Re: [patch 2/5] signalfd v2 - signalfd core ...

[Davide Libenzi <davidel@xmailserver.org>]

On Thu, 8 Mar 2007, David M. Lloyd wrote:

> On Wed, 2007-03-07 at 17:21 -0800, Davide Libenzi wrote:
> > int signalfd_dequeue(int fd, siginfo_t *info, long timeo);
> > 
> > The "fd" parameter must ba a signalfd file descriptor. The "info" parameter
> > is a pointer to the siginfo that will receive the dequeued signal, and
> > "timeo" is a timeout in milliseconds, or -1 for infinite.
> > The signalfd_dequeue function returns 0 if successfull.
> 
> Does this support non-blocking mode?  It doesn't seem to at my level of
> understanding anyway.  If I use this with EPOLLET for example, I'd
> expect to get a single EPOLLIN when a signal arrives, which would
> indicate to me that I must call signalfd_dequeue() in a loop until I get
> EAGAIN in order to be sure I've consumed all the outstanding signals so
> that the edge-triggered notification can be "re-armed".

This patch, if you get a POLLIN, you have a signal to read for sure (well, 
unless you another thread/task reads it before you - but that's just 
somthing you have to take care). There is not explicit check for 
O_NONBLOCK now, but a zero timeout would do exactly the same thing.


- Davide