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Diff for /loncom/loncnew between versions 1.11 and 1.35

version 1.11, 2003/06/25 01:54:44	version 1.35, 2003/12/12 09:57:28
Line 7	Line 7
# Copyright Michigan State University Board of Trustees	# Copyright Michigan State University Board of Trustees
#	#
# This file is part of the LearningOnline Network with CAPA (LON-CAPA).	# This file is part of the LearningOnline Network with CAPA (LON-CAPA).
#	## LON-CAPA is free software; you can redistribute it and/or modify
# LON-CAPA is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by	# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or	# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.	# (at your option) any later version.
Line 27	Line 26
# http://www.lon-capa.org/	# http://www.lon-capa.org/
#	#
#	#
# new lonc handles n requestors spread out bver m connections to londs.	# new lonc handles n request out bver m connections to londs.
# This module is based on the Event class.	# This module is based on the Event class.
# Development iterations:	# Development iterations:
# - Setup basic event loop. (done)	# - Setup basic event loop. (done)
Line 44	Line 43
# - Detect transmission timeouts.	# - Detect transmission timeouts.
#	#

# Change log:	use strict;
# $Log$
# Revision 1.11 2003/06/25 01:54:44 foxr
# Fix more problems with transaction failure.
#
# Revision 1.10 2003/06/24 02:46:04 foxr
# Put a limit on the number of times we'll retry a connection.
# Start getting the signal stuff put in as well...note that need to get signals
# going or else 6the client will permanently give up on dead servers.
#
# Revision 1.9 2003/06/13 02:38:43 foxr
# Add logging in 'expected format'
#
# Revision 1.8 2003/06/11 02:04:35 foxr
# Support delayed transactions... this is done uniformly by encapsulating
# transactions in an object ... a LondTransaction that is implemented by
# LondTransaction.pm
#
# Revision 1.7 2003/06/03 01:59:39 foxr
# complete coding to support deferred transactions.
#
#

use lib "/home/httpd/lib/perl/";	use lib "/home/httpd/lib/perl/";
use lib "/home/foxr/newloncapa/types";
use Event qw(:DEFAULT );	use Event qw(:DEFAULT );
use POSIX qw(:signal_h);	use POSIX qw(:signal_h);
	use POSIX;
use IO::Socket;	use IO::Socket;
use IO::Socket::INET;	use IO::Socket::INET;
use IO::Socket::UNIX;	use IO::Socket::UNIX;
Line 89 use LONCAPA::HashIterator;	Line 66 use LONCAPA::HashIterator;
#	#
# Disable all signals we might receive from outside for now.	# Disable all signals we might receive from outside for now.
#	#
$SIG{QUIT} = IGNORE;
$SIG{HUP} = IGNORE;
$SIG{USR1} = IGNORE;
$SIG{INT} = IGNORE;
$SIG{CHLD} = IGNORE;
$SIG{__DIE__} = IGNORE;


# Read the httpd configuration file to get perl variables	# Read the httpd configuration file to get perl variables
Line 107 my %perlvar = %{$perlvarref};	Line 78 my %perlvar = %{$perlvarref};
# parent and shared variables.	# parent and shared variables.

my %ChildHash; # by pid -> host.	my %ChildHash; # by pid -> host.
	my %HostToPid; # By host -> pid.
	my %HostHash; # by loncapaname -> IP.


my $MaxConnectionCount = 10; # Will get from config later.	my $MaxConnectionCount = 10; # Will get from config later.
my $ClientConnection = 0; # Uniquifier for client events.	my $ClientConnection = 0; # Uniquifier for client events.

my $DebugLevel = 0;	my $DebugLevel = 0;
	my $NextDebugLevel= 2; # So Sigint can toggle this.
my $IdleTimeout= 3600; # Wait an hour before pruning connections.	my $IdleTimeout= 3600; # Wait an hour before pruning connections.

#	#
# The variables below are only used by the child processes.	# The variables below are only used by the child processes.
#	#
my $RemoteHost; # Name of host child is talking to.	my $RemoteHost; # Name of host child is talking to.
my $UnixSocketDir= "/home/httpd/sockets";	my $UnixSocketDir= $perlvar{'lonSockDir'};
my $IdleConnections = Stack->new(); # Set of idle connections	my $IdleConnections = Stack->new(); # Set of idle connections
my %ActiveConnections; # Connections to the remote lond.	my %ActiveConnections; # Connections to the remote lond.
my %ActiveTransactions; # LondTransactions in flight.	my %ActiveTransactions; # LondTransactions in flight.
Line 128 my $WorkQueue = Queue->new(); # Qu	Line 102 my $WorkQueue = Queue->new(); # Qu
my $ConnectionCount = 0;	my $ConnectionCount = 0;
my $IdleSeconds = 0; # Number of seconds idle.	my $IdleSeconds = 0; # Number of seconds idle.
my $Status = ""; # Current status string.	my $Status = ""; # Current status string.
my $ConnectionRetries=5; # Number of connection retries allowed.	my $RecentLogEntry = "";
my $ConnectionRetriesLeft=5; # Number of connection retries remaining.	my $ConnectionRetries=2; # Number of connection retries allowed.
	my $ConnectionRetriesLeft=2; # Number of connection retries remaining.

