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Diff for /loncom/loncnew between versions 1.51 and 1.100

version 1.51, 2004/08/26 12:35:10	version 1.100, 2011/06/17 17:41:37
Line 26	Line 26
# http://www.lon-capa.org/	# http://www.lon-capa.org/
#	#
#	#
# new lonc handles n request out bver m connections to londs.	# new lonc handles n request out over 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 60 use LONCAPA::Stack;	Line 60 use LONCAPA::Stack;
use LONCAPA::LondConnection;	use LONCAPA::LondConnection;
use LONCAPA::LondTransaction;	use LONCAPA::LondTransaction;
use LONCAPA::Configuration;	use LONCAPA::Configuration;
use LONCAPA::HashIterator;	use Fcntl qw(:flock);


# Read the httpd configuration file to get perl variables	# Read the httpd configuration file to get perl variables
Line 72 my %perlvar = %{$perlvarref};	Line 72 my %perlvar = %{$perlvarref};
#	#
# parent and shared variables.	# parent and shared variables.

my %ChildHash; # by pid -> host.	my %ChildPid; # by pid -> host.
my %HostToPid; # By host -> pid.	my %ChildHost; # by host.
my %HostHash; # by loncapaname -> IP.	my %listening_to; # Socket->host table for who the parent
	# is listening to.
	my %parent_dispatchers; # host-> listener watcher events.

	my %parent_handlers; # Parent signal handlers...

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 $NextDebugLevel= 2; # So Sigint can toggle this.
my $IdleTimeout= 600; # Wait 10 minutes before pruning connections.	my $IdleTimeout= 5*60; # Seconds to wait prior to pruning connections.

my $LogTransactions = 0; # When True, all transactions/replies get logged.	my $LogTransactions = 0; # When True, all transactions/replies get logged.
	my $executable = $0; # Get the full path to me.

#	#
# 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 $RemoteHostId; # default lonid of host child is talking to.
	my @all_host_ids;
my $UnixSocketDir= $perlvar{'lonSockDir'};	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.
Line 100 my $ConnectionCount = 0;	Line 106 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 $RecentLogEntry = "";	my $RecentLogEntry = "";
my $ConnectionRetries=2; # Number of connection retries allowed.	my $ConnectionRetries=5; # Number of connection retries allowed.
my $ConnectionRetriesLeft=2; # Number of connection retries remaining.	my $ConnectionRetriesLeft=5; # Number of connection retries remaining.
my $LondVersion = "unknown"; # Version of lond we talk with.	my $LondVersion = "unknown"; # Version of lond we talk with.
my $KeyMode = ""; # e.g. ssl, local, insecure from last connect.	my $KeyMode = ""; # e.g. ssl, local, insecure from last connect.
	my $LondConnecting = 0; # True when a connection is being built.



	my $I_am_child = 0; # True if this is the child process.

my $LongTickLength = 10000000; #Tick Frequency when Idle
my $ShortTickLength = 1; #Tick Frequency when Active (many places in
# the code assume this is one)
my $TickLength = $ShortTickLength;#number of seconds to wait until ticking
#	#
# The hash below gives the HTML format for log messages	# The hash below gives the HTML format for log messages
# given a severity.	# given a severity.
Line 122 $LogFormats{"WARNING"} = "<font color='	Line 129 $LogFormats{"WARNING"} = "<font color='
$LogFormats{"DEFAULT"} = " %s ";	$LogFormats{"DEFAULT"} = " %s ";


	# UpdateStatus;
	# Update the idle status display to show how many connections
	# are left, retries and other stuff.
	#
	sub UpdateStatus {
	if ($ConnectionRetriesLeft > 0) {
	ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
	." Retries remaining: ".$ConnectionRetriesLeft
	." ($KeyMode)");
	} else {
	ShowStatus(GetServerHost()." >> DEAD <<");
	}
	}


=pod	=pod

Line 130 $LogFormats{"DEFAULT"} = " %s ";	Line 151 $LogFormats{"DEFAULT"} = " %s ";
Makes an entry into the permanent log file.	Makes an entry into the permanent log file.

=cut	=cut

sub LogPerm {	sub LogPerm {
my $message=shift;	my $message=shift;
my $execdir=$perlvar{'lonDaemons'};	my $execdir=$perlvar{'lonDaemons'};
my $now=time;	my $now=time;
my $local=localtime($now);	my $local=localtime($now);
my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");	my $fh=IO::File->new(">>$execdir/logs/lonnet.perm.log");
	chomp($message);
print $fh "$now:$message:$local\n";	print $fh "$now:$message:$local\n";
}	}

Line 175 sub Log {	Line 198 sub Log {
my $now = time;	my $now = time;
my $local = localtime($now);	my $local = localtime($now);
my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";	my $finalformat = "$local ($$) [$RemoteHost] [$Status] ";
my $finalformat = $finalformat.$format."\n";	$finalformat = $finalformat.$format."\n";

# open the file and put the result.	# open the file and put the result.

Line 249 sub SocketDump {	Line 272 sub SocketDump {
and as what we return in a SIGUSR1	and as what we return in a SIGUSR1

=cut	=cut

sub ShowStatus {	sub ShowStatus {
my $state = shift;	my $state = shift;
my $now = time;	my $now = time;
Line 259 sub ShowStatus {	Line 283 sub ShowStatus {

=pod	=pod

=head 2 SocketTimeout	=head2 SocketTimeout

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


=cut	=cut

sub SocketTimeout {	sub SocketTimeout {
my $Socket = shift;	my $Socket = shift;
Log("WARNING", "A socket timeout was detected");	Log("WARNING", "A socket timeout was detected");
Debug(0, " SocketTimeout called: ");	Debug(5, " SocketTimeout called: ");
$Socket->Dump(0);	$Socket->Dump(0);
if(exists($ActiveTransactions{$Socket})) {	if(exists($ActiveTransactions{$Socket})) {
FailTransaction($ActiveTransactions{$Socket});	FailTransaction($ActiveTransactions{$Socket});
Line 278 sub SocketTimeout {	Line 303 sub SocketTimeout {
# a connection failure:	# a connection failure:
$ConnectionRetriesLeft--;	$ConnectionRetriesLeft--;
if($ConnectionRetriesLeft <= 0) {	if($ConnectionRetriesLeft <= 0) {
Log("CRITICAL", "Host marked dead: ".GetServerHost());	Log("CRITICAL", "Host marked DEAD: ".GetServerHost());
	$LondConnecting = 0;
}	}

}	}

	#
	# This function should be called by the child in all cases where it must
	# exit. The child process must create a lock file for the AF_UNIX socket
	# in order to prevent connection requests from lonnet in the time between
	# process exit and the parent picking up the listen again.
	#
	# Parameters:
	# exit_code - Exit status value, however see the next parameter.
	# message - If this optional parameter is supplied, the exit
	# is via a die with this message.
	#
	sub child_exit {
	my ($exit_code, $message) = @_;

	# Regardless of how we exit, we may need to do the lock thing:

	#
	# Create a lock file since there will be a time window
	# between our exit and the parent's picking up the listen
	# during which no listens will be done on the
	# lonnet client socket.
	#
	my $lock_file = &GetLoncSocketPath().".lock";
	open(LOCK,">$lock_file");
	print LOCK "Contents not important";
	close(LOCK);
	unlink(&GetLoncSocketPath());

	if ($message) {
	die($message);
	} else {
	exit($exit_code);
	}
	}
#----------------------------- Timer management ------------------------	#----------------------------- Timer management ------------------------

=pod	=pod

=head2 Tick	=head2 Tick

Invoked each timer tick.	Invoked each timer tick.

