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- hard_timeout wasn't a good idea, now setting alarms and more gracefully exit

    1: package Apache::run;
    2: #
    3: # $Id: run.pm,v 1.32 2003/03/24 22:43:31 albertel Exp $
    4: #
    5: # Copyright Michigan State University Board of Trustees
    6: #
    7: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
    8: #
    9: # LON-CAPA is free software; you can redistribute it and/or modify
   10: # it under the terms of the GNU General Public License as published by
   11: # the Free Software Foundation; either version 2 of the License, or
   12: # (at your option) any later version.
   13: #
   14: # LON-CAPA is distributed in the hope that it will be useful,
   15: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   16: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   17: # GNU General Public License for more details.
   18: #
   19: # You should have received a copy of the GNU General Public License
   20: # along with LON-CAPA; if not, write to the Free Software
   21: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   22: #
   23: # /home/httpd/html/adm/gpl.txt
   24: #
   25: # http://www.lon-capa.org/
   26: #
   27: 
   28: use HTML::Entities;
   29: 
   30: $Apache::run::EVALUATE_STRING=<<'ENDEVALUATE';  
   31:   my %_LONCAPA_INTERNAL_oldexpressions=();
   32:   while (!$_LONCAPA_INTERNAL_oldexpressions{$_}) {
   33:     $_LONCAPA_INTERNAL_oldexpressions{$_}=1;
   34:     $_ =~s/((?:\$|\&)(?:[\#|\$]*[A-Za-z][\w]*|\{[A-Za-z][\w]*\}))([\[\{][^\$\&\]\}]+[\]\}])*?(\([^\$\&\)]+\))*?(?=[^\[\{\(]|$)/eval(defined(eval($1.$2))?eval('$1.$2.$3'):'$1.$2.$3')/seg;
   35:     if (scalar(values(%_LONCAPA_INTERNAL_oldexpressions))>10) {last;}
   36:   }
   37: ENDEVALUATE
   38: 
   39: sub evaluate {
   40:     my ($expression,$safeeval,$decls) = @_;
   41:     unless (defined($expression)) { return ''; }
   42:     if ($Apache::lonxml::evaluate < 1) { return $expression; }
   43:     my $result = '';
   44:     $@='';
   45:     $Apache::run::timeout=0;
   46:     $main::SIG{'ALRM'} = sub {
   47: 	$Apache::run::timeout=1;
   48: 	Apache->request->print("timeout<br /> \n");
   49:     };
   50:     eval {
   51: 	alarm(Apache->request->server->timeout);
   52: 	$safeeval->reval('{'.$decls.';$_=<<\'EXPRESSION\';'."\n".$expression.
   53: 			 "\n".'EXPRESSION'."\n".$EVALUATE_STRING.'}');
   54: 	alarm(0);
   55:     };
   56:     my $error=$@;
   57:     if ($error eq '' && !$Apache::run::timeout) {
   58: 	$result = $safeeval->reval('return $_;');
   59: 	chomp $result;
   60:     } else {
   61: 	if ($Apache::run::timeout) {
   62: 	    $error = 'Code ran too long. It ran for more than '.
   63: 		Apache->request->server->timeout.' seconds';
   64: 	}
   65: 	&Apache::lonxml::error('substitution on <pre>'.$expression.
   66: 			       '</pre> with <pre>'.$decls.
   67: 			       '</pre> caused <pre>'.$error);
   68:     }
   69:     return $result
   70: }
   71: 
   72: sub run {
   73:     my ($code,$safeeval,$hideerrors) = @_;
   74:     my @result;
   75:     $@='';
   76:     $Apache::run::timeout=0;
   77:     $main::SIG{'ALRM'} = sub {
   78: 	$Apache::run::timeout=1;
   79: 	Apache->request->print("timeout<br /> \n");
   80:     };
   81:     eval {
   82: 	alarm(Apache->request->server->timeout);
   83: 	@result=$safeeval->reval($code);
   84: 	alarm(0);
   85:     };
   86:     my $error=$@;
   87:     if (($Apache::run::timeout || $error ne '') && !$hideerrors) {
   88: 	if ($Apache::run::timeout) {
   89: 	    $error = 'Code ran too long. It ran for more than '.
   90: 		Apache->request->server->timeout.' seconds';
   91: 	}
   92: 	&Apache::lonxml::error('<pre>'.&HTML::Entities::encode($error).
   93: 			       '</pre> occured while running <pre>'.
   94: 			       &HTML::Entities::encode($code).'</pre>');
   95:     }
   96:     if ( $#result < '1') {
   97: 	return $result[0];
   98:     } else {
   99: 	&Apache::lonxml::debug("<b>Got lots results</b>:$#result:");
  100: 	return (@result);
  101:     }
  102: }
  103: 
  104: sub dump {
  105:   my ($target,$safeeval)=@_;
  106:   my $dump='';
  107:   foreach my $symname (sort keys %{$safeeval->varglob('main::')}) {
  108:     if (($symname!~/^\_/) && ($symname!~/\:$/)) {
  109:       my $line;
  110:       if ($safeeval->reval('defined($'.$symname.')')) {
  111: 	$line='$'.$symname.'='.$safeeval->reval('$'.$symname);
  112:       }	
  113:       if ($safeeval->reval('defined(@'.$symname.')')) {
  114: 	$line='@'.$symname.'=('.
  115: 	  $safeeval->reval('join(",",@'.$symname.')').")";
  116:       }
  117:       if ($safeeval->reval('defined(%'.$symname.')')) {
  118: 	$line='%'.$symname.'=(';
  119: 	$line.=$safeeval->reval('join(",",map { $_."=>".$'.
  120: 				$symname.'{$_} } sort keys %'.
  121: 				$symname.')').")"
  122:       }
  123:       if ($line ne '') { $dump.=&HTML::Entities::encode($line)."<br />\n"; }
  124:     }
  125:   }
  126:   $dump.='';
  127:   return $dump;
  128: }
  129: 
  130: 1;
  131: __END__;