#	#
# The hash below gives the HTML format for log messages	# The hash below gives the HTML format for log messages
Line 204 sub Log {	Line 179 sub Log {
my $execdir = $perlvar{'lonDaemons'};	my $execdir = $perlvar{'lonDaemons'};
my $fh = IO::File->new(">>$execdir/logs/lonc.log");	my $fh = IO::File->new(">>$execdir/logs/lonc.log");
my $msg = sprintf($finalformat, $message);	my $msg = sprintf($finalformat, $message);
	$RecentLogEntry = $msg;
print $fh $msg;	print $fh $msg;


Line 226 sub GetPeername {	Line 202 sub GetPeername {
my $peerip;	my $peerip;
if($AdrFamily == AF_INET) {	if($AdrFamily == AF_INET) {
($peerport, $peerip) = sockaddr_in($peer);	($peerport, $peerip) = sockaddr_in($peer);
my $peername = gethostbyaddr($iaddr, $AdrFamily);	my $peername = gethostbyaddr($peerip, $AdrFamily);
return $peername;	return $peername;
} elsif ($AdrFamily == AF_UNIX) {	} elsif ($AdrFamily == AF_UNIX) {
my $peerfile;	my $peerfile;
Line 234 sub GetPeername {	Line 210 sub GetPeername {
return $peerfile;	return $peerfile;
}	}
}	}
#----------------------------- Timer management ------------------------
=pod	=pod

=head2 Debug	=head2 Debug
Line 247 sub Debug {	Line 222 sub Debug {
my $level = shift;	my $level = shift;
my $message = shift;	my $message = shift;
if ($level <= $DebugLevel) {	if ($level <= $DebugLevel) {
print $message." host = ".$RemoteHost."\n";	Log("INFO", "-Debug- $message host = $RemoteHost");
}	}
}	}

Line 277 sub ShowStatus {	Line 252 sub ShowStatus {

=pod	=pod

	=head 2 SocketTimeout

	Called when an action on the socket times out. The socket is
	destroyed and any active transaction is failed.


	=cut
	sub SocketTimeout {
	my $Socket = shift;

	KillSocket($Socket); # A transaction timeout also counts as
	# a connection failure:
	$ConnectionRetriesLeft--;
	}
	#----------------------------- Timer management ------------------------

	=pod

=head2 Tick	=head2 Tick

Invoked each timer tick.	Invoked each timer tick.
Line 286 Invoked each timer tick.	Line 279 Invoked each timer tick.

sub Tick {	sub Tick {
my $client;	my $client;
ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount);	if($ConnectionRetriesLeft > 0) {
Debug(10,"Tick");	ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
Debug(10," Current connection count: ".$ConnectionCount);	." Retries remaining: ".$ConnectionRetriesLeft);
foreach $client (keys %ActiveClients) {	} else {
Debug(10," Have client: with id: ".$ActiveClients{$client});	ShowStatus(GetServerHost()." >> DEAD <<");
}	}
# Is it time to prune connection count:	# Is it time to prune connection count:

Line 299 sub Tick {	Line 292 sub Tick {
($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?	($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
$IdleSeconds++;	$IdleSeconds++;
if($IdleSeconds > $IdleTimeout) { # Prune a connection...	if($IdleSeconds > $IdleTimeout) { # Prune a connection...
$Socket = $IdleConnections->pop();	my $Socket = $IdleConnections->pop();
KillSocket($Socket);	KillSocket($Socket);
}	}
} else {	} else {
$IdleSeconds = 0; # Reset idle count if not idle.	$IdleSeconds = 0; # Reset idle count if not idle.
}	}
	#
	# For each inflight transaction, tick down its timeout counter.
	#