=cut	=cut


sub Tick {	sub Tick {
	my ($Event) = @_;
	my $clock_watcher = $Event->w;

my $client;	my $client;
if($ConnectionRetriesLeft > 0) {	UpdateStatus();
ShowStatus(GetServerHost()." Connection count: ".$ConnectionCount
." Retries remaining: ".$ConnectionRetriesLeft
." ($KeyMode)");
} else {
ShowStatus(GetServerHost()." >> DEAD <<");
}
# Is it time to prune connection count:	# Is it time to prune connection count:


if($IdleConnections->Count() &&	if($IdleConnections->Count() &&
($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?	($WorkQueue->Count() == 0)) { # Idle connections and nothing to do?
$IdleSeconds+=$TickLength;	$IdleSeconds++;
if($IdleSeconds > $IdleTimeout) { # Prune a connection...	if($IdleSeconds > $IdleTimeout) { # Prune a connection...
my $Socket = $IdleConnections->pop();	my $Socket = $IdleConnections->pop();
KillSocket($Socket);	KillSocket($Socket);
if ($IdleConnections->Count() == 0) {	$IdleSeconds = 0; # Otherwise all connections get trimmed to fast.
&SetupTimer($LongTickLength);	UpdateStatus();
	if(($ConnectionCount == 0)) {
	&child_exit(0);

}	}
}	}
} else {	} else {
Line 332 sub Tick {	Line 394 sub 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.
#	#
	# Note this code is dead now...
	#
my $Requests = $WorkQueue->Count();	my $Requests = $WorkQueue->Count();
if (($ConnectionCount == 0) && ($Requests > 0)) {	if (($ConnectionCount == 0) && ($Requests > 0) && (!$LondConnecting)) {
if ($ConnectionRetriesLeft > 0) {	if ($ConnectionRetriesLeft > 0) {
my $Connections = ($Requests <= $MaxConnectionCount) ?	Debug(5,"Work but no connections, Make a new one");
$Requests : $MaxConnectionCount;	my $success;
Debug(5,"Work but no connections, start ".$Connections." of them");	$success = &MakeLondConnection;
my $successCount = 0;	if($success == 0) { # All connections failed:
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");	Debug(5,"Work in queue failed to make any connectiouns\n");
EmptyQueue(); # Fail pending transactions with con_lost.	EmptyQueue(); # Fail pending transactions with con_lost.
CloseAllLondConnections(); # Should all be closed but....	CloseAllLondConnections(); # Should all be closed but....
}	}
} else {	} else {
	$LondConnecting = 0;
ShowStatus(GetServerHost()." >>> DEAD!!! <<<");	ShowStatus(GetServerHost()." >>> DEAD!!! <<<");
Debug(5,"Work in queue, but gave up on connections..flushing\n");	Debug(5,"Work in queue, but gave up on connections..flushing\n");
EmptyQueue(); # Connections can't be established.	EmptyQueue(); # Connections can't be established.
Line 358 sub Tick {	Line 418 sub Tick {
}	}
if ($ConnectionCount == 0) {	if ($ConnectionCount == 0) {
$KeyMode = "";	$KeyMode = "";
	$clock_watcher->cancel();
}	}
	&UpdateStatus();
}	}

=pod	=pod
Line 377 Trigger disconnections of idle sockets.	Line 439 Trigger disconnections of idle sockets.

=cut	=cut

my $timer;
sub SetupTimer {	sub SetupTimer {
my ($newLength)=@_;	Debug(6, "SetupTimer");
Debug(6, "SetupTimer $TickLength->$newLength");	Event->timer(interval => 1, cb => \&Tick,
$TickLength=$newLength;	hard => 1);
if ($timer) { $timer->cancel; }
$timer=Event->timer(interval => $TickLength, cb => \&Tick );
}	}

=pod	=pod
Line 429 sub ServerToIdle {	Line 488 sub ServerToIdle {

Event callback for when a client socket is writable.	Event callback for when a client socket is writable.

This callback is established when a transaction reponse is	This callback is established when a transaction response is
avaiable from lond. The response is forwarded to the unix socket	available from lond. The response is forwarded to the unix socket
as it becomes writable in this sub.	as it becomes writable in this sub.

Parameters:	Parameters:
Line 445 the data and Event->w->fd is the socket	Line 504 the data and Event->w->fd is the socket
sub ClientWritable {	sub ClientWritable {
my $Event = shift;	my $Event = shift;
my $Watcher = $Event->w;	my $Watcher = $Event->w;
	if (!defined($Watcher)) {
	&child_exit(-1,'No watcher for event in ClientWritable');
	}
my $Data = $Watcher->data;	my $Data = $Watcher->data;
my $Socket = $Watcher->fd;	my $Socket = $Watcher->fd;

Line 483 sub ClientWritable {	Line 545 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!!	if($result == 0) { # client hung up on us!!
Log("INFO", "lonc pipe client hung up on us!");	# Log("INFO", "lonc pipe client hung up on us!");
$Watcher->cancel;	$Watcher->cancel;
$Socket->shutdown(2);	$Socket->shutdown(2);
$Socket->close();	$Socket->close();
Line 497 sub ClientWritable {	Line 559 sub ClientWritable {
if($errno == POSIX::EWOULDBLOCK \|\|	if($errno == POSIX::EWOULDBLOCK \|\|
$errno == POSIX::EAGAIN \|\|	$errno == POSIX::EAGAIN \|\|
$errno == POSIX::EINTR) {	$errno == POSIX::EINTR) {
# No action taken?	# No action taken...the socket will be writable firing the event again
	# which will result in a retry of the write.
} else { # Unanticipated errno.	} else { # Unanticipated errno.
&Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);	&Debug(5,"ClientWritable error or peer shutdown".$RemoteHost);
$Watcher->cancel; # Stop the watcher.	$Watcher->cancel; # Stop the watcher.
Line 508 sub ClientWritable {	Line 571 sub ClientWritable {
}	}
} else {	} else {
$Watcher->cancel(); # A delayed request...just cancel.	$Watcher->cancel(); # A delayed request...just cancel.
	return;
}	}
}	}

Line 525 Parameters:	Line 589 Parameters:

=item Socket	=item Socket

Socket on which the lond transaction occured. This is a	Socket on which the lond transaction occurred. This is a
LondConnection. The data received is in the TransactionReply member.	LondConnection. The data received are in the TransactionReply member.

=item Transaction	=item Transaction

Line 547 sub CompleteTransaction {	Line 611 sub CompleteTransaction {
StartClientReply($Transaction, $data);	StartClientReply($Transaction, $data);
} else { # Delete deferred transaction file.	} else { # Delete deferred transaction file.
Log("SUCCESS", "A delayed transaction was completed");	Log("SUCCESS", "A delayed transaction was completed");
LogPerm("S:$Transaction->getClient() :".$Transaction->getRequest());	LogPerm("S:".$Transaction->getClient().":".$Transaction->getRequest());
unlink $Transaction->getFile();	unlink($Transaction->getFile());
}	}
}	}

Line 566 sub CompleteTransaction {	Line 630 sub CompleteTransaction {

=item data	=item data

The data to send to apached client.	The data to send to apache client.

=cut	=cut

Line 611 Parameters:	Line 675 Parameters:

sub FailTransaction {	sub FailTransaction {
my $transaction = shift;	my $transaction = shift;
Log("WARNING", "Failing transaction ".$transaction->getRequest());
Debug(1, "Failing transaction: ".$transaction->getRequest());	# If the socket is dead, that's already logged.

	if ($ConnectionRetriesLeft > 0) {
	Log("WARNING", "Failing transaction "
	.$transaction->getLoggableRequest());
	}
	Debug(1, "Failing transaction: ".$transaction->getLoggableRequest());
if (!$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());
Line 622 sub FailTransaction {	Line 692 sub FailTransaction {
}	}

=pod	=pod

=head1 EmptyQueue	=head1 EmptyQueue

Fails all items in the work queue with con_lost.	Fails all items in the work queue with con_lost.
Note that each item in the work queue is a transaction.	Note that each item in the work queue is a transaction.

