--- loncom/lonmaxima 2006/03/03 22:35:09 1.2
+++ loncom/lonmaxima 2007/08/03 18:18:05 1.32
@@ -3,7 +3,7 @@
# The LearningOnline Network with CAPA
# Connect to MAXIMA CAS
#
-# $Id: lonmaxima,v 1.2 2006/03/03 22:35:09 www Exp $
+# $Id: lonmaxima,v 1.32 2007/08/03 18:18:05 albertel Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -30,13 +30,7 @@
# http://www.lon-capa.org/
#
-# global variables
-$PREFORK = 5; # number of children to maintain
-$MAX_CLIENTS_PER_CHILD = 5; # number of clients each child should process
-%children = (); # keys are current child process IDs
-$children = 0; # current number of children
-
-use IPC::Open3;
+use Expect;
use IO::Select;
use IO::Socket;
use IO::File;
@@ -45,59 +39,34 @@ use POSIX;
use lib '/home/httpd/lib/perl/';
use LONCAPA::Configuration;
-# Scary: cannot use strict!!!
-##### use strict;
-
-sub maximareply {
- my $cmd=shift;
- my $reply='';
- my $error='';
- my $exitstatus='';
-
- unless ($cmd=~/\;\n$/) { $cmd.=";\n"; }
- my $pid = open3($cmd_in, $cmd_out, $cmd_err, 'maxima');
- $children{$pid} = 1;
-
- print $cmd_in $cmd;
- close $cmd_in;
+use strict;
- &status("Command sent");
+# global variables
+my $PREFORK = 5; # number of children to maintain
+my $MAX_CLIENTS_PER_CHILD = 50; # number of clients each child should process
+my %children = (); # keys are current child process IDs
+my $children = 0; # current number of children
+my $status; # string for current status
+my $pidfile; # file containg parent process pid
+my $port; # path to UNIX socket file
+my %perlvar; # configuration file info
+my $lastlog; # last string that was logged
- my $selector = IO::Select->new();
- $selector->add($cmd_err, $cmd_out);
-
- while (my @ready = $selector->can_read) {
- foreach my $fh (@ready) {
- if (fileno($fh) == fileno($cmd_err)) {
- $error.=<$cmd_err>;
- } else {
- my $line = scalar <$cmd_out>;
- if ($line=~/^(\(\%o|\s)/) {
- $line=~s/^\(.*\)/ /;
- $reply.=$line;
- }
- }
- $selector->remove($fh) if eof($fh);
- }
- }
- close $cmd_out;
- close $cmd_err;
- &status("Command processed");
- return ($reply,$error,$exitstatus);
-}
+use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children $status
+ $pidfile $port %perlvar $lastlog);
# ------------------------------------------------------------ Service routines
sub REAPER { # takes care of dead children
# and MAXIMA processes
$SIG{CHLD} = \&REAPER;
my $pid = wait;
- $children --;
- delete $children{$pid};
+ $children--;
+ delete($children{$pid});
}
sub HUNTSMAN { # signal handler for SIGINT
local($SIG{CHLD}) = 'IGNORE'; # we're going to kill our children
- kill 'INT' => keys %children;
+ kill('INT' => keys(%children));
unlink($pidfile);
unlink($port);
&logthis('---- Shutdown ----');
@@ -109,7 +78,7 @@ sub HUNTSMAN { # si
# --------------------------------------------------------------------- Logging
sub logthis {
- my $message=shift;
+ my ($message)=@_;
my $execdir=$perlvar{'lonDaemons'};
my $fh=IO::File->new(">>$execdir/logs/lonmaxima.log");
my $now=time;
@@ -121,7 +90,7 @@ sub logthis {
# -------------------------------------------------------------- Status setting
sub status {
- my $what=shift;
+ my ($what)=@_;
my $now=time;
my $local=localtime($now);
$status=$local.': '.$what;
@@ -131,7 +100,7 @@ sub status {
# -------------------------------------------------------- Escape Special Chars
sub escape {
- my $str=shift;
+ my ($str)=@_;
$str =~ s/(\W)/"%".unpack('H2',$1)/eg;
return $str;
}
@@ -139,7 +108,7 @@ sub escape {
# ----------------------------------------------------- Un-Escape Special Chars
sub unescape {
- my $str=shift;
+ my ($str)=@_;
$str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
return $str;
}
@@ -150,12 +119,12 @@ sub catchexception {
$SIG{QUIT}='DEFAULT';
$SIG{__DIE__}='DEFAULT';
chomp($signal);
- &logthis("<font color=red>CRITICAL: "
- ."ABNORMAL EXIT. Child $$ died through "
- ."\"$signal\"</font>");
+ &logthis("<font color=\"red\">CRITICAL: "
+ ."ABNORMAL EXIT. Child $$ died through "
+ ."\"$signal\"</font>");
die("Signal abend");
}
