--- loncom/lonmaxima 2006/03/08 15:58:03 1.15 +++ loncom/lonmaxima 2006/03/08 22:30:11 1.16 @@ -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 1.16 2006/03/08 22:30:11 www Exp $ # # Copyright Michigan State University Board of Trustees # @@ -30,7 +30,7 @@ # http://www.lon-capa.org/ # - +use Expect; use IPC::Open3; use IO::Select; use IO::Socket; @@ -43,18 +43,16 @@ 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 %usedmaximaports $status +use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children $status $pidfile $port %perlvar $lastlog); # ------------------------------------------------------------ Service routines @@ -63,8 +61,6 @@ sub REAPER { # ta $SIG{CHLD} = \&REAPER; my $pid = wait; $children--; - &logthis("Child $pid for port or process $children{$pid} died"); - delete($usedmaximaports{$children{$pid}}); delete($children{$pid}); } @@ -129,6 +125,8 @@ sub catchexception { die("Signal abend"); } + + # ---------------------------------------------------------------- Main program # -------------------------------- Set signal handlers to record abnormal exits @@ -204,12 +202,10 @@ 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. @@ -218,19 +214,12 @@ while (1) { sleep; # wait for a signal (i.e., child's death) for (my $i = $children; $i < $PREFORK; $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 +232,35 @@ 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 # 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 + my $command=Expect->spawn('maxima'); + $command->log_stdout(0); + + &getmaximaoutput($command); + 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"; - } + &status('Accepting connections'); + my $client = $server->accept() or last; + while (my $cmd=<$client>) { + &status('Processing command'); + print $command &unescape($cmd).";\n"; + print $client &escape(&getmaximaoutput($command))."\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); } + $command->soft_close(); # this exit is VERY important, otherwise the child will become # a producer of more and more children, forking yourself into @@ -307,26 +269,20 @@ sub make_new_child { } } -sub maximareply { - my ($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)); - } +sub getmaximaoutput { + my ($command)=@_; + my (undef,undef,undef,$output)=$command->expect(20, -re => '\(\%i\d+\)'); + my $foundoutput=0; + my $realoutput=''; + foreach my $line (split(/\n/,$output)) { + if ($line=~/\;/) { $foundoutput=1; next; } + if (!$foundoutput) { next; } + my ($label)=($line=~s/^(\(\%o\d+\))//); + if ($label) { + $label=~s/\S/ /g; + $line=$label.$line; + } + $realoutput.=$line."\n"; + } + return $realoutput; } - -