From e304a615d07928865ba511bd361706415d24aeed Mon Sep 17 00:00:00 2001
From: Mark McDowall <markus.mcd5@gmail.com>
Date: Mon, 13 Apr 2015 12:16:47 -0700
Subject: [PATCH] Fixed: DB locking due to Progress Messaging

---
 .../Instrumentation/DatabaseTarget.cs         |  4 ++--
 .../ProgressMessageTarget.cs                  | 21 +++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/NzbDrone.Core/Instrumentation/DatabaseTarget.cs b/src/NzbDrone.Core/Instrumentation/DatabaseTarget.cs
index 66cff3142..b61f217fc 100644
--- a/src/NzbDrone.Core/Instrumentation/DatabaseTarget.cs
+++ b/src/NzbDrone.Core/Instrumentation/DatabaseTarget.cs
@@ -5,6 +5,7 @@ using NLog.Common;
 using NLog.Config;
 using NLog;
 using NLog.Targets;
+using NLog.Targets.Wrappers;
 using NzbDrone.Common.Instrumentation;
 using NzbDrone.Core.Datastore;
 using NzbDrone.Core.Lifecycle;
@@ -12,7 +13,6 @@ using NzbDrone.Core.Messaging.Events;
 
 namespace NzbDrone.Core.Instrumentation
 {
-
     public class DatabaseTarget : TargetWithLayout, IHandle<ApplicationShutdownRequested>
     {
         private readonly SQLiteConnection _connection;
@@ -30,7 +30,7 @@ namespace NzbDrone.Core.Instrumentation
         {
             Rule = new LoggingRule("*", LogLevel.Info, this);
 
-            LogManager.Configuration.AddTarget("DbLogger", this);
+            LogManager.Configuration.AddTarget("DbLogger", new AsyncTargetWrapper(this));
             LogManager.Configuration.LoggingRules.Add(Rule);
             LogManager.ConfigurationReloaded += OnLogManagerOnConfigurationReloaded;
             LogManager.ReconfigExistingLoggers();
diff --git a/src/NzbDrone.Core/ProgressMessaging/ProgressMessageTarget.cs b/src/NzbDrone.Core/ProgressMessaging/ProgressMessageTarget.cs
index 2b8d5cff8..a1181c454 100644
--- a/src/NzbDrone.Core/ProgressMessaging/ProgressMessageTarget.cs
+++ b/src/NzbDrone.Core/ProgressMessaging/ProgressMessageTarget.cs
@@ -2,6 +2,7 @@
 using NLog.Config;
 using NLog;
 using NLog.Targets;
+using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Lifecycle;
 using NzbDrone.Core.Messaging.Commands;
 using NzbDrone.Core.Messaging.Events;
@@ -14,6 +15,8 @@ namespace NzbDrone.Core.ProgressMessaging
         private readonly IManageCommandQueue _commandQueueManager;
         private static LoggingRule _rule;
 
+        private const string REENTRY_LOCK = "ProgressMessagingLock";
+
         public ProgressMessageTarget(IEventAggregator eventAggregator, IManageCommandQueue commandQueueManager)
         {
             _eventAggregator = eventAggregator;
@@ -22,6 +25,8 @@ namespace NzbDrone.Core.ProgressMessaging
 
         protected override void Write(LogEventInfo logEvent)
         {
+            if (!ReentryPreventionCheck()) return;
+
             var command = GetCurrentCommand();
 
             if (IsClientMessage(logEvent, command))
@@ -29,6 +34,8 @@ namespace NzbDrone.Core.ProgressMessaging
                 _commandQueueManager.SetMessage(command, logEvent.FormattedMessage);
                 _eventAggregator.PublishEvent(new CommandUpdatedEvent(command));
             }
+
+            MappedDiagnosticsContext.Remove(REENTRY_LOCK);
         }
 
         private CommandModel GetCurrentCommand()
@@ -53,6 +60,20 @@ namespace NzbDrone.Core.ProgressMessaging
             return logEvent.Properties.ContainsKey("Status");
         }
 
+        private bool ReentryPreventionCheck()
+        {
+            var reentryLock = MappedDiagnosticsContext.Get(REENTRY_LOCK);
+            var commandId = MappedDiagnosticsContext.Get("CommandId");
+
+            if (reentryLock.IsNullOrWhiteSpace() || reentryLock != commandId)
+            {
+                MappedDiagnosticsContext.Set(REENTRY_LOCK, MappedDiagnosticsContext.Get("CommandId"));
+                return true;
+            }
+
+            return false;
+        }
+
         public void Handle(ApplicationStartedEvent message)
         {
             _rule = new LoggingRule("*", LogLevel.Trace, this);