[Az.Accounts] Use mutex to prevent cross process file I/O

src/Accounts/Accounts/ChangeLog.md

@@ -19,6 +19,8 @@
 -->
 ## Upcoming Release
 
+* Fixed an issue that may cause authentication errors in multi-process scenarios such as running multiple Azure PowerShell cmdlets using `Start-Job` [#9448]
+
 ## Version 1.9.0
 * Supported discovering environment setting by default and adding environment via `Add-AzEnvironment`
 * Update preloaded assemblies [#12024], [#11976]

src/Accounts/Authentication.ResourceManager/ProtectedFileProvider.cs

@@ -36,13 +36,18 @@ public abstract class ProtectedFileProvider : IFileProvider, IDisposable
         public const int MaxTries = 30;
         static readonly TimeSpan RetryInterval = TimeSpan.FromMilliseconds(500);
         protected Stream _stream;
-        object _initializationLock = new object();
+
+        /// <summary>
+        /// Use a Mutex to prevent cross-process file I/O
+        /// </summary>
+        /// <returns></returns>
+        private static readonly Mutex _initializationLock = new Mutex(false, @"Local\AzurePowerShellProtectedFileProviderInit");
         public string FilePath { get; set; }
 
         protected IDataStore DataStore { get; set; }
 
         /// <summary>
-        /// 
+        ///
         /// </summary>
         public Stream Stream
         {
@@ -87,7 +92,8 @@ public StreamWriter CreateWriter()
 
         protected virtual void InitializeStream()
         {
-            lock (_initializationLock)
+            _initializationLock.WaitOne();
+            try
             {
                 if (_stream == null)
                 {
@@ -96,10 +102,13 @@ protected virtual void InitializeStream()
                     {
                         throw new UnauthorizedAccessException(string.Format(Resources.FileLockFailure, FilePath));
                     }
-
                     _stream = stream;
                 }
             }
+            finally
+            {
+                _initializationLock.ReleaseMutex();
+            }
         }
 
         protected abstract Stream AcquireLock(string filePath);

src/Accounts/Authentication/Authentication/ProtectedFileTokenCache.cs

@@ -12,12 +12,14 @@
 // limitations under the License.
 // ----------------------------------------------------------------------------------
 
+using Hyak.Common;
 using Microsoft.Azure.Commands.Common.Authentication.Abstractions;
 using Microsoft.Azure.Commands.Common.Authentication.Properties;
 using Microsoft.IdentityModel.Clients.ActiveDirectory;
 using System;
 using System.IO;
 using System.Security.Cryptography;
+using System.Threading;
 
 #if NETSTANDARD
 namespace Microsoft.Azure.Commands.Common.Authentication.Core
@@ -41,7 +43,10 @@ public class ProtectedFileTokenCache : TokenCache, IAzureTokenCache
 #endif
                  "TokenCache.dat");
 
-        private static readonly object fileLock = new object();
+        /// <summary>
+        /// A mutex to prevent IO to token cache file across threads / processes.
+        /// </summary>
+        private static readonly Mutex fileLock = new Mutex(false, @"Local\AzurePowerShellAdalTokenCacheFile");
 
         private static readonly Lazy<ProtectedFileTokenCache> instance = new Lazy<ProtectedFileTokenCache>(() => new ProtectedFileTokenCache());
 
@@ -123,12 +128,13 @@ void EnsureStateSaved()
 
         private void ReadFileIntoCache(string cacheFileName = null)
         {
-            if(cacheFileName == null)
+            if (cacheFileName == null)
             {
                 cacheFileName = ProtectedFileTokenCache.CacheFileName;
             }
 
-            lock (fileLock)
+            fileLock.WaitOne();
+            try
             {
                 if (_store.FileExists(cacheFileName))
                 {
@@ -150,11 +156,15 @@ private void ReadFileIntoCache(string cacheFileName = null)
                     }
                 }
             }
+            finally
+            {
+                fileLock.ReleaseMutex();
+            }
         }
 
         private void WriteCacheIntoFile(string cacheFileName = null)
         {
-            if(cacheFileName == null)
+            if (cacheFileName == null)
             {
                 cacheFileName = ProtectedFileTokenCache.CacheFileName;
             }
@@ -165,19 +175,25 @@ private void WriteCacheIntoFile(string cacheFileName = null)
             var dataToWrite = Serialize();
 #endif
 
-            lock(fileLock)
+            fileLock.WaitOne();
+            try
             {
                 if (HasStateChanged)
                 {
                     _store.WriteFile(cacheFileName, dataToWrite);
-                    HasStateChanged =  false;
+                    HasStateChanged = false;
                 }
             }
+            finally
+            {
+                fileLock.ReleaseMutex();
+            }
         }
 
         private void EnsureCacheFile(string cacheFileName = null)
         {
-            lock (fileLock)
+            fileLock.WaitOne();
+            try
             {
                 if (_store.FileExists(cacheFileName))
                 {
@@ -207,6 +223,10 @@ private void EnsureCacheFile(string cacheFileName = null)
 #endif
                 _store.WriteFile(cacheFileName, dataToWrite);
             }
+            finally
+            {
+                fileLock.ReleaseMutex();
+            }
         }
     }
 }

src/Accounts/Authentication/AzureSessionInitializer.cs

@@ -26,6 +26,7 @@
 #if NETSTANDARD
 using Microsoft.Azure.Commands.Common.Authentication.Core;
 #endif
+using Hyak.Common;
 
 namespace Microsoft.Azure.Commands.Common.Authentication
 {
@@ -73,8 +74,10 @@ static IAzureTokenCache InitializeTokenCache(IDataStore store, string cacheDirec
                     var cachePath = Path.Combine(cacheDirectory, cacheFile);
                     result = new ProtectedFileTokenCache(cachePath, store);
                 }
-                catch
+                catch (Exception ex)
                 {
+                    TracingAdapter.Information("[AzureSessionInitializer]: Cannot initialize token cache in 'CurrentUser' mode. Falling back to 'Process' mode.");
+                    TracingAdapter.Information($"[AzureSessionInitializer]: Message: {ex.Message}; Stacktrace: {ex.StackTrace}");
                 }
             }
 
@@ -159,10 +162,12 @@ static ContextAutosaveSettings InitializeSessionSettings(IDataStore store, strin
                     store.WriteFile(autoSavePath, JsonConvert.SerializeObject(result));
                 }
             }
-            catch
+            catch (Exception ex)
             {
                 // ignore exceptions in reading settings from disk
                 result.Mode = ContextSaveMode.Process;
+                TracingAdapter.Information("[AzureSessionInitializer]: Cannot read settings from disk. Falling back to 'Process' mode.");
+                TracingAdapter.Information($"[AzureSessionInitializer]: Message: {ex.Message}; Stacktrace: {ex.StackTrace}");
             }
 
             return result;