--- loncom/lonmaxima 2006/03/03 23:47:55 1.6
+++ loncom/lonmaxima 2006/03/08 15:58:03 1.15
@@ -3,7 +3,7 @@
# The LearningOnline Network with CAPA
# Connect to MAXIMA CAS
#
-# $Id: lonmaxima,v 1.6 2006/03/03 23:47:55 albertel Exp $
+# $Id: lonmaxima,v 1.15 2006/03/08 15:58:03 www Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -43,65 +43,28 @@ 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 $reply='';
- my $error='';
- my $exitstatus='';
-
- unless ($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($fh);
- }
- }
- close($cmd_out);
- close($cmd_err);
- &status("Command processed");
- return ($reply,$error,$exitstatus);
-}
-
# ------------------------------------------------------------ Service routines
sub REAPER { # takes care of dead children
# and MAXIMA processes
$SIG{CHLD} = \&REAPER;
my $pid = wait;
$children--;
+ &logthis("Child $pid for port or process $children{$pid} died");
+ delete($usedmaximaports{$children{$pid}});
delete($children{$pid});
}
@@ -166,8 +129,6 @@ sub catchexception {
die("Signal abend");
}
-
-
# ---------------------------------------------------------------- Main program
# -------------------------------- Set signal handlers to record abnormal exits
@@ -240,28 +201,36 @@ close(PIDSAVE);
&status('Starting');
+# Install signal handlers.
+$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;
+ &logthis("Current pool: ".join(', ',keys %usedmaximaports));
+ foreach my $testport ($STARTPORT .. $STARTPORT+$PREFORK-1) {
+ if (!$usedmaximaports{$testport}) { $newport=$testport; }
+ }
+ if ($newport) {
+ &make_new_child($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);
@@ -274,21 +243,63 @@ sub make_new_child {
# Parent records the child's birth and returns.
sigprocmask(SIG_UNBLOCK, $sigset)
or die("Can't unblock SIGINT for fork: $!\n");
- $children{$pid} = 1;
+ $children{$pid} = $maximaport;
$children++;
+ $usedmaximaports{$maximaport}=1;
return;
} else {
+ &logthis("Starting child on port $maximaport");
# 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: $!\n");
-
- &process_requests($server);
+
+ # 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";
+ my $maximaselect=IO::Select->new($maximaserver);
+ sleep(1);
+
+ # 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} = "Maxima $maximapid port $maximaport";
+ my $prompt=<$cmd_out>;
+ &logthis("Maxima $maximapid: $prompt");
+
+ # hopefully, MAXIMA calls us back
+ &status("Waiting $maximapid on $maximaport");
+ my $maximaclient=$maximaserver->accept();
+ $maximaclient->blocking(0);
+ $maximaselect->add($maximaclient);
+ &status("$maximapid on $maximaport connected.");
+ &logthis("Maxima $maximapid on port $maximaport connected.");
+ sleep(2);
+
+ &logthis('Initial reply: '.&maximareply($maximaselect));
+ # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
+ for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
+ &status('Accepting connections for '.$maximapid.' on '.$maximaport);
+ my $client = $server->accept() or last;
+ while (my $cmd=<$client>) {
+ &status('Processing command by '.$maximapid.' on '.$maximaport);
+ &maximawrite($maximaselect,&unescape($cmd).";\n");
+ print $client &escape(&maximareply($maximaselect))."\n";
+ }
+ }
# 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.
@@ -296,15 +307,26 @@ sub make_new_child {
}
}
-sub process_requests {
- my ($server) = @_;
- # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
- for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
- &status('Accepting connections');
- my $client = $server->accept() or last;
- while (my $cmd=<$client>) {
- &status('Processing command');
- print $client &escape((&maximareply(&unescape($cmd)))[0])."\n";
- }
- }
+sub maximareply {
+ my ($maximaselect)=@_;
+ my $output='';
+
+ foreach my $ready ($maximaselect->can_read(1)) {
+ my $data = '';
+ my $rv = $ready->recv($data, POSIX::BUFSIZ, 0);
+ $output.=$data;
+ }
+ return $output;
+}
+
+sub maximawrite {
+ my ($maximaselect,$cmd)=@_;
+ my $ready=($maximaselect->can_write(1));
+ if (ref($ready)) {
+ print $ready $cmd;
+ } else {
+ &logthis("Cannot write: ".&maximareply($maximaselect));
+ }
}
+
+