--- loncom/homework/bridgetask.pm	2005/05/24 19:33:28	1.30
+++ loncom/homework/bridgetask.pm	2005/05/31 16:31:01	1.35
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA 
 # definition of tags that give a structure to a document
 #
-# $Id: bridgetask.pm,v 1.30 2005/05/24 19:33:28 albertel Exp $
+# $Id: bridgetask.pm,v 1.35 2005/05/31 16:31:01 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -144,6 +144,20 @@ sub add_grading_button {
     my $result=' <input type="submit" name="gradeasubmission" value="'.
 	&mt("Get a submission to grade").'" />';
     $result.='<input type="hidden" name="grade_target" value="webgrade" />';
+    if ( 1) {
+	#need a permissions for limitng this to 'powerful users'
+
+	my ($entries,$ready,$locks)=&get_queue_counts('gradingqueue');
+	$result.='<p>'.&mt("Grading Queue has [_1] entries. [_2] of them are ready to be graded and [_3] of them are currently being graded",$entries,$ready,$locks);
+
+	$result.=' <input type="submit" name="reviewagrading" value="'.
+	    &mt("Select an entry from the grading queue").'" /> </p>'."\n";
+
+	($entries,$ready,$locks)=&get_queue_counts('reviewqueue');
+	$result.='<p>'.&mt("Review Queue has [_1] entries. [_2] of them are ready to be graded and [_3] of them are currently being graded",$entries,$ready,$locks);
+	$result.=' <input type="submit" name="reviewasubmission" value="'.
+	    &mt("Select an entry from the review queue").'" /> </p>'."\n";
+    }
     return $result;
 }
 
@@ -266,42 +280,65 @@ sub start_Task {
 	}
     } elsif ( ($target eq 'grade' && $env{'form.webgrade'}) ||
 	      $target eq 'webgrade') {
+	my $webgrade='yes';
 	if ($target eq 'webgrade') {
-	    $result.=$head_tag_start.$body_tag_start.$form_tag_start;
-	    $result.='<input type="hidden" name="webgrade" value="yes" />';
-	    $result.='<br />Before'.&show_queue('gradingqueue');
-	}
-	my $todo;
-	# don't get something new from the queue if they hit the stop button
-	if (!($env{'form.stop'} && $target eq 'webgrade')) {
-	    $todo=&get_from_queue('gradingqueue');
-	}
+	    $result.=$head_tag_start.$body_tag_start;
+	    $result.='<br />Review'.&show_queue('reviewqueue');
+	    $result.='<br />Grade'.&show_queue('gradingqueue');
+	}
+	# FIXME Blast! still need to reorg this, need to reshow the
+        #       queue being reviewed once done with the grade pass...
+        #       Hrrm, vaildation pass should perhaps say 'not_locked'
+        #       perhaps do a search if there is a key that is mine and if
+        #       there isn't reshow the queue....
+	my ($todo,$status_code)=&get_key_todo($target);
+
+	&Apache::lonnet::logthis("got todo -$todo- stat -$status_code-");
 	if ($todo) {
 	    &setup_env_for_other_user($todo,$safeeval);
 	    my ($symb,$uname,$udom)=&decode_queue_key($todo);
 	    $result.="\n".'<table><tr><td>Found '.
 		&Apache::lonnet::gettitle($symb).' for '.$uname.' at '.$udom.'</td></tr></table>';
-	    $result.='<input type="hidden" name="gradingkey" value="'.
+	    $form_tag_start.=
+		'<input type="hidden" name="gradingkey" value="'.
