Messages in this thread |  | | From | Rusty Russell <> | Subject | Re: [PATCH] thread wakeup fix for 2.4.0-test7 | Date | Sat, 26 Aug 2000 13:25:55 +1000 |
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In message <Pine.LNX.4.10.10008251011290.9381-100000@penguin.transmeta.com> you write: > On Fri, 25 Aug 2000, Rusty Russell wrote: > > > > BUG: thread 1 is doing poll() on an fd, thread 2 closes it, > > and thread 1 doesn't wake up. Included is a small test program and > > Makefile. > > Why do you call this a bug? > > Thread 1 still has the fd open (it's used by the poll()). > > The fact that thread 2 removed it from the fd table is immaterial.
Your implementation disagrees with you: poll already returns POLLNVAL. With the patch it just returns it immediately, rather than returning it when/if it times out.
Single Unix Specification also disagrees with you:
The close() function will deallocate the file descriptor indicated by fildes. To deallocate means to make the file descriptor available for return by subsequent calls to open() or other functions that allocate file descriptors.
So we could sleep in close (forever, maybe) until the polls are finished if you prefer.
close doesn't close. This would be a ``bug'', Linus.
Rusty. -- Hacking time. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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