Don't waste time spinning on a mutex that cannot be unlocked, yield as it may be unlocked by another process, if not then whenever we get back here try again (repeat if same result), else fall through with lock, execute event loop, unlock and yield (as per normal)

source/eventy/engine.d

@@ -109,8 +109,22 @@ public final class Engine : Thread
         {
             /* TODO: Implement me */
 
-            /* Lock the queue-set */
-            queueLock.lock();
+            /**
+            * TODO: If lock fails, then yield
+            */
+
+            /**
+            * Lock the queue-set
+            *
+            * Additionally:
+            * Don't waste time spinning on mutex,
+            * if it is not lockable then yield
+            */
+            while(!queueLock.tryLock_nothrow())
+            {
+                yield();
+            }
+
 
             foreach(Queue queue; queues)
             {