 		&Apache::lonnet::escape($todo).'" />';
 	    $Apache::bridgetask::queue_key=$todo;
 	    &Apache::structuretags::initialize_storage();
 	    &Apache::lonhomework::showhash(%Apache::lonhomework::history);
 	    if ($target eq 'webgrade') {
-		$result.='<br />After'.&show_queue('gradingqueue');
+		$result.='<br />After -'.&show_queue($env{'form.queue'});
 		$result.="\n".'<table width="100%" style="width:100%" border="1">';
+		if ($status_code eq 'selected') {
+		    $form_tag_start.=
+			'<input type="hidden" name="queuemode" value="selected" />';
+		}
 	    }
 	} else {
 	    if ($target eq 'webgrade') {
-		$result.="\n".'<table><tr><td><b>';
-		if ($env{'form.stop'}) {
-		    $result.=&mt("Stopped grading.");
+		$result.="\n";
+		if      ($status_code eq 'stop') {
+		    $result.='<b>'.&mt("Stopped grading.").'</b>';
+		} elsif ($status_code eq 'lock_failed') {
+		    $result.='<b>'.&mt("Failed to lock the request record.").'</b>';
+		} elsif ($status_code eq 'unlock') {
+		    $result.='<b>'.&mt("Unlocked the requested record.").'</b>';
+		    $result.=&show_queue($env{'form.queue'},1);
+		} elsif ($status_code eq 'show_list') {
+		    $result.=&show_queue($env{'form.queue'},1);
 		} else {
-		    $result.=&mt("No user to be graded.");
+		    $result.='<b>'.&mt("No user to be graded.").'</b>';
 		}
-		$result.='</b></td></tr></table>';
 	    }
+	    $webgrade='no';
 	    my $bodytext=&Apache::lonxml::get_all_text("/task",$parser);
 	}
+	if ($target eq 'webgrade' && defined($env{'form.queue'})) {
+	    $result.=$form_tag_start;
+	    $result.='<input type="hidden" name="webgrade" value="'.
+		$webgrade.'" />';
+	    $result.='<input type="hidden" name="queue" value="'.
+		$env{'form.queue'}.'" />';
+	}
     } else {
 	# page_start returned a starting result, delete it if we don't need it
 	$result = '';
@@ -309,6 +346,78 @@ sub start_Task {
     return $result;
 }
 
+sub get_key_todo {
+    my ($target)=@_;
+    my $todo;
+
+    if (defined($env{'form.reviewasubmission'})) {
+	&Apache::lonnet::logthis("review a submission....");
+	$env{'form.queue'}='reviewqueue';
+	return (undef,'show_list');
+    }
+
+    if (defined($env{'form.reviewagrading'})) {
+	&Apache::lonxml::debug("review a grading....");
+	$env{'form.queue'}='gradingqueue';
+	return (undef,'show_list');
+    }
+
+    my $queue=$env{'form.queue'};
+
+    if (!defined($queue)) {
+	$env{'form.queue'}=$queue='gradingqueue';
+    }
+
+    my $gradingkey=&Apache::lonnet::unescape($env{'form.gradingkey'});
+
+    if (defined($env{'form.queue'}) && defined($env{'form.gradingkey'})
+	&& !defined($env{'form.gradingaction'}) 
+	&& $env{'form.queuemode'} eq 'selected') {
+	
+	my $who=&queue_key_locked($queue,$gradingkey);
+	my $me=$env{'user.name'}.'@'.$env{'user.domain'};
+	if ($who eq $me) {
+	    &Apache::lonxml::debug("Found a key was given to me");
+	    return ($gradingkey,'selected');
+	} else {
+	    return (undef,'show_list');
+	}
+
+    }
+
+    if ($target eq 'webgrade' && $env{'form.queuemode'} eq 'selected') {
+	if ($env{'form.gradingaction'} eq 'resume') {
+	    delete($env{'form.gradingaction'});
+	    &Apache::lonxml::debug("Resuming a key");
+	    return ($gradingkey);
+	} elsif ($env{'form.gradingaction'} eq 'unlock') {
+	    &Apache::lonxml::debug("Unlocking a key ".
