Re: [RFC] try* interfaces in posix_mq 0.8.0pre

["Iñaki Baz Castillo" <ibc@aliax.net>]

2011/2/27 Eric Wong <normalperson@yhbt.net>:
> I just pushed this out to RubyGems.org (and ruby_posix_mq.git).
> Let us know what you think, thanks!
>
>  posix_mq 0.8.0pre - kinder, gentler and less exceptional
>
>  This adds trysend, tryreceive, and tryshift interfaces to avoid
>  exceptions on common EAGAIN errors for non-blocking users.  EAGAIN
>  during non-blocking messages is common when there are multiple
>  readers/writer threads/processes working on the same queue.
>
>  trysend is like send, except it returns true for success and false for
>  EAGAIN.  send (still) returns nil, which I now consider a mistake but
>  won't change until post-1.0...
>
>  tryreceive and tryshift are like receive and shift respectively,
>  but they return nil for EAGAIN and the same return values
>  for their non-shift variants.
>
>  None of these methods call mq_setattr() beforehand to set the
>  non-blocking flag, it assumes the user set it once before they were ever
>  called and never changes it.  Checking/setting the non-blocking flag
>  every time is needless overhead and still subject to race conditions if
>  multiple processes/queues keep flipping flag on the same queue
>  descriptor.
>
>  These interfaces are not yet final, feedback is appreciated
>  at ruby.posix.mq@librelist.org.

Hi Eric, nice addition. In my benchmarks raising/rescuing exception is
really expensive. When a Ruby server gets congested and starts
raising/rescuing exceptions things become even worse. So I strongly
agree with your new features (similar to Gio in Unicorn, right?) :)

I will test it ASAP and comment here.



-- 
Iñaki Baz Castillo
<ibc@aliax.net>