src/runtime/src/comms.rs

@@ -696,27 +696,6 @@ async fn handle_connection(
     }
 }
 
-async fn load_and_run_idle_kernel(
-    buffer: &Vec<u8>,
-    control: &Rc<RefCell<kernel::Control>>,
-    up_destinations: &Rc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
-    aux_mutex: &Rc<Mutex<bool>>,
-    routing_table: &drtio_routing::RoutingTable,
-    timer: GlobalTimer,
-) {
-    info!("Loading idle kernel");
-    let res = handle_flash_kernel(buffer, control, up_destinations, aux_mutex, routing_table, timer).await;
-    match res {
-        Err(_) => warn!("error loading idle kernel"),
-        _ => (),
-    }
-    info!("Running idle kernel");
-    let _ = handle_run_kernel(None, control, up_destinations, aux_mutex, routing_table, timer)
-        .await
-        .map_err(|_| warn!("error running idle kernel"));
-    info!("Idle kernel terminated");
-}
-
 pub fn main(timer: GlobalTimer, cfg: Config) {
     let net_addresses = net_settings::get_addresses(&cfg);
     info!("network addresses: {}", net_addresses);
@@ -777,7 +756,6 @@ pub fn main(timer: GlobalTimer, cfg: Config) {
     moninj::start(timer, &aux_mutex, &drtio_routing_table);
 
     let control: Rc<RefCell<kernel::Control>> = Rc::new(RefCell::new(kernel::Control::start()));
-    let idle_kernel = Rc::new(cfg.read("idle_kernel").ok());
     if let Ok(buffer) = cfg.read("startup_kernel") {
         info!("Loading startup kernel...");
         let routing_table = drtio_routing_table.borrow();
@@ -804,35 +782,26 @@ pub fn main(timer: GlobalTimer, cfg: Config) {
         }
     }
     
-    mgmt::start(cfg);
+    let cfg = Rc::new(cfg);
+    let restart_idle = Rc::new(Semaphore::new(1, 1));
+    mgmt::start(cfg.clone(), restart_idle.clone());
 
     task::spawn(async move {
-        let connection = Rc::new(Semaphore::new(0, 1));
+        let connection = Rc::new(Semaphore::new(1, 1));
         let terminate = Rc::new(Semaphore::new(0, 1));
-        {
+        let can_restart_idle = Rc::new(Semaphore::new(1, 1));
-            let control = control.clone();
+        let restart_idle = restart_idle.clone();
-            let idle_kernel = idle_kernel.clone();
-            let connection = connection.clone();
-            let terminate = terminate.clone();
-            let up_destinations = up_destinations.clone();
-            let aux_mutex = aux_mutex.clone();
-            let routing_table = drtio_routing_table.clone();
-            task::spawn(async move {
-                let routing_table = routing_table.borrow();
-                select_biased! {
-                    _ = (async {
-                        if let Some(buffer) = &*idle_kernel {
-                            load_and_run_idle_kernel(&buffer, &control, &up_destinations, &aux_mutex, &routing_table, timer).await;
-                        }
-                    }).fuse() => (),
-                    _ = terminate.async_wait().fuse() => ()
-                }
-                connection.signal();
-            });
-        }
-
         loop {
-            let mut stream = TcpStream::accept(1381, 0x10_000, 0x10_000).await.unwrap();
+            let control = control.clone();
+            let mut maybe_stream = select_biased! {
+                s = (async {
+                        TcpStream::accept(1381, 0x10_000, 0x10_000).await.unwrap()
+                    }).fuse() => Some(s),
+                _ = (async { 
+                        restart_idle.async_wait().await; 
+                        can_restart_idle.async_wait().await; 
+                    }).fuse() => None
+            };
 
             if connection.try_wait().is_none() {
                 // there is an existing connection
@@ -840,32 +809,58 @@ pub fn main(timer: GlobalTimer, cfg: Config) {
                 connection.async_wait().await;
             }
 
+            let maybe_idle_kernel = cfg.read("idle_kernel").ok();
+            if maybe_idle_kernel.is_none() && maybe_stream.is_none() {
+                control.borrow_mut().restart(); // terminate idle kernel if running
+            }
+
             let control = control.clone();
-            let idle_kernel = idle_kernel.clone();
             let connection = connection.clone();
             let terminate = terminate.clone();
+            let can_restart_idle = can_restart_idle.clone();
             let up_destinations = up_destinations.clone();
             let aux_mutex = aux_mutex.clone();
             let routing_table = drtio_routing_table.clone();
 