+				     &check_queue_unlock($queue,$gradingkey,1));
+	    return (undef,'unlock');
+	} elsif ($env{'form.gradingaction'} eq 'select') {
+	    &Apache::lonxml::debug("Locking a key");
+	    if (&lock_key($queue,$gradingkey)) {
+		&Apache::lonxml::debug("Success $queue");
+		return ($gradingkey);
+	    }
+	    &Apache::lonxml::debug("Failed $queue");
+	    return (undef,'lock_failed');
+	}
+    }
+
+    if ($env{'form.queuemode'} ne 'selected') {
+	# don't get something new from the queue if they hit the stop button
+    	if (!($env{'form.stop'} && $target eq 'webgrade') 
+	    && !$env{'form.gradingaction'}) {
+	    &Apache::lonxml::debug("Getting anew $queue");
+	    return (&get_from_queue($queue));
+	} else {
+	    return (undef,'stop');
+	}
+    }
+    return (undef,undef)
+}
+
 sub end_Task {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval)=@_;
     my $result='';
@@ -351,10 +460,10 @@ sub end_Task {
 	    &Apache::lonhomework::showhash(%Apache::lonhomework::results);
 	    &Apache::structuretags::finalize_storage();
 	    if ($award eq 'SUBMITTED') {
-		&add_to_queue('gradingqueue');
+		&add_to_queue('gradingqueue',$Apache::inputtags::slot_name);
 	    }
 	}
-	if ($target eq 'grade' && $env{'form.webgrade'}) {
+	if ($target eq 'grade' && $env{'form.webgrade'} eq 'yes') {
 	    my $optional_required=
 		&Apache::lonxml::get_param('OptionalRequired',$parstack,
 					   $safeeval);
@@ -386,22 +495,33 @@ sub end_Task {
 		$env{'user.name'}.'@'.$env{'user.domain'};
 	    if ($review) {
 		$Apache::lonhomework::results{"resource.$version.status"}='review';
-		&move_to_review_queue();
+		if ($env{'form.queue'} eq 'reviewqueue') {
+		    &check_queue_unlock($env{'form.queue'});
+		    &Apache::lonxml::debug(" still needs review not changing status.");
+		} else {
+		    &move_between_queues('gradingqueue','reviewqueue');
+		}
 	    } elsif ($ungraded) {
 		$Apache::lonhomework::results{"resource.$version.status"}='ungraded';
-		&check_queue_unlock('gradingqueue');
+		# FIXME if in review queue need to move back to grading queue
+		if ($env{'form.queue'} eq 'reviewqueue') {
+		    &Apache::lonxml::debug("moving back.");
+		    &move_between_queues('reviewqueue','gradingqueue');
+		} else {
+		    &check_queue_unlock($env{'form.queue'});
+		}
 	    } elsif ($mandatory_failed) {
 		$Apache::lonhomework::results{"resource.$version.status"}='fail';
 		$Apache::lonhomework::results{"resource.$version.0.solved"}='incorrect_by_override';
 		$Apache::lonhomework::results{"resource.$version.0.award"}='INCORRECT';
 		$Apache::lonhomework::results{"resource.$version.0.awarded"}='0';
-		&remove_from_queue('gradingqueue');
+		&remove_from_queue($env{'form.queue'});
 	    } else {
 		$Apache::lonhomework::results{"resource.$version.status"}='pass';
 		$Apache::lonhomework::results{"resource.$version.0.solved"}='correct_by_override';
 		$Apache::lonhomework::results{"resource.$version.0.award"}='EXACT_ANS';
 		$Apache::lonhomework::results{"resource.$version.0.awarded"}='1';
-		&remove_from_queue();
+		&remove_from_queue($env{'form.queue'});
 	    }
 	    $Apache::lonhomework::results{"resource.status"}=