=cut	=cut

sub EmptyQueue {	sub EmptyQueue {
$ConnectionRetriesLeft--; # Counts as connection failure too.	$ConnectionRetriesLeft--; # Counts as connection failure too.
while($WorkQueue->Count()) {	while($WorkQueue->Count()) {
Line 643 sub EmptyQueue {	Line 715 sub EmptyQueue {
Close all connections open on lond prior to exit e.g.	Close all connections open on lond prior to exit e.g.

=cut	=cut

sub CloseAllLondConnections {	sub CloseAllLondConnections {
foreach my $Socket (keys %ActiveConnections) {	foreach my $Socket (keys %ActiveConnections) {
if(exists($ActiveTransactions{$Socket})) {	if(exists($ActiveTransactions{$Socket})) {
Line 651 sub CloseAllLondConnections {	Line 724 sub CloseAllLondConnections {
KillSocket($Socket);	KillSocket($Socket);
}	}
}	}
=cut

=pod	=pod

Line 671 Parameters:	Line 743 Parameters:

=item Restart	=item Restart

nonzero if we are allowed to create a new connection.	non-zero if we are allowed to create a new connection.


=cut	=cut

sub KillSocket {	sub KillSocket {
my $Socket = shift;	my $Socket = shift;

Line 691 sub KillSocket {	Line 763 sub KillSocket {
delete ($ActiveTransactions{$Socket});	delete ($ActiveTransactions{$Socket});
}	}
if(exists($ActiveConnections{$Socket})) {	if(exists($ActiveConnections{$Socket})) {
	$ActiveConnections{$Socket}->cancel;
delete($ActiveConnections{$Socket});	delete($ActiveConnections{$Socket});
$ConnectionCount--;	$ConnectionCount--;
if ($ConnectionCount < 0) { $ConnectionCount = 0; }	if ($ConnectionCount < 0) { $ConnectionCount = 0; }
Line 699 sub KillSocket {	Line 772 sub KillSocket {
# work queue, the work all gets failed with con_lost.	# work queue, the work all gets failed with con_lost.
#	#
if($ConnectionCount == 0) {	if($ConnectionCount == 0) {
	$LondConnecting = 0; # No connections so also not connecting.
EmptyQueue();	EmptyQueue();
CloseAllLondConnections; # Should all already be closed but...	CloseAllLondConnections; # Should all already be closed but...
}	}
	UpdateStatus();
}	}

=pod	=pod
Line 713 is readable. The action is state depend	Line 788 is readable. The action is state depend

=head3 State=Initialized	=head3 State=Initialized

We''re waiting for the challenge, this is a no-op until the	We are waiting for the challenge, this is a no-op until the
state changes.	state changes.

=head3 State=Challenged	=head3 State=Challenged
Line 723 The connection must echo the challenge b	Line 798 The connection must echo the challenge b

=head3 State=ChallengeReplied	=head3 State=ChallengeReplied

The challenge has been replied to. The we are receiveing the	The challenge has been replied to. Then we are receiving the
'ok' from the partner.	'ok' from the partner.

=head3 State=ReadingVersionString	=head3 State=ReadingVersionString
Line 749 The the key has been requested, now we a	Line 824 The the key has been requested, now we a
=head3 State=Idle	=head3 State=Idle

The encryption key has been negotiated or we have finished	The encryption key has been negotiated or we have finished
reading data from the a transaction. If the callback data has	reading data from the a transaction. If the callback data have
a client as well as the socket iformation, then we are	a client as well as the socket information, then we are
doing a transaction and the data received is relayed to the client	doing a transaction and the data received are relayed to the client
before the socket is put on the idle list.	before the socket is put on the idle list.

=head3 State=SendingRequest	=head3 State=SendingRequest
Line 768 to readable to receive the reply.	Line 843 to readable to receive the reply.
The parameter to this function are:	The parameter to this function are:

The event. Implicit in this is the watcher and its data. The data	The event. Implicit in this is the watcher and its data. The data
contains at least the lond connection object and, if a	contain at least the lond connection object and, if a
transaction is in progress, the socket attached to the local client.	transaction is in progress, the socket attached to the local client.

=cut	=cut
Line 798 sub LondReadable {	Line 873 sub LondReadable {
"Lond connection lost.");	"Lond connection lost.");
if(exists($ActiveTransactions{$Socket})) {	if(exists($ActiveTransactions{$Socket})) {
FailTransaction($ActiveTransactions{$Socket});	FailTransaction($ActiveTransactions{$Socket});
	} else {
	# Socket is connecting and failed... need to mark
	# no longer connecting.

	$LondConnecting = 0;
}	}
$Watcher->cancel();	$Watcher->cancel();
KillSocket($Socket);	KillSocket($Socket);
Line 868 sub LondReadable {	Line 948 sub LondReadable {
CompleteTransaction($Socket,	CompleteTransaction($Socket,
$ActiveTransactions{$Socket});	$ActiveTransactions{$Socket});
} else {	} else {
Log("SUCCESS", "Connection ".$ConnectionCount." to "	my $count = $Socket->GetClientData();
	Log("SUCCESS", "Connection ".$count." to "
.$RemoteHost." now ready for action");	.$RemoteHost." now ready for action");
}	}
ServerToIdle($Socket); # Next work unit or idle.	ServerToIdle($Socket); # Next work unit or idle.

	#
	$LondConnecting = 0; # Best spot I can think of for this.
	#

} elsif ($State eq "SendingRequest") {	} elsif ($State eq "SendingRequest") {
# We need to be writable for this and probably don't belong	# We need to be writable for this and probably don't belong
# here inthe first place.	# here inthe first place.

Deubg(6, "SendingRequest state encountered in readable");	Debug(6, "SendingRequest state encountered in readable");
$Watcher->poll("w");	$Watcher->poll("w");
$Watcher->cb(\&LondWritable);	$Watcher->cb(\&LondWritable);

Line 901 event. The action taken is very state d	Line 986 event. The action taken is very state d
=head3 State = Connected	=head3 State = Connected

The connection is in the process of sending the 'init' hailing to the	The connection is in the process of sending the 'init' hailing to the
lond on the remote end. The connection object''s Writable member is	lond on the remote end. The Writable member of the connection object
called. On error, ConnectionError is called to destroy the connection	is called. On error, call ConnectionError to destroy the connection
and remove it from the ActiveConnections hash	and remove it from the ActiveConnections hash.

=head3 Initialized	=head3 Initialized

Line 985 sub LondWritable {	Line 1070 sub LondWritable {
" has been disconnected");	" has been disconnected");
if(exists($ActiveTransactions{$Socket})) {	if(exists($ActiveTransactions{$Socket})) {
FailTransaction($ActiveTransactions{$Socket});	FailTransaction($ActiveTransactions{$Socket});
	} else {
	# In the process of conneting, so need to turn that off.

