/// <devdoc>The default implementation is for the open connection objects, and
/// it simply throws. Our private closed-state connection objects
/// override this and do the correct thing.</devdoc>
// User code should either override DbConnectionInternal.Activate when it comes out of the pool
// or override DbConnectionFactory.CreateConnection when the connection is created for non-pooled connections
internal virtual bool TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource <DbConnectionInternal> retry, DbConnectionOptions userOptions)
{
throw ADP.ConnectionAlreadyOpen(State);
}
internal virtual void CloseConnection(DbConnection owningObject, DbConnectionFactory connectionFactory)
{
// The implementation here is the implementation required for the
// "open" internal connections, since our own private "closed"
// singleton internal connection objects override this method to
// prevent anything funny from happening (like disposing themselves
// or putting them into a connection pool)
//
// Derived class should override DbConnectionInternal.Deactivate and DbConnectionInternal.Dispose
// for cleaning up after DbConnection.Close
// protected override void Deactivate() { // override DbConnectionInternal.Close
// // do derived class connection deactivation for both pooled & non-pooled connections
// }
// public override void Dispose() { // override DbConnectionInternal.Close
// // do derived class cleanup
// base.Dispose();
// }
//
// overriding DbConnection.Close is also possible, but must provider for their own synchronization
// public override void Close() { // override DbConnection.Close
// base.Close();
// // do derived class outer connection for both pooled & non-pooled connections
// // user must do their own synchronization here
// }
//
// if the DbConnectionInternal derived class needs to close the connection it should
// delegate to the DbConnection if one exists or directly call dispose
// DbConnection owningObject = (DbConnection)Owner;
// if (null != owningObject) {
// owningObject.Close(); // force the closed state on the outer object.
// }
// else {
// Dispose();
// }
//
////////////////////////////////////////////////////////////////
// DON'T MESS WITH THIS CODE UNLESS YOU KNOW WHAT YOU'RE DOING!
////////////////////////////////////////////////////////////////
Debug.Assert(null != owningObject, "null owningObject");
Debug.Assert(null != connectionFactory, "null connectionFactory");
SqlClientEventSource.Log.TryPoolerTraceEvent("<prov.DbConnectionInternal.CloseConnection|RES|CPOOL> {0} Closing.", ObjectID);
// if an exception occurs after the state change but before the try block
// the connection will be stuck in OpenBusy state. The commented out try-catch
// block doesn't really help because a ThreadAbort during the finally block
// would just revert the connection to a bad state.
// Open->Closed: guarantee internal connection is returned to correct pool
if (connectionFactory.SetInnerConnectionFrom(owningObject, DbConnectionOpenBusy.SingletonInstance, this))
{
// Lock to prevent race condition with cancellation
lock (this)
{
bool lockToken = ObtainAdditionalLocksForClose();
try
{
PrepareForCloseConnection();
DbConnectionPool connectionPool = Pool;
// Detach from enlisted transactions that are no longer active on close
DetachCurrentTransactionIfEnded();
// The singleton closed classes won't have owners and
// connection pools, and we won't want to put them back
// into the pool.
if (null != connectionPool)
{
connectionPool.PutObject(this, owningObject); // PutObject calls Deactivate for us...
// NOTE: Before we leave the PutObject call, another
// thread may have already popped the connection from
// the pool, so don't expect to be able to verify it.
}
else
{
Deactivate(); // ensure we de-activate non-pooled connections, or the data readers and transactions may not get cleaned up...
// To prevent an endless recursion, we need to clear
// the owning object before we call dispose so that
// we can't get here a second time... Ordinarily, I
// would call setting the owner to null a hack, but
// this is safe since we're about to dispose the
// object and it won't have an owner after that for
// certain.
_owningObject.Target = null;
if (IsTransactionRoot)
{
SetInStasis();
}
else
{
Dispose();
}
}
}
finally
{
ReleaseAdditionalLocksForClose(lockToken);
// if a ThreadAbort puts us here then its possible the outer connection will not reference
// this and this will be orphaned, not reclaimed by object pool until outer connection goes out of scope.
connectionFactory.SetInnerConnectionEvent(owningObject, DbConnectionClosedPreviouslyOpened.SingletonInstance);
}
}
}
}
internal DbConnectionPool GetConnectionPool(DbConnectionFactory connectionFactory)
{
// When this method returns null it indicates that the connection
// factory should not use pooling.
// We don't support connection pooling on Win9x;
// PoolGroupOptions will only be null when we're not supposed to pool
// connections.