 		$Apache::lonhomework::results{"resource.$version.status"};
@@ -435,22 +555,35 @@ sub end_Task {
     return $result;
 }
 
-sub move_to_review_queue {
-
-    &Apache::lonxml::debug("Want to move");
+sub move_between_queues {
+    my ($src_queue,$dest_queue)=@_;
+    my $cur_data=&get_queue_data($src_queue);
+    if (!$cur_data) { return 'not_exist'; }
+    my $result=&add_to_queue($dest_queue,$cur_data->[0]);
+    if ($result ne 'ok') {
+	return $result;
+    }
+    &check_queue_unlock($src_queue);
+    return &remove_from_queue($src_queue);
 }
 
 sub check_queue_unlock {
-    my ($queue)=@_;
+    my ($queue,$key,$allow_not_me)=@_;
     my ($symb,$cid,$udom,$uname)=&Apache::lonxml::whichuser();
+    if (!defined($key)) {
+	$key="$symb\0queue\0$uname\@$udom";
+    }
     my $cnum=$env{'course.'.$cid.'.num'};
     my $cdom=$env{'course.'.$cid.'.domain'};
-    my $key="$symb\0queue\0$uname\@$udom";
     my $me=$env{'user.name'}.'@'.$env{'user.domain'};
     my $who=&queue_key_locked($queue,$key,$cdom,$cnum);
     if  ($who eq $me) {
-	&Apache::lonnet::del($queue,["$key\0locked"],$cdom,$cnum);
+	return &Apache::lonnet::del($queue,["$key\0locked"],$cdom,$cnum);
+    } elsif ($allow_not_me) {
+	&Apache::lonxml::debug("unlocking $who by $me");
+	return &Apache::lonnet::del($queue,["$key\0locked"],$cdom,$cnum);
     }
+    return 'not_owner';
 }
 
 sub remove_from_queue {
@@ -460,7 +593,7 @@ sub remove_from_queue {
     my $cdom=$env{'course.'.$cid.'.domain'};
     my $key="$symb\0queue\0$uname\@$udom";
     my @keys=($key,"$key\0locked");
-    &Apache::lonnet::del($queue,\@keys,$cdom,$cnum);
+    return &Apache::lonnet::del($queue,\@keys,$cdom,$cnum);
 }
 
 sub setup_env_for_other_user {
@@ -474,44 +607,92 @@ sub setup_env_for_other_user {
     &Apache::lonxml::initialize_rndseed($safeeval);
 }
 
-sub add_to_queue {
+sub get_queue_data {
     my ($queue)=@_;
     my ($symb,$cid,$udom,$uname)=&Apache::lonxml::whichuser();
     my $cnum=$env{'course.'.$cid.'.num'};
     my $cdom=$env{'course.'.$cid.'.domain'};
+    my $todo="$symb\0queue\0$uname\@$udom";
+    my ($key,$value)=&Apache::lonnet::get($queue,[$todo],$cdom,$cnum);
+    if ($key eq $todo && ref($value)) {
+	return $value;
+    }
+    return undef;
+}
+
+sub add_to_queue {
+    my ($queue,$slot_name)=@_;
+    my ($symb,$cid,$udom,$uname)=&Apache::lonxml::whichuser();
+    my $cnum=$env{'course.'.$cid.'.num'};
+    my $cdom=$env{'course.'.$cid.'.domain'};
     my %data;
-    $data{"$symb\0queue\0$uname\@$udom"}=[$Apache::inputtags::slot_name];
-    &Apache::lonnet::put($queue,\%data,$cdom,$cnum);
+    $data{"$symb\0queue\0$uname\@$udom"}=[$slot_name];
+    return &Apache::lonnet::put($queue,\%data,$cdom,$cnum);
 }
 
 sub show_queue {
-    my ($queue)=@_;
+    my ($queue,$with_selects)=@_;
     my $result;
     my ($symb,$cid,$udom,$uname)=&Apache::lonxml::whichuser();
     my $cnum=$env{'course.'.$cid.'.num'};
     my $cdom=$env{'course.'.$cid.'.domain'};
     my $regexp="^$symb\0";
     my %queue=&Apache::lonnet::dump($queue,$cdom,$cnum,$regexp);
-    $result.="\n<h3>Current Queue</h3><table border='1'><tr><th>resource</th>".
