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Diff for /loncom/loncnew between versions 1.11 and 1.42

version 1.11, 2003/06/25 01:54:44 version 1.42, 2004/02/17 09:43:21
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 36 Line 35
 #    - Add ability to create/negotiate lond connections (done).  #    - Add ability to create/negotiate lond connections (done).
 #    - Add general logic for dispatching requests and timeouts. (done).  #    - Add general logic for dispatching requests and timeouts. (done).
 #    - Add support for the lonc/lond requests.          (done).  #    - Add support for the lonc/lond requests.          (done).
 #    - Add logging/status monitoring.  #    - Add logging/status monitoring.                    (done)
 #    - Add Signal handling - HUP restarts. USR1 status report.  #    - Add Signal handling - HUP restarts. USR1 status report. (done)
 #    - Add Configuration file I/O                       (done).  #    - Add Configuration file I/O                       (done).
 #    - Add management/status request interface.  #    - Add management/status request interface.         (done)
 #    - Add deferred request capability.                  (done)  #    - Add deferred request capability.                  (done)
 #    - Detect transmission timeouts.  #    - Detect transmission timeouts.                     (done)
 #  
   
 # Change log:  
 #    $Log$  
 #    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 strict;
 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 86  use LONCAPA::Configuration; Line 63  use LONCAPA::Configuration;
 use LONCAPA::HashIterator;  use LONCAPA::HashIterator;
   
   
 #  
 #   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
 # normally set in apache modules:  # normally set in apache modules:
   
Line 107  my %perlvar    = %{$perlvarref}; Line 73  my %perlvar    = %{$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.
   
   my $LogTransactions = 0; # When True, all transactions/replies get logged.
   
 #  #
 #  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 99  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.
   my $LondVersion     = "unknown"; # Version of lond we talk with.
   
 #  #
 #   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 177  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 200  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 208  sub GetPeername {
  return $peerfile;   return $peerfile;
     }      }
 }  }
 #----------------------------- Timer management ------------------------  
 =pod  =pod
   
 =head2 Debug  =head2 Debug
Line 247  sub Debug { Line 220  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 250  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;
       Log("WARNING", "A socket timeout was detected");
       Debug(0, " SocketTimeout called: ");
       $Socket->Dump();
       if(exists($ActiveTransactions{$Socket})) {
         FailTransaction($ActiveTransactions{$Socket});
       }
       KillSocket($Socket); # A transaction timeout also counts as
                                   # a connection failure:
       $ConnectionRetriesLeft--;
       if($ConnectionRetriesLeft <= 0) {
    Log("CRITICAL", "Host marked dead: ".GetServerHost());
       }
   
   }
   #----------------------------- Timer management ------------------------
   
   =pod
   
 =head2 Tick  =head2 Tick
   
 Invoked  each timer tick.  Invoked  each timer tick.
Line 286  Invoked  each timer tick. Line 286  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 299  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 325  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.
    CloseAllLondConnections(); # Should all be closed but....
     }      }
  } 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.
       CloseAllLondConnections(); # Should all already be closed but...
  }   }
                 
     }      }
Line 345  Trigger disconnections of idle sockets. Line 363  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 385  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 443  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 461  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 514  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;
   
     if (!$Transaction->isDeferred()) { # Normal transaction      if (!$Transaction->isDeferred()) { # Normal transaction
  my $data   = $Socket->GetReply(); # Data to send.   my $data   = $Socket->GetReply(); # Data to send.
    if($LogTransactions) {
       Log("SUCCESS", "Reply from lond: '$data'");
    }
  StartClientReply($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();
     }      }
 }  }
   
 =pod  =pod
   
 =head1 StartClientReply  =head1 StartClientReply
   
    Initiates a reply to a client where the reply data is a parameter.     Initiates a reply to a client where the reply data is a parameter.
Line 519  sub CompleteTransaction { Line 548  sub CompleteTransaction {
     The data to send to apached client.      The data to send to apached client.
   
 =cut  =cut
   
 sub StartClientReply {  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 536  sub StartClientReply { Line 566  sub StartClientReply {
       cb       => \&ClientWritable,        cb       => \&ClientWritable,
       data     => $data);        data     => $data);
 }  }
   
 =pod  =pod
   
 =head2 FailTransaction  =head2 FailTransaction
   
   Finishes a transaction with failure because the associated lond socket    Finishes a transaction with failure because the associated lond socket
Line 546  sub StartClientReply { Line 578  sub StartClientReply {
   - The transaction is 'live' in which case we initiate the sending    - The transaction is 'live' in which case we initiate the sending
     of "con_lost" to the client.      of "con_lost" to the client.
   
