chore: use custom refill interval in rate limiter tests

Specify custom interval in order to avoid race condition
in tests which wait for the limiter to refill for the exact
amount of time.

Signed-off-by: Egor Lazarchuk <[email protected]>

Author: ShadowCurse

src/vmm/src/rate_limiter/mod.rs

@@ -774,6 +774,13 @@ pub(crate) mod tests {
 
     use super::*;
 
+    // Define custom refill interval to be a bit bigger. This will help
+    // in tests which wait for a limiter refill in 2 stages. This will make it so
+    // second wait will always result in the limiter being refilled. Otherwise
+    // there is a chance for a race condition between limiter refilling and limiter
+    // checking.
+    const TEST_REFILL_TIMER_INTERVAL_MS: u64 = REFILL_TIMER_INTERVAL_MS + 10;
+
     impl TokenBucket {
         // Resets the token bucket: budget set to max capacity and last-updated set to now.
         fn reset(&mut self) {
@@ -1009,11 +1016,11 @@ pub(crate) mod tests {
         // since consume failed, limiter should be blocked now
         assert!(l.is_blocked());
         // wait half the timer period
-        thread::sleep(Duration::from_millis(REFILL_TIMER_INTERVAL_MS / 2));
+        thread::sleep(Duration::from_millis(TEST_REFILL_TIMER_INTERVAL_MS / 2));
         // limiter should still be blocked
         assert!(l.is_blocked());
         // wait the other half of the timer period
-        thread::sleep(Duration::from_millis(REFILL_TIMER_INTERVAL_MS / 2));
+        thread::sleep(Duration::from_millis(TEST_REFILL_TIMER_INTERVAL_MS / 2));
         // the timer_fd should have an event on it by now
         l.event_handler().unwrap();
         // limiter should now be unblocked
@@ -1042,11 +1049,11 @@ pub(crate) mod tests {
         // since consume failed, limiter should be blocked now
         assert!(l.is_blocked());
         // wait half the timer period
-        thread::sleep(Duration::from_millis(REFILL_TIMER_INTERVAL_MS / 2));
+        thread::sleep(Duration::from_millis(TEST_REFILL_TIMER_INTERVAL_MS / 2));
         // limiter should still be blocked
         assert!(l.is_blocked());
         // wait the other half of the timer period
-        thread::sleep(Duration::from_millis(REFILL_TIMER_INTERVAL_MS / 2));
+        thread::sleep(Duration::from_millis(TEST_REFILL_TIMER_INTERVAL_MS / 2));
         // the timer_fd should have an event on it by now
         l.event_handler().unwrap();
         // limiter should now be unblocked
@@ -1076,11 +1083,11 @@ pub(crate) mod tests {
         // since consume failed, limiter should be blocked now
         assert!(l.is_blocked());
         // wait half the timer period
-        thread::sleep(Duration::from_millis(REFILL_TIMER_INTERVAL_MS / 2));
+        thread::sleep(Duration::from_millis(TEST_REFILL_TIMER_INTERVAL_MS / 2));
         // limiter should still be blocked
         assert!(l.is_blocked());
         // wait the other half of the timer period
-        thread::sleep(Duration::from_millis(REFILL_TIMER_INTERVAL_MS / 2));
+        thread::sleep(Duration::from_millis(TEST_REFILL_TIMER_INTERVAL_MS / 2));
         // the timer_fd should have an event on it by now
         l.event_handler().unwrap();
         // limiter should now be unblocked