feat(init): watchdog: pinger thread PINGs servers (framework answers, no server code), main kills after 5s unanswered -> crash path; not pinged: terminal, pm (handlers wait for user); give-up drains queued ping; spawntest hang check

crates/init/src/manifest.rs

@@ -58,6 +58,9 @@ pub struct Program {
     /// Its clients keep state in it (a subscription, focus, a handle), so
     /// they are restarted after it is.
     pub restarts_clients: bool,
+    /// Pinged by the watchdog (see init's watchdog.rs): not if a handler of
+    /// its waits for the user, which a ping cannot tell from a hang.
+    pub pinged: bool,
 }
 
 /// Enough for a small program: its image, stack and a little heap.
@@ -85,6 +88,7 @@ const fn server(name: &'static str, file: &'static [u8], limits: Limits) -> Prog
         takes_ctrl_c: false,
         restart: true,
         restarts_clients: false,
+        pinged: true,
     }
 }
 
@@ -103,8 +107,8 @@ pub const SERVERS: &[Program] = &[
         ..server("display", b"bin/display", Limits { pages: 1280, regions: 4, ..SMALL })
     },
     // Text on the display, lines from the keyboard (it takes input focus).
-    // Its clients wait on lines and Ctrl+C.
-    Program { uses: &["display"], restarts_clients: true, ..server("terminal", b"bin/terminal", SMALL) },
+    // Its clients wait on lines and Ctrl+C; `READ` waits for the user.
+    Program { uses: &["display"], restarts_clients: true, pinged: false, ..server("terminal", b"bin/terminal", SMALL) },
     server("session", b"bin/session", SMALL),
 ];
 
@@ -133,6 +137,8 @@ pub const SESSION: &[Program] = &[Program {
     spawns: Some(Limits { pages: 512, endpoints: 8, notifications: 8, regions: 8 }),
     // The shell holds handles to the apps it ran, which die with it.
     restarts_clients: true,
+    // Installing waits for the user's consent.
+    pinged: false,
     ..server("permission", b"bin/permission", Limits { pages: 96, ..SMALL })
 }];