Subj : Re: returning arguments
To   : comp.programming.threads
From : Huub
Date : Tue Jun 28 2005 06:14 pm

David Butenhof wrote:
> Torsten Robitzki wrote:
> 
>> Huub wrote:
>>
>>> Is it possible to return more than 1 value from a thread?
>>
>>
>> Sure, just use a struct to return what ever you want to.
> 
> 
> To (perhaps) make this more clear... technically, there's exactly ONE 
> return value from a thread. But the TYPE of that value is "void*" 
> (pointer). You can carry any pointer type in that "void* container". On 
> most contemporary mainstream systems you can get away with carrying any 
> scalar type x with sizeof(x) <= sizeof(void*).
> 
> However, it's easy enough to malloc a structure and return a pointer to 
> that structure. The joiner can free the storage later.
> 
Is the right way to do it?

struct displaygegevens
{
	int gasstatus;
	int rookstatus;
	int temperatuur;
};

void *LeesSensoren(void *threadid)
{
	...
	try
	{
		...
		displaygegevens = {gasstatus, rookstatus, temperatuur};
		return (void*)displaygegevens;
	}
	catch(..)
	{
	}
}

void x()
{
	try
	{
		int retv;
		void *retp;
		rc = pthread_create(...);
		pthread_exit(NULL);
		rc = pthread_join(.....);
		assert (rc == 0);
		return(retv = (int)retp);
	}
	catch (..)
	{
	}
}
}

.