Re: [boost] Boost.Coroutine

Subject: Re: [boost] Boost.Coroutine
From: Daniel Larimer (dlarimer_at_[hidden])
Date: 2010-03-03 03:57:36

Ok, so my example below was not quite accurate.  In reality I was trying to wait on two futures at once.   If I switch it to wait on just one then it all works.    It appears to be unhappy with one of
my futures that didn't "return" going out of scope.   I only care about one OR the other, but not both.

Is there a way to cancel?  

I can work around only being able to have "one" return type for my future, but thought the multiple future route made the most sense.

Dan

On Mar 3, 2010, at 3:46 AM, Daniel Larimer wrote:

> I am attempting to use boost.coroutine; however, it is not behaving for me.  Perhaps someone could shed some light?  Here is what happens:
> 
> 
> 1 start coroutine A
> 2    do some work.... 
> 
> 3    my_wait_for_value()
> 4		future<R> f(self);
                    future<Error>  err(self)
> 5		callback = make_callback(f);
                   error_callback = make_callback(err)
> 		
> 6		r = do_wait( f, err )
> 7			boost::coroutines::wait( f, err ) // blocks and the coroutine exits	, goto A
> 8			return *f;
> 9	        print( "here" )
> 10		return r;		
> 11  do some more work
> 
> 
> A start coroutine B
> B	do some work
> C	callback_from_coroutine_A ( R ) // goto line 8
> D	....
> 
> back to line 8
> 
> 8			r = *f; // got the right future value
> 9		print("here")
> 10		return r;
> 11	????? 
> 
> 
> After returning r on line 10, I should end up back on line 11, but instead end up on line D.
> 
> I clearly setup the future, waited, started another coroutine, set the value of the future, returned 2 levels of the stack, but the 3rd level dumped me off back in a different coroutine.  
> 
> Running on Mac OS X 10.6.  Single threaded code. 
> 
> Dan
> 
>