feat(userspace): Call/ReplyRecv IPC, malformed-request replies, servers exit on dead endpoint; drop send/receive compat, select!, async_syscall

crates/servers/storage-server/src/lib.rs

@@ -36,10 +36,17 @@ pub fn run() -> ! {
 
     let ep = types::bounded::CapSlot::new(0).unwrap();
 
+    let mut next = syscall::receive_msg(ep);
     loop {
-        let (w0, w1, _w2, _w3) = syscall::receive(ep);
-
-        match w0 {
+        let message = match next {
+            Ok(m) => m,
+            Err(e) => {
+                libkos::println!("storage: endpoint unusable ({:?}), exiting", e);
+                syscall::exit();
+            }
+        };
+        let [w0, w1, _, _] = message.words();
+        let reply = match w0 {
             CMD_READ_FILE => {
                 let filename_len = w1;
                 let buf = shared_buf();
@@ -60,12 +67,14 @@ pub fn run() -> ! {
                     libkos::println!("NOT FOUND");
                 }
 
-                syscall::send(ep, file_size, 0, 0, 0);
+                [file_size, 0, 0, 0]
             }
-            _ => {
-                syscall::send(ep, 0, 0, 0, 0);
-            }
-        }
+            _ => [0, 0, 0, 0],
+        };
+        next = match message {
+            syscall::Received::Call { .. } => syscall::reply_recv(ep, reply, None),
+            _ => syscall::receive_msg(ep),
+        };
     }
 }