 Deleting the transaction means killing it from the   Deleting the transaction means killing it from the %ActiveTransactions hash.
 %ActiveTransactions hash.  
   
 Parameters:  Parameters:
   
Line 555  Parameters: Line 586  Parameters:
     
    The LondTransaction we are failing.     The LondTransaction we are failing.
     
   
 =cut  =cut
   
 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();
Line 576  sub FailTransaction { Line 609  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 624  Close all connections open on lond prior
   
 =cut  =cut
 sub CloseAllLondConnections {  sub CloseAllLondConnections {
     foreach $Socket (keys %ActiveConnections) {      foreach my $Socket (keys %ActiveConnections) {
  KillSocket($Socket);        if(exists($ActiveTransactions{$Socket})) {
    FailTransaction($ActiveTransactions{$Socket});
         }
         KillSocket($Socket);
     }      }
 }  }
 =cut  =cut
Line 621  nonzero if we are allowed to create a ne Line 658  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 634  sub KillSocket { Line 672  sub KillSocket {
     }      }
     if(exists($ActiveConnections{$Socket})) {      if(exists($ActiveConnections{$Socket})) {
  delete($ActiveConnections{$Socket});   delete($ActiveConnections{$Socket});
    $ConnectionCount--;
    if ($ConnectionCount < 0) { $ConnectionCount = 0; }
     }      }
     $ConnectionCount--;  
   
     #  If the connection count has gone to zero and there is work in the      #  If the connection count has gone to zero and there is work in the
     #  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();
    CloseAllLondConnections; # Should all already be closed but...
     }      }
 }  }
   
Line 667  The connection must echo the challenge b Line 706  The connection must echo the challenge b
 The challenge has been replied to.  The we are receiveing the   The challenge has been replied to.  The we are receiveing the 
 'ok' from the partner.  'ok' from the partner.
   
   =head3  State=ReadingVersionString
   
   We have requested the lond version and are reading the
   version back.  Upon completion, we'll store the version away
   for future use(?).
   
   =head3 State=HostSet
   
   We have selected the domain name of our peer (multhomed hosts)
   and are getting the reply (presumably ok) back.
   
 =head3 State=RequestingKey  =head3 State=RequestingKey
   
 The ok has been received and we need to send the request for  The ok has been received and we need to send the request for
Line 710  sub LondReadable { Line 760  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: $status");
  # bad return from socket read. Currently this means that  
       if($status != 0) {
    # 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 734  sub LondReadable { Line 789  sub LondReadable {
     $State = $Socket->GetState(); # Update in case of transition.      $State = $Socket->GetState(); # Update in case of transition.
     &Debug(6, "After read, state is ".$State);      &Debug(6, "After read, state is ".$State);
   
    if($State eq "Initialized") {      if($State eq "Initialized") {
   
   
     } elsif ($State eq "ChallengeReceived") {      } elsif ($State eq "ChallengeReceived") {
  #  The challenge must be echoed back;  The state machine   #  The challenge must be echoed back;  The state machine
  # in the connection takes care of setting that up.  Just   # in the connection takes care of setting that up.  Just
  # need to transition to writable:   # need to transition to writable:
   
  $Watcher->cb(\&LondWritable);   $Watcher->cb(\&LondWritable);
  $Watcher->poll("w");   $Watcher->poll("w");
   
     } elsif ($State eq "ChallengeReplied") {      } elsif ($State eq "ChallengeReplied") {
   
       } elsif ($State eq "RequestingVersion") {
    # Need to ask for the version... that is writiability:
   
    $Watcher->cb(\&LondWritable);
    $Watcher->poll("w");
   
       } elsif ($State eq "ReadingVersionString") {
    # Read the rest of the version string... 
       } elsif ($State eq "SetHost") {
    # Need to request the actual domain get set...
   
    $Watcher->cb(\&LondWritable);
    $Watcher->poll("w");
       } elsif ($State eq "HostSet") {
    # Reading the 'ok' from the peer.
   
