Hello,
I've been using iBATIS for a couple of months now, it's a nice framework
so thanks for the hard work. I'm currently using 1.5.1 + 1.8.1 of the
mapper/access layer, but verified the following works the same in the
newest beta versions. I've run into what appears to be a bug in the
DataAccess session handling setup, but if I'm approaching this
incorrectly I'm looking for suggestions. The basic thing I want to do
is have an independent connection that I can use to log status and
errors to a database without being affected by the success/fail of any
existing transaction in progress, and without having to affect the code
outside of the database logger with respect to transactions. The most
obvious way I see to do this with support from iBATIS is to define a
separate Dao context for logging. This is where I ran into a problem.
If I have multiple DAO contexts defined and attempt to open or start a
transaction on more than one context on the same thread I am receiving
the "session already option / transaction already started" exception. I
setup a test similar to the MultipleDAOTest in the iBATIS test cases
like so:
[Test]
public void TestMultipleDAO()
{
DomDaoManagerBuilder builder = new DomDaoManagerBuilder();
builder.Configure("dao.config");
IDaoManager mgr1 = DaoManager.GetInstance("Context1");
IDaoManager mgr2 = DaoManager.GetInstance("Context2");
IPatronDAO pDao = mgr1[typeof(IPatronDAO)] as IPatronDAO;
ILogDAO lDao = mgr2[typeof(ILogDAO)] as ILogDAO;
mgr1.OpenConnection();
mgr2.OpenConnection(); <--- this is where the exception is
thrown
...
mgr1.CloseConnection();
mgr2.CloseConnection();
}
I traced this into the iBATIS source, and see that when the
DomDaoManagerBuilder creates a DaoManager instance
(DaoManager.NewInstance), the internal DaoManager constructor is
invoked, which immediately calls SessionStoreFactory with the DaoManager
id to create a session store. The problem appears to be that the call
to the SessionStoreFactory will always receive an empty string for id of
the Dao Context, since DomDaoManagerBuilder::GetContexts() doesn't
actually set the context id until after DaoManager.NewInstance()
returns. As a result, sessions for all contexts on the same thread are
keyed on the default string _IBATIS_LOCAL_DAOSESSION_ from
AbstractSessionStore, which I confirmed through VS2005 debugging. As
soon as you create one session (openconnection or begintransaction), all
contexts' LocalDaoSession reference this session because the sessionName
is the same for all.
DataMapper does not appear have this problem because in constructing a
mapper the id is set during construction, prior to calling the session
store factory.
My hope is that I'm doing something wrong, and would welcome the
assistance.
Thank you, Shane