	$LondConnecting = 0;
}	}
$Watcher->cancel();	$Watcher->cancel();
KillSocket($Socket);	KillSocket($Socket);
Line 1071 sub LondWritable {	Line 1160 sub LondWritable {
}	}

}	}

=pod	=pod

=cut	=cut


sub QueueDelayed {	sub QueueDelayed {
Debug(3,"QueueDelayed called");	Debug(3,"QueueDelayed called");

Line 1081 sub QueueDelayed {	Line 1173 sub QueueDelayed {

Debug(4, "Delayed path: ".$path);	Debug(4, "Delayed path: ".$path);
opendir(DIRHANDLE, $path);	opendir(DIRHANDLE, $path);

my @alldelayed = grep /\.$RemoteHost$/, readdir DIRHANDLE;	my $host_id_re = '(?:'.join('\|',map {quotemeta($_)} (@all_host_ids)).')';
	my @alldelayed = grep(/\.$host_id_re$/, readdir(DIRHANDLE));
closedir(DIRHANDLE);	closedir(DIRHANDLE);
my $dfname;	foreach my $dfname (sort(@alldelayed)) {
my $reqfile;	my $reqfile = "$path/$dfname";
foreach $dfname (sort @alldelayed) {	my ($host_id) = ($dfname =~ /\.([^.]*)$/);
$reqfile = "$path/$dfname";	Debug(4, "queueing ".$reqfile." for $host_id");
Debug(4, "queueing ".$reqfile);
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."\n"; # 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 $Transaction = LondTransaction->new("sethost:$host_id:$cmd");
$Transaction->SetDeferred($reqfile);	$Transaction->SetDeferred($reqfile);
QueueTransaction($Transaction);	QueueTransaction($Transaction);
}	}
Line 1105 sub QueueDelayed {	Line 1197 sub QueueDelayed {
=head2 MakeLondConnection	=head2 MakeLondConnection

Create a new lond connection object, and start it towards its initial	Create a new lond connection object, and start it towards its initial
idleness. Once idle, it becomes elligible to receive transactions	idleness. Once idle, it becomes eligible to receive transactions
from the work queue. If the work queue is not empty when the	from the work queue. If the work queue is not empty when the
connection is completed and becomes idle, it will dequeue an entry and	connection is completed and becomes idle, it will dequeue an entry and
start off on it.	start off on it.
Line 1117 sub MakeLondConnection {	Line 1209 sub MakeLondConnection {
.GetServerPort());	.GetServerPort());

my $Connection = LondConnection->new(&GetServerHost(),	my $Connection = LondConnection->new(&GetServerHost(),
&GetServerPort());	&GetServerPort(),
	&GetHostId());

if($Connection eq undef) { # Needs to be more robust later.	if($Connection eq undef) {
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 {

	$LondConnecting = 1; # Connection in progress.
# 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
Line 1132 sub MakeLondConnection {	Line 1226 sub MakeLondConnection {
#	#
my $Socket = $Connection->GetSocket();	my $Socket = $Connection->GetSocket();
if($Socket eq undef) {	if($Socket eq undef) {
die "did not get a socket from the connection";	&child_exit(-1, "did not get a socket from the connection");
} else {	} else {
&Debug(9,"MakeLondConnection got socket: ".$Socket);	&Debug(9,"MakeLondConnection got socket: ".$Socket);
}	}
Line 1145 sub MakeLondConnection {	Line 1239 sub MakeLondConnection {
data => $Connection,	data => $Connection,
desc => 'Connection to lond server');	desc => 'Connection to lond server');
$ActiveConnections{$Connection} = $event;	$ActiveConnections{$Connection} = $event;
	if ($ConnectionCount == 0) {
	&SetupTimer; # Need to handle timeouts with connections...
	}
$ConnectionCount++;	$ConnectionCount++;
	$Connection->SetClientData($ConnectionCount);
Debug(4, "Connection count = ".$ConnectionCount);	Debug(4, "Connection count = ".$ConnectionCount);
if($ConnectionCount == 1) { # First Connection:	if($ConnectionCount == 1) { # First Connection:
QueueDelayed;	QueueDelayed;
}	}
Log("SUCESS", "Created connection ".$ConnectionCount	Log("SUCCESS", "Created connection ".$ConnectionCount
." to host ".GetServerHost());	." to host ".GetServerHost());
return 1; # Return success.	return 1; # Return success.
}	}
Line 1172 reply.	Line 1269 reply.

=item $Client	=item $Client

Connection to the client that is making this request We got the	Connection to the client that is making this request. We got the
request from this socket, and when the request has been relayed to	request from this socket, and when the request has been relayed to
lond and we get a reply back from lond it will get sent to this	lond and we get a reply back from lond it will get sent to this
socket.	socket.
Line 1236 sub QueueTransaction {	Line 1333 sub QueueTransaction {
if(!defined $LondSocket) { # Need to queue request.	if(!defined $LondSocket) { # Need to queue request.
Debug(5,"Must queue...");	Debug(5,"Must queue...");
$WorkQueue->enqueue($requestData);	$WorkQueue->enqueue($requestData);
if($ConnectionCount < $MaxConnectionCount) {	Debug(5, "Queue Transaction startnew $ConnectionCount $LondConnecting");
	if(($ConnectionCount < $MaxConnectionCount) && (! $LondConnecting)) {

if($ConnectionRetriesLeft > 0) {	if($ConnectionRetriesLeft > 0) {
Debug(5,"Starting additional lond connection");	Debug(5,"Starting additional lond connection");
if(MakeLondConnection() == 0) {	if(&MakeLondConnection() == 0) {
EmptyQueue(); # Fail transactions, can't make connection.	EmptyQueue(); # Fail transactions, can't make connection.
CloseAllLondConnections; # Should all be closed but...	CloseAllLondConnections; # Should all be closed but...
}	}
&SetupTimer($ShortTickLength);
} else {	} else {
ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");	ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
	$LondConnecting = 0;
EmptyQueue(); # It's worse than that ... he's dead Jim.	EmptyQueue(); # It's worse than that ... he's dead Jim.
CloseAllLondConnections; # Should all be closed but..	CloseAllLondConnections; # Should all be closed but..
}	}
Line 1256 sub QueueTransaction {	Line 1355 sub QueueTransaction {
}	}
}	}

#-------------------------- Lonc UNIX socket handling ---------------------	#-------------------------- Lonc UNIX socket handling -------------------

=pod	=pod

=head2 ClientRequest	=head2 ClientRequest

Callback that is called when data can be read from the UNIX domain	Callback that is called when data can be read from the UNIX domain
socket connecting us with an apache server process.	socket connecting us with an apache server process.

Line 1291 sub ClientRequest {	Line 1390 sub ClientRequest {
$data = $data.$thisread; # Append new data.	$data = $data.$thisread; # Append new data.
$watcher->data($data);	$watcher->data($data);
if($data =~ /\n$/) { # Request entirely read.	if($data =~ /\n$/) { # Request entirely read.
if($data eq "close_connection_exit\n") {	if ($data eq "close_connection_exit\n") {
Log("CRITICAL",	Log("CRITICAL",
"Request Close Connection ... exiting");	"Request Close Connection ... exiting");
CloseAllLondConnections();	CloseAllLondConnections();
exit;	exit;
	} elsif ($data eq "reset_retries\n") {
	Log("INFO", "Resetting Connection Retries.");
	$ConnectionRetriesLeft = $ConnectionRetries;
	&UpdateStatus();
	my $Transaction = LondTransaction->new($data);
	$Transaction->SetClient($socket);
	StartClientReply($Transaction, "ok\n");
	$watcher->cancel();
	return;
}	}
Debug(8, "Complete transaction received: ".$data);	Debug(8, "Complete transaction received: ".$data);
if($LogTransactions) {	if ($LogTransactions) {
Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.	Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
}	}
my $Transaction = LondTransaction->new($data);	my $Transaction = LondTransaction->new($data);
Line 1309 sub ClientRequest {	Line 1417 sub ClientRequest {

