[PATCH] POLLRDHUP/EPOLLRDHUP handling for half-closed devices notifications
commitf348d70a324e15afc701a494f32ec468abb7d1eb
authorDavide Libenzi <davidel@xmailserver.org>
Sat, 25 Mar 2006 11:07:39 +0000 (25 03:07 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Sat, 25 Mar 2006 16:22:56 +0000 (25 08:22 -0800)
treea4cb43429f7f08a6621c581bd99e4a03198e8c67
parent501f2499b897ca4be68b1acc7a4bc8cf66f5fd24
[PATCH] POLLRDHUP/EPOLLRDHUP handling for half-closed devices notifications

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>
28 files changed:
fs/eventpoll.c
include/asm-alpha/poll.h
include/asm-arm/poll.h
include/asm-arm26/poll.h
include/asm-cris/poll.h
include/asm-frv/poll.h
include/asm-h8300/poll.h
include/asm-i386/poll.h
include/asm-ia64/poll.h
include/asm-m32r/poll.h
include/asm-m68k/poll.h
include/asm-mips/poll.h
include/asm-parisc/poll.h
include/asm-powerpc/poll.h
include/asm-s390/poll.h
include/asm-sh/poll.h
include/asm-sh64/poll.h
include/asm-sparc/poll.h
include/asm-sparc64/poll.h
include/asm-v850/poll.h
include/asm-x86_64/poll.h
include/asm-xtensa/poll.h
net/bluetooth/af_bluetooth.c
net/core/datagram.c
net/dccp/proto.c
net/ipv4/tcp.c
net/sctp/socket.c
net/unix/af_unix.c