Re: Should we nonblocking open FIFO files in COPY? - Mailing list pgsql-hackers

On Tue, Dec 26, 2017 at 11:48:58AM -0800, Robert Haas wrote:
> On Thu, Dec 21, 2017 at 10:10 PM, Adam Lee <ali@pivotal.io> wrote:
> > I have an issue that COPY from a FIFO, which has no writers, could not be
> > canceled, because COPY invokes AllocateFile() -> fopen() -> blocking open().
> 
> Hmm.  What about the case where we try to open a plain file that's on
> an inaccessible filesystem, e.g. due to a disk failure?  Allowing
> cancel to work just for FIFOs would be OK, I guess, but allowing it
> for other open() calls that hang would be better.  I'm not sure if we
> can make it work that way, but it would be nice if we could.

That is doable, just stat() and check before open().

-- 
Adam Lee