From 303596f99c95f826b9e61b34d8de5946fa272880 Mon Sep 17 00:00:00 2001
From: Panagiotis Kanavos <pkanavos@gmail.com>
Date: Tue, 14 Feb 2012 12:29:25 +0200
Subject: [PATCH] Replace manual reset event with asynch reset event for
 pausing the up/download agent

---
 trunk/Pithos.Core/Agents/AsyncManualResetEvent.cs |   55 +++++++++++++++++++++
 trunk/Pithos.Core/Agents/NetworkAgent.cs          |   10 ++--
 2 files changed, 61 insertions(+), 4 deletions(-)
 create mode 100644 trunk/Pithos.Core/Agents/AsyncManualResetEvent.cs

diff --git a/trunk/Pithos.Core/Agents/AsyncManualResetEvent.cs b/trunk/Pithos.Core/Agents/AsyncManualResetEvent.cs
new file mode 100644
index 0000000..00ec851
--- /dev/null
+++ b/trunk/Pithos.Core/Agents/AsyncManualResetEvent.cs
@@ -0,0 +1,55 @@
+// -----------------------------------------------------------------------
+// <copyright file="AsyncManualResetEvent.cs" company="Microsoft">
+// TODO: Update copyright text.
+// </copyright>
+// -----------------------------------------------------------------------
+
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Pithos.Core.Agents
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Text;
+
+    /// <summary>
+    /// TODO: Update summary.
+    /// </summary>
+    public class AsyncManualResetEvent
+    {
+        private volatile TaskCompletionSource<bool> _tcs;
+
+        public AsyncManualResetEvent()
+        {
+            _tcs = new TaskCompletionSource<bool>();
+        }
+
+        public AsyncManualResetEvent(bool signalled)
+        {            
+            _tcs = new TaskCompletionSource<bool>();
+            if (signalled)
+                _tcs.SetResult(true);
+        }
+        public Task WaitAsync() { return _tcs.Task; }
+
+        public void Wait()
+        {            
+            _tcs.Task.Wait();
+        }
+
+        public void Set() { _tcs.TrySetResult(true); }
+
+        public void Reset()
+        {
+            while (true)
+            {
+                var tcs = _tcs;
+                if (!tcs.Task.IsCompleted ||
+                    Interlocked.CompareExchange(ref _tcs, new TaskCompletionSource<bool>(), tcs) == tcs)
+                    return;
+            }
+        }
+    }
+}
diff --git a/trunk/Pithos.Core/Agents/NetworkAgent.cs b/trunk/Pithos.Core/Agents/NetworkAgent.cs
index e3f2923..5151c4f 100644
--- a/trunk/Pithos.Core/Agents/NetworkAgent.cs
+++ b/trunk/Pithos.Core/Agents/NetworkAgent.cs
@@ -65,7 +65,6 @@ namespace Pithos.Core.Agents
         readonly ConcurrentDictionary<string,DateTime> _deletedFiles=new ConcurrentDictionary<string, DateTime>();
 
 
-        private readonly ManualResetEventSlim _pauseAgent = new ManualResetEventSlim(true);
 
         [System.ComponentModel.Composition.Import]
         public IStatusKeeper StatusKeeper { get; set; }
@@ -80,8 +79,11 @@ namespace Pithos.Core.Agents
         public IPithosSettings Settings { get; set; }
 
         private bool _firstPoll = true;
+        
         private TaskCompletionSource<bool> _tcs;
-        private ConcurrentDictionary<string,DateTime> _lastSeen=new ConcurrentDictionary<string, DateTime>();
+        private readonly AsyncManualResetEvent _pauseAgent = new AsyncManualResetEvent(true);
+
+        private ConcurrentDictionary<string, DateTime> _lastSeen = new ConcurrentDictionary<string, DateTime>();
 
         public void Start()
         {
@@ -522,7 +524,7 @@ namespace Pithos.Core.Agents
 
             using (log4net.ThreadContext.Stacks["Retrieve Remote"].Push(accountInfo.UserName))
             {
-                _pauseAgent.Wait();
+                await _pauseAgent.WaitAsync();
 
                 Log.Info("Scheduled");
                 var client = new CloudFilesClient(accountInfo)
@@ -537,7 +539,7 @@ namespace Pithos.Core.Agents
 
                 try
                 {
-                    _pauseAgent.Wait();
+                    await _pauseAgent.WaitAsync();
                     //Get the poll time now. We may miss some deletions but it's better to keep a file that was deleted
                     //than delete a file that was created while we were executing the poll                    
                     var pollTime = DateTime.Now;
-- 
1.7.10.4