-	"<th>user</th><th>type</th><th>data</th></tr>";
+    my ($tmp)=%queue;
+    if ($tmp=~/^error: 2 /) {
+	return "\n<h3>Current Queue - $queue</h3><table border='1'><tr><td>Empty</td></tr></table>";
+    }
+    $result.="\n<h3>Current Queue - $queue </h3><table border='1'><tr>";
+    if ($with_selects) { $result.="<th></th>"; }
+    $result.="<th>resource</th><th>user</th><th>type</th><th>data</th></tr>";
     foreach my $key (sort(keys(%queue))) {
-	if ($key=~/locked$/) {
+	if ($key=~/locked$/ && !$with_selects) {
 	    my ($symb,$uname,$udom) = &decode_queue_key($key);
 	    my $title=&Apache::lonnet::gettitle($symb);
 	    $result.="<tr><td>$title</td><td>$uname</td>";
 	    $result.='<td>lock</td><td>'.$queue{$key}.'</td></tr>';
-	} elsif ($key=~/timestamp$/) {
+	} elsif ($key=~/timestamp$/ && !$with_selects) {
 	    my ($symb,undef) = split("\0",$key);
 	    my $title=&Apache::lonnet::gettitle($symb);
 	    $result.="<tr><td>$title</td><td></td>";
 	    $result.='<td>last queue modification time</td><td>'.
 		&Apache::lonlocal::locallocaltime($queue{$key})."</td></tr>";
-	} else {
+	} elsif ($key!~/(timestamp|locked)$/) {
 	    my ($symb,$uname,$udom) = &decode_queue_key($key);
 	    my $title=&Apache::lonnet::gettitle($symb);
-	    $result.="<tr><td>$title</td><td>$uname</td>";
+	    $result.="<tr>";
 	    my $slot=$queue{$key}->[0];
 	    my %slot_data=&Apache::lonnet::get_slot($slot);
+	    if ($with_selects) {
+		my $ekey=&Apache::lonnet::escape($key);
+		my ($action,$description)=('select',&mt('Select'));
+		if (exists($queue{"$key\0locked"})) {
+		    my $me=$env{'user.name'}.'@'.$env{'user.domain'};
+		    if ($me eq $queue{"$key\0locked"}) {
+			($action,$description)=('resume',&mt('Resume'));
+		    } else {
+			($action,$description)=('unlock',&mt('Unlock'));
+		    }
+		}
+		if (time > $slot_data{'endtime'}) {
+		    $result.=(<<FORM);
+<td>
+<form method="POST">
+ <input type="hidden" name="gradingkey" value="$ekey" />
+ <input type="hidden" name="queue" value="$queue" />
+ <input type="hidden" name="gradingaction" value="$action" />
+ <input type="hidden" name="webgrade" value="no" />
+ <input type="hidden" name="queuemode" value="selected" />
+ <input type="submit" name="submit" value="$description" />
+</form>
+</td>
+FORM
+
+                } else {
+		    $result.='<td>'.&mt("In Progress").'</td>'
+		}
+	    }
+	    $result.="<td>$title</td><td>$uname</td>";
 	    $result.='<td>queue entry</td><td>Slot: '.$slot.' End time: '.
 		&Apache::lonlocal::locallocaltime($slot_data{'endtime'}).
