private void PoolCreateRequest(object state)
{
// called by pooler to ensure pool requests are currently being satisfied -
// creation mutex has not been obtained
if (State.Running == _state)
{
// in case WaitForPendingOpen ever failed with no subsequent OpenAsync calls,
// start it back up again
if (!_pendingOpens.IsEmpty && _pendingOpensWaiting == 0)
{
Thread waitOpenThread = new Thread(WaitForPendingOpen);
waitOpenThread.IsBackground = true;
waitOpenThread.Start();
}
// Before creating any new objects, reclaim any released objects that were
// not closed.
ReclaimEmancipatedObjects();
if (!ErrorOccurred)
{
if (NeedToReplenish)
{
// Check to see if pool was created using integrated security and if so, make
// sure the identity of current user matches that of user that created pool.
// If it doesn't match, do not create any objects on the ThreadPool thread,
// since either Open will fail or we will open a object for this pool that does
// not belong in this pool. The side effect of this is that if using integrated
// security min pool size cannot be guaranteed.
if (UsingIntegrateSecurity && !_identity.Equals(DbConnectionPoolIdentity.GetCurrent()))
{
return;
}
int waitResult = BOGUS_HANDLE;
try
{
try { }
finally
{
waitResult = WaitHandle.WaitAny(_waitHandles.GetHandles(withCreate: true), CreationTimeout);
}
if (CREATION_HANDLE == waitResult)
{
DbConnectionInternal newObj;
// Check ErrorOccurred again after obtaining mutex
if (!ErrorOccurred)
{
while (NeedToReplenish)
{
// Don't specify any user options because there is no outer connection associated with the new connection
newObj = CreateObject(owningObject: null, userOptions: null, oldConnection: null);
// We do not need to check error flag here, since we know if
// CreateObject returned null, we are in error case.
if (null != newObj)
{
PutNewObject(newObj);
}
else
{
break;
}
}
}
}
else if (WaitHandle.WaitTimeout == waitResult)
{
// do not wait forever and potential block this worker thread
// instead wait for a period of time and just requeue to try again
QueuePoolCreateRequest();
}
}
finally
{
if (CREATION_HANDLE == waitResult)
{
// reuse waitResult and ignore its value
_waitHandles.CreationSemaphore.Release(1);
}
}
}
}
}
}
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)
{
// There is no concept of Windows identity on non-Windows platform. Hence we
// cannot support Windows authentication.
if (!ADP.IsWindows)
{
throw new PlatformNotSupportedException(SR.GetString(SR.ADP_FeatureNotSupportedOnNonWindowsPlatform, DbConnectionStringKeywords.IntegratedSecurity));
}
// 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
DbConnectionPoolProviderInfo connectionPoolProviderInfo = connectionFactory.CreateConnectionPoolProviderInfo(this.ConnectionOptions);
// optimistically create pool, but its callbacks are delayed until after actual add
DbConnectionPool newPool = new DbConnectionPool(connectionFactory, this, currentIdentity, connectionPoolProviderInfo);
lock (this)
{
// Did someone already add it to the list?
if (!_poolCollection.TryGetValue(currentIdentity, out pool))
{
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;
newPool = null;
}
else
{
// else pool entry has been disabled so don't create new pools
Debug.Assert(PoolGroupStateDisabled == _state, "state should be disabled");
}
}
else
{
// else found an existing pool to use instead
Debug.Assert(PoolGroupStateActive == _state, "state should be active since a pool exists and lock holds");
}
}
if (null != newPool)
{
// don't need to call connectionFactory.QueuePoolForRelease(newPool) because
// pool callbacks were delayed and no risk of connections being created
newPool.Shutdown();
}
}
// 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);
}