Settings Mutex Per Twine Application.

1 files changed, 35 insertions, 3 deletions

diff --git a/Software/Visual_Studio/Tango.Settings/SettingsManager.cs b/Software/Visual_Studio/Tango.Settings/SettingsManager.cs
index 3a30ffbbb..0383af5be 100644
--- a/Software/Visual_Studio/Tango.Settings/SettingsManager.cs
+++ b/Software/Visual_Studio/Tango.Settings/SettingsManager.cs
@@ -4,7 +4,9 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using Tango.Logging;
 
@@ -18,6 +20,7 @@ namespace Tango.Settings
         #region Singleton
 
         private static object _syncLock = new object();
+        private static String MUTEX_NAME = Assembly.GetEntryAssembly().GetName().Name;
 
         private static SettingsManager _default;
         /// <summary>
@@ -153,9 +156,38 @@ namespace Tango.Settings
         {
             EnsureLoaded();
 
-            _logManager.Log("Saving settings to " + FilePath + "...");
-            String json = JsonConvert.SerializeObject(_settingsCollection, _jsonSettings);
-            File.WriteAllText(FilePath, json);
+            using (var mutex = new Mutex(false, MUTEX_NAME))
+            {
+                var mutexAcquired = false;
+                try
+                {
+                    mutexAcquired = mutex.WaitOne(5000);
+                }
+                catch (AbandonedMutexException)
+                {
+                    mutexAcquired = true;
+                }
+
+                // if it wasn't acquired, it timed out, so can handle that how ever we want
+                if (!mutexAcquired)
+                {
+                    _logManager.Log("Error saving settings due to Mutex not acquired");
+                    return;
+                }
+
+                // otherwise, we've acquired the mutex and should do what we need to do,
+                // then ensure that we always release the mutex
+                try
+                {
+                    _logManager.Log("Saving settings to " + FilePath + "...");
+                    String json = JsonConvert.SerializeObject(_settingsCollection, _jsonSettings);
+                    File.WriteAllText(FilePath, json);
+                }
+                finally
+                {
+                    mutex.ReleaseMutex();
+                }
+            }
         }
     }
 }