 		"</td></tr>";
@@ -521,6 +702,37 @@ sub show_queue {
     return $result;
 }
 
+sub get_queue_counts {
+    my ($queue)=@_;
+    my $result;
+    my ($symb,$cid,$udom,$uname)=&Apache::lonxml::whichuser();
+    my $cnum=$env{'course.'.$cid.'.num'};
+    my $cdom=$env{'course.'.$cid.'.domain'};
+    my $regexp="^$symb\0";
+    my %queue=&Apache::lonnet::dump($queue,$cdom,$cnum,$regexp);
+    my ($tmp)=%queue;
+    if ($tmp=~/^error: 2 /) {
+	return (0,0,0);
+    }
+    my ($entries,$ready_to_grade,$locks)=(0,0,0);
+    foreach my $key (sort(keys(%queue))) {
+	if ($key=~/locked$/) {
+	    $locks++;
+	} elsif ($key=~/timestamp$/) {
+	    #ignore
+	} elsif ($key!~/(timestamp|locked)$/) {
+	    my ($symb,$uname,$udom) = &decode_queue_key($key);
+	    $entries++;
+	    my $slot=$queue{$key}->[0];
+	    my %slot_data=&Apache::lonnet::get_slot($slot);
+	    if (time > $slot_data{'endtime'}) {
+		$ready_to_grade++;
+	    }
+	}
+    }
+    return ($entries,$ready_to_grade,$locks);
+}
+
 sub decode_queue_key {
     my ($key)=@_;
     my ($symb,undef,$user) = split("\0",$key);
@@ -530,6 +742,11 @@ sub decode_queue_key {
 
 sub queue_key_locked {
     my ($queue,$key,$cdom,$cnum)=@_;
+    if (!defined($cdom) || !defined($cnum)) {
+	my (undef,$cid)=&Apache::lonxml::whichuser();
+	$cnum=$env{'course.'.$cid.'.num'};
+	$cdom=$env{'course.'.$cid.'.domain'};
+    }
     my ($key_locked,$value)=
 	&Apache::lonnet::get($queue,["$key\0locked"],$cdom,$cnum);
     if ($key_locked eq "$key\0locked") {
@@ -545,18 +762,18 @@ sub pick_from_queue_data {
 	if ($check_section) {
 	    my $section=&Apache::lonnet::getsection($uname,$udom);
 	    if ($section eq $check_section) {
-		&Apache::lonnet::logthis("my sec");
+		&Apache::lonxml::debug("my sec");
 		next;
 	    }
 	}
 	my $slot=$queuedata->{$key}[0];
 	my %slot_data=&Apache::lonnet::get_slot($slot);
 	if ($slot_data{'endtime'} > time) { 
-	    &Apache::lonnet::logthis("not time");
+	    &Apache::lonxml::debug("not time");
 	    next;
 	}
 	if (&queue_key_locked($queue,$key,$cdom,$cnum)) {
-	    &Apache::lonnet::logthis("someone already has um.");
+	    &Apache::lonxml::debug("someone already has um.");
 	    next;
 	}
 	return $key;
@@ -585,53 +802,62 @@ sub find_mid_grade {
     return undef;
 }
 
+sub lock_key {
+    my ($queue,$todo)=@_;
+    my $me=$env{'user.name'}.'@'.$env{'user.domain'};
+    my (undef,$cid)=&Apache::lonxml::whichuser();
+    my $cnum=$env{'course.'.$cid.'.num'};
+    my $cdom=$env{'course.'.$cid.'.domain'};
+    my $success=&Apache::lonnet::newput($queue,{"$todo\0locked"=> $me},
+					$cdom,$cnum);
+    &Apache::lonxml::debug("success $success $todo");
+    if ($success eq 'ok') {
+	return 1;
+    }
+    return 0;
+}
+
 sub get_from_queue {
     my ($queue)=@_;
     my $result;
     my ($symb,$cid,$udom,$uname)=&Apache::lonxml::whichuser();
     my $cnum=$env{'course.'.$cid.'.num'};
     my $cdom=$env{'course.'.$cid.'.domain'};
-    my $todo;
-    # FIXME need to find if I am 'mid grading'
-    $todo=&find_mid_grade($queue,$symb,$cdom,$cnum);
-    &Apache::lonnet::logthis("found ".join(':',&decode_queue_key($todo)));
+    my $todo=&find_mid_grade($queue,$symb,$cdom,$cnum);
