public void TestConnectionDoesNotLeak()
{
var applicationName = nameof(TestConnectionDoesNotLeak) + Guid.NewGuid();
var connectionString = new SqlConnectionStringBuilder(ConnectionStringProvider.ConnectionString)
{
ApplicationName = applicationName,
}
.ConnectionString;
using (ConnectionStringProvider.UseConnectionString(connectionString))
using (var engine = this.CreateEngine())
{
var @lock = engine.CreateLock(nameof(TestConnectionDoesNotLeak));
for (var i = 0; i < 30; ++i)
{
using (@lock.Acquire())
{
CountActiveSessions().ShouldEqual(1, this.GetType().Name);
}
// still alive due to pooling
CountActiveSessions().ShouldEqual(1, this.GetType().Name);
}
}
using (var connection = SqlHelpers.CreateConnection(connectionString))
{
SqlTestHelper.ClearPool(connection);
// checking immediately seems flaky; likely clear pool finishing
// doesn't guarantee that SQL will immediately reflect the clear
var maxWaitForPoolsToClear = TimeSpan.FromSeconds(5);
var stopwatch = Stopwatch.StartNew();
do
{
var activeCount = CountActiveSessions();
if (activeCount == 0)
{
return;
}
Thread.Sleep(25);
}while (stopwatch.Elapsed < maxWaitForPoolsToClear);
}
int CountActiveSessions()
{
using var connection = SqlHelpers.CreateConnection(ConnectionStringProvider.ConnectionString);
connection.Open();
using var command = connection.CreateCommand();
command.CommandText = $@"SELECT COUNT(*) FROM sys.dm_exec_sessions WHERE program_name = '{applicationName}'";
return((int)command.ExecuteScalar());
}
}
public void TestIsolationLevelLeakage()
{
const string IsolationLevelQuery = @"
SELECT CASE transaction_isolation_level
WHEN 0 THEN 'Unspecified'
WHEN 1 THEN 'ReadUncommitted'
WHEN 2 THEN 'ReadCommitted'
WHEN 3 THEN 'RepeatableRead'
WHEN 4 THEN 'Serializable'
WHEN 5 THEN 'Snapshot' END AS isolationLevel
FROM sys.dm_exec_sessions
WHERE session_id = @@SPID";
var connectionString = new SqlConnectionStringBuilder(ConnectionStringProvider.ConnectionString)
{
ApplicationName = nameof(TestIsolationLevelLeakage),
// makes it easy to test for leaks since all connections are the same
MaxPoolSize = 1,
}
.ConnectionString;
using (var connection = SqlHelpers.CreateConnection(connectionString)) { SqlTestHelper.ClearPool(connection); }
using var engine = new TEngineFactory().Create <TransactionBasedConnectionStringProvider>();
var @lock = engine.CreateLock(nameof(TestIsolationLevelLeakage));
@lock.Acquire().Dispose();
using (var connection = SqlHelpers.CreateConnection(connectionString))
{
connection.Open();
using var command = connection.CreateCommand();
command.CommandText = IsolationLevelQuery;
command.ExecuteScalar().ShouldEqual(IsolationLevel.ReadCommitted.ToString());
}
@lock.AcquireAsync().Result.Dispose();
using (var connection = SqlHelpers.CreateConnection(connectionString))
{
connection.Open();
using var command = connection.CreateCommand();
command.CommandText = IsolationLevelQuery;
command.ExecuteScalar().ShouldEqual(IsolationLevel.ReadCommitted.ToString());
}
}