}	}

	#
	# Accept a connection request for a client (lonc child) and
	# start up an event watcher to keep an eye on input from that
	# Event. This can be called both from NewClient and from
	# ChildProcess.
	# Parameters:
	# $socket - The listener socket.
	# Returns:
	# NONE
	# Side Effects:
	# An event is made to watch the accepted connection.
	# Active clients hash is updated to reflect the new connection.
	# The client connection count is incremented.
	#
	sub accept_client {
	my ($socket) = @_;

	Debug(8, "Entering accept for lonc UNIX socket\n");
	my $connection = $socket->accept(); # Accept the client connection.
	Debug(8,"Connection request accepted from "
	.GetPeername($connection, AF_UNIX));


	my $description = sprintf("Connection to lonc client %d",
	$ClientConnection);
	Debug(9, "Creating event named: ".$description);
	Event->io(cb => \&ClientRequest,
	poll => 'r',
	desc => $description,
	data => "",
	fd => $connection);
	$ActiveClients{$connection} = $ClientConnection;
	$ClientConnection++;
	}

=pod	=pod

Line 1317 sub ClientRequest {	Line 1459 sub ClientRequest {
Callback that is called when a connection is received on the unix	Callback that is called when a connection is received on the unix
socket for a new client of lonc. The callback is parameterized by the	socket for a new client of lonc. The callback is parameterized by the
event.. which is a-priori assumed to be an io event, and therefore has	event.. which is a-priori assumed to be an io event, and therefore has
an fd member that is the Listener socket. We Accept the connection	an fd member that is the Listener socket. We accept the connection
and register a new event on the readability of that socket:	and register a new event on the readability of that socket:

=cut	=cut
Line 1327 sub NewClient {	Line 1469 sub NewClient {
my $event = shift; # Get the event parameters.	my $event = shift; # Get the event parameters.
my $watcher = $event->w;	my $watcher = $event->w;
my $socket = $watcher->fd; # Get the event' socket.	my $socket = $watcher->fd; # Get the event' socket.
my $connection = $socket->accept(); # Accept the client connection.
Debug(8,"Connection request accepted from "
.GetPeername($connection, AF_UNIX));


my $description = sprintf("Connection to lonc client %d",	&accept_client($socket);
$ClientConnection);
Debug(9, "Creating event named: ".$description);
Event->io(cb => \&ClientRequest,
poll => 'r',
desc => $description,
data => "",
fd => $connection);
$ActiveClients{$connection} = $ClientConnection;
$ClientConnection++;
}	}

=pod	=pod
Line 1351 sub NewClient {	Line 1480 sub NewClient {
Returns the name of the UNIX socket on which to listen for client	Returns the name of the UNIX socket on which to listen for client
connections.	connections.

	=head2 Parameters:

	host (optional) - Name of the host socket to return.. defaults to
	the return from GetServerHost().

=cut	=cut

sub GetLoncSocketPath {	sub GetLoncSocketPath {
return $UnixSocketDir."/".GetServerHost();
	my $host = GetServerHost(); # Default host.
	if (@_) {
	($host) = @_; # Override if supplied.
	}
	return $UnixSocketDir."/".$host;
}	}

=pod	=pod
Line 1371 sub GetServerHost {	Line 1510 sub GetServerHost {

=pod	=pod

	=head2 GetServerId

	Returns the hostid whose lond we talk with.

	=cut

	sub GetHostId {
	return $RemoteHostId; # Setup by the fork.
	}

	=pod

=head2 GetServerPort	=head2 GetServerPort

Returns the lond port number.	Returns the lond port number.
Line 1388 sub GetServerPort {	Line 1539 sub GetServerPort {
Setup a lonc listener event. The event is called when the socket	Setup a lonc listener event. The event is called when the socket
becomes readable.. that corresponds to the receipt of a new	becomes readable.. that corresponds to the receipt of a new
connection. The event handler established will accept the connection	connection. The event handler established will accept the connection
(creating a communcations channel), that int turn will establish	(creating a communications channel), that in turn will establish
another event handler to subess requests.	another event handler to subess requests.

	=head2 Parameters:

	host (optional) Name of the host to set up a unix socket to.

=cut	=cut

sub SetupLoncListener {	sub SetupLoncListener {
	my ($host,$SocketName) = @_;
	if (!$host) { $host = &GetServerHost(); }
	if (!$SocketName) { $SocketName = &GetLoncSocketPath($host); }


my $socket;
my $SocketName = GetLoncSocketPath();
unlink($SocketName);	unlink($SocketName);

	my $socket;
unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,	unless ($socket =IO::Socket::UNIX->new(Local => $SocketName,
Listen => 10,	Listen => 250,
Type => SOCK_STREAM)) {	Type => SOCK_STREAM)) {
die "Failed to create a lonc listner socket";	if($I_am_child) {
	&child_exit(-1, "Failed to create a lonc listener socket");
	} else {
	die "Failed to create a lonc listner socket";
	}
}	}
Event->io(cb => \&NewClient,	return $socket;
poll => 'r',
desc => 'Lonc listener Unix Socket',
fd => $socket);
}	}

#	#
Line 1436 into the status file.	Line 1596 into the status file.

We also use this to reset the retries count in order to allow the	We also use this to reset the retries count in order to allow the
client to retry connections with a previously dead server.	client to retry connections with a previously dead server.

=cut	=cut

sub ChildStatus {	sub ChildStatus {
Line 1444 sub ChildStatus {	Line 1605 sub ChildStatus {

Debug(2, "Reporting child status because : ".$watcher->data);	Debug(2, "Reporting child status because : ".$watcher->data);
my $docdir = $perlvar{'lonDocRoot'};	my $docdir = $perlvar{'lonDocRoot'};
my $fh = IO::File->new(">>$docdir/lon-status/loncstatus.txt");
print $fh $$."\t".$RemoteHost."\t".$Status."\t".	open(LOG,">>$docdir/lon-status/loncstatus.txt");
	flock(LOG,LOCK_EX);
	print LOG $$."\t".$RemoteHost."\t".$Status."\t".
$RecentLogEntry."\n";	$RecentLogEntry."\n";
#	#
# Write out information about each of the connections:	# Write out information about each of the connections:
#	#
if ($DebugLevel > 2) {	if ($DebugLevel > 2) {
print $fh "Active connection statuses: \n";	print LOG "Active connection statuses: \n";
my $i = 1;	my $i = 1;
print STDERR "================================= Socket Status Dump:\n";	print STDERR "================================= Socket Status Dump:\n";
foreach my $item (keys %ActiveConnections) {	foreach my $item (keys %ActiveConnections) {
my $Socket = $ActiveConnections{$item}->data;	my $Socket = $ActiveConnections{$item}->data;
my $state = $Socket->GetState();	my $state = $Socket->GetState();
print $fh "Connection $i State: $state\n";	print LOG "Connection $i State: $state\n";
print STDERR "---------------------- Connection $i \n";	print STDERR "---------------------- Connection $i \n";
$Socket->Dump(-1); # Ensure it gets dumped..	$Socket->Dump(-1); # Ensure it gets dumped..
$i++;	$i++;
}	}
}	}
	flock(LOG,LOCK_UN);
	close(LOG);
$ConnectionRetriesLeft = $ConnectionRetries;	$ConnectionRetriesLeft = $ConnectionRetries;
	UpdateStatus();
}	}

=pod	=pod
Line 1484 sub SignalledToDeath {	Line 1650 sub SignalledToDeath {
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\"");
exit 0;	exit 0;

}	}

	=pod

=head2 ToggleDebug	=head2 ToggleDebug

This sub toggles trace debugging on and off.	This sub toggles trace debugging on and off.
Line 1505 sub ToggleDebug {	Line 1673 sub ToggleDebug {

}	}

	=pod

=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.
	Optional parameter:
	$socket - if provided, this is a socket already open for listening
	on the client socket. Otherwise, a new listener is set up.

