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Diff for /loncom/lonmaxima between versions 1.1 and 1.10

version 1.1, 2006/03/03 16:07:34 version 1.10, 2006/03/04 06:56:10
Line 29 Line 29
 #   # 
 # http://www.lon-capa.org/  # http://www.lon-capa.org/
 #  #
   
     
 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;
   
   # global variables
   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 $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 $status
       $pidfile $port %perlvar $lastlog);
    
 sub maximareply {  sub maximareply {
     my $cmd=shift;      my ($cmd) = @_;
     my $reply='';      my $reply='';
     my $error='';      my $error='';
     my $exitstatus='';      my $exitstatus='';
   
     unless ($cmd=~/\;\n$/) { $cmd.=";\n"; }      unless ($cmd=~/\;\n$/) { $cmd.=";\n"; }
     my $pid = open3($cmd_in, $cmd_out, $cmd_err, 'maxima');  
       
     $SIG{CHLD} = sub {  
  $exitstatus="$? on $pid\n" if waitpid($pid, 0) > 0;  
     };  
   
       my ($cmd_in, $cmd_out, $cmd_err);
       my $maximapid = open3($cmd_in, $cmd_out, $cmd_err, 'maxima');
       $children{$maximapid} = 1;
       
     print $cmd_in $cmd;      print $cmd_in $cmd;
     close $cmd_in;      close($cmd_in);
   
       &status("Command sent");
   
       $SIG{ALRM} = sub { kill 9 => $maximapid; }; 
       alarm(5);
   
       my $selector = IO::Select->new();
   
     my $selector = IO::Select->new( );  
     $selector->add($cmd_err, $cmd_out);      $selector->add($cmd_err, $cmd_out);
           
     while (my @ready = $selector->can_read) {      while (my @ready = $selector->can_read()) {
  foreach my $fh (@ready) {   foreach my $fh (@ready) {
     if (fileno($fh) == fileno($cmd_err)) {      if (ref($fh) 
    && ref($cmd_err)
    && fileno($fh) == fileno($cmd_err)) {
  $error.=<$cmd_err>;   $error.=<$cmd_err>;
     } else {      } else {
  my $line = scalar <$cmd_out>;   my $line = scalar(<$cmd_out>);
                 if ($line=~/^(\(\%o|\s)/) {                  if ($line=~/^(\(\%o|\s)/) {
                    $line=~s/^\(.*\)/     /;       $line=~s/^\(.*\)/     /; 
                    $reply.=$line;       $reply.=$line; 
        }   }
     }      }
     $selector->remove($fh) if eof($fh);      $selector->remove($fh) if eof($fh);
  }   }
     }      }
     close $cmd_out;      alarm(0);
     close $cmd_err;      $SIG{ALRM} = 'DEFAULT';
       if (ref($cmd_out)) { close($cmd_out); }
       if (ref($cmd_err)) { close($cmd_err); }
   
       &status("Command processed");
     return ($reply,$error,$exitstatus);      return ($reply,$error,$exitstatus);
 }  }
    
   # ------------------------------------------------------------ Service routines 
   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
   }
   
   
 print join("\n----\n",&maximareply('1234'));   
 print join("\n----\n",&maximareply('x0: 5;x1: 7;integrate (x^2, x, x0, x1);'));  # --------------------------------------------------------------------- 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");
   }
   
   
   
   # ---------------------------------------------------------------- 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;
   }
       
    
   # ---------------------------------------------------- Fork once and dissociate
    
   my $fpid=fork;
   exit if $fpid;
   die("Couldn't fork: $!") unless defined($fpid);
    
   POSIX::setsid() or die "Can't start new session: $!";
    
   # ------------------------------------------------------- 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");
   
    &process_requests($server);
   
           # tidy up gracefully and finish
   
           # this exit is VERY important, otherwise the child will become
           # a producer of more and more children, forking yourself into
           # process death.
           exit;
       }
   }
   
   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";
    }
       }    
   }
Removed from v.1.1  
changed lines
  Added in v.1.10

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