On Wed, 25 May 2011, Mattias Gaertner wrote:
On Wed, 25 May 2011 12:22:53 +0200 (CEST)
[email protected] wrote:
On Wed, 25 May 2011, Giuliano Colla wrote:
Mattias Gaertner ha scritto:
This might help:
http://wiki.lazarus.freepascal.org/Multithreaded_Application_Tutorial
Mattias
I have a question related to this subject. Working with Borland's stuff
(Kylix) I stumbled into a problem, and I'd like to know if the same applies
also to Lazarus.
I had a multithread application with a thread which receives data through a
communication line. I thought it safe to use a TStringList, which AFAIK is
not a visual object. The main thread would create the StringList, the other
thread would append strings to the list, and when it was done, the main
thread would perform the required processing. The logic of the application
itself made it sure that there was no conflict whatsoever. It turned out that
it didn't work at all, silently filling with garbage the List, and I was
forced to move all code related to the StringList in the main thread, with a
slight overhead which, IMO should not have been necessary. I couldn't
understand if it was a Kylix bug or a feature.
How would Lazarus behave with respect to this scenario? The scheme I
described is expected to work?
No. You should use a TMultiReadExclusiveWriteSynchronizer object to
synchronize access to your object, or use a critical section.
Ehm, he made sure that only one thread accesses the TStringList at a
time.
To me, this is not obvious from his mail ?
If the main thread only starts work after the secondary thread is done,
there should be no problem.
Michael.
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