DbConnectionPool pool = null;
if (null != _poolGroupOptions)
{
DbConnectionPoolIdentity currentIdentity = DbConnectionPoolIdentity.NoIdentity;
if (_poolGroupOptions.PoolByIdentity)
{
// if we're pooling by identity (because integrated security is
// being used for these connections) then we need to go out and
// search for the connectionPool that matches the current identity.
currentIdentity = DbConnectionPoolIdentity.GetCurrent();
// If the current token is restricted in some way, then we must
// not attempt to pool these connections.
if (currentIdentity.IsRestricted)
{
currentIdentity = null;
}
}
if (null != currentIdentity)
{
if (!_poolCollection.TryGetValue(currentIdentity, out pool)) // find the pool
{
lock (this)
{
// Did someone already add it to the list?
if (!_poolCollection.TryGetValue(currentIdentity, out pool))
{
DbConnectionPoolProviderInfo connectionPoolProviderInfo = connectionFactory.CreateConnectionPoolProviderInfo(this.ConnectionOptions);
DbConnectionPool newPool = new DbConnectionPool(connectionFactory, this, currentIdentity, connectionPoolProviderInfo);
if (MarkPoolGroupAsActive())
{
// If we get here, we know for certain that we there isn't
// a pool that matches the current identity, so we have to
// add the optimistically created one
newPool.Startup(); // must start pool before usage
bool addResult = _poolCollection.TryAdd(currentIdentity, newPool);
Debug.Assert(addResult, "No other pool with current identity should exist at this point");
pool = newPool;
}
else
{
// else pool entry has been disabled so don't create new pools
Debug.Assert(PoolGroupStateDisabled == _state, "state should be disabled");
// don't need to call connectionFactory.QueuePoolForRelease(newPool) because
// pool callbacks were delayed and no risk of connections being created
newPool.Shutdown();
}
}
else
{
// else found an existing pool to use instead
Debug.Assert(PoolGroupStateActive == _state, "state should be active since a pool exists and lock holds");
}
}
}
// the found pool could be in any state
}
}
if (null == pool)
{
lock (this)
{
// keep the pool entry state active when not pooling
MarkPoolGroupAsActive();
}
}
return(pool);
}
internal virtual bool TryReplaceConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource <DbConnectionInternal> retry, DbConnectionOptions userOptions)
{
throw ADP.MethodNotImplemented();
}
internal bool Prune()
{
// must only call from DbConnectionFactory.PruneConnectionPoolGroups on background timer thread
// must lock(DbConnectionFactory._connectionPoolGroups.SyncRoot) before calling ReadyToRemove
// to avoid conflict with DbConnectionFactory.CreateConnectionPoolGroup replacing pool entry
lock (this) {
if (_poolCollection.Count > 0)
{
var newPoolCollection = new ConcurrentDictionary <DbConnectionPoolIdentity, DbConnectionPool>();
foreach (var entry in _poolCollection)
{
DbConnectionPool pool = entry.Value;
if (pool != null)
{
// TODO: SQLBU 422890
// Pruning a pool while a connection is currently attempting to connect
// will cause the pool to be prematurely abandoned. The only known effect so
// far is that the errorWait throttling will be reset when this occurs.
// We should be able to avoid this situation by not pruning the pool if
// it's _waitCount is non-zero (i.e. no connections *in* the pool, but also
// no connections attempting to be created for the pool).
// Actually prune the pool if there are no connections in the pool and no errors occurred.
// Empty pool during pruning indicates zero or low activity, but
// an error state indicates the pool needs to stay around to
// throttle new connection attempts.
if ((!pool.ErrorOccurred) && (0 == pool.Count))
{
// Order is important here. First we remove the pool
// from the collection of pools so no one will try
// to use it while we're processing and finally we put the
// pool into a list of pools to be released when they
// are completely empty.
DbConnectionFactory connectionFactory = pool.ConnectionFactory;
connectionFactory.PerformanceCounters.NumberOfActiveConnectionPools.Decrement();
connectionFactory.QueuePoolForRelease(pool, false);
}
else
{
newPoolCollection.TryAdd(entry.Key, entry.Value);
}
}
}
_poolCollection = newPoolCollection;
}
// must be pruning thread to change state and no connections
// otherwise pruning thread risks making entry disabled soon after user calls ClearPool
if (0 == _poolCollection.Count)
{
if (PoolGroupStateActive == _state)
{
_state = PoolGroupStateIdle;
Bid.Trace("<prov.DbConnectionPoolGroup.ClearInternal|RES|INFO|CPOOL> %d#, Idle\n", ObjectID);
}
else if (PoolGroupStateIdle == _state)
{
_state = PoolGroupStateDisabled;
Bid.Trace("<prov.DbConnectionPoolGroup.ReadyToRemove|RES|INFO|CPOOL> %d#, Disabled\n", ObjectID);
}
}
return(PoolGroupStateDisabled == _state);
}
}