     } elsif ($State eq "RequestingKey") {      } elsif ($State eq "RequestingKey") {
  #  The ok was received.  Now we need to request the key   #  The ok was received.  Now we need to request the key
Line 758  sub LondReadable { Line 828  sub LondReadable {
     } elsif ($State eq "ReceivingKey") {      } elsif ($State eq "ReceivingKey") {
   
     } elsif ($State eq "Idle") {      } elsif ($State eq "Idle") {
      
    # This is as good a spot as any to get the peer version
    # string:
      
    if($LondVersion eq "unknown") {
       $LondVersion = $Socket->PeerVersion();
       Log("INFO", "Connected to lond version: $LondVersion");
    }
  # 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 783  sub LondReadable { Line 865  sub LondReadable {
   
   
     } else {      } else {
  # Invalid state.   # Invalid state.
  Debug(4, "Invalid state in LondReadable");   Debug(4, "Invalid state in LondReadable");
     }      }
 }  }
Line 865  sub LondWritable { Line 947  sub LondWritable {
   
     SocketDump(6,$Socket);      SocketDump(6,$Socket);
   
       #  If the socket is writable, we must always write.
       # Only by writing will we undergo state transitions.
       # Old logic wrote in state specific code below, however
       # That forces us at least through another invocation of
       # this function after writability is possible again.
       # This logic also factors out common code for handling
       # write failures... in all cases, write failures 
       # Kill the socket.
       #  This logic makes the branches of the >big< if below
       # so that the writing states are actually NO-OPs.
   
       if ($Socket->Writable() != 0) {
         #  The write resulted in an error.
         # We'll treat this as if the socket got disconnected:
         Log("WARNING", "Connection to ".$RemoteHost.
     " has been disconnected");
         if(exists($ActiveTransactions{$Socket})) {
    FailTransaction($ActiveTransactions{$Socket});
         }
         $Watcher->cancel();
         KillSocket($Socket);
         return;
       }
   
   
   
     if      ($State eq "Connected")         {      if      ($State eq "Connected")         {
   
  if ($Socket->Writable() != 0) {  
     #  The write resulted in an error.  
     # We'll treat this as if the socket got disconnected:  
     Log("WARNING", "Connection to ".$RemoteHost.  
  " has been disconnected");  
     $Watcher->cancel();  
     KillSocket($Socket);  
     return;  
  }  
  #  "init" is being sent...   #  "init" is being sent...
    
   
     } elsif ($State eq "Initialized")       {      } elsif ($State eq "Initialized")       {
   
  # Now that init was sent, we switch    # Now that init was sent, we switch 
Line 886  sub LondWritable { Line 984  sub LondWritable {
   
  $Watcher->cb(\&LondReadable);   $Watcher->cb(\&LondReadable);
  $Watcher->poll("r");   $Watcher->poll("r");
   
     } elsif ($State eq "ChallengeReceived") {      } elsif ($State eq "ChallengeReceived") {
  # We received the challenge, now we    # We received the challenge, now we 
  # are echoing it back. This is a no-op,   # are echoing it back. This is a no-op,
  # we're waiting for the state to change   # we're waiting for the state to change
   
  if($Socket->Writable() != 0) {  
   
     $Watcher->cancel();  
     KillSocket($Socket);  
     return;  
  }  
   
     } elsif ($State eq "ChallengeReplied")  {      } elsif ($State eq "ChallengeReplied")  {
  # The echo was sent back, so we switch   # The echo was sent back, so we switch
  # to watching readability.   # to watching readability.
   
  $Watcher->cb(\&LondReadable);   $Watcher->cb(\&LondReadable);
  $Watcher->poll("r");   $Watcher->poll("r");
       } elsif ($State eq "RequestingVersion") {
    # Sending the peer a version request...
   
       } elsif ($State eq "ReadingVersionString") {
    # Transition to read since we have sent the
    # version command and now just need to read the
    # version string from the peer:
         
    $Watcher->cb(\&LondReadable);
    $Watcher->poll("r");
         
       } elsif ($State eq "SetHost") {
    #  Setting the remote domain...
   
       } elsif ($State eq "HostSet") {
    # Back to readable to get the ok.
         
    $Watcher->cb(\&LondReadable);
    $Watcher->poll("r");
         
   
     } elsif ($State eq "RequestingKey")     {      } elsif ($State eq "RequestingKey")     {
  # At this time we're requesting the key.   # At this time we're requesting the key.
  # again, this is essentially a no-op.   # again, this is essentially a no-op.
  # we'll write the next chunk until the  
  # state changes.  
   
  if($Socket->Writable() != 0) {  
     # Write resulted in an error.  
   
