/// <summary>
/// Manual database locking is used here in order to avoid deadlocks (may depend on usage of READ_COMMITTED_SNAPSHOT),
/// see integration test AddUnregisteredPrincipalsParallel.
/// </summary>
/// <remarks>
/// Note that lock resource name is case-sensitive in SQL Server.
/// </remarks>
private CustomLockInfo CreteCustomLock(string userName)
{
string key = $"AuthorizationDataLoader.{userName}";
key = CsUtility.LimitWithHash(key, 255); // SQL Server limits key length to 255.
try
{
_sqlExecuter.ExecuteSql(
$@"DECLARE @lockResult int;
EXEC @lockResult = sp_getapplock {SqlUtility.QuoteText(key)}, 'Exclusive';
IF @lockResult < 0
BEGIN
RAISERROR('AuthorizationDataLoader lock.', 16, 10);
ROLLBACK;
RETURN;
END");
return(new CustomLockInfo(key));
}
catch (FrameworkException ex) when(ex.Message.TrimEnd().EndsWith("AuthorizationDataLoader lock."))
{
throw new UserException(
"Cannot initialize the new user, because the user record is locked by another command that is still running.",
ex);
}
}