f348d70a32
Implement the half-closed devices notifiation, by adding a new POLLRDHUP (and its alias EPOLLRDHUP) bit to the existing poll/select sets. Since the existing POLLHUP handling, that does not report correctly half-closed devices, was feared to be changed, this implementation leaves the current POLLHUP reporting unchanged and simply add a new bit that is set in the few places where it makes sense. The same thing was discussed and conceptually agreed quite some time ago: http://lkml.org/lkml/2003/7/12/116 Since this new event bit is added to the existing Linux poll infrastruture, even the existing poll/select system calls will be able to use it. As far as the existing POLLHUP handling, the patch leaves it as is. The pollrdhup-2.6.16.rc5-0.10.diff defines the POLLRDHUP for all the existing archs and sets the bit in the six relevant files. The other attached diff is the simple change required to sys/epoll.h to add the EPOLLRDHUP definition. There is "a stupid program" to test POLLRDHUP delivery here: http://www.xmailserver.org/pollrdhup-test.c It tests poll(2), but since the delivery is same epoll(2) will work equally. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
29 lines
515 B
C
29 lines
515 B
C
#ifndef __ASM_POLL_H
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#define __ASM_POLL_H
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#define POLLIN 0x0001
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#define POLLPRI 0x0002
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#define POLLOUT 0x0004
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#define POLLERR 0x0008
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#define POLLHUP 0x0010
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#define POLLNVAL 0x0020
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#define POLLRDNORM 0x0040
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#define POLLRDBAND 0x0080
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#define POLLWRNORM POLLOUT
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#define POLLWRBAND 0x0100
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/* These seem to be more or less nonstandard ... */
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#define POLLMSG 0x0400
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#define POLLREMOVE 0x1000
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#define POLLRDHUP 0x2000
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struct pollfd {
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int fd;
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short events;
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short revents;
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};
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#endif /* __ASM_POLL_H */
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