     $Watcher->cancel();  
     KillSocket($Socket);  
     return;  
   
  }  
     } elsif ($State eq "ReceivingKey")      {      } elsif ($State eq "ReceivingKey")      {
  # Now we need to wait for the key   # Now we need to wait for the key
  # to come back from the peer:   # to come back from the peer:
Line 928  sub LondWritable { Line 1029  sub LondWritable {
  $Watcher->poll("r");   $Watcher->poll("r");
   
     } elsif ($State eq "SendingRequest")    {      } elsif ($State eq "SendingRequest")    {
    
  # At this time we are sending a request to the   # At this time we are sending a request to the
  # peer... write the next chunk:   # peer... write the next chunk:
   
  if($Socket->Writable() != 0) {  
   
     if(exists($ActiveTransactions{$Socket})) {  
  Debug(3, "Lond connection lost, failing transactions");  
  FailTransaction($ActiveTransactions{$Socket});  
     }  
     $Watcher->cancel();  
     KillSocket($Socket);  
     return;  
       
  }  
   
     } elsif ($State eq "ReceivingReply")    {      } elsif ($State eq "ReceivingReply")    {
  # The send has completed.  Wait for the   # The send has completed.  Wait for the
Line 971  sub QueueDelayed { Line 1062  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 1072  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 1099  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 1175  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 1214  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.
       CloseAllLondConnections; # Should all be closed but...
    }
       } else {
    ShowStatus(GetServerHost()." >>> DEAD !!!! <<<");
    EmptyQueue(); # It's worse than that ... he's dead Jim.
    CloseAllLondConnections; # Should all be closed but..
       }
  }   }
     } else { # Can start the request:      } else { # Can start the request:
  Debug(8,"Can start...");   Debug(8,"Can start...");
Line 1158  sub ClientRequest { Line 1258  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 1177  sub ClientRequest { Line 1277  sub ClientRequest {
     exit;      exit;
  }   }
  Debug(8, "Complete transaction received: ".$data);   Debug(8, "Complete transaction received: ".$data);
    if($LogTransactions) {
       Log("SUCCESS", "Transaction: '$data'"); # Transaction has \n.
    }
  my $Transaction = LondTransaction->new($data);   my $Transaction = LondTransaction->new($data);
  $Transaction->SetClient($socket);   $Transaction->SetClient($socket);
  QueueTransaction($Transaction);   QueueTransaction($Transaction);
Line 1285  sub SetupLoncListener { Line 1388  sub SetupLoncListener {
       fd     => $socket);        fd     => $socket);
 }  }
   
   #
   #   Toggle transaction logging.
   #  Implicit inputs:  
   #     LogTransactions
   #  Implicit Outputs:
   #     LogTransactions
   sub ToggleTransactionLogging {
       print STDERR "Toggle transaction logging...\n";
       if(!$LogTransactions) {
    $LogTransactions = 1;
       } else {
    $LogTransactions = 0;
       }
   
   
       Log("SUCCESS", "Toggled transaction logging: $LogTransactions \n");
   }
   
   =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";
       #
       #  Write out information about each of the connections:
       #
       print $fh "Active connection statuses: \n";
       my $i = 1;
       print STDERR  "================================= Socket Status Dump:\n";
       foreach my $item (keys %ActiveConnections) {
    my $Socket = $ActiveConnections{$item}->data;
    my $state  = $Socket->GetState();
    print $fh "Connection $i State: $state\n";
    print STDERR "---------------------- Connection $i \n";
    $Socket->Dump();
    $i++;
       }
       $ConnectionRetriesLeft = $ConnectionRetries;
   }
   
 =pod  =pod
   
 =head2 SignalledToDeath  =head2 SignalledToDeath
Line 1293  Called in response to a signal that caus Line 1450  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 1490  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   => "USR2",
     cb       => \&ToggleTransactionLogging);
       Event->signal(signal   => "INT",
     cb       => \&ToggleDebug,
     data     => "INT");
   
     SetupTimer();      SetupTimer();
           
Line 1333  sub ChildProcess { Line 1519  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 1532  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 ($childpid != 0) { Line 1583  if ($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 1599  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 1617  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 1636  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
   
 The event class is used to build this as a single process with an  The event class is used to build this as a single process with an
Removed from v.1.11  
changed lines
  Added in v.1.42

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