--- loncom/lonmaxima 2006/03/03 23:41:38 1.5
+++ loncom/lonmaxima 2006/03/08 03:18:42 1.12
@@ -3,7 +3,7 @@
# The LearningOnline Network with CAPA
# Connect to MAXIMA CAS
#
-# $Id: lonmaxima,v 1.5 2006/03/03 23:41:38 albertel Exp $
+# $Id: lonmaxima,v 1.12 2006/03/08 03:18:42 www Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -43,57 +43,34 @@ use LONCAPA::Configuration;
use strict;
# global variables
+my $STARTPORT = 5664; # port for first child's server
my $PREFORK = 5; # number of children to maintain
my $MAX_CLIENTS_PER_CHILD = 5; # number of clients each child should process
my %children = (); # keys are current child process IDs
+my %usedmaximaports = (); # keys are the used maximaports
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 $lastlog; # last string that was logged
-
-use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children $status
+use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children %usedmaximaports $status
$pidfile $port %perlvar $lastlog);
sub maximareply {
- my ($cmd) = @_;
+ my ($cmd,$maximaclient,$maximapid) = @_;
my $reply='';
- my $error='';
- my $exitstatus='';
-
+ while (my $line=<$maximaclient>) {
+ $reply.=$line;
+ }
unless ($cmd=~/\;\n$/) { $cmd.=";\n"; }
-
- my ($cmd_in, $cmd_out, $cmd_err);
- my $pid = open3($cmd_in, $cmd_out, $cmd_err, 'maxima');
- $children{$pid} = 1;
-
- print $cmd_in $cmd;
- close($cmd_in);
-
- &status("Command sent");
-
- 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);
- }
+ print $maximaclient $cmd;
+ &status("Command sent to $maximapid");
+ while (my $line=<$maximaclient>) {
+ $reply.=$line;
}
- close($cmd_out);
- close($cmd_err);
- &status("Command processed");
- return ($reply,$error,$exitstatus);
+ &status("Command processed by $maximapid");
+ return $reply;
}
# ------------------------------------------------------------ Service routines
@@ -101,13 +78,14 @@ sub REAPER { # ta
# and MAXIMA processes
$SIG{CHLD} = \&REAPER;
my $pid = wait;
- $children --;
- delete $children{$pid};
+ $children--;
+ delete($usedmaximaports{$children{$pid}});
+ 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 ----');
@@ -197,7 +175,7 @@ if (-e $pidfile) {
my $lfh=IO::File->new("$pidfile");
my $pide=<$lfh>;
chomp($pide);
- if (kill 0 => $pide) { die "already running"; }
+ if (kill(0 => $pide)) { die "already running"; }
}
# ------------------------------------------------------- Listen to UNIX socket
@@ -208,26 +186,25 @@ $port = "$perlvar{'lonSockDir'}/maximaso
unlink($port);
-my $server;
-unless (
- $server = IO::Socket::UNIX->new(Local => $port,
- Type => SOCK_STREAM,
- Listen => 10 )
- ) {
- my $st=120+int(rand(240));
- &logthis(
- "WARNING: ".
- "Can't make server socket ($st secs): .. exiting");
- sleep($st);
- exit;
- };
+my $server = IO::Socket::UNIX->new(Local => $port,
+ Type => SOCK_STREAM,
+ Listen => 10 );
+if (!$server) {
+ my $st=120+int(rand(240));
+
+ &logthis("WARNING: ".
+ "Can't make server socket ($st secs): .. exiting");
+
+ 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: $!";
@@ -239,45 +216,48 @@ print PIDSAVE "$$\n";
close(PIDSAVE);
&logthis("CRITICAL: ---------- Starting ----------");
&status('Starting');
-
-
+
+# Install signal handlers.
+$SIG{CHLD} = \&REAPER;
+$SIG{INT} = $SIG{TERM} = \&HUNTSMAN;
-
+my $maximaport=$STARTPORT;
# Fork off our children.
for (1 .. $PREFORK) {
- &make_new_child($server);
+ &make_new_child($server,$maximaport);
+ $maximaport++;
}
-# Install signal handlers.
-$SIG{CHLD} = \&REAPER;
-$SIG{INT} = $SIG{TERM} = \&HUNTSMAN;
-
# And maintain the population.
while (1) {
&status('Parent process, sleeping');
sleep; # wait for a signal (i.e., child's death)
for (my $i = $children; $i < $PREFORK; $i++) {
&status('Parent process, starting child');
- &make_new_child($server); # top up the child pool
+ my $newport;
+ foreach $newport ($STARTPORT .. $STARTPORT+$PREFORK-1) {
+ if (!defined($usedmaximaports{$newport})) { last; }
+ }
+ &make_new_child($server,$newport); # top up the child pool
}
}
sub make_new_child {
- my ($server) = @_;
+ my ($server,$maximaport) = @_;
# block signal for fork
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 (my $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";
- $children{$pid} = 1;
+ or die("Can't unblock SIGINT for fork: $!\n");
+ $children{$pid} = $maximaport;
$children++;
return;
} else {
@@ -286,12 +266,43 @@ sub make_new_child {
# unblock signals
sigprocmask(SIG_UNBLOCK, $sigset)
- or die "Can't unblock SIGINT for fork: $!\n";
-
- &process_requests($server);
+ or die("Can't unblock SIGINT for fork: $!\n");
+
+ # open the MAXIMA port
+ my $maximaserver = IO::Socket::INET->new(LocalPort => $maximaport,
+ Type => SOCK_STREAM,
+ Proto => 'tcp',
+ Reuse => 1,
+ Listen => 10 )
+ or die "making socket: $@\n";
+
+ # open MAXIMA to talk to that port
+ my ($cmd_in, $cmd_out, $cmd_err);
+ my $maximapid = open3($cmd_in, $cmd_out, $cmd_err, "maxima -s $maximaport");
+ $children{$maximapid} = 1;
+
+ my $prompt=<$cmd_out>;
+ &logthis("Maxima $maximapid: $prompt");
+
+ &status("Waiting $maximapid on $maximaport");
+ # Hopefully, MAXIMA calls us back
+ my $maximaclient=$maximaserver->accept();
+ &status("$maximapid on $maximaport connected.");
+ &logthis("Maxima $maximapid on port $maximaport connected.");
+
+ # Absorb initial prompts
+ &logthis(&maximareply("0;\n",$maximaclient,$maximapid));
+
+ # Ready for action
+
+ &process_requests($server,$maximaclient,$maximapid);
# tidy up gracefully and finish
+ if (ref($cmd_out)) { close($cmd_out); }
+ if (ref($cmd_err)) { close($cmd_err); }
+ if (ref($cmd_in)) { close($cmd_in); }
+
# this exit is VERY important, otherwise the child will become
# a producer of more and more children, forking yourself into
# process death.
@@ -300,14 +311,14 @@ sub make_new_child {
}
sub process_requests {
- my ($server) = @_;
+ my ($server,$maximaclient,$maximapid) = @_;
# handle connections until we've reached $MAX_CLIENTS_PER_CHILD
for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
- &status('Accepting connections');
+ &status('Accepting connections for '.$maximapid.' on '.$maximaport);
my $client = $server->accept() or last;
while (my $cmd=<$client>) {
- &status('Processing command');
- print $client &escape((&maximareply(&unescape($cmd)))[0])."\n";
+ &status('Processing command by '.$maximapid.' on '.$maximaport);
+ print $client &escape((&maximareply(&unescape($cmd),$maximaclient,$maximapid))[0])."\n";
}
}
}