	foreach my $item (keys %ActiveConnections) {
	my $State = $ActiveConnections{$item}->data->GetState();
	if ($State ne 'Idle') {
	Debug(5,"Ticking Socket $State $item");
	$ActiveConnections{$item}->data->Tick();
	}
	}
# Do we have work in the queue, but no connections to service them?	# Do we have work in the queue, but no connections to service them?
# If so, try to make some new connections to get things going again.	# If so, try to make some new connections to get things going again.
#	#
Line 315 sub Tick {	Line 318 sub Tick {
if ($ConnectionRetriesLeft > 0) {	if ($ConnectionRetriesLeft > 0) {
my $Connections = ($Requests <= $MaxConnectionCount) ?	my $Connections = ($Requests <= $MaxConnectionCount) ?
$Requests : $MaxConnectionCount;	$Requests : $MaxConnectionCount;
Debug(1,"Work but no connections, start ".$Connections." of them");	Debug(5,"Work but no connections, start ".$Connections." of them");
for ($i =0; $i < $Connections; $i++) {	my $successCount = 0;
MakeLondConnection();	for (my $i =0; $i < $Connections; $i++) {
	$successCount += MakeLondConnection();
	}
	if($successCount == 0) { # All connections failed:
	Debug(5,"Work in queue failed to make any connectiouns\n");
	EmptyQueue(); # Fail pending transactions with con_lost.
}	}
} else {	} else {
Debug(1,"Work in queue, but gave up on connections..flushing\n");	ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
	Debug(5,"Work in queue, but gave up on connections..flushing\n");
EmptyQueue(); # Connections can't be established.	EmptyQueue(); # Connections can't be established.
}	}

Line 345 Trigger disconnections of idle sockets.	Line 354 Trigger disconnections of idle sockets.

sub SetupTimer {	sub SetupTimer {
Debug(6, "SetupTimer");	Debug(6, "SetupTimer");
Event->timer(interval => 1, debug => 1, cb => \&Tick );	Event->timer(interval => 1, cb => \&Tick );
}	}

=pod	=pod
Line 367 sub ServerToIdle {	Line 376 sub ServerToIdle {
my $Socket = shift; # Get the socket.	my $Socket = shift; # Get the socket.
delete($ActiveTransactions{$Socket}); # Server has no transaction	delete($ActiveTransactions{$Socket}); # Server has no transaction

&Debug(6, "Server to idle");	&Debug(5, "Server to idle");

# If there's work to do, start the transaction:	# If there's work to do, start the transaction:

$reqdata = $WorkQueue->dequeue(); # This is a LondTransaction	my $reqdata = $WorkQueue->dequeue(); # This is a LondTransaction
unless($reqdata eq undef) {	if ($reqdata ne undef) {
Debug(9, "Queue gave request data: ".$reqdata->getRequest());	Debug(5, "Queue gave request data: ".$reqdata->getRequest());
&StartRequest($Socket, $reqdata);	&StartRequest($Socket, $reqdata);

} else {	} else {

# There's no work waiting, so push the server to idle list.	# There's no work waiting, so push the server to idle list.
&Debug(8, "No new work requests, server connection going idle");	&Debug(5, "No new work requests, server connection going idle");
$IdleConnections->push($Socket);	$IdleConnections->push($Socket);
}	}
}	}
Line 425 sub ClientWritable {	Line 434 sub ClientWritable {
# request.	# request.

&Debug(9,"Send result is ".$result." Defined: ".defined($result));	&Debug(9,"Send result is ".$result." Defined: ".defined($result));
if(defined($result)) {	if($result ne undef) {
&Debug(9, "send result was defined");	&Debug(9, "send result was defined");
if($result == length($Data)) { # Entire string sent.	if($result == length($Data)) { # Entire string sent.
&Debug(9, "ClientWritable data all written");	&Debug(9, "ClientWritable data all written");
Line 443 sub ClientWritable {	Line 452 sub ClientWritable {

} else { # Partial string sent.	} else { # Partial string sent.
$Watcher->data(substr($Data, $result));	$Watcher->data(substr($Data, $result));
	if($result == 0) { # client hung up on us!!
	Log("INFO", "lonc pipe client hung up on us!");
	$Watcher->cancel;
	$Socket->shutdown(2);
	$Socket->close();
	}
}	}

} else { # Error of some sort...	} else { # Error of some sort...
Line 490 The transaction that is being completed.	Line 505 The transaction that is being completed.
=cut	=cut

sub CompleteTransaction {	sub CompleteTransaction {
&Debug(6,"Complete transaction");	&Debug(5,"Complete transaction");
my $Socket = shift;	my $Socket = shift;
my $Transaction = shift;	my $Transaction = shift;

Line 499 sub CompleteTransaction {	Line 514 sub CompleteTransaction {
StartClientReply($Transaction, $data);	StartClientReply($Transaction, $data);
} else { # Delete deferred transaction file.	} else { # Delete deferred transaction file.
Log("SUCCESS", "A delayed transaction was completed");	Log("SUCCESS", "A delayed transaction was completed");
LogPerm("S:$Client:".$Transaction->getRequest());	LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());
unlink $Transaction->getFile();	unlink $Transaction->getFile();
}	}
}	}
Line 523 sub StartClientReply {	Line 538 sub StartClientReply {
my $Transaction = shift;	my $Transaction = shift;
my $data = shift;	my $data = shift;


my $Client = $Transaction->getClient();	my $Client = $Transaction->getClient();

