Hi,

I have a lot of historical data to pull in a IStrategy over
28 currency pairs, and this often causes the onTick
and onBar queues to overload and accumulate an excessive
number of pending callback events.

Can I safely offload Indicator queries and historical
data retrievals to another Thread, other than the
onTick/onBar callback thread, so that these events can
execute concurrently while I'm pulling historical data
to get my system "primed"?

I'm always "religious" about making sure Order operations
are on the callback Thread, or are marshalled onto the
callback Thread using IContext.executeTask(Callable).

So I guess what I'm really asking is which operations
do not require execution on the callback Thread, and
can safely be done on an auxiliary thread? Is retrieving
data using IHistory something which can be done on
a secondary thread?

Thanks!
HyperScalper

Yes IHistory operations can be handled in an auxiliary thread, this was actually one of the very first things I implemented when I started working with JForex. A BarHistoryReader component populates historical buffers.
While live bars and ticks occur, if the BHR is still busy, these bars and ticks are deemed to be part of the historical context and are sent into the BHR also. The BHR terminates after assembling the appropriate historical information including the live occurrences appearing while it was busy assembling. When the historical picture including the live data sent in is fully assembled, the BHR detaches from the buffers it was populating and dies. Meanwhile subsequent live ticks and bars are fed into the same buffers the BHR was using now by the main thread. That main thread notifies a BufferProcessing thread which goes to work on the newly updated buffers so the main thread can return asap from each onbar() / ontick() call.

Yes it is and it is trivial to check that. Note that if you are loading huge amounts of data with IHistory.read* asynchronous methods, their listeners already work in their own thread.

Perfect !! I implemented the sample Strategy code as a test
as shown in the JavaDoc for

void readBars(Instrument instrument,
Period period,
OfferSide side,
Filter filter,
int numberOfCandlesBefore,
long time,
int numberOfCandlesAfter,
LoadingDataListener barListener,
LoadingProgressListener loadingProgress)
throws JFException

Worked the first time through! This will really help me.
Just need to take care on synchronization where that's
needed.

HyperScalper