Proposal: Add tryReadChan to Chan

[Neil Mitchell]

Hi Mitar,

>> I never managed to narrow it down enough to a test case that showed
>> Chan was at fault, but I'm still "slightly wary" of it - eliminating
>> Chan made the bug go away, but that's hardly conclusive.
>
> And it is still happening with current trunk version? Does it happen
> with both -threaded and without it?

No idea if it happens with anything after 6.12.3. I think it happened
in threaded and without.

> Because maybe it is nothing wrong with a primitive itself, but just
> its implementation.

Entirely possible - or the use of that primitive makes latent bugs in
other functions show up. My knowledge on this bug can be best
described as "vaguely uneasy" - I have no good technical information
on it.

Thanks, Neil