=cut	=cut

sub ChildProcess {	sub ChildProcess {
	# We've inherited all the
	# events of our parent and those have to be cancelled or else
	# all holy bloody chaos will result.. trust me, I already made
	# >that< mistake.

	my $host = GetServerHost();
	foreach my $listener (keys %parent_dispatchers) {
	my $watcher = $parent_dispatchers{$listener};
	my $s = $watcher->fd;
	if ($listener ne $host) { # Close everyone but me.
	Debug(5, "Closing listen socket for $listener");
	$s->close();
	}
	Debug(5, "Killing watcher for $listener");

	$watcher->cancel();
	delete($parent_dispatchers{$listener});

	}

	# kill off the parent's signal handlers too!
	#

	for my $handler (keys %parent_handlers) {
	my $watcher = $parent_handlers{$handler};
	$watcher->cancel();
	delete($parent_handlers{$handler});
	}

	$I_am_child = 1; # Seems like in spite of it all I may still getting
	# parent event dispatches.. flag I'm a child.


#	#
# Signals must be handled by the Event framework...	# Signals must be handled by the Event framework...
#	#

Event->signal(signal => "QUIT",	Event->signal(signal => "QUIT",
cb => \&SignalledToDeath,	cb => \&SignalledToDeath,
Line 1533 sub ChildProcess {	Line 1737 sub ChildProcess {
cb => \&ToggleDebug,	cb => \&ToggleDebug,
data => "INT");	data => "INT");

SetupTimer($LongTickLength);	# Block the pipe signal we'll get when the socket disconnects. We detect
	# socket disconnection via send/receive failures. On disconnect, the
SetupLoncListener();	# socket becomes readable .. which will force the disconnect detection.

	my $set = POSIX::SigSet->new(SIGPIPE);
	sigprocmask(SIG_BLOCK, $set);

	# Figure out if we got passed a socket or need to open one to listen for
	# client requests.

	my ($socket) = @_;
	if (!$socket) {

	$socket = SetupLoncListener();
	}
	# Establish an event to listen for client connection requests.


	Event->io(cb => \&NewClient,
	poll => 'r',
	desc => 'Lonc Listener Unix Socket',
	fd => $socket);

$Event::Debuglevel = $DebugLevel;	$Event::DebugLevel = $DebugLevel;

Debug(9, "Making initial lond connection for ".$RemoteHost);	Debug(9, "Making initial lond connection for ".$RemoteHost);

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

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

	# need to accept the connection since the event may not fire.

	&accept_client($socket);

Debug(9,"Entering event loop");	Debug(9,"Entering event loop");
my $ret = Event::loop(); # Start the main event loop.	my $ret = Event::loop(); # Start the main event loop.


die "Main event loop exited!!!";	&child_exit (-1,"Main event loop exited!!!");
}	}

# Create a new child for host passed in:	# Create a new child for host passed in:

sub CreateChild {	sub CreateChild {
	my ($host, $hostid) = @_;

my $sigset = POSIX::SigSet->new(SIGINT);	my $sigset = POSIX::SigSet->new(SIGINT);
sigprocmask(SIG_BLOCK, $sigset);	sigprocmask(SIG_BLOCK, $sigset);
my $host = shift;
$RemoteHost = $host;	$RemoteHost = $host;
	ShowStatus('Parent keeping the flock'); # Update time in status message.
Log("CRITICAL", "Forking server for ".$host);	Log("CRITICAL", "Forking server for ".$host);
my $pid = fork;	my $pid = fork;
if($pid) { # Parent	if($pid) { # Parent
$RemoteHost = "Parent";	$RemoteHost = "Parent";
$ChildHash{$pid} = $host;	$ChildPid{$pid} = $host;
$HostToPid{$host}= $pid;
sigprocmask(SIG_UNBLOCK, $sigset);	sigprocmask(SIG_UNBLOCK, $sigset);
	undef(@all_host_ids);
} else { # child.	} else { # child.
	$RemoteHostId = $hostid;
ShowStatus("Connected to ".$RemoteHost);	ShowStatus("Connected to ".$RemoteHost);
$SIG{INT} = 'DEFAULT';	$SIG{INT} = 'DEFAULT';
sigprocmask(SIG_UNBLOCK, $sigset);	sigprocmask(SIG_UNBLOCK, $sigset);
ChildProcess; # Does not return.	&ChildProcess(); # Does not return.
}	}
	}

	# parent_client_connection:
	# Event handler that processes client connections for the parent process.
	# This sub is called when the parent is listening on a socket and
	# a connection request arrives. We must:
	# Start a child process to accept the connection request.
	# Kill our listen on the socket.
	# Parameter:
	# event - The event object that was created to monitor this socket.
	# event->w->fd is the socket.
	# Returns:
	# NONE
	#
	sub parent_client_connection {
	if ($I_am_child) {
	# Should not get here, but seem to anyway:
	&Debug(5," Child caught parent client connection event!!");
	my ($event) = @_;
	my $watcher = $event->w;
	$watcher->cancel(); # Try to kill it off again!!
	} else {
	&Debug(9, "parent_client_connection");
	my ($event) = @_;
	my $watcher = $event->w;
	my $socket = $watcher->fd;
	my $connection = $socket->accept(); # Accept the client connection.
	Event->io(cb => \&get_remote_hostname,
	poll => 'r',
	data => "",
	fd => $connection);
	}
}	}

	sub get_remote_hostname {
	my ($event) = @_;
	my $watcher = $event->w;
	my $socket = $watcher->fd;

	my $thisread;
	my $rv = $socket->recv($thisread, POSIX::BUFSIZ, 0);
	Debug(8, "rcv: data length = ".length($thisread)." read =".$thisread);
	if (!defined($rv) \|\| length($thisread) == 0) {
	# Likely eof on socket.
	Debug(5,"Client Socket closed on lonc for p_c_c");
	close($socket);
	$watcher->cancel();
	return;
	}

	my $data = $watcher->data().$thisread;
	$watcher->data($data);
	if($data =~ /\n$/) { # Request entirely read.
	chomp($data);
	} else {
	return;
	}

	&Debug(5,"Creating child for $data (parent_client_connection)");
	(my $hostname,my $lonid,@all_host_ids) = split(':',$data);
	$ChildHost{$hostname}++;
	if ($ChildHost{$hostname} == 1) {
	&CreateChild($hostname,$lonid);
	} else {
	&Log('WARNING',"Request for a second child on $hostname");
	}
	# Clean up the listen since now the child takes over until it exits.
	$watcher->cancel(); # Nolonger listening to this event
	$socket->send("done\n");
	$socket->close();
	}

	# parent_listen:
	# Opens a socket and starts a listen for the parent process on a client UNIX
	# domain socket.
	#
	# This involves:
	# Creating a socket for listen.
	# Removing any socket lock file
	# Adding an event handler for this socket becoming readable
	# To the parent's event dispatcher.
	# Parameters:
	# loncapa_host - LonCAPA cluster name of the host represented by the client
	# socket.
	# Returns:
	# NONE
	#
	sub parent_listen {
	my ($loncapa_host) = @_;
	Debug(5, "parent_listen: $loncapa_host");

	my ($socket,$file);
	if (!$loncapa_host) {
	$loncapa_host = 'common_parent';
	$file = $perlvar{'lonSockCreate'};
	} else {
	$file = &GetLoncSocketPath($loncapa_host);
	}
	$socket = &SetupLoncListener($loncapa_host,$file);

	$listening_to{$socket} = $loncapa_host;
	if (!$socket) {
	die "Unable to create a listen socket for $loncapa_host";
	}

	my $lock_file = $file.".lock";
	unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]

	my $watcher =
	Event->io(cb => \&parent_client_connection,
	poll => 'r',
	desc => "Parent listener unix socket ($loncapa_host)",
	data => "",
	fd => $socket);
	$parent_dispatchers{$loncapa_host} = $watcher;

