[Qt-interest] Problem with FD_SET and select

[Flavio Ceolin]

On Sep 18, 2009, at 3:30 AM, Thiago Macieira wrote:

> Em Sexta-feira 18. Setembro 2009, às 04.33.58, Flavio Ceolin escreveu:
>> void ThreadCommRead::run()
>> {
>>        fd_set fds;
>>        int aux=0;
>>        FD_ZERO(&fds);
>>        FD_SET(m_handle,&fds);
>>        while(running){
>>                aux = select(m_handle+1,&fds,NULL,NULL,&timer);
>>                if(aux>0){
>>                        m_mutex->lock();
>>                        if((nbytes =  
>> read(m_handle,buffer,BUFFERSIZE))>0)
>>                        emit dataRead(buffer,nbytes);
>>                        m_mutex->unlock();
>>                }
>>        }
>> }
>>
>
> Where is timer set? It has to be reset at every loop, because the  
> select(2)
> call could modify it.
>
> According to the manual of select(2), it returns zero if the timer  
> expires. It
> looks like that's what's happening in your example.
>
> -- 
> Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
>  Senior Product Manager - Nokia, Qt Development Frameworks
>      PGP/GPG: 0x6EF45358; fingerprint:
>      E067 918B B660 DBD1 105C  966C 33F5 F005 6EF4 5358
>
> Qt Developer Days 2009 | Registration Now Open!
> Munich, Germany: Oct 12 - 14     San Francisco, California: Nov 2 - 4
>      http://qt.nokia.com/qtdevdays2009
> _______________________________________________
> Qt-interest mailing list
> Qt-interest at trolltech.com
> http://lists.trolltech.com/mailman/listinfo/qt-interest

Hi Thiago,

timer is set on constructor of class, this is the code:

ThreadCommRead::ThreadCommRead(int handle,QObject* parent=  
NULL,QMutex* mutex=NULL)
	:QThread(parent)
{
	m_handle = handle;
	m_mutex = mutex;
	timer.tv_sec = 2;
	timer.tv_usec = 0;
}


Flavio Ceolin
skype: flavio.ceolin
msn: flavio.ceolin at hotmail.com
phone: +55 14 32276948
mobile:  +55 13 97044877
flavio.ceolin at gmail.com