&Debug(8," Reply was: ".$data);	&Debug(8," Reply was: ".$data);
my $Serial = $ActiveClients{$Client};	my $Serial = $ActiveClients{$Client};
my $desc = sprintf("Connection to lonc client %d",	my $desc = sprintf("Connection to lonc client %d",

$Serial);	$Serial);
Event->io(fd => $Client,	Event->io(fd => $Client,
poll => "w",	poll => "w",
Line 559 Parameters:	Line 574 Parameters:

sub FailTransaction {	sub FailTransaction {
my $transaction = shift;	my $transaction = shift;
	Log("WARNING", "Failing transaction ".$transaction->getRequest());
Debug(1, "Failing transaction: ".$transaction->getRequest());	Debug(1, "Failing transaction: ".$transaction->getRequest());
if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.	if (!$transaction->isDeferred()) { # If the transaction is deferred we'll get to it.
my $client = $transaction->getClient();	my $client = $transaction->getClient();
Debug(1," Replying con_lost to ".$transaction->getRequest());	Debug(1," Replying con_lost to ".$transaction->getRequest());
StartClientReply($transaction, "con_lost\n");	StartClientReply($transaction, "con_lost\n");
}	}
	if($ConnectionRetriesLeft <= 0) {
	Log("CRITICAL", "Host marked dead: ".GetServerHost());
	}

}	}

Line 576 sub FailTransaction {	Line 595 sub FailTransaction {

=cut	=cut
sub EmptyQueue {	sub EmptyQueue {
	$ConnectionRetriesLeft--; # Counts as connection failure too.
while($WorkQueue->Count()) {	while($WorkQueue->Count()) {
my $request = $WorkQueue->dequeue(); # This is a transaction	my $request = $WorkQueue->dequeue(); # This is a transaction
FailTransaction($request);	FailTransaction($request);
Line 590 Close all connections open on lond prior	Line 610 Close all connections open on lond prior

=cut	=cut
sub CloseAllLondConnections {	sub CloseAllLondConnections {
foreach $Socket (keys %ActiveConnections) {	foreach my $Socket (keys %ActiveConnections) {
KillSocket($Socket);	KillSocket($Socket);
}	}
}	}
Line 621 nonzero if we are allowed to create a ne	Line 641 nonzero if we are allowed to create a ne
sub KillSocket {	sub KillSocket {
my $Socket = shift;	my $Socket = shift;

	Log("WARNING", "Shutting down a socket");
$Socket->Shutdown();	$Socket->Shutdown();

# If the socket came from the active connection set,	# If the socket came from the active connection set,
Line 641 sub KillSocket {	Line 662 sub KillSocket {
# work queue, the work all gets failed with con_lost.	# work queue, the work all gets failed with con_lost.
#	#
if($ConnectionCount == 0) {	if($ConnectionCount == 0) {
EmptyQueue;	EmptyQueue();
}	}
}	}

Line 710 sub LondReadable {	Line 731 sub LondReadable {
my $Socket = $Watcher->data;	my $Socket = $Watcher->data;
my $client = undef;	my $client = undef;

&Debug(6,"LondReadable called state = ".$State);	&Debug(6,"LondReadable called state = ".$Socket->GetState());


my $State = $Socket->GetState(); # All action depends on the state.	my $State = $Socket->GetState(); # All action depends on the state.

SocketDump(6, $Socket);	SocketDump(6, $Socket);
	my $status = $Socket->Readable();

if($Socket->Readable() != 0) {	&Debug(2, "Socket->Readable returned: $status");

	if($status != 0) {
# bad return from socket read. Currently this means that	# bad return from socket read. Currently this means that
# The socket has become disconnected. We fail the transaction.	# The socket has become disconnected. We fail the transaction.

