On Fri, 30 Jan 2004, Branden Robinson wrote:
> On Thu, Jan 29, 2004 at 08:58:25PM -0500, Thomas Dickey wrote:
> > On Wed, Jan 28, 2004 at 11:37:39PM -0500, Branden Robinson wrote:
> >
> > > Don Armstrong and I both have PowerPC machines, but he experiences the
> > > problem, and I don't.
> > >
> > > I prepared an unstripped, unoptimized, trace-enabled xterm binary for
> > > PowerPC and Don and I each produced xterm Traces and system call
> > > straces.
> > >
> > > Hopefully these will be of some use in tracking down the bug.
> >
> > They seem to give some hints. Your trace shows the process-ids, no
> > timestamps
> > and Don's doesn't show process-ids. But stripping away that column, I can
> > see
> > that his process is (I'm guessing) running on a network connection while
> > yours
> > is local machine (that's guessing by looking at some of the calls they
> > make).
> > His is getting occasional EAGAIN errno's reading from the pty (perhaps
> > because
> > it's slower). I don't see any detail from the subprocess on his - perhaps
> > it
> > doesn't use the -f option of strace. Anyway, it seems that the failure is
> > on the child process, since I don't see a call on the parent side that
> > fails.
>
> Don was running across a network connection, but he said he experienced
> the exact same problem locally.
So it's not that (network delay). But a little more information might
help. From the original report, I think this chunk in main.c is where
it's failing - but no idea why (around line 3415):
#ifndef USE_POSIX_TERMIOS
if (ioctl(tty, TCSETA, &tio) == -1)
HsSysError(cp_pipe[1], ERROR_TIOCSETP);
#else /* USE_POSIX_TERMIOS */
if (tcsetattr(tty, TCSANOW, &tio) == -1)
HsSysError(cp_pipe[1], ERROR_TIOCSETP);
#endif /* USE_POSIX_TERMIOS */
Since the '23' would be ERROR_TIOCSETP. There're several calls before
that in the child process, and I can only guess what's going on. (This
one looks hard enough even if I could reproduce it). I generally do
something like
strace -tfo foo.out ./xterm
for this sort of thing...
--
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net
