version 1.12, 2006/03/08 03:18:42
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version 1.23, 2007/02/03 04:09:30
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Line 30
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Line 30
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# http://www.lon-capa.org/ |
# http://www.lon-capa.org/ |
# |
# |
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use Expect; |
use IPC::Open3; |
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use IO::Select; |
use IO::Select; |
use IO::Socket; |
use IO::Socket; |
use IO::File; |
use IO::File; |
Line 43 use LONCAPA::Configuration;
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Line 42 use LONCAPA::Configuration;
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use strict; |
use strict; |
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# global variables |
# global variables |
my $STARTPORT = 5664; # port for first child's server |
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my $PREFORK = 5; # number of children to maintain |
my $PREFORK = 5; # number of children to maintain |
my $MAX_CLIENTS_PER_CHILD = 5; # number of clients each child should process |
my $MAX_CLIENTS_PER_CHILD = 50; # number of clients each child should process |
my %children = (); # keys are current child process IDs |
my %children = (); # keys are current child process IDs |
my %usedmaximaports = (); # keys are the used maximaports |
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my $children = 0; # current number of children |
my $children = 0; # current number of children |
my $status; # string for current status |
my $status; # string for current status |
my $pidfile; # file containg parent process pid |
my $pidfile; # file containg parent process pid |
my $port; # path to UNIX socket file |
my $port; # path to UNIX socket file |
my %perlvar; # configuration file info |
my %perlvar; # configuration file info |
my $lastlog; # last string that was logged |
my $lastlog; # last string that was logged |
use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children %usedmaximaports $status |
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use vars qw($PREFORK $MAX_CLIENTS_PER_CHILD %children $children $status |
$pidfile $port %perlvar $lastlog); |
$pidfile $port %perlvar $lastlog); |
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sub maximareply { |
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my ($cmd,$maximaclient,$maximapid) = @_; |
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my $reply=''; |
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while (my $line=<$maximaclient>) { |
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$reply.=$line; |
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} |
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unless ($cmd=~/\;\n$/) { $cmd.=";\n"; } |
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print $maximaclient $cmd; |
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&status("Command sent to $maximapid"); |
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while (my $line=<$maximaclient>) { |
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$reply.=$line; |
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} |
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&status("Command processed by $maximapid"); |
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return $reply; |
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} |
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# ------------------------------------------------------------ Service routines |
# ------------------------------------------------------------ Service routines |
sub REAPER { # takes care of dead children |
sub REAPER { # takes care of dead children |
# and MAXIMA processes |
# and MAXIMA processes |
$SIG{CHLD} = \&REAPER; |
$SIG{CHLD} = \&REAPER; |
my $pid = wait; |
my $pid = wait; |
$children--; |
$children--; |
delete($usedmaximaports{$children{$pid}}); |
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delete($children{$pid}); |
delete($children{$pid}); |
} |
} |
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Line 221 close(PIDSAVE);
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Line 202 close(PIDSAVE);
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# Install signal handlers. |
# Install signal handlers. |
$SIG{CHLD} = \&REAPER; |
$SIG{CHLD} = \&REAPER; |
$SIG{INT} = $SIG{TERM} = \&HUNTSMAN; |
$SIG{INT} = $SIG{TERM} = \&HUNTSMAN; |
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my $maximaport=$STARTPORT; |
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# Fork off our children. |
# Fork off our children. |
for (1 .. $PREFORK) { |
for (1 .. $PREFORK) { |
&make_new_child($server,$maximaport); |
&make_new_child($server); |
$maximaport++; |
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} |
} |
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# And maintain the population. |
# And maintain the population. |
Line 235 while (1) {
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Line 214 while (1) {
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sleep; # wait for a signal (i.e., child's death) |
sleep; # wait for a signal (i.e., child's death) |
for (my $i = $children; $i < $PREFORK; $i++) { |
for (my $i = $children; $i < $PREFORK; $i++) { |
&status('Parent process, starting child'); |
&status('Parent process, starting child'); |
my $newport; |
&make_new_child($server); # top up the child pool |
foreach $newport ($STARTPORT .. $STARTPORT+$PREFORK-1) { |
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if (!defined($usedmaximaports{$newport})) { last; } |
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} |
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&make_new_child($server,$newport); # top up the child pool |
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} |
} |
} |
} |
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sub make_new_child { |
sub make_new_child { |
my ($server,$maximaport) = @_; |
my ($server) = @_; |
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# block signal for fork |
# block signal for fork |
my $sigset = POSIX::SigSet->new(SIGINT); |
my $sigset = POSIX::SigSet->new(SIGINT); |
Line 257 sub make_new_child {
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Line 232 sub make_new_child {
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# Parent records the child's birth and returns. |
# Parent records the child's birth and returns. |
sigprocmask(SIG_UNBLOCK, $sigset) |
sigprocmask(SIG_UNBLOCK, $sigset) |
or die("Can't unblock SIGINT for fork: $!\n"); |
or die("Can't unblock SIGINT for fork: $!\n"); |
$children{$pid} = $maximaport; |
$children{$pid} = 1; |
$children++; |
$children++; |
return; |
return; |
} else { |
} else { |
Line 267 sub make_new_child {