	Log("WARNING",
	"Lond connection lost.");
if(exists($ActiveTransactions{$Socket})) {	if(exists($ActiveTransactions{$Socket})) {
Debug(3,"Lond connection lost failing transaction");
FailTransaction($ActiveTransactions{$Socket});	FailTransaction($ActiveTransactions{$Socket});
}	}
$Watcher->cancel();	$Watcher->cancel();
KillSocket($Socket);	KillSocket($Socket);
	$ConnectionRetriesLeft--; # Counts as connection failure
return;	return;
}	}
SocketDump(6,$Socket);	SocketDump(6,$Socket);
Line 760 sub LondReadable {	Line 786 sub LondReadable {
} elsif ($State eq "Idle") {	} elsif ($State eq "Idle") {
# If necessary, complete a transaction and then go into the	# If necessary, complete a transaction and then go into the
# idle queue.	# idle queue.
	# Note that a trasition to idle indicates a live lond
	# on the other end so reset the connection retries.
	#
	$ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
$Watcher->cancel();	$Watcher->cancel();
if(exists($ActiveTransactions{$Socket})) {	if(exists($ActiveTransactions{$Socket})) {
Debug(8,"Completing transaction!!");	Debug(5,"Completing transaction!!");
CompleteTransaction($Socket,	CompleteTransaction($Socket,
$ActiveTransactions{$Socket});	$ActiveTransactions{$Socket});
} else {	} else {
Line 872 sub LondWritable {	Line 902 sub LondWritable {
# We'll treat this as if the socket got disconnected:	# We'll treat this as if the socket got disconnected:
Log("WARNING", "Connection to ".$RemoteHost.	Log("WARNING", "Connection to ".$RemoteHost.
" has been disconnected");	" has been disconnected");
	FailTransaction($ActiveTransactions{$Socket});
$Watcher->cancel();	$Watcher->cancel();
KillSocket($Socket);	KillSocket($Socket);
return;	return;
Line 971 sub QueueDelayed {	Line 1002 sub QueueDelayed {
Debug(4, "Delayed path: ".$path);	Debug(4, "Delayed path: ".$path);
opendir(DIRHANDLE, $path);	opendir(DIRHANDLE, $path);

@alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;	my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;
Debug(4, "Got ".$alldelayed." delayed files");
closedir(DIRHANDLE);	closedir(DIRHANDLE);
my $dfname;	my $dfname;
my $reqfile;	my $reqfile;
Line 982 sub QueueDelayed {	Line 1012 sub QueueDelayed {
my $Handle = IO::File->new($reqfile);	my $Handle = IO::File->new($reqfile);
my $cmd = <$Handle>;	my $cmd = <$Handle>;
chomp $cmd; # There may or may not be a newline...	chomp $cmd; # There may or may not be a newline...
$cmd = $cmd."\ny"; # now for sure there's exactly one newline.	$cmd = $cmd."\n"; # now for sure there's exactly one newline.
my $Transaction = LondTransaction->new($cmd);	my $Transaction = LondTransaction->new($cmd);
$Transaction->SetDeferred($reqfile);	$Transaction->SetDeferred($reqfile);
QueueTransaction($Transaction);	QueueTransaction($Transaction);
Line 1009 sub MakeLondConnection {	Line 1039 sub MakeLondConnection {
my $Connection = LondConnection->new(&GetServerHost(),	my $Connection = LondConnection->new(&GetServerHost(),
&GetServerPort());	&GetServerPort());

if($Connection == undef) { # Needs to be more robust later.	if($Connection eq undef) { # Needs to be more robust later.
Log("CRITICAL","Failed to make a connection with lond.");	Log("CRITICAL","Failed to make a connection with lond.");
$ConnectionRetriesLeft--;	$ConnectionRetriesLeft--;
return 0; # Failure.	return 0; # Failure.
} else {	} else {
$ConnectionRetriesLeft = $ConnectionRetries; # success resets the count
# The connection needs to have writability	# The connection needs to have writability
# monitored in order to send the init sequence	# monitored in order to send the init sequence
# that starts the whole authentication/key	# that starts the whole authentication/key
# exchange underway.	# exchange underway.
#	#
my $Socket = $Connection->GetSocket();	my $Socket = $Connection->GetSocket();
if($Socket == undef) {	if($Socket eq undef) {
die "did not get a socket from the connection";	die "did not get a socket from the connection";
} else {	} else {
&Debug(9,"MakeLondConnection got socket: ".$Socket);	&Debug(9,"MakeLondConnection got socket: ".$Socket);
}	}

	$Connection->SetTimeoutCallback(\&SocketTimeout);
$event = Event->io(fd => $Socket,
	my $event = Event->io(fd => $Socket,
poll => 'w',	poll => 'w',
cb => \&LondWritable,	cb => \&LondWritable,
data => $Connection,	data => $Connection,
Line 1084 sub StartRequest {	Line 1115 sub StartRequest {
$ActiveTransactions{$Lond} = $Request;	$ActiveTransactions{$Lond} = $Request;

