Add _locker to PreparedSqlLiteInsertCommand to pass StressAsync

Author: tofutim

src/SQLite.Net/PreparedSqlLiteInsertCommand.cs

@@ -24,6 +24,7 @@
 using System;
 using JetBrains.Annotations;
 using SQLite.Net.Interop;
+using System.Diagnostics;
 
 namespace SQLite.Net
 {
@@ -63,11 +64,12 @@ public void Dispose()
             Dispose(false);
         }
 
+        static readonly object _locker = new object();
+
         [PublicAPI]
         public int ExecuteNonQuery(object[] source)
         {
             Connection.TraceListener.WriteLine("Executing: {0}", CommandText);
-
             if (!Initialized)
             {
                 Statement = Prepare();
@@ -84,7 +86,12 @@ public int ExecuteNonQuery(object[] source)
                         Connection.StoreDateTimeAsTicks, Connection.Serializer);
                 }
             }
-            var r = sqlitePlatform.SQLiteApi.Step(Statement);
+
+            Result r;
+            lock (_locker)
+            {
+                r = sqlitePlatform.SQLiteApi.Step(Statement);
+            }
 
             if (r == Result.Done)
             {
@@ -104,6 +111,7 @@ public int ExecuteNonQuery(object[] source)
                 throw NotNullConstraintViolationException.New(r, sqlitePlatform.SQLiteApi.Errmsg16(Connection.Handle));
             }
             sqlitePlatform.SQLiteApi.Reset(Statement);
+
             throw SQLiteException.New(r, r.ToString());
         }
 
@@ -130,4 +138,4 @@ private void Dispose(bool disposing)
             }
         }
     }
-}
+}

tests/AsyncTests.cs

@@ -190,8 +190,11 @@ public async Task StressAsync()
             {
                 tasks.Add(Task.Factory.StartNew(async delegate
                 {
+                    string taskDesc = "";
+
                     try
                     {
+                        taskDesc = "CONNECT";
                         SQLiteAsyncConnection conn = GetAsyncConnection();
 
                         // each connection retains the global journal_mode but somehow resets busy_timeout to 100
@@ -203,6 +206,8 @@ public async Task StressAsync()
                         {
                             FirstName = i.ToString(),
                         };
+
+                        taskDesc = "INSERT";
                         await conn.InsertAsync(obj);
 
                         if (obj.Id == 0)
@@ -212,6 +217,8 @@ public async Task StressAsync()
                                 errors.Add("Bad Id");
                             }
                         }
+
+                        taskDesc = "SELECT";
                         var obj3 = await (from c in conn.Table<Customer>() where c.Id == obj.Id select c).ToListAsync();
                         Customer obj2 = obj3.FirstOrDefault();
                         if (obj2 == null)
@@ -226,7 +233,7 @@ public async Task StressAsync()
                     {
                         lock (errors)
                         {
-                            errors.Add(ex.Message);
+                            errors.Add(string.Format("{0}: {1}", taskDesc, ex.Message));
                         }
                     }
                 }));