Re: Blocking I/O and Ravenscar

["Jeffrey R. Carter" <spam.jrcarter.not@acm.nospam.org>]

Maciej Sobczak wrote:
> Basically, Ravenscar forbids any blocking operations except waiting on
> a protected entry or a suspension object.
> 
> How can I perform a blocking I/O without breaking this restriction?
> 
> Let's say I would like to read a byte from a socket.
> An entry with the simple barrier Is_Ready can do the job in terms of
> the interface, but implementation-wise it only pushes the problem away
> - who will set the Is_Ready flag after the byte is actually read from
> the blocking physical device and put in the buffer? A separate task?
> It would need to be non-Ravenscar - there seems to be a chicken&egg
> problem here.

I'm not sure where you got this idea; I don't recall any restrictions on 
blocking by tasks.

-- 
Jeff Carter
"English bed-wetting types."
Monty Python & the Holy Grail
15