| Subject: | Bug with EINTR handling in Expect.pm |
| Date: | Sat, 6 Dec 2008 03:49:13 -0800 (PST) |
| To: | RGiersig [...] cpan.org, bug-Expect [...] rt.cpan.org |
| From: | Rubio <_rubio_ [...] yahoo.com> |
Greetings,
I just wanted to point out a little bug with the new EINTR handling in 1.21 (and thanks for adding this, by the way; I was the original requester, or at least one of them).
You've wrappered the select() call in a SELECT: { BLOCK } so you could restart it on EINTR, but you used "next SELECT" to implement that restart which doesn't do what is intended.
As the perl docs put it:
"Note that a block by itself is semantically identical to a loop
that executes once. Thus next will exit such a block early."
which is exactly what happens here--the select in fact does not restart. (oops.)
Contrast with:
"Note that a block by itself is semantically identical to a loop
that executes once. Thus redo inside such a block will effectively
turn it into a looping construct."
So the trivial fix, replace the "next" with "redo", and voila, it works perfectly:
*** Expect.pm.ORIG Thu Jul 19 07:23:51 2007
--- Expect.pm Sat Dec 6 05:42:18 2008
***************
*** 792,798 ****
if ($!{EINTR} and $Expect::IgnoreEintr) {
print STDERR ("ignoring EINTR, restarting select()...\r\n")
if ($Expect::Exp_Internal or $Expect::Debug);
! next SELECT;
}
print STDERR ("select() returned error code '$!'\r\n")
if ($Expect::Exp_Internal or $Expect::Debug);
--- 792,798 ----
if ($!{EINTR} and $Expect::IgnoreEintr) {
print STDERR ("ignoring EINTR, restarting select()...\r\n")
if ($Expect::Exp_Internal or $Expect::Debug);
! redo SELECT;
}
print STDERR ("select() returned error code '$!'\r\n")
if ($Expect::Exp_Internal or $Expect::Debug);
Thanks for your work on this, Expect.pm is a lifesaver.
--Rubio