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Diff for /loncom/lonmaxima between versions 1.1 and 1.20

version 1.1, 2006/03/03 16:07:34 version 1.20, 2006/05/10 02:15:51
Line 29 Line 29
 #   # 
 # http://www.lon-capa.org/  # http://www.lon-capa.org/
 #  #
    
   use Expect; 
 use IPC::Open3;  use IPC::Open3;
 use IO::Select;  use IO::Select;
 # Scary: cannot use strict!!!  use IO::Socket;
 ##### use strict;  use IO::File;
   use Symbol;
   use POSIX;
   use lib '/home/httpd/lib/perl/';
   use LONCAPA::Configuration;
    
   use strict;
   
 sub maximareply {  # global variables
     my $cmd=shift;  my $PREFORK                = 5;        # number of children to maintain
     my $reply='';  my $MAX_CLIENTS_PER_CHILD  = 50;       # number of clients each child should process
     my $error='';  my %children               = ();       # keys are current child process IDs
     my $exitstatus='';  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
   
     unless ($cmd=~/\;\n$/) { $cmd.=";\n"; }  use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children $status
     my $pid = open3($cmd_in, $cmd_out, $cmd_err, 'maxima');      $pidfile $port %perlvar $lastlog);
        
     $SIG{CHLD} = sub {  # ------------------------------------------------------------ Service routines 
  $exitstatus="$? on $pid\n" if waitpid($pid, 0) > 0;  sub REAPER {                        # takes care of dead children 
     };                                      # and MAXIMA processes
       $SIG{CHLD} = \&REAPER;
       my $pid = wait;
       $children--;
       delete($children{$pid});
   }
    
   sub HUNTSMAN {                      # signal handler for SIGINT
       local($SIG{CHLD}) = 'IGNORE';   # we're going to kill our children
       kill('INT' => keys(%children));
       unlink($pidfile);
       unlink($port);
       &logthis('---- Shutdown ----');
       exit;                           # clean up with dignity
   }
   
   
    
   # --------------------------------------------------------------------- Logging
    
   sub logthis {
       my ($message)=@_;
       my $execdir=$perlvar{'lonDaemons'};
       my $fh=IO::File->new(">>$execdir/logs/lonmaxima.log");
       my $now=time;
       my $local=localtime($now);
       $lastlog=$local.': '.$message;
       print $fh "$local ($$): $message\n";
   }
    
   # -------------------------------------------------------------- Status setting
    
   sub status {
       my ($what)=@_;
       my $now=time;
       my $local=localtime($now);
       $status=$local.': '.$what;
       $0='lonmaxima: '.$what.' '.$local;
   }
    
   # -------------------------------------------------------- Escape Special Chars
    
   sub escape {
       my ($str)=@_;
       $str =~ s/(\W)/"%".unpack('H2',$1)/eg;
       return $str;
   }
    
   # ----------------------------------------------------- Un-Escape Special Chars
    
   sub unescape {
       my ($str)=@_;
       $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
       return $str;
   }
    
   # ------------------------ grabs exception and records it to log before exiting
   sub catchexception {
       my ($signal)=@_;
       $SIG{QUIT}='DEFAULT';
       $SIG{__DIE__}='DEFAULT';
       chomp($signal);
       &logthis("<font color=\"red\">CRITICAL: "
        ."ABNORMAL EXIT. Child $$ died through "
        ."\"$signal\"</font>");
       die("Signal abend");
   }
   
     print $cmd_in $cmd;  
     close $cmd_in;  
   
     my $selector = IO::Select->new( );  
     $selector->add($cmd_err, $cmd_out);  # ---------------------------------------------------------------- Main program
   # -------------------------------- Set signal handlers to record abnormal exits
    
    
   $SIG{'QUIT'}=\&catchexception;
   $SIG{__DIE__}=\&catchexception;
    
   # ---------------------------------- Read loncapa_apache.conf and loncapa.conf
   &status("Read loncapa.conf and loncapa_apache.conf");
   %perlvar=%{&LONCAPA::Configuration::read_conf('loncapa.conf')};
    
   # ----------------------------- Make sure this process is running from user=www
   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");
       exit 1;
   }
    
