[PATCH 0/6] ds: less is more

[PATCH 0/6] ds: less is more

[Eric Wong]

What's better than Free Software? Freedom FROM software!

Eric Wong (6):
  ds: drop more unused subs
  ds: add a note about planned future changes
  ds: drop set_writer_func support
  ds: drop checks for invalid descriptors
  ds: drop unused EVENT: label in epoll code path
  ds: drop write_set_watch field

 lib/PublicInbox/DS.pm        | 83 +++++-------------------------------
 lib/PublicInbox/EvCleanup.pm |  2 +-
 2 files changed, 12 insertions(+), 73 deletions(-)

-- 
EW

[PATCH 1/6] ds: drop more unused subs

[Eric Wong]

ToClose and HaveEpoll are of no use to us and I see no
future use for them, either.
---
 lib/PublicInbox/DS.pm        | 18 ------------------
 lib/PublicInbox/EvCleanup.pm |  2 +-
 2 files changed, 1 insertion(+), 19 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 9142f21..89042cf 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -95,24 +95,6 @@ sub Reset {
     *EventLoop = *FirstTimeEventLoop;
 }
 
-=head2 C<< CLASS->HaveEpoll() >>
-
-Returns a true value if this class will use IO::Epoll for async IO.
-
-=cut
-sub HaveEpoll {
-    _InitPoller();
-    return $HaveEpoll;
-}
-
-=head2 C<< CLASS->ToClose() >>
-
-Return the list of sockets that are awaiting close() at the end of the
-current event loop.
-
-=cut
-sub ToClose { return @ToClose; }
-
 =head2 C<< CLASS->SetLoopTimeout( $timeout ) >>
 
 Set the loop timeout for the event loop to some value in milliseconds.
diff --git a/lib/PublicInbox/EvCleanup.pm b/lib/PublicInbox/EvCleanup.pm
index b2f8c08..afed24f 100644
--- a/lib/PublicInbox/EvCleanup.pm
+++ b/lib/PublicInbox/EvCleanup.pm
@@ -38,7 +38,7 @@ sub _run_all ($) {
 	$_->() foreach @$run;
 }
 
-# ensure PublicInbox::DS::ToClose fires after timers fire
+# ensure PublicInbox::DS::ToClose processing after timers fire
 sub _asap_close () { $asapq->[1] ||= _asap_timer() }
 
 sub _run_asap () { _run_all($asapq) }
-- 
EW

[PATCH 2/6] ds: add a note about planned future changes

[Eric Wong]

Sometimes I get bored with the email part of this project and
need a distraction :P
---
 lib/PublicInbox/DS.pm | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 89042cf..3b0cbe6 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -5,8 +5,14 @@
 #
 # This is a fork of the (for now) unmaintained Danga::Socket 1.61.
 # Unused features will be removed, and updates will be made to take
-# advantage of newer kernels
-
+# advantage of newer kernels.
+#
+# API changes to diverge from Danga::Socket will happen to better
+# accomodate new features and improve scalability.  Do not expect
+# this to be a stable API like Danga::Socket.
+# Bugs encountered (and likely fixed) are reported to
+# bug-Danga-Socket@rt.cpan.org and visible at:
+# https://rt.cpan.org/Public/Dist/Display.html?Name=Danga-Socket
 package PublicInbox::DS;
 use strict;
 use bytes;
-- 
EW

[PATCH 3/6] ds: drop set_writer_func support

[Eric Wong]

This is not used by perlbal for OpenSSL support, either;
and it does not appear to be the right layer for doing
write translations anyways (IO::Socket::SSL uses `tie').
---
 lib/PublicInbox/DS.pm | 21 ++-------------------
 1 file changed, 2 insertions(+), 19 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 3b0cbe6..b2c4b44 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -33,7 +33,6 @@ use fields ('sock',              # underlying socket
             'write_set_watch',   # bool: true if we internally set watch_write rather than by a subclass
             'closed',            # bool: socket is closed
             'event_watch',       # bitmask of events the client is interested in (POLLIN,OUT,etc.)
-            'writer_func',       # subref which does writing.  must return bytes written (or undef) and set $! on errors
             );
 
 use Errno  qw(EINPROGRESS EWOULDBLOCK EISCONN ENOTSOCK
@@ -629,18 +628,6 @@ sub sock {
     return $self->{sock};
 }
 