$Lond->InitiateTransaction($Request->getRequest());	$Lond->InitiateTransaction($Request->getRequest());
$event = Event->io(fd => $Socket,	my $event = Event->io(fd => $Socket,
poll => "w",	poll => "w",
cb => \&LondWritable,	cb => \&LondWritable,
data => $Lond,	data => $Lond,
Line 1123 sub QueueTransaction {	Line 1154 sub QueueTransaction {

my $LondSocket = $IdleConnections->pop();	my $LondSocket = $IdleConnections->pop();
if(!defined $LondSocket) { # Need to queue request.	if(!defined $LondSocket) { # Need to queue request.
Debug(8,"Must queue...");	Debug(5,"Must queue...");
$WorkQueue->enqueue($requestData);	$WorkQueue->enqueue($requestData);
if($ConnectionCount < $MaxConnectionCount) {	if($ConnectionCount < $MaxConnectionCount) {
Debug(4,"Starting additional lond connection");	if($ConnectionRetriesLeft > 0) {
MakeLondConnection();	Debug(5,"Starting additional lond connection");
	if(MakeLondConnection() == 0) {
	EmptyQueue(); # Fail transactions, can't make connection.
	}
	} else {
	ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
	EmptyQueue(); # It's worse than that ... he's dead Jim.
	}
}	}
} else { # Can start the request:	} else { # Can start the request:
Debug(8,"Can start...");	Debug(8,"Can start...");
Line 1158 sub ClientRequest {	Line 1196 sub ClientRequest {
my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);	my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
Debug(8, "rcv: data length = ".length($thisread)	Debug(8, "rcv: data length = ".length($thisread)
." read =".$thisread);	." read =".$thisread);
unless (defined $rv && length($thisread)) {	unless (defined $rv && length($thisread)) {
# Likely eof on socket.	# Likely eof on socket.
Debug(5,"Client Socket closed on lonc for ".$RemoteHost);	Debug(5,"Client Socket closed on lonc for ".$RemoteHost);
close($socket);	close($socket);
Line 1285 sub SetupLoncListener {	Line 1323 sub SetupLoncListener {
fd => $socket);	fd => $socket);
}	}

	=pod

	=head2 ChildStatus

	Child USR1 signal handler to report the most recent status
	into the status file.

	We also use this to reset the retries count in order to allow the
	client to retry connections with a previously dead server.
	=cut
	sub ChildStatus {
	my $event = shift;
	my $watcher = $event->w;

	Debug(2, "Reporting child status because : ".$watcher->data);
	my $docdir = $perlvar{'lonDocRoot'};
	my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
	print $fh $$."\t".$RemoteHost."\t".$Status."\t".
	$RecentLogEntry."\n";
	$ConnectionRetriesLeft = $ConnectionRetries;
	}

=pod	=pod

=head2 SignalledToDeath	=head2 SignalledToDeath
Line 1293 Called in response to a signal that caus	Line 1353 Called in response to a signal that caus

=cut	=cut

=pod

sub SignalledToDeath {	sub SignalledToDeath {
my ($signal) = @_;	my $event = shift;
	my $watcher= $event->w;

	Debug(2,"Signalled to death! via ".$watcher->data);
	my ($signal) = $watcher->data;
chomp($signal);	chomp($signal);
Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "	Log("CRITICAL", "Abnormal exit. Child $$ for $RemoteHost "
."died through "."\"$signal\"");	."died through "."\"$signal\"");
LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "	LogPerm("F:lonc: $$ on $RemoteHost signalled to death: "
."\"$signal\"");	."\"$signal\"");
die("Signal abnormal end");	exit 0;

}	}

	=head2 ToggleDebug

	This sub toggles trace debugging on and off.

	=cut

	sub ToggleDebug {
	my $Current = $DebugLevel;
	$DebugLevel = $NextDebugLevel;
	$NextDebugLevel = $Current;

	Log("SUCCESS", "New debugging level for $RemoteHost now $DebugLevel");

	}

=head2 ChildProcess	=head2 ChildProcess

This sub implements a child process for a single lonc daemon.	This sub implements a child process for a single lonc daemon.
Line 1314 This sub implements a child process for	Line 1393 This sub implements a child process for
sub ChildProcess {	sub ChildProcess {


# For now turn off signals.	#
	# Signals must be handled by the Event framework...
$SIG{QUIT} = \&SignalledToDeath;	#
$SIG{HUP} = IGNORE;
$SIG{USR1} = IGNORE;	Event->signal(signal => "QUIT",
$SIG{INT} = IGNORE;	cb => \&SignalledToDeath,
$SIG{CHLD} = IGNORE;	data => "QUIT");
$SIG{__DIE__} = \&SignalledToDeath;	Event->signal(signal => "HUP",
	cb => \&ChildStatus,
	data => "HUP");
	Event->signal(signal => "USR1",
	cb => \&ChildStatus,
	data => "USR1");
	Event->signal(signal => "INT",
	cb => \&ToggleDebug,
	data => "INT");

SetupTimer();	SetupTimer();