-
+
# ---------------------------------------------------------------- Main program
@@ -167,18 +136,16 @@ $SIG{__DIE__}=\&catchexception;
# ---------------------------------- Read loncapa_apache.conf and loncapa.conf
&status("Read loncapa.conf and loncapa_apache.conf");
-my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf');
-%perlvar=%{$perlvarref};
-undef $perlvarref;
+%perlvar=%{&LONCAPA::Configuration::read_conf('loncapa.conf')};
# ----------------------------- Make sure this process is running from user=www
my $wwwid=getpwnam('www');
if ($wwwid!=$<) {
- my $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
- my $subj="LON: $currenthostid User ID mismatch";
- system("echo 'User ID mismatch. lonmaxima must be run as user www.' |\
+ my $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
+ my $subj="LON: User ID mismatch";
+ system("echo 'User ID mismatch. lonmaxima must be run as user www.' |\
mailto $emailto -s '$subj' > /dev/null");
- exit 1;
+ exit 1;
}
# --------------------------------------------- Check if other instance running
@@ -186,11 +153,12 @@ if ($wwwid!=$<) {
$pidfile="$perlvar{'lonDaemons'}/logs/lonmaxima.pid";
if (-e $pidfile) {
- my $lfh=IO::File->new("$pidfile");
- my $pide=<$lfh>;
- chomp($pide);
- if (kill 0 => $pide) { die "already running"; }
+ my $lfh=IO::File->new("$pidfile");
+ my $pide=<$lfh>;
+ chomp($pide);
+ if (kill(0 => $pide)) { die "already running"; }
}
+
# ------------------------------------------------------- Listen to UNIX socket
&status("Opening socket");
@@ -199,101 +167,200 @@ $port = "$perlvar{'lonSockDir'}/maximaso
unlink($port);
-unless (
- $server = IO::Socket::UNIX->new(Local => $port,
- Type => SOCK_STREAM,
- Listen => 10 )
- ) {
- my $st=120+int(rand(240));
- &logthis(
- "<font color=blue>WARNING: ".
- "Can't make server socket ($st secs): .. exiting</font>");
- sleep($st);
- exit;
- };
+my $server = IO::Socket::UNIX->new(Local => $port,
+ Type => SOCK_STREAM,
+ Listen => 10 );
+if (!$server) {
+ my $st=120+int(rand(240));
+
+ &logthis("<font color=blue>WARNING: ".
+ "Can't make server socket ($st secs): .. exiting</font>");
+
+ sleep($st);
+ exit;
+}
# ---------------------------------------------------- Fork once and dissociate
my $fpid=fork;
exit if $fpid;
-die "Couldn't fork: $!" unless defined ($fpid);
+die("Couldn't fork: $!") unless defined($fpid);
POSIX::setsid() or die "Can't start new session: $!";
# ------------------------------------------------------- Write our PID on disk
my $execdir=$perlvar{'lonDaemons'};
-open (PIDSAVE,">$execdir/logs/lonmaxima.pid");
+open(PIDSAVE,">$execdir/logs/lonmaxima.pid");
print PIDSAVE "$$\n";
close(PIDSAVE);
&logthis("<font color='red'>CRITICAL: ---------- Starting ----------</font>");
&status('Starting');
-
-
-
-
-# Fork off our children.
-for (1 .. $PREFORK) {
- make_new_child( );
-}
-
+
# Install signal handlers.
$SIG{CHLD} = \&REAPER;
$SIG{INT} = $SIG{TERM} = \&HUNTSMAN;
+# Fork off our children.
+for (1 .. $PREFORK) {
+ &make_new_child($server);
+}
+
# And maintain the population.
while (1) {
&status('Parent process, sleeping');
sleep; # wait for a signal (i.e., child's death)
- for ($i = $children; $i < $PREFORK; $i++) {
+ for (my $i = $children; $i < $PREFORK; $i++) {
&status('Parent process, starting child');
- make_new_child( ); # top up the child pool
+ &make_new_child($server); # top up the child pool
}
}
sub make_new_child {
- my $pid;
- my $sigset;
-
+ my ($server) = @_;
+
# block signal for fork
- $sigset = POSIX::SigSet->new(SIGINT);
+ my $sigset = POSIX::SigSet->new(SIGINT);
sigprocmask(SIG_BLOCK, $sigset)
- or die "Can't block SIGINT for fork: $!\n";
+ or die("Can't block SIGINT for fork: $!\n");
- die "fork: $!" unless defined ($pid = fork);
+ die("fork: $!") unless defined(my $pid = fork);
if ($pid) {
# Parent records the child's birth and returns.
sigprocmask(SIG_UNBLOCK, $sigset)
- or die "Can't unblock SIGINT for fork: $!\n";
+ or die("Can't unblock SIGINT for fork: $!\n");
$children{$pid} = 1;
$children++;
return;
