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Diff for /loncom/lonmaxima between versions 1.1 and 1.43

version 1.1, 2006/03/03 16:07:34 version 1.43, 2018/10/29 02:57:30
Line 29 Line 29
 #   # 
 # http://www.lon-capa.org/  # http://www.lon-capa.org/
 #  #
    
 use IPC::Open3;  use Expect; 
 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 $extra_children         = 0;
     my $exitstatus='';  my %children               = ();       # keys are current child process IDs
   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 $pid = wait;
       if (exists($children{$pid})) {
    $children--;
    delete($children{$pid});
    if ($extra_children) {
       $extra_children--;
    }
       }    
   }
    
   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");
   }
   
   
   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");
   %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 $subj="LON: User ID mismatch";
       system("echo 'User ID mismatch.  lonmaxima must be run as user www.' |".
              " mailto -s '$subj' $emailto > /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));
   
     print $cmd_in $cmd;      &logthis("<font color=blue>WARNING: ".
     close $cmd_in;       "Can't make server socket ($st secs):  .. exiting</font>");
   
     my $selector = IO::Select->new( );      sleep($st);
     $selector->add($cmd_err, $cmd_out);      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 < $PREFORK+$extra_children; $i++) {
           &status('Parent process, starting child');
           &make_new_child($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.
           
    my $ppid = getppid();
        
           # unblock signals
           sigprocmask(SIG_UNBLOCK, $sigset)
               or die("Can't unblock SIGINT for fork: $!\n");
   
           &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');
               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');
                   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
    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
           # process death.
           exit;
       }
   }
   
   {
       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;
     }      }
     $selector->remove($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 ($command,$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;
       }
   }
Removed from v.1.1  
changed lines
  Added in v.1.43

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