chore: Add extra condition for emulator tests with concurrent txn

chore: Add extra condition for emulator tests with concurrent txn in ManagedSession

chore: add a lock on test fixture table creation

Author: purvavasudeo

apis/Google.Cloud.Spanner.Data/Google.Cloud.Spanner.Data.CommonTesting/SpannerTableFixture.cs

@@ -1,4 +1,4 @@
-// Copyright 2018 Google LLC
+// Copyright 2018 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -24,16 +24,22 @@ namespace Google.Cloud.Spanner.Data.CommonTesting
     /// </summary>
     public abstract class SpannerTableFixture : SpannerFixtureBase
     {
+        private readonly object _lock = new object();
+
         public string TableName { get; }
 
         public SpannerTableFixture(string tableName)
         {
             TableName = tableName;
-            if (Database.Fresh)
+            lock(_lock)
             {
-                Logger.DefaultLogger.Debug($"Creating table {TableName}");
-                CreateTable();
+                if (Database.Fresh)
+                {
+                    Logger.DefaultLogger.Debug($"Creating table {TableName}");
+                    CreateTable();
+                }
             }
+
             RetryHelpers.ResetStats();
             Logger.DefaultLogger.Debug($"Populating table {TableName}");
             PopulateTable(Database.Fresh);

apis/Google.Cloud.Spanner.V1/Google.Cloud.Spanner.V1/ManagedSession.cs

@@ -154,7 +154,10 @@ internal bool SessionHasExpired(double intervalInDays = SoftRefreshIntervalInDay
     {
         DateTime currentTime = _clock.GetCurrentDateTimeUtc();
         DateTime? sessionCreateTime = _session?.CreateTime.ToDateTime(); // Inherent conversion into UTC DateTime
-        if (_session == null || _session.Expired || currentTime - sessionCreateTime >= TimeSpan.FromDays(intervalInDays))
+        if (_session == null
+            || _session.Expired
+            || !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("SPANNER_EMULATOR_HOST"))
+            || currentTime - sessionCreateTime >= TimeSpan.FromDays(intervalInDays))
         {
             return true;
         }