From eef2b974ab8e325adb030f279e03a362d31dc0e1 Mon Sep 17 00:00:00 2001
From: justcoding121 <jehonathant@gmail.com>
Date: Tue, 24 Apr 2018 11:02:17 -0400
Subject: [PATCH] Use semaphore slim async lock on dequeue task object

---
 EventHook/Helpers/AsyncConcurrentQueue.cs | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/EventHook/Helpers/AsyncConcurrentQueue.cs b/EventHook/Helpers/AsyncConcurrentQueue.cs
index 9ac2e02..488d9b0 100644
--- a/EventHook/Helpers/AsyncConcurrentQueue.cs
+++ b/EventHook/Helpers/AsyncConcurrentQueue.cs
@@ -17,10 +17,10 @@ internal class AsyncConcurrentQueue<T>
         private readonly ConcurrentQueue<T> queue = new ConcurrentQueue<T>();
 
         /// <summary>
-        ///     Keeps any pending Dequeue task to wake up once data arrives
+        ///     Wake up any pending dequeue task
         /// </summary>
         private TaskCompletionSource<bool> dequeueTask;
-
+        private SemaphoreSlim @dequeueTaskLock = new SemaphoreSlim(1);
         private CancellationToken taskCancellationToken;
 
         internal AsyncConcurrentQueue(CancellationToken taskCancellationToken)
@@ -36,8 +36,11 @@ internal void Enqueue(T value)
         {
             queue.Enqueue(value);
 
-            //wake up the dequeue task with result
-            dequeueTask?.TrySetResult(true);
+            //signal 
+            dequeueTaskLock.Wait();
+            dequeueTask.TrySetResult(true);
+            dequeueTaskLock.Release();
+
         }
 
         /// <summary>
@@ -54,10 +57,13 @@ internal async Task<T> DequeueAsync()
                 return result;
             }
 
+            await dequeueTaskLock.WaitAsync();
             dequeueTask = new TaskCompletionSource<bool>();
+            dequeueTaskLock.Release();
+
             taskCancellationToken.Register(() => dequeueTask.TrySetCanceled());
             await dequeueTask.Task;
-
+            
             queue.TryDequeue(out result);
             return result;
         }