[Interest] How to speed-up chameleons

[Romain Beaumont]

It might not be necessary (ie you can use something else instead) but it
might be faster ;)


2014-06-12 8:22 GMT+02:00 <igor.mironchik at gmail.com>:

>   Hi.
>
> First chameleon waits for another, i.e. he doing nothing while another
> will not come to the meeting place. And here semaphore is not necessary.
>
> Most slow place is QEventDispatcherWin32::processEvents()
>
>  *From:* Romain Beaumont <romain.rom1 at gmail.com>
> *Sent:* Wednesday, June 11, 2014 7:54 PM
> *To:* Igor Mironchik <igor.mironchik at gmail.com>
> *Cc:* interest at qt-project.org
> *Subject:* Re: [Interest] How to speed-up chameleons
>
>  "first chameleon should wait a second;" this sound like semaphore to me,
> but I don't know this chameleon problem.
> What part of Qt is causing it to be slow ? QThread ? the signal/slot ?
>
>
> 2014-06-11 18:51 GMT+02:00 <igor.mironchik at gmail.com>:
>
>>   Hi.
>>
>> What do you suggest?
>>
>>  *From:* Romain Beaumont <romain.rom1 at gmail.com>
>> *Sent:* Wednesday, June 11, 2014 5:12 PM
>> *To:* Keith Gardner <kreios4004 at gmail.com>
>> *Cc:* igor.mironchik at gmail.com ; interest at qt-project.org
>> *Subject:* Re: [Interest] How to speed-up chameleons
>>
>>   Hi,
>> Why do you need to use Qt signals/slots ?
>> Isn't there something more appropriate to this task ?
>>
>>
>> 2014-06-11 15:36 GMT+02:00 Keith Gardner <kreios4004 at gmail.com>:
>>
>>>     I have one question to you. Why new syntax of QObject::connect()
>>>> improve performance for a 5%.
>>>>
>>>> I mean that if in code change
>>>>
>>>> connect( sender, SIGNAL( signal() ), receiver, SLOT( slot() ) );
>>>>
>>>> to
>>>>
>>>> connect( sender, &Sender::signal, receiver, &Receiver::slot );
>>>>
>>>> then code works faster... Why? May be somebody know the answer, I don’t
>>>> want to read Qt’s code for the answer on this question.
>>>>
>>>
>>> I would guess would be that the first connect is performing a string
>>> lookup and validating the arguments at run time.  SIGNAL and SLOT are
>>> taking the macro parameters and turning them into character arrays.
>>>
>>> The second connect is working with function pointers which allows for
>>> the compiler validate their existence and ensure that the arguments are
>>> compatible at compile time instead of run time.
>>>
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>>>
>>
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>
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