Add timeout macro to simplify timeout logic

tool/src/timeout.rs

@@ -1,3 +1,26 @@
+#[macro_export]
+macro_rules! timeout {
+    ($t:expr, $f:expr) => {{
+        let mut result = Err($crate::Error::Timeout);
+        while $t.running() {
+            match $f {
+                Ok(ok) => {
+                    result = Ok(ok);
+                    break;
+                },
+                Err(err) => match err {
+                    $crate::Error::WouldBlock => (),
+                    _ => {
+                        result = Err(err);
+                        break;
+                    }
+                },
+            }
+        }
+        result
+    }};
+}
+
 pub trait Timeout {
     fn reset(&mut self);
     fn running(&self) -> bool;