	}

	sub parent_clean_up {
	my ($loncapa_host) = @_;
	Debug(1, "parent_clean_up: $loncapa_host");

	my $socket_file = &GetLoncSocketPath($loncapa_host);
	unlink($socket_file); # No problem if it doesn't exist yet [startup e.g.]
	my $lock_file = $socket_file.".lock";
	unlink($lock_file); # No problem if it doesn't exist yet [startup e.g.]
	}



	# This sub initiates a listen on the common unix domain lonc client socket.
	# loncnew starts up with no children, and only spawns off children when a
	# connection request occurs on the common client unix socket. The spawned
	# child continues to run until it has been idle a while at which point it
	# eventually exits and once more the parent picks up the listen.
	#
	# Parameters:
	# NONE
	# Implicit Inputs:
	# The configuration file that has been read in by LondConnection.
	# Returns:
	# NONE
	#
	sub listen_on_common_socket {
	Debug(5, "listen_on_common_socket");
	&parent_listen();
	}

	# server_died is called whenever a child process exits.
	# Since this is dispatched via a signal, we must process all
	# dead children until there are no more left. The action
	# is to:
	# - Remove the child from the bookeeping hashes
	# - Re-establish a listen on the unix domain socket associated
	# with that host.
	# Parameters:
	# The event, but we don't actually care about it.
	sub server_died {
	&Debug(9, "server_died called...");

	while(1) { # Loop until waitpid nowait fails.
	my $pid = waitpid(-1, WNOHANG);
	if($pid <= 0) {
	return; # Nothing left to wait for.
	}
	# need the host to restart:

	my $host = $ChildPid{$pid};
	if($host) { # It's for real...
	&Debug(9, "Caught sigchild for $host");
	delete($ChildPid{$pid});
	delete($ChildHost{$host});
	&parent_clean_up($host);

	} else {
	&Debug(5, "Caught sigchild for pid not in hosts hash: $pid");
	}
	}

	}

#	#
# Parent process logic pass 1:	# Parent process logic pass 1:
# For each entry in the hosts table, we will	# For each entry in the hosts table, we will
Line 1624 ShowStatus("Forking node servers");	Line 2031 ShowStatus("Forking node servers");
Log("CRITICAL", "--------------- Starting children ---------------");	Log("CRITICAL", "--------------- Starting children ---------------");

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

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

# Maintain the population:	# Maintain the population:

ShowStatus("Parent keeping the flock");	ShowStatus("Parent keeping the flock");

#
# Set up parent signals:
#

$SIG{INT} = \&Terminate;
$SIG{TERM} = \&Terminate;
$SIG{HUP} = \&Restart;
$SIG{USR1} = \&CheckKids;
$SIG{USR2} = \&UpdateKids; # LonManage update request.

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

	# We need to setup a SIGChild event to handle the exit (natural or otherwise)
	# of the children.

	Event->signal(cb => \&server_died,
	desc => "Child exit handler",
	signal => "CHLD");


	# Set up all the other signals we set up.

	$parent_handlers{INT} = Event->signal(cb => \&Terminate,
	desc => "Parent INT handler",
	signal => "INT");
	$parent_handlers{TERM} = Event->signal(cb => \&Terminate,
	desc => "Parent TERM handler",
	signal => "TERM");
	$parent_handlers{HUP} = Event->signal(cb => \&KillThemAll,
	desc => "Parent HUP handler.",
	signal => "HUP");
	$parent_handlers{USR1} = Event->signal(cb => \&CheckKids,
	desc => "Parent USR1 handler",
	signal => "USR1");
	$parent_handlers{USR2} = Event->signal(cb => \&UpdateKids,
	desc => "Parent USR2 handler.",
	signal => "USR2");

	# Start procdesing events.

	$Event::DebugLevel = $DebugLevel;
	Debug(9, "Parent entering event loop");
	my $ret = Event::loop();
	die "Main Event loop exited: $ret";

=pod	=pod

=head1 CheckKids	=head1 CheckKids

Since kids do not die as easily in this implementation	Since kids do not die as easily in this implementation
as the previous one, there is no need to restart the	as the previous one, there is no need to restart the
dead ones (all dead kids get restarted when they die!!)	dead ones (all dead kids get restarted when they die!!)
The only thing this function does is to pass USR1 to the	The only thing this function does is to pass USR1 to the
kids so that they report their status.	kids so that they report their status.
Line 1682 sub CheckKids {	Line 2094 sub CheckKids {
my $now=time;	my $now=time;
my $local=localtime($now);	my $local=localtime($now);
print $fh "LONC status $local - parent $$ \n\n";	print $fh "LONC status $local - parent $$ \n\n";
foreach my $pid (keys %ChildHash) {	foreach my $host (keys %parent_dispatchers) {
	print $fh "LONC Parent process listening for $host\n";
	}
	foreach my $pid (keys %ChildPid) {
Debug(2, "Sending USR1 -> $pid");	Debug(2, "Sending USR1 -> $pid");
kill 'USR1' => $pid; # Tell Child to report status.	kill 'USR1' => $pid; # Tell Child to report status.
sleep 1; # Wait so file doesn't intermix.
}	}

}	}

=pod	=pod
Line 1719 sub UpdateKids {	Line 2134 sub UpdateKids {

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

# Just in case we need to kill our own lonc, we wait a few seconds to	# I'm not sure what I was thinking in the first implementation.
# give it a chance to receive and relay lond's response to the	# someone will have to work hard to convince me the effect is any
# re-init command.	# different than Restart, especially now that we don't start up
#	# per host servers automatically, may as well just restart.
	# The down side is transactions that are in flight will get timed out
sleep(2); # Wait a couple of seconds.	# (lost unless they are critical).

my %hosts; # Indexed by loncapa hostname, value=ip.	&KillThemAll();

# 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.
}
}
}	}


Line 1802 sub UpdateKids {	Line 2150 sub UpdateKids {
=head1 Restart	=head1 Restart

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

=cut	=cut
Line 1812 sub Restart {	Line 2160 sub Restart {
Log("CRITICAL", "Restarting");	Log("CRITICAL", "Restarting");
my $execdir = $perlvar{'lonDaemons'};	my $execdir = $perlvar{'lonDaemons'};
unlink("$execdir/logs/lonc.pid");	unlink("$execdir/logs/lonc.pid");
exec("$execdir/loncnew");	exec("$executable");
}	}

=pod	=pod
Line 1826 SIGHUP. Responds to sigint and sigterm.	Line 2174 SIGHUP. Responds to sigint and sigterm.

sub KillThemAll {	sub KillThemAll {
Debug(2, "Kill them all!!");	Debug(2, "Kill them all!!");
local($SIG{CHLD}) = 'IGNORE'; # Our children >will< die.
foreach my $pid (keys %ChildHash) {	#local($SIG{CHLD}) = 'IGNORE';
my $serving = $ChildHash{$pid};	# Our children >will< die.
Debug(2, "Killing lonc for $serving pid = $pid");	# but we need to catch their death and cleanup after them in case this is
ShowStatus("Killing lonc for $serving pid = $pid");	# a restart set of kills
Log("CRITICAL", "Killing lonc for $serving pid = $pid");	my @allpids = keys(%ChildPid);
	foreach my $pid (@allpids) {
	my $serving = $ChildPid{$pid};
	ShowStatus("Nicely Killing lonc for $serving pid = $pid");
	Log("CRITICAL", "Nicely Killing lonc for $serving pid = $pid");
kill 'QUIT' => $pid;	kill 'QUIT' => $pid;
delete($ChildHash{$pid});
}	}
my $execdir = $perlvar{'lonDaemons'};	ShowStatus("Finished killing child processes off.");
unlink("$execdir/logs/lonc.pid");	}


