On Sat, Oct 17, 2009 at 12:46:37PM -0400, Mikhail T. wrote: > Hello! > > I'm investigating a problem caused by (what seems like a spurious) > SIGPIPE. The program creates a child process using pipe, exchanges a few > messages with the child (via write and read) and closes the pipe. > > Some times -- in about 60% of the cases -- this causes a SIGPIPE to be > delivered to the parent... > > Now, it is quite possible for the child to have already exited by the > time the parent closes its end of the pipe -- but why should that cause > a SIGPIPE, unless the parent tries to write something to the widowed > pipe, which it does not? > > >From pipe(2): > > A pipe that has had an end closed is considered widowed. Writing > on such > a pipe causes the writing process to receive a SIGPIPE signal. > > There is no other mention of SIGPIPE in that manual page... > > I set SIGPIPE on ignore around the pipe-closing as a work-around, but I > think, this is a bug... > > The thing is part of TclX' self-test (test signal-3.0) -- and it was not > dying from SIGPIPE before the FreeBSD-7.x, as far as I can remember... > It still seems to be fine on Linux... > > Have there been any changes in this area in FreeBSD? Thanks!
Take ktrace of both parent and child.
pgplSQFAnR1s0.pgp
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