[Qt-interest] Demo Browser and Qt::Concurrent query

[Thiago Macieira]

Em Quarta-feira 20 Janeiro 2010, às 08:17:45, Nitin Mahajan escreveu:
> > You're using a QNetworkReply object from a thread that it
> > doesn't belong to
> > (that's not allowed) and you're doing GUI operations from a
> > thread, which is
> > also not allowed.
> > 
> > You can open a file and write to it in a thread. But you
> > may not do GUI and you
> > may not read from the QNetworkReply in it.
> 
> Thanks for the inputs. Suppose I decide to do only the file write(No
> reading from QNetworkReply or No GUI ops) operation in a separate thread,
> in this particular case, Whether spawning of threads very frequently would
> also result into overhead and inturn GUI drawing in main thread becomes
> slow?

Yes, the spawning of threads can be a slow / costly operation. It depends on 
what operating system you're running, though.

QtConcurrent uses QThreadPool, which means it will reuse existing threads and 
avoid spawning new.

In any case, what kind of network connection will you be on that you can 
download fast enough for disk I/O to be a bottleneck?

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
  Senior Product Manager - Nokia, Qt Development Frameworks
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