ! {
                 )
                 .expect("couldn't initiate UX op");
             }
-            Some(Opcode::StopProgress) => msg_scalar_unpack!(msg, t0, t1, t2, t3, {
+            Some(Opcode::StopProgress) => msg_blocking_scalar_unpack!(msg, t0, t1, t2, t3, {
                 let token = [t0 as u32, t1 as u32, t2 as u32, t3 as u32];
                 if token != token_lock.unwrap_or(default_nonce) {
                     log::warn!("Attempt to access modals without a mutex lock. Ignoring.");
                     continue;
                 }
                 send_message(
                     renderer_cid,
-                    Message::new_scalar(Opcode::FinishProgress.to_usize().unwrap(), 0, 0, 0, 0),
+                    Message::new_scalar(Opcode::FinishProgress.to_usize().unwrap(), msg.sender as usize, 0, 0, 0),
                 )
                 .expect("couldn't update progress bar");
             }),
@@ -401,10 +401,6 @@ fn wrapped_main() -> ! {
                     log::warn!("Attempt to access modals without a mutex lock. Ignoring.");
                     continue;
                 }
-                if let Some(sender) = dynamic_notification_listener.take() {
-                    // unblock the listener with no key hit response
-                    xous::return_scalar2(sender, 0, 0,).unwrap();
-                }
                 send_message(
                     renderer_cid,
                     Message::new_scalar(
@@ -700,9 +696,11 @@ fn wrapped_main() -> ! {
                     }
                 }
             }
-            Some(Opcode::FinishProgress) => {
+            Some(Opcode::FinishProgress) => msg_scalar_unpack!(msg, caller, _, _, _, {
                 renderer_modal.gam.relinquish_focus().unwrap();
                 op = RendererState::None;
+                // unblock the caller, which was forwarded on as the first argument
+                xous::return_scalar(caller as Sender, 0).ok();
                 token_lock = next_lock(&mut work_queue);
                 /*
                 if work_queue.len() > 0 {
@@ -712,7 +710,7 @@ fn wrapped_main() -> ! {
                 } else {
                     token_lock = None;
                 }*/
-            }
+            }),
             Some(Opcode::DoUpdateDynamicNotification) => match op {
                 RendererState::RunDynamicNotification(config) => {
                     //log::set_max_level(log::LevelFilter::Trace);
@@ -747,6 +745,10 @@ fn wrapped_main() -> ! {
             Some(Opcode::DoCloseDynamicNotification) => {
                 renderer_modal.gam.relinquish_focus().unwrap();
                 op = RendererState::None;
+                if let Some(sender) = dynamic_notification_listener.take() {
+                    // unblock the listener with no key hit response
+                    xous::return_scalar2(sender, 0, 0,).unwrap();
+                }
                 token_lock = next_lock(&mut work_queue);
             },
             Some(Opcode::HandleDynamicNotificationKeyhit) => msg_scalar_unpack!(msg, k, _, _, _, {

services/shellchat/src/main.rs

@@ -457,7 +457,6 @@ fn wrapped_main() -> ! {
                     }
                 }
             }
-            tt.sleep_ms(100).ok(); // this allows the shellchat context to foreground before calling the redraw
             xous::send_message(main_conn,
                 xous::Message::new_scalar(ShellOpcode::Redraw.to_usize().unwrap(), 0, 0, 0, 0)
             ).ok();