[LON-CAPA-cvs] cvs: loncom / loncnew

[foxr]

foxr		Wed Sep 29 06:37:35 2004 EDT

  Modified files:              
    /loncom	loncnew 
  Log:
  Start adding logic for parent listen.  All this is still conditionalized on
  the DieWhenIdle variable, and is incomplete.  Do not set DieWhenIdle to true
  as the current effect is DieBeforeStarting. (RF).
  
  
Index: loncom/loncnew
diff -u loncom/loncnew:1.60 loncom/loncnew:1.61
--- loncom/loncnew:1.60	Wed Sep 22 07:11:54 2004
+++ loncom/loncnew	Wed Sep 29 06:37:35 2004
@@ -2,7 +2,7 @@
 # The LearningOnline Network with CAPA
 # lonc maintains the connections to remote computers
 #
-# $Id: loncnew,v 1.60 2004/09/22 11:11:54 foxr Exp $
+# $Id: loncnew,v 1.61 2004/09/29 10:37:35 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -1571,6 +1571,9 @@
 =head2 ChildProcess
 
 This sub implements a child process for a single lonc daemon.
+Optional parameter:
+   $socket  - if provided, this is a socket already open for listen
+              on the client socket. Otherwise, a new listen is set up.
 
 =cut
 
@@ -1579,7 +1582,7 @@
 
     #
     #  Signals must be handled by the Event framework...
-#
+    #
 
     Event->signal(signal   => "QUIT",
 		  cb       => \&SignalledToDeath,
@@ -1597,7 +1600,11 @@
 		  data     => "INT");
 
     
-    my $socket =  SetupLoncListener();
+    my ($socket) = @_;
+    if (!$socket) {
+
+	$socket =  SetupLoncListener();
+    }
     Event->io(cb   => \&NewClient,
 	      poll => 'r',
 	      desc => 'Lonc Listener Unix Socket',
@@ -1609,7 +1616,7 @@
 
 # Setup the initial server connection:
     
-     # &MakeLondConnection(); // let first work requirest do+     # &MakeLondConnection(); // let first work requirest do it.
 
 
     Debug(9,"Entering event loop");
@@ -1641,8 +1648,89 @@
 	sigprocmask(SIG_UNBLOCK, $sigset);
 	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.
+#     Setup an event to handle the child process exit. (SIGCHLD).
+# Parameter:
+#    event       - The event object that was created to monitor this socket.
+#                  event->w->fd is the socket.
+# Returns:
+#    NONE
+#
+sub parent_client_connection {
+    die "DieWhenIdle processing not completely operational yet";
+
+}
+
+# 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 $socket    = &SetupLoncListener($loncapa_host);
+    if (!$socket) {
+	die "Unable to create a listen socket for $loncapa_host";
+    }
+    
+    my $lock_file = &GetLoncSocketPath().".lock";
+    unlink($lock_file);		# No problem if it doesn't exist yet [startup e.g.]
+
+    Event->io(cb    => &parent_client_connection,
+	      poll  => 'r',
+	      desc  => 'Parent listener unix socket',
+	      fd    => $socket);
+
+}
+
+
+# listen_on_all_unix_sockets:
+#    This sub initiates a listen on all unix domain lonc client sockets.
+#    This will be called in the case where we are trimming idle processes.
+#    When idle processes are trimmed, loncnew starts up with no children,
+#    and only spawns off children when a connection request occurs on the
+#    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_all_unix_sockets {
+    Debug(5, "listen_on_all_unix_sockets");
+    my $host_iterator      =   &LondConnection::GetHostIterator();
+    while (!$host_iterator->end()) {
+	my $host_entry_ref =   $host_iterator->get();
+	my $host_name      = $host_entry_ref->[0];
+	Debug(9, "Listen for $host_name");
+	&parent_listen($host_name);
+	$host_iterator->next();
+    }
 }
+
 #
 #  Parent process logic pass 1:
 #   For each entry in the hosts table, we will
@@ -1694,8 +1782,8 @@
 my $HostIterator = LondConnection::GetHostIterator;
 
 if ($DieWhenIdle) {
-    print "Die when idle socket monitoring is not yet implemented\n";
-    exit(-1);
+    $RemoteHost = "[parent]";
+    &listen_on_all_unix_sockets();
 } else {
     
     while (! $HostIterator->end()) {
@@ -1713,14 +1801,18 @@
 
 ShowStatus("Parent keeping the flock");
 
-#
-#   Set up parent signals:
-#
 
 if ($DieWhenIdle) {
-    print "Die when idle main processing not yet implemented";
-    exit (-1);
+    $Event::DebugLevel = $DebugLevel;
+    Debug(9, "Parent entering event loop");
+    my $ret = Event::loop();
+    die "Main Event loop exited: $ret";
+
+
 } else {
+    #
+    #   Set up parent signals:
+    #
     
     $SIG{INT}  = \&Terminate;
     $SIG{TERM} = \&Terminate;