Line 1333 sub ChildProcess {	Line 1420 sub ChildProcess {

# Setup the initial server connection:	# Setup the initial server connection:

# &MakeLondConnection(); // let first work requirest do it.	# &MakeLondConnection(); // let first work requirest do it.


Debug(9,"Entering event loop");	Debug(9,"Entering event loop");
Line 1346 sub ChildProcess {	Line 1433 sub ChildProcess {
# Create a new child for host passed in:	# Create a new child for host passed in:

sub CreateChild {	sub CreateChild {
	my $sigset = POSIX::SigSet->new(SIGINT);
	sigprocmask(SIG_BLOCK, $sigset);
my $host = shift;	my $host = shift;
$RemoteHost = $host;	$RemoteHost = $host;
Log("CRITICAL", "Forking server for ".$host);	Log("CRITICAL", "Forking server for ".$host);
$pid = fork;	my $pid = fork;
if($pid) { # Parent	if($pid) { # Parent
$ChildHash{$pid} = $RemoteHost;	$RemoteHost = "Parent";
	$ChildHash{$pid} = $host;
	$HostToPid{$host}= $pid;
	sigprocmask(SIG_UNBLOCK, $sigset);

} else { # child.	} else { # child.
ShowStatus("Connected to ".$RemoteHost);	ShowStatus("Connected to ".$RemoteHost);
ChildProcess;	$SIG{INT} = 'DEFAULT';
	sigprocmask(SIG_UNBLOCK, $sigset);
	ChildProcess; # Does not return.
}	}

}	}
Line 1389 if ($childpid != 0) {	Line 1484 if ($childpid != 0) {
#	#

ShowStatus("Parent writing pid file:");	ShowStatus("Parent writing pid file:");
$execdir = $perlvar{'lonDaemons'};	my $execdir = $perlvar{'lonDaemons'};
open (PIDSAVE, ">$execdir/logs/lonc.pid");	open (PIDSAVE, ">$execdir/logs/lonc.pid");
print PIDSAVE "$$\n";	print PIDSAVE "$$\n";
close(PIDSAVE);	close(PIDSAVE);



if (POSIX::setsid() < 0) {	if (POSIX::setsid() < 0) {
print "Could not create new session\n";	print "Could not create new session\n";
exit -1;	exit -1;
Line 1403 ShowStatus("Forking node servers");	Line 1500 ShowStatus("Forking node servers");

Log("CRITICAL", "--------------- Starting children ---------------");	Log("CRITICAL", "--------------- Starting children ---------------");

	LondConnection::ReadConfig; # Read standard config files.
my $HostIterator = LondConnection::GetHostIterator;	my $HostIterator = LondConnection::GetHostIterator;
while (! $HostIterator->end()) {	while (! $HostIterator->end()) {

$hostentryref = $HostIterator->get();	my $hostentryref = $HostIterator->get();
CreateChild($hostentryref->[0]);	CreateChild($hostentryref->[0]);
	$HostHash{$hostentryref->[0]} = $hostentryref->[4];
$HostIterator->next();	$HostIterator->next();
}	}
	$RemoteHost = "Parent Server";

# Maintain the population:	# Maintain the population:

Line 1418 ShowStatus("Parent keeping the flock");	Line 1518 ShowStatus("Parent keeping the flock");
#	#
# Set up parent signals:	# Set up parent signals:
#	#
$SIG{INT} = &KillThemAll;
$SIG{TERM} = &KillThemAll;	$SIG{INT} = \&Terminate;
	$SIG{TERM} = \&Terminate;
	$SIG{HUP} = \&Restart;
	$SIG{USR1} = \&CheckKids;
	$SIG{USR2} = \&UpdateKids; # LonManage update request.

while(1) {	while(1) {
$deadchild = wait();	my $deadchild = wait();
if(exists $ChildHash{$deadchild}) { # need to restart.	if(exists $ChildHash{$deadchild}) { # need to restart.
$deadhost = $ChildHash{$deadchild};	my $deadhost = $ChildHash{$deadchild};
	delete($HostToPid{$deadhost});
delete($ChildHash{$deadchild});	delete($ChildHash{$deadchild});
Log("WARNING","Lost child pid= ".$deadchild.	Log("WARNING","Lost child pid= ".$deadchild.
"Connected to host ".$deadhost);	"Connected to host ".$deadhost);
Line 1432 while(1) {	Line 1537 while(1) {
CreateChild($deadhost);	CreateChild($deadhost);
}	}
}	}



	=pod

	=head1 CheckKids

	Since kids do not die as easily in this implementation
	as the previous one, there is no need to restart the
	dead ones (all dead kids get restarted when they die!!)
	The only thing this function does is to pass USR1 to the
	kids so that they report their status.

