--- loncom/lonmaxima 2006/03/08 15:58:03 1.15
+++ loncom/lonmaxima 2018/12/05 23:02:38 1.44
@@ -3,7 +3,7 @@
# The LearningOnline Network with CAPA
# Connect to MAXIMA CAS
#
-# $Id: lonmaxima,v 1.15 2006/03/08 15:58:03 www Exp $
+# $Id: lonmaxima,v 1.44 2018/12/05 23:02:38 raeburn Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -30,8 +30,7 @@
# http://www.lon-capa.org/
#
-
-use IPC::Open3;
+use Expect;
use IO::Select;
use IO::Socket;
use IO::File;
@@ -43,18 +42,18 @@ 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 $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 %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 %usedmaximaports $status
+
+use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children $status
$pidfile $port %perlvar $lastlog);
# ------------------------------------------------------------ Service routines
@@ -62,10 +61,13 @@ sub REAPER { # ta
# 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{$pid});
+ if (exists($children{$pid})) {
+ $children--;
+ delete($children{$pid});
+ if ($extra_children) {
+ $extra_children--;
+ }
+ }
}
sub HUNTSMAN { # signal handler for SIGINT
@@ -129,12 +131,21 @@ sub catchexception {
die("Signal abend");
}
+
+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
$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");
@@ -145,8 +156,8 @@ my $wwwid=getpwnam('www');
if ($wwwid!=$<) {
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");
+ system("echo 'User ID mismatch. lonmaxima must be run as user www.' |".
+ " mail -s '$subj' $emailto > /dev/null");
exit 1;
}
@@ -204,33 +215,24 @@ close(PIDSAVE);
# 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,$maximaport);
- $maximaport++;
+ &make_new_child($server);
}
# And maintain the population.
while (1) {
&status('Parent process, sleeping');
sleep; # wait for a signal (i.e., child's death)
- for (my $i = $children; $i < $PREFORK; $i++) {
+ for (my $i = $children; $i < $PREFORK+$extra_children; $i++) {
&status('Parent process, starting child');
- 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,$newport); # top up the child pool
- }
+ &make_new_child($server); # top up the child pool
}
}
sub make_new_child {
- my ($server,$maximaport) = @_;
+ my ($server) = @_;
# block signal for fork
my $sigset = POSIX::SigSet->new(SIGINT);
@@ -243,62 +245,66 @@ 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} = $maximaport;
+ $children{$pid} = 1;
$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
+
+ my $ppid = getppid();
# unblock signals
sigprocmask(SIG_UNBLOCK, $sigset)
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";
- 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
+ &logthis('New process started');
+
+ my $command = new Expect();
+ $command->log_stdout(0);
+ #$command->log_file("$execdir/logs/lonmaxima.session.log");
+ $command->spawn('maxima');
+ &getmaximaoutput($command, 2); # wait for maxima to finish initialization
+ # 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;
+ };
+
+
for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
- &status('Accepting connections for '.$maximapid.' on '.$maximaport);
+ &status('Accepting connections');
my $client = $server->accept() or last;
+ &sync($command);
+ print $command ("display2d:false;simp:true;kill(all);\n");
+ &getmaximaoutput($command,2);
+ &sync($command);
+ my $syntaxerr = 0;
while (my $cmd=<$client>) {
- &status('Processing command by '.$maximapid.' on '.$maximaport);
- &maximawrite($maximaselect,&unescape($cmd).";\n");
- print $client &escape(&maximareply($maximaselect))."\n";
+ &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);
+ kill('USR1' => $ppid);
+ $client->close();
+ $command->hard_close();
+ exit;
+ }
+ &sync($command);
+ &status('Waiting for commands');
}
}
+ kill('USR1' => $ppid);
+ print $command ("quit();\n");
# tidy up gracefully and finish
-
- if (ref($cmd_out)) { close($cmd_out); }
- if (ref($cmd_err)) { close($cmd_err); }
- if (ref($cmd_in)) { close($cmd_in); }
+ sleep(15);
+ $command->soft_close();
# this exit is VERY important, otherwise the child will become
# a producer of more and more children, forking yourself into
@@ -307,26 +313,73 @@ sub make_new_child {
}
}
-sub maximareply {
- my ($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));
- }
+{
+ 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 = '(\(\%i(1)\)|[Ii]ncorrect syntax\:)';
+ } elsif ($command->match() =~ /\(\%i(\d+)\)/) {
+ my $nextmatch = $1+1;
+ $regexp = '(\(\%i'.$nextmatch.'\)|[Ii]ncorrect syntax\:)';
+ }
+ }
+ my $timeout = 20;
+ my (undef,$error,$matched,$output) =
+ $command->expect($timeout, -re => $regexp);
+
+ if ($numcheck && lc($matched) eq 'incorrect syntax:') {
+ $syntaxerr = 1;
+ if (wantarray) {
+ return ($matched,$syntaxerr);
+ } else {
+ return $matched;
+ }
+ }
+ if ($error) {
+ return 'Error: '.$error;
+ }
+ $output =~ s/\r+//gs; # 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=~/^[Ii]ncorrect 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;
+ }
+}