	#
	# Kill all children via KILL. Just in case the
	# first shot didn't get them.

	sub really_kill_them_all_dammit
	{
	Debug(2, "Kill them all Dammit");
	local($SIG{CHLD} = 'IGNORE'); # In case some purist reenabled them.
	foreach my $pid (keys %ChildPid) {
	my $serving = $ChildPid{$pid};
	&ShowStatus("Nastily killing lonc for $serving pid = $pid");
	Log("CRITICAL", "Nastily killing lonc for $serving pid = $pid");
	kill 'KILL' => $pid;
	delete($ChildPid{$pid});
	my $execdir = $perlvar{'lonDaemons'};
	unlink("$execdir/logs/lonc.pid");
	}
}	}

=pod	=pod
Line 1849 Terminate the system.	Line 2218 Terminate the system.
=cut	=cut

sub Terminate {	sub Terminate {
KillThemAll;	&Log("CRITICAL", "Asked to kill children.. first be nice...");
	&KillThemAll;
	#
	# By now they really should all be dead.. but just in case
	# send them all SIGKILL's after a bit of waiting:

	sleep(4);
	&Log("CRITICAL", "Now kill children nasty");
	&really_kill_them_all_dammit;
Log("CRITICAL","Master process exiting");	Log("CRITICAL","Master process exiting");
exit 0;	exit 0;

}	}

	sub my_hostname {
	use Sys::Hostname;
	my $name = &hostname();
	&Debug(9,"Name is $name");
	return $name;
	}

=pod	=pod

=head1 Theory	=head1 Theory
Line 1895 A hash of lond connections that have no	Line 2280 A hash of lond connections that have no
can be closed if they are idle for a long enough time.	can be closed if they are idle for a long enough time.

=cut	=cut

	=pod

	=head1 Log messages

	The following is a list of log messages that can appear in the
	lonc.log file. Each log file has a severity and a message.

	=over 2

	=item Warning A socket timeout was detected

	If there are pending transactions in the socket's queue,
	they are failed (saved if critical). If the connection
	retry count gets exceeded by this, the
	remote host is marked as dead.
	Called when timeouts occurred during the connection and
	connection dialog with a remote host.

	=item Critical Host makred DEAD <hostname>

	The numer of retry counts for contacting a host was
	exceeded. The host is marked dead an no
	further attempts will be made by that child.

	=item Info lonc pipe client hung up on us

	Write to the client pipe indicated no data transferred
	Socket to remote host is shut down. Reply to the client
	is discarded. Note: This is commented out in &ClientWriteable

	=item Success Reply from lond: <data>

	Can be enabled for debugging by setting LogTransactions to nonzero.
	Indicates a successful transaction with lond, <data> is the data received
	from the remote lond.

	=item Success A delayed transaction was completed

	A transaction that must be reliable was executed and completed
	as lonc restarted. This is followed by a mesage of the form

	S: client-name : request

	=item WARNING Failing transaction <cmd>:<subcmd>

	Transaction failed on a socket, but the failure retry count for the remote
	node has not yet been exhausted (the node is not yet marked dead).
	cmd is the command, subcmd is the subcommand. This results from a con_lost
	when communicating with lond.

	=item WARNING Shutting down a socket

	Called when a socket is being closed to lond. This is emitted both when
	idle pruning is being done and when the socket has been disconnected by the remote.

	=item WARNING Lond connection lost.

	Called when a read from lond's socket failed indicating lond has closed the
	connection or died. This should be followed by one or more

	"WARNING Failing transaction..." msgs for each in-flight or queued transaction.

	=item INFO Connected to lond version: <version>

	When connection negotiation is complete, the lond version is requested and logged here.

	=item SUCCESS Connection n to host now ready for action

	Emitted when connection has been completed with lond. n is then number of
	concurrent connections and host, the host to which the connection has just
	been established.

	=item WARNING Connection to host has been disconnected

	Write to a lond resulted in failure status. Connection to lond is dropped.

	=item SUCCESS Created connection n to host host

	Initial connection request to host..(before negotiation).

	=item CRITICAL Request Close Connection ... exiting

	Client has sent "close_connection_exit" The loncnew server is exiting.

	=item INFO Resetting Connection Retries

	Client has sent "reset_retries" The lond connection retries are reset to zero for the
	corresponding lond.

	=item SUCCESS Transaction <data>

	Only emitted if the global variable $LogTransactions was set to true.
	A client has requested a lond transaction <data> is the contents of the request.

	=item SUCCESS Toggled transaction logging <LogTransactions>

	The state of the $LogTransactions global has been toggled, and its current value
	(after being toggled) is displayed. When non zero additional logging of transactions
	is enabled for debugging purposes. Transaction logging is toggled on receipt of a USR2
	signal.

	=item CRITICAL Abnormal exit. Child <pid> for <host> died thorugh signal.

	QUIT signal received. lonc child process is exiting.

	=item SUCCESS New debugging level for <RemoteHost> now <DebugLevel>

	Debugging toggled for the host loncnew is talking with.
	Currently debugging is a level based scheme with higher number
	conveying more information. The daemon starts out at
	DebugLevel 0 and can toggle back and forth between that and
	DebugLevel 2 These are controlled by
	the global variables $DebugLevel and $NextDebugLevel
	The debug level can go up to 9.
	SIGINT toggles the debug level. The higher the debug level the
	more debugging information is spewed. See the Debug
	sub in loncnew.

	=item CRITICAL Forking server for host

	A child is being created to service requests for the specified host.


	=item WARNING Request for a second child on hostname

	Somehow loncnew was asked to start a second child on a host that already had a child
	servicing it. This request is not honored, but themessage is emitted. This could happen
	due to a race condition. When a client attempts to contact loncnew for a new host, a child
	is forked off to handle the requests for that server. The parent then backs off the Unix
	domain socket leaving it for the child to service all requests. If in the time between
	creating the child, and backing off, a new connection request comes in to the unix domain
	socket, this could trigger (unlikely but remotely possible),.

	=item CRITICAL ------ Starting Children ----

	This message should probably be changed to "Entering event loop" as the loncnew only starts
	children as needed. This message is emitted as new events are established and
	the event processing loop is entered.

	=item INFO Updating connections via SIGUSR2

	SIGUSR2 received. The original code would kill all clients, re-read the host file,
	then restart children for each host. Now that children are started on demand, this
	just kills all child processes and lets requests start them as needed again.


	=item CRITICAL Restarting

	SigHUP received. all the children are killed and the script exec's itself to start again.

	=item CRITICAL Nicely killing lonc for host pid = <pid>

	Attempting to kill the child that is serving the specified host (pid given) cleanly via
	SIGQUIT. The child should handle that, clean up nicely and exit.

	=item CRITICAL Nastily killing lonc for host pid = <pid>

	The child specified did not die when requested via SIGQUIT. Therefore it is killed
	via SIGKILL.

	=item CRITICAL Asked to kill children.. first be nice..

	In the parent's INT handler. INT kills the child processes. This inidicate loncnew
	is about to attempt to kill all known children via SIGQUIT. This message should be followed
	by one "Nicely killing" message for each extant child.

	=item CRITICAL Now kill children nasty

	In the parent's INT handler. remaining children are about to be killed via
	SIGKILL. Should be followed by a Nastily killing... for each lonc child that
	refused to die.

	=item CRITICAL Master process exiting

	In the parent's INT handler. just prior to the exit 0 call.

	=back

	=cut

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