             // we make sure the value of terminate is 0 before we start
             let _ = terminate.try_wait();
+            let _ = can_restart_idle.try_wait();
             task::spawn(async move {
                 let routing_table = routing_table.borrow();
                 select_biased! {
                     _ = (async {
-                        let _ = handle_connection(&mut stream, control.clone(), &up_destinations, &aux_mutex, &routing_table, timer)
+                        if let Some(stream) = &mut maybe_stream {
-                            .await
+                            let _ = handle_connection(stream, control.clone(), &up_destinations, &aux_mutex, &routing_table, timer)
-                            .map_err(|e| warn!("connection terminated: {}", e));
+                                .await
-                        if let Some(buffer) = &*idle_kernel {
+                                .map_err(|e| warn!("connection terminated: {}", e));
-                            load_and_run_idle_kernel(&buffer, &control, &up_destinations, &aux_mutex, &routing_table, timer).await;
+                        }
+                        can_restart_idle.signal();
+                        match maybe_idle_kernel {
+                            Some(buffer) => {
+                                loop {
+                                    info!("loading idle kernel");
+                                    match handle_flash_kernel(&buffer, &control, &up_destinations, &aux_mutex, &routing_table, timer).await {
+                                        Ok(_) => {
+                                            info!("running idle kernel");
+                                            match handle_run_kernel(None, &control, &up_destinations, &aux_mutex, &routing_table, timer).await {
+                                                Ok(_) => info!("idle kernel finished"),
+                                                Err(_) => warn!("idle kernel running error")
+                                            }
+                                        },
+                                        Err(_) => warn!("idle kernel loading error")
+                                    }
+                                }
+                            },
+                            None => info!("no idle kernel found")
                         }
                     }).fuse() => (),
                     _ = terminate.async_wait().fuse() => ()
                 }
                 connection.signal();
-                let _ = stream.flush().await;
+                if let Some(stream) = maybe_stream {
-                let _ = stream.abort().await;
+                    let _ = stream.flush().await;
+                    let _ = stream.abort().await;
+                }
             });
         }
     });
@@ -914,7 +909,8 @@ pub fn soft_panic_main(timer: GlobalTimer, cfg: Config) -> ! {
 
     Sockets::init(32);
     
-    mgmt::start(cfg);
+    let dummy = Rc::new(Semaphore::new(0, 1));
+    mgmt::start(Rc::new(cfg), dummy);
 
     // getting eth settings disables the LED as it resets GPIO
     // need to re-enable it here

src/runtime/src/mgmt.rs

@@ -6,6 +6,7 @@ use libasync::{smoltcp::TcpStream, task};
 use libboard_artiq::logger::{BufferLogger, LogBufferRef};
 use libboard_zynq::{slcr, smoltcp};
 use libconfig::Config;
+use libcortex_a9::semaphore::Semaphore;
 use log::{self, debug, error, info, warn, LevelFilter};
 use num_derive::FromPrimitive;
 use num_traits::FromPrimitive;
@@ -111,7 +112,7 @@ async fn read_key(stream: &mut TcpStream) -> Result<String> {
     Ok(String::from_utf8(buffer).unwrap())
 }
 
-async fn handle_connection(stream: &mut TcpStream, pull_id: Rc<RefCell<u32>>, cfg: Rc<Config>) -> Result<()> {
+async fn handle_connection(stream: &mut TcpStream, pull_id: Rc<RefCell<u32>>, cfg: Rc<Config>, restart_idle: Rc<Semaphore>) -> Result<()> {
     if !expect(&stream, b"ARTIQ management\n").await? {
         return Err(Error::UnexpectedPattern);
     }
@@ -200,6 +201,9 @@ async fn handle_connection(stream: &mut TcpStream, pull_id: Rc<RefCell<u32>>, cf
                 let value = cfg.write(&key, buffer);
                 if value.is_ok() {
                     debug!("write success");
+                    if key == "idle_kernel" {
+                        restart_idle.signal();
+                    }
                     write_i8(stream, Reply::Success as i8).await?;
                 } else {
                     // this is an error because we do not expect write to fail
@@ -213,6 +217,9 @@ async fn handle_connection(stream: &mut TcpStream, pull_id: Rc<RefCell<u32>>, cf
                 let value = cfg.remove(&key);
                 if value.is_ok() {
                     debug!("erase success");
+                    if key == "idle_kernel" {
+                        restart_idle.signal();
+                    }
                     write_i8(stream, Reply::Success as i8).await?;
                 } else {
                     warn!("erase failed");
@@ -229,17 +236,17 @@ async fn handle_connection(stream: &mut TcpStream, pull_id: Rc<RefCell<u32>>, cf
     }
 }
 
-pub fn start(cfg: Config) {
+pub fn start(cfg: Rc<Config>, restart_idle: Rc<Semaphore>) {
     task::spawn(async move {
         let pull_id = Rc::new(RefCell::new(0u32));
-        let cfg = Rc::new(cfg);
         loop {
             let mut stream = TcpStream::accept(1380, 2048, 2048).await.unwrap();
             let pull_id = pull_id.clone();
             let cfg = cfg.clone();
+            let restart_idle = restart_idle.clone();
             task::spawn(async move {
                 info!("received connection");
-                let _ = handle_connection(&mut stream, pull_id, cfg)
+                let _ = handle_connection(&mut stream, pull_id, cfg, restart_idle)
                     .await
                     .map_err(|e| warn!("connection terminated: {:?}", e));
                 let _ = stream.flush().await;