--- loncom/lonmaxima 2006/03/04 06:51:02 1.9 +++ loncom/lonmaxima 2007/05/15 17:28:32 1.28 @@ -3,7 +3,7 @@ # The LearningOnline Network with CAPA # Connect to MAXIMA CAS # -# $Id: lonmaxima,v 1.9 2006/03/04 06:51:02 albertel Exp $ +# $Id: lonmaxima,v 1.28 2007/05/15 17:28:32 albertel 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; @@ -44,7 +43,7 @@ use strict; # global variables 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 %children = (); # keys are current child process IDs my $children = 0; # current number of children my $status; # string for current status @@ -52,58 +51,10 @@ my $pidfile; # 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 $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 $maximapid = open3($cmd_in, $cmd_out, $cmd_err, 'maxima'); - $children{$maximapid} = 1; - - print $cmd_in $cmd; - close($cmd_in); - - &status("Command sent"); - - $SIG{ALRM} = sub { kill 9 => $maximapid; }; - alarm(5); - - my $selector = IO::Select->new(); - - $selector->add($cmd_err, $cmd_out); - - while (my @ready = $selector->can_read()) { - foreach my $fh (@ready) { - if (ref($fh) - && ref($cmd_err) - && fileno($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); - } - } - alarm(0); - $SIG{ALRM} = 'DEFAULT'; - if (ref($cmd_out)) { close($cmd_out); } - if (ref($cmd_err)) { close($cmd_err); } - - &status("Command processed"); - return ($reply,$error,$exitstatus); -} - # ------------------------------------------------------------ Service routines sub REAPER { # takes care of dead children # and MAXIMA processes @@ -248,15 +199,15 @@ close(PIDSAVE); &status('Starting'); +# Install signal handlers. +$SIG{CHLD} = \&REAPER; +$SIG{INT} = $SIG{TERM} = \&HUNTSMAN; + # Fork off our children. for (1 .. $PREFORK) { &make_new_child($server); } -# Install signal handlers. -$SIG{CHLD} = \&REAPER; -$SIG{INT} = $SIG{TERM} = \&HUNTSMAN; - # And maintain the population. while (1) { &status('Parent process, sleeping'); @@ -292,10 +243,42 @@ sub make_new_child { sigprocmask(SIG_UNBLOCK, $sigset) or die("Can't unblock SIGINT for fork: $!\n"); - &process_requests($server); + &logthis('New process started'); + + my $command=Expect->spawn('maxima'); + $command->log_stdout(0); + #$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 $command ("reset;display2d:false;kill(all);\n"); + &getmaximaoutput($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 + $command->soft_close(); + # this exit is VERY important, otherwise the child will become # a producer of more and more children, forking yourself into # process death. @@ -303,15 +286,68 @@ sub make_new_child { } } -sub process_requests { - my ($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"; +{ + 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 $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; + $line=$label.$line; + } + $realoutput.=$line."\n"; + } + if (wantarray) { + return ($realoutput,$syntaxerr); + } else { + return $realoutput; + } }