	=cut

	sub CheckKids {
	Debug(2, "Checking status of children");
	my $docdir = $perlvar{'lonDocRoot'};
	my $fh = IO::File->new(">$docdir/lon-status/loncstatus.txt");
	my $now=time;
	my $local=localtime($now);
	print $fh "LONC status $local - parent $$ \n\n";
	foreach my $pid (keys %ChildHash) {
	Debug(2, "Sending USR1 -> $pid");
	kill 'USR1' => $pid; # Tell Child to report status.
	sleep 1; # Wait so file doesn't intermix.
	}
	}

	=pod

	=head1 UpdateKids

	parent's SIGUSR2 handler. This handler:

	=item

	Rereads the hosts file.

	=item

	Kills off (via sigint) children for hosts that have disappeared.

	=item

	QUITs children for hosts that already exist (this just forces a status display
	and resets the connection retry count for that host.

	=item

	Starts new children for hosts that have been added to the hosts.tab file since
	the start of the master program and maintains them.

	=cut

	sub UpdateKids {

	Log("INFO", "Updating connections via SIGUSR2");

	# Just in case we need to kill our own lonc, we wait a few seconds to
	# give it a chance to receive and relay lond's response to the
	# re-init command.
	#

	sleep(2); # Wait a couple of seconds.

	my %hosts; # Indexed by loncapa hostname, value=ip.

	# Need to re-read the host table:


	LondConnection::ReadConfig();
	my $I = LondConnection::GetHostIterator;
	while (! $I->end()) {
	my $item = $I->get();
	$hosts{$item->[0]} = $item->[4];
	$I->next();
	}

	# The logic below is written for clarity not for efficiency.
	# Since I anticipate that this function is only rarely called, that's
	# appropriate. There are certainly ways to combine the loops below,
	# and anyone wishing to obscure the logic is welcome to go for it.
	# Note that we don't re-direct sigchild. Instead we do what's needed
	# to the data structures that keep track of children to ensure that
	# when sigchild is honored, no new child is born.
	#

	# For each existing child; if it's host doesn't exist, kill the child.

	foreach my $child (keys %ChildHash) {
	my $oldhost = $ChildHash{$child};
	if (!(exists $hosts{$oldhost})) {
	Log("CRITICAL", "Killing child for $oldhost host no longer exists");
	delete $ChildHash{$child};
	delete $HostToPid{$oldhost};
	kill 'QUIT' => $child;
	}
	}
	# For each remaining existing child; if it's host's ip has changed,
	# Restart the child on the new IP.

	foreach my $child (keys %ChildHash) {
	my $oldhost = $ChildHash{$child};
	my $oldip = $HostHash{$oldhost};
	if ($hosts{$oldhost} ne $oldip) {

	# kill the old child.

	Log("CRITICAL", "Killing child for $oldhost host ip has changed...");
	delete $ChildHash{$child};
	delete $HostToPid{$oldhost};
	kill 'QUIT' => $child;

	# Do the book-keeping needed to start a new child on the
	# new ip.

	$HostHash{$oldhost} = $hosts{$oldhost};
	CreateChild($oldhost);
	}
	}
	# Finally, for each new host, not in the host hash, create a
	# enter the host and create a new child.
	# Force a status display of any existing process.

	foreach my $host (keys %hosts) {
	if(!(exists $HostHash{$host})) {
	Log("INFO", "New host $host discovered in hosts.tab...");
	$HostHash{$host} = $hosts{$host};
	CreateChild($host);
	} else {
	kill 'HUP' => $HostToPid{$host}; # status display.
	}
	}
	}


	=pod

	=head1 Restart

	Signal handler for HUP... all children are killed and
	we self restart. This is an el-cheapo way to re read
	the config file.

	=cut

	sub Restart {
	&KillThemAll; # First kill all the children.
	Log("CRITICAL", "Restarting");
	my $execdir = $perlvar{'lonDaemons'};
	unlink("$execdir/logs/lonc.pid");
	exec("$execdir/loncnew");
	}

	=pod

	=head1 KillThemAll

	Signal handler that kills all children by sending them a
	SIGHUP. Responds to sigint and sigterm.

	=cut

sub KillThemAll {	sub KillThemAll {
	Debug(2, "Kill them all!!");
	local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
	foreach my $pid (keys %ChildHash) {
	my $serving = $ChildHash{$pid};
	Debug(2, "Killing lonc for $serving pid = $pid");
	ShowStatus("Killing lonc for $serving pid = $pid");
	Log("CRITICAL", "Killing lonc for $serving pid = $pid");
	kill 'QUIT' => $pid;
	delete($ChildHash{$pid});
	}
	my $execdir = $perlvar{'lonDaemons'};
	unlink("$execdir/logs/lonc.pid");

	}

	=pod

	=head1 Terminate

	Terminate the system.

	=cut

	sub Terminate {
	KillThemAll;
	Log("CRITICAL","Master process exiting");
	exit 0;

}	}
	=pod

=head1 Theory	=head1 Theory

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>

Removed from v.1.11
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	Added in v.1.35