+    &Apache::lonxml::debug("found ".join(':',&decode_queue_key($todo)));
     if ($todo) { return $todo; }
     while (1) {
 	my $starttime=time;
 	&Apache::lonnet::put($queue,{"$symb\0timestamp"=>$starttime},
 			     $cdom,$cnum);
-	&Apache::lonnet::logthis("$starttime");
+	&Apache::lonxml::debug("$starttime");
 	my $regexp="^$symb\0queue\0";
 	my %queue=&Apache::lonnet::dump($queue,$cdom,$cnum,$regexp);
-	#make a pass looking for a user in my section
+	#make a pass looking for a user _not_ in my section
 	if ($env{'request.course.sec'}) {
-	    &Apache::lonnet::logthis("sce");
+	    &Apache::lonxml::debug("sce");
 	    $todo=&pick_from_queue_data($queue,$env{'request.course.sec'},
 					\%queue,$cdom,$cnum);
-	    &Apache::lonnet::logthis("sce $todo");
+	    &Apache::lonxml::debug("sce $todo");
 	}
-	# no one in our section so look for any user that is ready for grading
+	# no one _not_ in our section so look for any user that is
+	# ready for grading
 	if (!$todo) {
-	    &Apache::lonnet::logthis("no sce");
-	    $todo=&pick_from_queue_data($env{'request.course.sec'},\%queue,
-					$cdom,$cnum);
-	    &Apache::lonnet::logthis("no sce $todo");
+	    &Apache::lonxml::debug("no sce");
+	    $todo=&pick_from_queue_data($queue,$env{'request.course.sec'},
+					\%queue,$cdom,$cnum);
+	    &Apache::lonxml::debug("no sce $todo");
 	}
 	# no user to grade 
 	if (!$todo) { last; }
-	&Apache::lonnet::logthis("got $todo");
+	&Apache::lonxml::debug("got $todo");
 	# otherwise found someone so lets try to lock them
-	my $success=&Apache::lonnet::newput($queue,
-					    {"$todo\0locked"=>
-						 $env{'user.name'}.'@'.$env{'user.domain'}},
-					   $cdom,$cnum);
-	# someone else already picked them
-	&Apache::lonnet::logthis("success $todo");
-	if ($success ne 'ok') { next; }
+	# unless someone else already picked them
+	if (!&lock_key($queue,$todo)) { next; }
 	my (undef,$endtime)=
 	    &Apache::lonnet::get($queue,["$symb\0timestamp"],
 				 $cdom,$cnum);
-	&Apache::lonnet::logthis("emd  $endtime");
+	&Apache::lonxml::debug("emd  $endtime");
 	# someone else already modified the queue, 
 	# perhaps our picked user wass already fully graded between
 	# when we picked him and when we locked his record? so lets
@@ -640,16 +866,16 @@ sub get_from_queue {
 	    my ($key,$value)=
 		&Apache::lonnet::get($queue,["$todo"],
 				     $cdom,$cnum);
-	    &Apache::lonnet::logthis("check  $key .. $value");
+	    &Apache::lonxml::debug("check  $key .. $value");
 	    if ($key eq $todo && ref($value)) {
 	    } else {
 		&Apache::lonnet::del($queue,["$todo\0locked"],
 				     $cdom,$cnum);
-		&Apache::lonnet::logthis("del");
+		&Apache::lonxml::debug("del");
 		next;
 	    }
 	}
-	&Apache::lonnet::logthis("last $todo");
+	&Apache::lonxml::debug("last $todo");
 	last;
     }
     return $todo;
@@ -696,9 +922,6 @@ sub start_Dimension {
 }
 
 sub get_instance {
-    #FIXME just grabbing the first one for now, need
-    #to randomly pick one until all have been seen
-    #then start repicking
     &Apache::response::pushrandomnumber();
     my @order=&Math::Random::random_permutation(@{$dimension{'instances'}});
     my $num=@order;