} else {
# Child can *not* return from this subroutine.
- $SIG{INT} = 'DEFAULT'; # make SIGINT kill us as it did before
+
# unblock signals
sigprocmask(SIG_UNBLOCK, $sigset)
- or die "Can't unblock SIGINT for fork: $!\n";
-
- # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
- for ($i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
- &status('Accepting connections');
- $client = $server->accept( ) or last;
- while ($cmd=<$client>) {
- &status('Processing command');
- print $client &escape((&maximareply(&unescape($cmd)))[0])."\n";
- }
+ or die("Can't unblock SIGINT for fork: $!\n");
+
+ &logthis('New process started');
+
+ my $command=Expect->spawn('maxima');
+ # soft/hard_close can take awhile and we really
+ # don't care we just want it gone
+ $SIG{INT} = sub {
+ my $pid = $command->pid();
+ kill('KILL'=>$pid);
+ exit;
+ };
+
+ $command->log_stdout(0);
+ #$command->log_file("$execdir/logs/lonmaxima.session.log");
+ &getmaximaoutput($command);
+
+ for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
+ &status('Accepting connections');
+ my $client = $server->accept() or last;
+ print $command ("display2d:false;kill(all);\n");
+ &getmaximaoutput($command,2);
+ &sync($command);
+ my $syntaxerr = 0;
+ while (my $cmd=<$client>) {
+ &status('Processing command');
+ print $command &unescape($cmd);
+ my ($reply,$syntaxerr) = &getmaximaoutput($command,1);
+ print $client &escape($reply)."\n";
+ if ($syntaxerr) {
+ last;
+ } elsif ($reply=~/^Error\:/) {
+ &logthis('Died through '.$reply);
+ $client->close();
+ $command->hard_close();
+ exit;
+ }
+ &sync($command);
+ &status('Waiting for commands');
+ }
}
-
+
# tidy up gracefully and finish
+ $command->soft_close();
+
# this exit is VERY important, otherwise the child will become
# a producer of more and more children, forking yourself into
# process death.
exit;
}
}
+
+{
+ my $counter;
+ sub sync {
+ my ($command)=@_;
+ $counter++;
+ my $expect=$counter.time;
+ print $command "$expect;\n";
+ while (1) {
+ my $output=&getmaximaoutput($command,1);
+ if (($output=~/\Q$expect\E/) || ($output=~/^Error\:/)) {
+ return;
+ }
+ }
+ }
+}
+
+sub getmaximaoutput {
+ my ($command,$numcheck)=@_;
+ my $regexp = '\(\%i\d+\)';
+ my $syntaxerr=0;
+ if ($numcheck) {
+ if ($numcheck eq 2) {
+ # command was the killall so should get a full reset on
+ # command numbers
+ $regexp = '(\(\%i(1)\)|Incorrect syntax\:)';
+ } elsif ($command->match() =~ /\(\%i(\d+)\)/) {
+ my $nextmatch = $1+1;
+ $regexp = '(\(\%i'.$nextmatch.'\)|Incorrect syntax\:)';
+ }
+ }
+ my $timeout = 20;
+ my (undef,$error,$matched,$output) =
+ $command->expect($timeout, -re => $regexp);
+
+ if ($numcheck && $matched eq 'Incorrect syntax:') {
+ $syntaxerr = 1;
+ if (wantarray) {
+ return ($matched,$syntaxerr);
+ } else {
+ return $matched;
+ }
+ }
+ if ($error) {
+ return 'Error: '.$error;
+ }
+ $output =~ s/\r+//g; # Remove Windows-style linebreaks
+ my $foundoutput=0;
+ my $found_label=0;
+ my $realoutput='';
+ foreach my $line (split(/\n/,$output)) {
+ if ($line=~/\;/) { $foundoutput=1; next; }
+ if (!$foundoutput) { next; }
+ if ($line=~/^Incorrect syntax:/) { $syntaxerr = 1; next; }
+ if ($line=~ /^(\(\%o\d+\))(.+)$/){
+ my $label = $1;
+ $line = $2;
+ $label =~s/\S/ /g;
+ $line=$label.$line;
+ $found_label=1;
+ }
+ if ($found_label) {
+ $realoutput.=$line."\n";
+ }
+ }
+ if (wantarray) {
+ return ($realoutput,$syntaxerr);
+ } else {
+ return $realoutput;
+ }
+}