--- loncom/lonmaxima	2007/05/15 17:28:32	1.28
+++ loncom/lonmaxima	2008/08/19 10:59:10	1.39
@@ -3,7 +3,7 @@
 # The LearningOnline Network with CAPA
 # Connect to MAXIMA CAS
 #
-# $Id: lonmaxima,v 1.28 2007/05/15 17:28:32 albertel Exp $
+# $Id: lonmaxima,v 1.39 2008/08/19 10:59:10 riegler Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -44,6 +44,7 @@ use strict;
 # global variables
 my $PREFORK                = 5;        # number of children to maintain
 my $MAX_CLIENTS_PER_CHILD  = 50;       # number of clients each child should process
+my $extra_children         = 0;
 my %children               = ();       # keys are current child process IDs
 my $children               = 0;        # current number of children
 my $status;                            # string for current status
@@ -60,8 +61,13 @@ sub REAPER {                        # ta
                                     # and MAXIMA processes
     $SIG{CHLD} = \&REAPER;
     my $pid = wait;
-    $children--;
-    delete($children{$pid});
+    if (exists($children{$pid})) {
+	$children--;
+	delete($children{$pid});
+	if ($extra_children) {
+	    $extra_children--;
+	}
+    }    
 }
  
 sub HUNTSMAN {                      # signal handler for SIGINT
@@ -126,6 +132,12 @@ sub catchexception {
 }
 
 
+sub child_announce_death {
+    $SIG{USR1} = \&child_announce_death;
+    if ($extra_children < $PREFORK*10) {
+	$extra_children++;
+    }
+}
 
 # ---------------------------------------------------------------- Main program
 # -------------------------------- Set signal handlers to record abnormal exits
@@ -133,6 +145,7 @@ sub catchexception {
  
 $SIG{'QUIT'}=\&catchexception;
 $SIG{__DIE__}=\&catchexception;
+$SIG{USR1} = \&child_announce_death;
  
 # ---------------------------------- Read loncapa_apache.conf and loncapa.conf
 &status("Read loncapa.conf and loncapa_apache.conf");
@@ -212,7 +225,7 @@ for (1 .. $PREFORK) {
 while (1) {
     &status('Parent process, sleeping');
     sleep;                          # wait for a signal (i.e., child's death)
-    for (my $i = $children; $i < $PREFORK; $i++) {
+    for (my $i = $children; $i < $PREFORK+$extra_children; $i++) {
         &status('Parent process, starting child');
         &make_new_child($server);           # top up the child pool
     }
@@ -237,7 +250,8 @@ sub make_new_child {
         return;
     } else {
         # Child can *not* return from this subroutine.
-        $SIG{INT} = 'DEFAULT';      # make SIGINT kill us as it did before
+        
+	my $ppid = getppid();
      
         # unblock signals
         sigprocmask(SIG_UNBLOCK, $sigset)
@@ -246,14 +260,22 @@ sub make_new_child {
         &logthis('New process started');
 
         my $command=Expect->spawn('maxima');
-        $command->log_stdout(0);
+	# 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 $command ("reset;display2d:false;kill(all);\n");
+            &sync($command);
+            print $command ("display2d:false;simp:true;kill(all);\n");
 	    &getmaximaoutput($command,2);
             &sync($command);
             my $syntaxerr = 0;
@@ -266,6 +288,7 @@ sub make_new_child {
                     last;
                 } elsif ($reply=~/^Error\:/) {
                     &logthis('Died through '.$reply);
+		    kill('USR1' => $ppid);
                     $client->close();
                     $command->hard_close();     
                     exit;
@@ -275,8 +298,10 @@ sub make_new_child {
             }
         }
 
+	kill('USR1' => $ppid);
+	print $command ("quit();\n");
         # tidy up gracefully and finish
-
+	sleep(15);
         $command->soft_close();
 
         # this exit is VERY important, otherwise the child will become
@@ -333,17 +358,22 @@ sub getmaximaoutput {
     }
     $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; }
-       (my $label, $line) = ($line=~ /^(\(\%o\d+\))(.+)$/);
-       if ($label) {
-           $label=~s/\S/ /g;
+       if ($line=~ /^(\(\%o\d+\))(.+)$/){
+           my $label = $1;
+           $line = $2;
+           $label =~s/\S/ /g;
            $line=$label.$line;
+	   $found_label=1;
+       }
+       if ($found_label) {
+	   $realoutput.=$line."\n";
        }
-       $realoutput.=$line."\n";
     }
     if (wantarray) {
         return ($realoutput,$syntaxerr);