Le dimanche 17 mars 2013 09:05:45 Ludo Brands a écrit :
Also, get rid of all these synchronizes. When using multiple threads,
you will be blocking your downloads too much. Every sock status change,
you create a string for the GUI, synchronize to update the screen, call
Application.Processmessages to make sure the GUI gets updated. That is a
huge waste of resources and slows down downloads considerably. On top of
that you have timers that also update the GUI.
Turn this around. Have TDownloadDaemon do the complete download and
nothing else. Put status in properties of TDownloadDaemon, using a
critical section if you want to pass strings, and poll your download
threads in the main thread to update the GUI. You have already a timer.
Make it faster (fe. 200ms) and update your GUI from there. Nobody will
see the difference. No more synchronize and Application.Processmessages
anymore and your program flow becomes so much easier. Multi-threading is
difficult and simplifying your program flow is key to getting it right.
I changed the project to GTK2 and got it running. It crashes not always
at the same time but it is systematically in the synchronize in
TDownloadDaemon.SockStatus and always when doing the HEAD. So that is a
synchronize called inside a synchronize from the TDownloadListLoop. You
should not call synchronize from the main loop. Worse,
TDownloadDaemon.SockStatus calls Synchronize(FOnProgress) which calls
TThread.Synchronize(self,AMethod). Self is TDownloadDaemon but since you
call TDownloadDaemon.SockStatus here from the main thread, synchronize
uses the wrong AThread. The first download it happens to work because
there is no thread running when you do HEAD. The second time you aren't
that lucky. In any case, this is an overly complex program flow and is
simply asking for problems.
Ludo
Thank you for all the advices. I just removed TDownloadDeamon thread to merge
it with TDownloader. And it works ! I still have to work on status/progress
system which is a bit messy. If you are interested, I've just commited the
changes in the svn repo.
Thank you again,
--
Geoffray Levasseur-Brandin geoffray.levasseur-bran...@ac-toulouse.fr
http://jeff.levasseur.tuxfamily.org/
GNU/PG : BF8BB8407CD26E89466CDA9BB1030FC59EF87775
Errare humanum est sed perseverare diabolicum aut cretinum.
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