-=head2 C<< $obj->set_writer_func( CODEREF ) >>
-
-Sets a function to use instead of C<syswrite()> when writing data to the socket.
-
-=cut
-sub set_writer_func {
-   my PublicInbox::DS $self = shift;
-   my $wtr = shift;
-   Carp::croak("Not a subref") unless !defined $wtr || UNIVERSAL::isa($wtr, "CODE");
-   $self->{writer_func} = $wtr;
-}
-
 =head2 C<< $obj->write( $data ) >>
 
 Write the specified data to the underlying handle.  I<data> may be scalar,
@@ -710,12 +697,8 @@ sub write {
         }
 
         my $to_write = $len - $self->{write_buf_offset};
-        my $written;
-        if (my $wtr = $self->{writer_func}) {
-            $written = $wtr->($bref, $to_write, $self->{write_buf_offset});
-        } else {
-            $written = syswrite($self->{sock}, $$bref, $to_write, $self->{write_buf_offset});
-        }
+        my $written = syswrite($self->{sock}, $$bref, $to_write,
+                               $self->{write_buf_offset});
 
         if (! defined $written) {
             if ($! == EPIPE) {
-- 
EW

[PATCH 4/6] ds: drop checks for invalid descriptors

[Eric Wong]

I've used Danga::Socket for well over a decade in various
projects at this point and have never seen the need for it.

If such a bug ever happens; the process should fall over so
it gets fixed ASAP.
---
 lib/PublicInbox/DS.pm | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index b2c4b44..e11b23d 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -269,16 +269,6 @@ sub EpollEventLoop {
             my $code;
             my $state = $ev->[1];
 
-            # if we didn't find a Perlbal::Socket subclass for that fd, try other
-            # pseudo-registered (above) fds.
-            if (! $pob) {
-                my $fd = $ev->[0];
-                warn "epoll() returned fd $fd w/ state $state for which we have no mapping.  removing.\n";
-                epoll_ctl($Epoll, EPOLL_CTL_DEL, $fd, 0);
-                POSIX::close($fd);
-                next;
-            }
-
             DebugLevel >= 1 && $class->DebugMsg("Event: fd=%d (%s), state=%d \@ %s\n",
                                                 $ev->[0], ref($pob), $ev->[1], time);
 
@@ -335,10 +325,6 @@ sub PollEventLoop {
 
             $pob = $DescriptorMap{$fd};
 
-            if (!$pob) {
-                next;
-            }
-
             $pob->event_read   if $state & POLLIN && ! $pob->{closed};
             $pob->event_write  if $state & POLLOUT && ! $pob->{closed};
             $pob->event_err    if $state & POLLERR && ! $pob->{closed};
@@ -371,11 +357,6 @@ sub KQueueEventLoop {
         foreach my $kev (@ret) {
             my ($fd, $filter, $flags, $fflags) = @$kev;
             my PublicInbox::DS $pob = $DescriptorMap{$fd};
-            if (!$pob) {
-                warn "kevent() returned fd $fd for which we have no mapping.  removing.\n";
-                POSIX::close($fd); # close deletes the kevent entry
-                next;
-            }
 
             DebugLevel >= 1 && $class->DebugMsg("Event: fd=%d (%s), flags=%d \@ %s\n",
                                                         $fd, ref($pob), $flags, time);
-- 
EW

[PATCH 5/6] ds: drop unused EVENT: label in epoll code path

[Eric Wong]

This was never used in Danga::Socket 1.61, either.
---
 lib/PublicInbox/DS.pm | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index e11b23d..78210dd 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -257,7 +257,6 @@ sub EpollEventLoop {
 
         # get up to 1000 events
         my $evcount = epoll_wait($Epoll, 1000, $timeout, \@events);
-      EVENT:
         for ($i=0; $i<$evcount; $i++) {
             my $ev = $events[$i];
 
-- 
EW

[PATCH 6/6] ds: drop write_set_watch field

[Eric Wong]

