--- loncom/lonmaxima 2006/03/04 15:47:26 1.11 +++ loncom/lonmaxima 2006/03/08 03:18:42 1.12 @@ -3,7 +3,7 @@ # The LearningOnline Network with CAPA # Connect to MAXIMA CAS # -# $Id: lonmaxima,v 1.11 2006/03/04 15:47:26 www Exp $ +# $Id: lonmaxima,v 1.12 2006/03/08 03:18:42 www Exp $ # # Copyright Michigan State University Board of Trustees # @@ -43,66 +43,34 @@ 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 -my $maximapid; # PID of Maxima process -use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children $status - $pidfile $port %perlvar $lastlog $maximapid); +use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children %usedmaximaports $status + $pidfile $port %perlvar $lastlog); sub maximareply { - my ($cmd) = @_; + my ($cmd,$maximaclient,$maximapid) = @_; my $reply=''; - my $error=''; - my $exitstatus=''; - + while (my $line=<$maximaclient>) { + $reply.=$line; + } unless ($cmd=~/\;\n$/) { $cmd.=";\n"; } - - my ($cmd_in, $cmd_out, $cmd_err); - $maximapid = open3($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); - } + print $maximaclient $cmd; + &status("Command sent to $maximapid"); + while (my $line=<$maximaclient>) { + $reply.=$line; } - 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); + &status("Command processed by $maximapid"); + return $reply; } # ------------------------------------------------------------ Service routines @@ -111,6 +79,7 @@ sub REAPER { # ta $SIG{CHLD} = \&REAPER; my $pid = wait; $children--; + delete($usedmaximaports{$children{$pid}}); delete($children{$pid}); } @@ -252,10 +221,12 @@ 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); + &make_new_child($server,$maximaport); + $maximaport++; } # And maintain the population. @@ -264,12 +235,16 @@ while (1) { 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; + foreach $newport ($STARTPORT .. $STARTPORT+$PREFORK-1) { + if (!defined($usedmaximaports{$newport})) { last; } + } + &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); @@ -282,7 +257,7 @@ 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++; return; } else { @@ -292,11 +267,42 @@ sub make_new_child { # 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: $@\n"; + + # open MAXIMA to talk to that port + my ($cmd_in, $cmd_out, $cmd_err); + my $maximapid = open3($cmd_in, $cmd_out, $cmd_err, "maxima -s $maximaport"); + $children{$maximapid} = 1; + + my $prompt=<$cmd_out>; + &logthis("Maxima $maximapid: $prompt"); + + &status("Waiting $maximapid on $maximaport"); + # Hopefully, MAXIMA calls us back + my $maximaclient=$maximaserver->accept(); + &status("$maximapid on $maximaport connected."); + &logthis("Maxima $maximapid on port $maximaport connected."); + + # Absorb initial prompts + &logthis(&maximareply("0;\n",$maximaclient,$maximapid)); + + # Ready for action + + &process_requests($server,$maximaclient,$maximapid); # 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. @@ -305,14 +311,14 @@ sub make_new_child { } sub process_requests { - my ($server) = @_; + my ($server,$maximaclient,$maximapid) = @_; # handle connections until we've reached $MAX_CLIENTS_PER_CHILD for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) { - &status('Accepting connections'); + &status('Accepting connections for '.$maximapid.' on '.$maximaport); my $client = $server->accept() or last; while (my $cmd=<$client>) { - &status('Processing command'); - print $client &escape((&maximareply(&unescape($cmd)))[0])."\n"; + &status('Processing command by '.$maximapid.' on '.$maximaport); + print $client &escape((&maximareply(&unescape($cmd),$maximaclient,$maximapid))[0])."\n"; } } }