Thread pool in Lazarus ?

[zotak]

There is such thing in Lazarus?
I'm starting few threads from different forms and I want to limit the global number of simultaneous threads to 3 (my processor has 4 cores).I need something like a thread pool that will queue the new  started threads so that only 3 simultaneous threads can run in parallel.

Thank you!

[Ocye]

Yes, and pretty simple to use. http://wiki.freepascal.org/Parallel_procedures

[Graeme]

I don't think Lazarus includes something like that as standard, but there are plenty of existing implementations you can use. eg: The tiOPF project http://www.tiopf.com includes a very well unit tested thread pool in the <tiopf>/Core/tiThreads.pas unit.

http://sourceforge.net/p/tiopf/code/ci/tiopf2/tree/Core/tiThread.pas
http://sourceforge.net/p/tiopf/code/ci/tiopf2/tree/Core/tiPool.pas

[kapibara]

Maciej Kaczkowski's MapViewer also contains a threadpool:

https://code.google.com/p/mapviewer/source/browse/

[JD]

@zotak
You can also use Pooling Objects for Delphi found at https://code.google.com/p/delphipooling/.

It works in Lazarus. I've used it in client-server applications to create a database connection pool on the server side AND a thread pool for querying and data retrieval on the client side. I like it because you can limit the size of the pool or allow it to grow dynamically if the need arises.

@Graeme
I unfortunately did not do a thorough appraisal of tiOPF before I wrote my data applications.  I would not have had to reinvent the wheel so often. I took a look at tiOPF2 & it would have helped me get up to speed faster if I had used it. When will tiOPF3 be ready?

JD