We never enable write watches ourselves for HTTP and NNTP,
and only enable the write watch with EvCleanup because it's
an "always on" watch.
---
 lib/PublicInbox/DS.pm | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 78210dd..6b04e76 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -30,7 +30,6 @@ use fields ('sock',              # underlying socket
             'write_buf',         # arrayref of scalars, scalarrefs, or coderefs to write
             'write_buf_offset',  # offset into first array of write_buf to start writing at
             'write_buf_size',    # total length of data in all write_buf items
-            'write_set_watch',   # bool: true if we internally set watch_write rather than by a subclass
             'closed',            # bool: socket is closed
             'event_watch',       # bitmask of events the client is interested in (POLLIN,OUT,etc.)
             );
@@ -690,7 +689,6 @@ sub write {
                     push @{$self->{write_buf}}, $bref;
                     $self->{write_buf_size} += $len;
                 }
-                $self->{write_set_watch} = 1 unless $self->{event_watch} & POLLOUT;
                 $self->watch_write(1);
                 return 0;
             } elsif ($! == ECONNRESET) {
@@ -717,11 +715,7 @@ sub write {
             DebugLevel >= 2 && $self->debugmsg("Wrote ALL %d bytes to %d (nq=%d)",
                                                $written, $self->{fd}, $need_queue);
             $self->{write_buf_offset} = 0;
-
-            if ($self->{write_set_watch}) {
-                $self->watch_write(0);
-                $self->{write_set_watch} = 0;
-            }
+            $self->watch_write(0);
 
             # this was our only write, so we can return immediately
             # since we avoided incrementing the buffer size or
@@ -739,7 +733,6 @@ sub write {
 
 sub on_incomplete_write {
     my PublicInbox::DS $self = shift;
-    $self->{write_set_watch} = 1 unless $self->{event_watch} & POLLOUT;
     $self->watch_write(1);
 }
 
@@ -858,11 +851,6 @@ sub watch_write {
     $event &= ~POLLOUT if ! $val;
     $event |=  POLLOUT if   $val;
 
-    if ($val && caller ne __PACKAGE__) {
-        # A subclass registered interest, it's now responsible for this.
-        $self->{write_set_watch} = 0;
-    }
-
     # If it changed, set it
     if ($event != $self->{event_watch}) {
         if ($HaveKQueue) {
-- 
EW

[PATCH 7/6] ds: remove PLCMap and per-socket PostLoopCallback

[Eric Wong]

We don't need and won't be needing per-socket PostLoopCallbacks.
---
 lib/PublicInbox/DS.pm | 25 ++-----------------------
 1 file changed, 2 insertions(+), 23 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 6b04e76..03612ce 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -58,7 +58,6 @@ our (
      @ToClose,                   # sockets to close when event loop is done
 
      $PostLoopCallback,          # subref to call at the end of each loop, if defined (global)
-     %PLCMap,                    # fd (num) -> PostLoopCallback (per-object)
 
      $LoopTimeout,               # timeout of event loop in milliseconds
      $DoneInit,                  # if we've done the one-time module init yet
@@ -85,7 +84,6 @@ sub Reset {
     @Timers = ();
 
     $PostLoopCallback = undef;
-    %PLCMap = ();
     $DoneInit = 0;
 
     # NOTE kqueue is close-on-fork, and we don't account for it, yet
@@ -389,18 +387,8 @@ The callback function will be passed two parameters: \%DescriptorMap
 sub SetPostLoopCallback {
     my ($class, $ref) = @_;
 
-    if (ref $class) {
-        # per-object callback
-        my PublicInbox::DS $self = $class;
-        if (defined $ref && ref $ref eq 'CODE') {
-            $PLCMap{$self->{fd}} = $ref;
-        } else {
-            delete $PLCMap{$self->{fd}};
-        }
-    } else {
-        # global callback
-        $PostLoopCallback = (defined $ref && ref $ref eq 'CODE') ? $ref : undef;
-    }
+    # global callback
+    $PostLoopCallback = (defined $ref && ref $ref eq 'CODE') ? $ref : undef;
 }
 
 # Internal function: run the post-event callback, send read events
@@ -426,11 +414,6 @@ sub PostEventLoop {
     # or global) cancels it
     my $keep_running = 1;
 
-    # per-object post-loop-callbacks
-    for my $plc (values %PLCMap) {
-        $keep_running &&= $plc->(\%DescriptorMap);
-    }
-
     # now we're at the very end, call callback if defined
     if (defined $PostLoopCallback) {
         $keep_running &&= $PostLoopCallback->(\%DescriptorMap);
@@ -580,10 +563,6 @@ sub _cleanup {
         }
     }
 
-    # now delete from mappings.  this fd no longer belongs to us, so we don't want
-    # to get alerts for it if it becomes writable/readable/etc.
-    delete $PLCMap{$self->{fd}};
-
     # we explicitly don't delete from DescriptorMap here until we
     # actually close the socket, as we might be in the middle of
     # processing an epoll_wait/etc that returned hundreds of fds, one
-- 
EW