--- loncom/lond	2006/05/11 17:53:22	1.325
+++ loncom/lond	2006/05/13 01:31:15	1.326
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.325 2006/05/11 17:53:22 albertel Exp $
+# $Id: lond,v 1.326 2006/05/13 01:31:15 www Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -62,7 +62,7 @@ my $status='';
 my $lastlog='';
 my $lond_max_wait_time = 13;
 
-my $VERSION='$Revision: 1.325 $'; #' stupid emacs
+my $VERSION='$Revision: 1.326 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -1051,6 +1051,41 @@ sub _do_hash_untie {
     sub _locking_hash_tie {
 	my ($file_prefix,$namespace,$how,$loghead,$what) = @_;
 
+# is this locked by an external program?
+
+        if (-e "$file_prefix.db.lock") {
+	    my $failed=0;
+	    eval {
+		local $SIG{__DIE__}='DEFAULT';
+		local $SIG{ALRM}=sub { 
+		    $failed=1;
+		    die("failed lock");
+		};
+		alarm(2*$lond_max_wait_time);
+		while (-e "$file_prefix.db.lock") {}
+		alarm(0);
+	    };
+	    if ($failed) {
+		$! = 100; # throwing error # 100
+		return undef;
+	    }
+	}
+
+# is this archived?
+
+        if (-e "$file_prefix.db.gz") {
+# lock immediately
+ 	   open(TOUCH,">>$file_prefix.db.lock");
+	   close(TOUCH);
+           system("gunzip $file_prefix.db.gz");
+	   if (-e "$file_prefix.hist.gz") {
+	       system("gunzip $file_prefix.hist.gz");
+	   }
+# all set, unlock
+           unlink("$file_prefix.db.lock");
+       }
+
+
 	my ($lock);
     
 	if ($how eq &GDBM_READER()) {