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Line 242 sub make_new_child {
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# unblock signals |
# unblock signals |
sigprocmask(SIG_UNBLOCK, $sigset) |
sigprocmask(SIG_UNBLOCK, $sigset) |
or die("Can't unblock SIGINT for fork: $!\n"); |
or die("Can't unblock SIGINT for fork: $!\n"); |
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# open the MAXIMA port |
&logthis('New process started'); |
my $maximaserver = IO::Socket::INET->new(LocalPort => $maximaport, |
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Type => SOCK_STREAM, |
my $command=Expect->spawn('maxima'); |
Proto => 'tcp', |
$command->log_stdout(0); |
Reuse => 1, |
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Listen => 10 ) |
&getmaximaoutput($command); |
or die "making socket: $@\n"; |
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for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) { |
# open MAXIMA to talk to that port |
&status('Accepting connections'); |
my ($cmd_in, $cmd_out, $cmd_err); |
my $client = $server->accept() or last; |
my $maximapid = open3($cmd_in, $cmd_out, $cmd_err, "maxima -s $maximaport"); |
print $command "kill(all);\n"; |
$children{$maximapid} = 1; |
&getmaximaoutput($command); |
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&sync($command); |
my $prompt=<$cmd_out>; |
while (my $cmd=<$client>) { |
&logthis("Maxima $maximapid: $prompt"); |
&status('Processing command'); |
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print $command &unescape($cmd); |
&status("Waiting $maximapid on $maximaport"); |
my ($reply,$finished,$syntaxerr) = &getmaximaoutput($command); |
# Hopefully, MAXIMA calls us back |
if ((!$finished) && (!$syntaxerr) && ($reply !~ /^Error\:/)) { |
my $maximaclient=$maximaserver->accept(); |
($reply,$finished,$syntaxerr) = &getmaximaoutput($command); |
&status("$maximapid on $maximaport connected."); |
} |
&logthis("Maxima $maximapid on port $maximaport connected."); |
print $client &escape($reply)."\n"; |
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if ($reply=~/^Error\:/) { |
# Absorb initial prompts |
&logthis('Died through '.$reply); |
&logthis(&maximareply("0;\n",$maximaclient,$maximapid)); |
$client->close(); |
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$command->hard_close(); |
# Ready for action |
exit; |
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} |
&process_requests($server,$maximaclient,$maximapid); |
&sync($command); |
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&status('Waiting for commands'); |
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} |
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} |
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# tidy up gracefully and finish |
# tidy up gracefully and finish |
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if (ref($cmd_out)) { close($cmd_out); } |
$command->soft_close(); |
if (ref($cmd_err)) { close($cmd_err); } |
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if (ref($cmd_in)) { close($cmd_in); } |
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# this exit is VERY important, otherwise the child will become |
# this exit is VERY important, otherwise the child will become |
# a producer of more and more children, forking yourself into |
# a producer of more and more children, forking yourself into |
Line 310 sub make_new_child {
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Line 286 sub make_new_child {
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} |
} |
} |
} |
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sub process_requests { |
{ |
my ($server,$maximaclient,$maximapid) = @_; |
my $counter; |
# handle connections until we've reached $MAX_CLIENTS_PER_CHILD |
sub sync { |
for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) { |
my ($command)=@_; |
&status('Accepting connections for '.$maximapid.' on '.$maximaport); |
$counter++; |
my $client = $server->accept() or last; |
my $expect=$counter.time; |
while (my $cmd=<$client>) { |
print $command "$expect;\n"; |
&status('Processing command by '.$maximapid.' on '.$maximaport); |
while (1) { |
print $client &escape((&maximareply(&unescape($cmd),$maximaclient,$maximapid))[0])."\n"; |
my $output=&getmaximaoutput($command); |
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if (($output=~/\Q$expect\E/) || ($output=~/^Error\:/)) { |
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return; |
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} |
} |
} |
} |
} |
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} |
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sub getmaximaoutput { |
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my ($command)=@_; |
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my (undef,$error,undef,$output)=$command->expect(20, -re => '\(\%i\d+\)'); |
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if ($error) { |
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return 'Error: '.$error; |
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} |
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$output =~ s/\r+//g; # Remove Windows-style linebreaks |
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my $hasoutput=0; |
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my $foundoutput=0; |
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my $syntaxerr=0; |
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my $realoutput=''; |
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foreach my $line (split(/\n/,$output)) { |
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if ($line=~/\;/) { $foundoutput=1; next; } |
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if (!$foundoutput) { next; } |
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if ($line=~/^Incorrect syntax:/) { $syntaxerr = 1; next; } |
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(my $label, $line) = ($line=~ /^(\(\%o\d+\))(.+)$/); |
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if ($label) { |
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$label=~s/\S/ /g; |
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$line=$label.$line; |
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$hasoutput = 1; |
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} |
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$realoutput.=$line."\n"; |
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} |
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if (wantarray) { |
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return ($realoutput,$hasoutput,$syntaxerr); |
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} else { |
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return $realoutput; |
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} |
} |
} |