Re: Problem with socketpair , AF_UNIX and select call - can anybody through any light on this!

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]


Somebody in the thread at some point said:
> Andy Green wrote,
>> Why don't you try removing the O_NONBLOCK since you test with
>> select...
> Never, ever, do that ... select only returns a hint that an IO operation 
> might succeed, not a guarantee (google for "spurious wakeup"), hence a 
> subsequent read/write might block if the descriptor isn't set to 
> O_NONBLOCK, and that's almost always not what's wanted or expected.

Wah, man select says it too

       Under  Linux,  select()  may  report  a  socket file descriptor
as "ready for reading", while nevertheless a subsequent read
       blocks. This could for example happen when data has arrived but
upon examination has wrong checksum and is discarded.  There
       may  be  other circumstances in which a file descriptor is
spuriously reported as ready.  Thus it may be safer to use O_NON-
       BLOCK on sockets that should not block.

Pretty freakish, thanks for the tip.


[Index of Archives]     [Current Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Yosemite News]     [Yosemite Photos]     [KDE Users]     [Fedora Tools]     [Fedora Docs]

  Powered by Linux