Re: new_line in a put_line

[Jeffrey Carter <jrcarter@acm.org>]

Warren W. Gay VE3WWG wrote:
> 
> The Rendezvous has the benefit that the request to perform output
> is queued. This results in greater efficiency on most platforms
> because it avoids having threads wake up and test to see if they
> won out on the condition variable set (protected object).

I think you're mistaken. After performing a protected procedure or 
entry, it's perfectly legal for the same task to check the barriers of 
the object. I don't know about implementations, but this is certainly 
intended behavior for protected objects. Thus, tasks don't have to "wake 
up" until they are ready to run.

> 
> It also guarantees "order". With the protected object approach a
> "Johnnie come lately" task could gain access while already blocked
> tasks are waiting to gain access -- destroying the waiting line
> sequence. This may create some confusing to read "output".

If you need to guarantee order for a protected operation it should be an 
entry. This guarantees the same order as for a task entry.

-- 
Jeff Carter
"You've got the brain of a four-year-old boy,
and I bet he was glad to get rid of it."
Horse Feathers