ds: simplify idle time expiry, slightly

While it doesn't look like $EXPMAP can be populated in
non-obvious ways via ->DESTROY, it still makes sense to keep it
close to some of our other code around cleanup to reduce
the likelyhood of subtle bugs in case semantics change..

1 files changed, 11 insertions, 13 deletions

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index c89c7b8b..a25e3fe8 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -40,7 +40,7 @@ my $wait_pids; # list of [ pid, callback, callback_arg ]
 my $later_q; # list of callbacks to run at some later interval
 my $EXPMAP; # fd -> idle_time
 our $EXPTIME = 180; # 3 minutes
-my ($reap_armed, $exp_timer);
+my ($reap_armed);
 my $ToClose; # sockets to close when event loop is done
 our (
      %DescriptorMap,             # fd (num) -> PublicInbox::DS object
@@ -77,7 +77,7 @@ sub Reset {
                 # we may be iterating inside one of these on our stack
                 my @q = delete @Stack{keys %Stack};
                 for my $q (@q) { @$q = () }
-                $EXPMAP = {};
+                $EXPMAP = undef;
                 $wait_pids = $later_q = $nextq = $ToClose = undef;
                 $_io = undef; # closes real $Epoll FD
                 $Epoll = undef; # may call DSKQXS::DESTROY
@@ -85,7 +85,7 @@ sub Reset {
                 $later_q || $ToClose || keys(%DescriptorMap) ||
                 $PostLoopCallback || keys(%UniqTimer));
 
-        $reap_armed = $exp_timer = undef;
+        $reap_armed = undef;
         $LoopTimeout = -1;  # no timeout by default
 }
 
@@ -672,27 +672,25 @@ sub later ($) {
 }
 
 sub expire_old () {
-        my $now = now();
-        my $exp = $EXPTIME;
-        my $old = $now - $exp;
-        my %new;
-        while (my ($fd, $idle_at) = each %$EXPMAP) {
+        my $cur = $EXPMAP or return;
+        $EXPMAP = undef;
+        my $old = now() - $EXPTIME;
+        while (my ($fd, $idle_at) = each %$cur) {
                 if ($idle_at < $old) {
                         my $ds_obj = $DescriptorMap{$fd};
-                        $new{$fd} = $idle_at if !$ds_obj->shutdn;
+                        $EXPMAP->{$fd} = $idle_at if !$ds_obj->shutdn;
                 } else {
-                        $new{$fd} = $idle_at;
+                        $EXPMAP->{$fd} = $idle_at;
                 }
         }
-        $EXPMAP = \%new;
-        $exp_timer = scalar(keys %new) ? later(\&expire_old) : undef;
+        add_uniq_timer('expire', 60, \&expire_old) if $EXPMAP;
 }
 
 sub update_idle_time {
         my ($self) = @_;
         my $sock = $self->{sock} or return;
         $EXPMAP->{fileno($sock)} = now();
-        $exp_timer //= later(\&expire_old);
+        add_uniq_timer('expire', 60, \&expire_old);
 }
 
 sub not_idle_long {