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

chore: Emulator changes

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.
@@ -29,11 +29,13 @@ public abstract class SpannerTableFixture : SpannerFixtureBase
         public SpannerTableFixture(string tableName)
         {
             TableName = tableName;
+ 
             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;
         }
@@ -189,7 +192,7 @@ private async Task CreateOrRefreshSessionsAsync(CancellationToken cancellationTo
 
                 // Hard refresh or initial session creation,
                 // wrap this in a Task since the _sessionCreationTask task could also be null if refresh completes/fails.
-                Task currentCreationTask = Task.Run(() => TriggerRefresh(HardRefreshIntervalInDays));
+                Task currentCreationTask = TriggerRefresh(HardRefreshIntervalInDays);
 
                 // 2b. Block the current caller on the task (Hard Refresh requirement)
                 // If we initiated the task, we are waiting for our own task.