   # --------------------------------------------- Check if other instance running
    
   $pidfile="$perlvar{'lonDaemons'}/logs/lonmaxima.pid";
    
   if (-e $pidfile) {
       my $lfh=IO::File->new("$pidfile");
       my $pide=<$lfh>;
       chomp($pide);
       if (kill(0 => $pide)) { die "already running"; }
   }
   
   # ------------------------------------------------------- Listen to UNIX socket
   &status("Opening socket");
    
   $port = "$perlvar{'lonSockDir'}/maximasock";
    
   unlink($port);
    
   
   my $server = IO::Socket::UNIX->new(Local  => $port,
      Type   => SOCK_STREAM,
      Listen => 10 );
   if (!$server) {
       my $st=120+int(rand(240));
   
       &logthis("<font color=blue>WARNING: ".
        "Can't make server socket ($st secs):  .. exiting</font>");
   
       sleep($st);
       exit;
   }
           
     while (my @ready = $selector->can_read) {   
  foreach my $fh (@ready) {  # ---------------------------------------------------- Fork once and dissociate
     if (fileno($fh) == fileno($cmd_err)) {   
  $error.=<$cmd_err>;  my $fpid=fork;
     } else {  exit if $fpid;
  my $line = scalar <$cmd_out>;  die("Couldn't fork: $!") unless defined($fpid);
                 if ($line=~/^(\(\%o|\s)/) {   
                    $line=~s/^\(.*\)/     /;   POSIX::setsid() or die "Can't start new session: $!";
                    $reply.=$line;    
        }  # ------------------------------------------------------- Write our PID on disk
    
   my $execdir=$perlvar{'lonDaemons'};
   open(PIDSAVE,">$execdir/logs/lonmaxima.pid");
   print PIDSAVE "$$\n";
   close(PIDSAVE);
   &logthis("<font color='red'>CRITICAL: ---------- Starting ----------</font>");
   &status('Starting');
        
   
   # Install signal handlers.
   $SIG{CHLD} = \&REAPER;
   $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
    
   # Fork off our children.
   for (1 .. $PREFORK) {
       &make_new_child($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; $i++) {
           &status('Parent process, starting child');
           &make_new_child($server);           # top up the child pool
       }
   }
                                                                                   
   sub make_new_child {
       my ($server) = @_;
   
       # block signal for fork
       my $sigset = POSIX::SigSet->new(SIGINT);
       sigprocmask(SIG_BLOCK, $sigset)
           or die("Can't block SIGINT for fork: $!\n");
        
       die("fork: $!") unless defined(my $pid = fork);
        
       if ($pid) {
           # 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++;
           return;
       } else {
           # 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");
   
           &logthis('New process started');
   
           my $command=Expect->spawn('maxima');
           $command->log_stdout(0);
   
           &getmaximaoutput($command);
   
           for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
              &status('Accepting connections');
              my $client = $server->accept()     or last;
              print $command "kill(all);reset();\n";
      &getmaximaoutput($command);
              &sync($command);
              while (my $cmd=<$client>) {
                 &status('Processing command');
                 print $command &unescape($cmd);
                 my $reply=&getmaximaoutput($command);
                 print $client &escape($reply)."\n";
                 if ($reply=~/^Error\:/) {
                    &logthis('Died through '.$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.
           exit;
       }
   }
   
   {
       my $counter;
       sub sync {
    my ($command)=@_;
    $counter++;
    my $expect=$counter.time;
    print $command "$expect;\n";
    while (1) {
       my $output=&getmaximaoutput($command);
       if (($output=~/\Q$expect\E/) || ($output=~/^Error\:/)) {
    return;
     }      }
     $selector->remove($fh) if eof($fh);  
  }   }
     }      }
     close $cmd_out;  
     close $cmd_err;  
     return ($reply,$error,$exitstatus);  
 }  }
   
 print join("\n----\n",&maximareply('1234'));  sub getmaximaoutput {
 print join("\n----\n",&maximareply('x0: 5;x1: 7;integrate (x^2, x, x0, x1);'));      my ($command)=@_;
       my (undef,$error,undef,$output)=$command->expect(20, -re => '\(\%i\d+\)');
       if ($error) {
          return 'Error: '.$error;
       }
       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;
   }
Removed from v.1.1  
changed lines
  Added in v.1.20

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