dd-b has asked for the wisdom of the Perl Monks concerning the following question:
In a fairly simple server (simulator; the actual guts aren't there, just the server infrastructure) using INET sockets running on Centos, I'm getting <$sock> returning undef with $! blank. SIGPIPE is ignored. I'm running out of ideas.
This chunk of code is in a subroutine, called to do all the input from the client:
$iologger->debug("socket blocking state ", $sock->blocking()); my $l = <$sock>; my $err = $!; $iologger->debug("Client input call err ", safe($err), " line ", safe($l)); if (!defined($l)) { my $d = Dumper($sock); $iologger->debug("Socket at error: $d"); die "eiread failed: $err"; } $iologger->info("Client input: ", safe($l)); return $l;
("safe()" is a function that turns undef into "[undef]" and an empty string into "[empty]" and passes through a non-empty string; so the log shows more clearly what's happening.)
Log output below shows it reading a number of lines, down to "h1,h2", and then on the next read call getting undef back. How can it get undef back, without $! being set? (The "Bad file descriptor" messages are lingering $! values, being reported when <$sock> returned a value, and hence don't mean anythying. The code is logging the $! value even when it's not meaningful. Lazy debug code, okay?)
2011-09-27 17:23:14,723 INFO simkserver: Accepted cmdcnt 1 starttime +17:23:14 2011-09-27 17:23:14,744 DEBUG simkserver.io: socket blocking state 1 2011-09-27 17:23:14,745 DEBUG simkserver.io: Client input call err Bad + file desc riptor line Proxy,127.0.0.1 2011-09-27 17:23:14,746 INFO simkserver.io: Client input: Proxy,127.0 +.0.1 2011-09-27 17:23:14,746 INFO simkserver: Connection is from proxy for + 127.0.0.1 2011-09-27 17:23:14,747 DEBUG simkserver.io: socket blocking state 1 2011-09-27 17:23:14,747 DEBUG simkserver.io: Client input call err Bad + file desc riptor line foo,3 2011-09-27 17:23:14,748 INFO simkserver.io: Client input: foo,3 2011-09-27 17:23:14,748 DEBUG simkserver: command foo arg1 3 2011-09-27 17:23:14,749 DEBUG simkserver.io: socket blocking state 1 2011-09-27 17:23:16,557 DEBUG simkserver.io: Client input call err Bad + file desc riptor line h1,h2 2011-09-27 17:23:16,574 INFO simkserver.io: Client input: h1,h2 2011-09-27 17:23:16,575 DEBUG simkserver.io: socket blocking state 1 2011-09-27 17:23:16,575 DEBUG simkserver.io: Client input call err [em +pty] line [undef] 2011-09-27 17:23:16,576 DEBUG simkserver.io: Socket at error: $VAR1 = +bless( \*S ymbol::GEN1, 'IO::Socket::INET' ); 2011-09-27 17:23:16,577 ERROR simkserver: Aborted transaction on excep +tion eirea d failed: at ./simkserver line 103, <GEN1> line 3.
(The logging calls are log4perl.)
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Re: "Impossible" socket error return
by ikegami (Patriarch) on Sep 27, 2011 at 23:36 UTC | |
by dd-b (Monk) on Sep 28, 2011 at 14:55 UTC | |
Re: "Impossible" socket error return
by onelesd (Pilgrim) on Sep 27, 2011 at 22:51 UTC |