1 # This library is free software; you can redistribute it and/or modify
2 # it under the same terms as Perl itself.
4 # This license differs from the rest of public-inbox
6 # This is a fork of the (for now) unmaintained Danga::Socket 1.61.
7 # Unused features will be removed, and updates will be made to take
8 # advantage of newer kernels.
10 # API changes to diverge from Danga::Socket will happen to better
11 # accomodate new features and improve scalability. Do not expect
12 # this to be a stable API like Danga::Socket.
13 # Bugs encountered (and likely fixed) are reported to
14 # bug-Danga-Socket@rt.cpan.org and visible at:
15 # https://rt.cpan.org/Public/Dist/Display.html?Name=Danga-Socket
16 package PublicInbox::DS;
22 use Fcntl qw(FD_CLOEXEC F_SETFD F_GETFD);
26 use PublicInbox::Syscall qw(:epoll);
28 use fields ('sock', # underlying socket
29 'fd', # numeric file descriptor
30 'write_buf', # arrayref of scalars, scalarrefs, or coderefs to write
31 'write_buf_offset', # offset into first array of write_buf to start writing at
32 'write_buf_size', # total length of data in all write_buf items
33 'write_set_watch', # bool: true if we internally set watch_write rather than by a subclass
34 'closed', # bool: socket is closed
35 'event_watch', # bitmask of events the client is interested in (POLLIN,OUT,etc.)
38 use Errno qw(EINPROGRESS EWOULDBLOCK EISCONN ENOTSOCK
39 EPIPE EAGAIN EBADF ECONNRESET ENOPROTOOPT);
40 use Carp qw(croak confess);
42 use constant DebugLevel => 0;
44 use constant POLLIN => 1;
45 use constant POLLOUT => 4;
46 use constant POLLERR => 8;
47 use constant POLLHUP => 16;
48 use constant POLLNVAL => 32;
50 our $HAVE_KQUEUE = eval { require IO::KQueue; 1 };
53 $HaveEpoll, # Flag -- is epoll available? initially undefined.
55 %DescriptorMap, # fd (num) -> PublicInbox::DS object
56 $Epoll, # Global epoll fd (for epoll mode only)
57 $KQueue, # Global kqueue fd ref (for kqueue mode only)
58 $_io, # IO::Handle for Epoll
59 @ToClose, # sockets to close when event loop is done
61 $PostLoopCallback, # subref to call at the end of each loop, if defined (global)
62 %PLCMap, # fd (num) -> PostLoopCallback (per-object)
64 $LoopTimeout, # timeout of event loop in milliseconds
65 $DoneInit, # if we've done the one-time module init yet
69 # this may be set to zero with old kernels
70 our $EPOLLEXCLUSIVE = EPOLLEXCLUSIVE;
73 #####################################################################
74 ### C L A S S M E T H O D S
75 #####################################################################
77 =head2 C<< CLASS->Reset() >>
85 $LoopTimeout = -1; # no timeout by default
88 $PostLoopCallback = undef;
92 # NOTE kqueue is close-on-fork, and we don't account for it, yet
93 # OTOH, we (public-inbox) don't need this sub outside of tests...
94 POSIX::close($$KQueue) if !$_io && $KQueue && $$KQueue >= 0;
97 $_io = undef; # close $Epoll
100 *EventLoop = *FirstTimeEventLoop;
103 =head2 C<< CLASS->SetLoopTimeout( $timeout ) >>
105 Set the loop timeout for the event loop to some value in milliseconds.
107 A timeout of 0 (zero) means poll forever. A timeout of -1 means poll and return
112 return $LoopTimeout = $_[1] + 0;
115 =head2 C<< CLASS->DebugMsg( $format, @args ) >>
117 Print the debugging message specified by the C<sprintf>-style I<format> and
122 my ( $class, $fmt, @args ) = @_;
124 printf STDERR ">>> $fmt\n", @args;
127 =head2 C<< CLASS->AddTimer( $seconds, $coderef ) >>
129 Add a timer to occur $seconds from now. $seconds may be fractional, but timers
130 are not guaranteed to fire at the exact time you ask for.
132 Returns a timer object which you can call C<< $timer->cancel >> on if you need to.
137 my ($secs, $coderef) = @_;
139 my $fire_time = Time::HiRes::time() + $secs;
141 my $timer = bless [$fire_time, $coderef], "PublicInbox::DS::Timer";
143 if (!@Timers || $fire_time >= $Timers[-1][0]) {
144 push @Timers, $timer;
148 # Now, where do we insert? (NOTE: this appears slow, algorithm-wise,
149 # but it was compared against calendar queues, heaps, naive push/sort,
150 # and a bunch of other versions, and found to be fastest with a large
151 # variety of datasets.)
152 for (my $i = 0; $i < @Timers; $i++) {
153 if ($Timers[$i][0] > $fire_time) {
154 splice(@Timers, $i, 0, $timer);
159 die "Shouldn't get here.";
162 # keeping this around in case we support other FD types for now,
163 # epoll_create1(EPOLL_CLOEXEC) requires Linux 2.6.27+...
164 sub set_cloexec ($) {
167 $_io = IO::Handle->new_from_fd($fd, 'r+') or return;
168 defined(my $fl = fcntl($_io, F_GETFD, 0)) or return;
169 fcntl($_io, F_SETFD, $fl | FD_CLOEXEC);
178 $KQueue = IO::KQueue->new();
179 $HaveKQueue = defined $KQueue;
181 *EventLoop = *KQueueEventLoop;
184 elsif (PublicInbox::Syscall::epoll_defined()) {
185 $Epoll = eval { epoll_create(1024); };
186 $HaveEpoll = defined $Epoll && $Epoll >= 0;
189 *EventLoop = *EpollEventLoop;
193 if (!$HaveEpoll && !$HaveKQueue) {
195 *EventLoop = *PollEventLoop;
199 =head2 C<< CLASS->EventLoop() >>
201 Start processing IO events. In most daemon programs this never exits. See
202 C<PostLoopCallback> below for how to exit the loop.
205 sub FirstTimeEventLoop {
211 EpollEventLoop($class);
212 } elsif ($HaveKQueue) {
213 KQueueEventLoop($class);
215 PollEventLoop($class);
219 # runs timers and returns milliseconds for next one, or next event loop
221 return $LoopTimeout unless @Timers;
223 my $now = Time::HiRes::time();
226 while (@Timers && $Timers[0][0] <= $now) {
227 my $to_run = shift(@Timers);
228 $to_run->[1]->($now) if $to_run->[1];
231 return $LoopTimeout unless @Timers;
233 # convert time to an even number of milliseconds, adding 1
234 # extra, otherwise floating point fun can occur and we'll
235 # call RunTimers like 20-30 times, each returning a timeout
236 # of 0.0000212 seconds
237 my $timeout = int(($Timers[0][0] - $now) * 1000) + 1;
239 # -1 is an infinite timeout, so prefer a real timeout
240 return $timeout if $LoopTimeout == -1;
242 # otherwise pick the lower of our regular timeout and time until
244 return $LoopTimeout if $LoopTimeout < $timeout;
248 ### The epoll-based event loop. Gets installed as EventLoop if IO::Epoll loads
256 my $timeout = RunTimers();
258 # get up to 1000 events
259 my $evcount = epoll_wait($Epoll, 1000, $timeout, \@events);
260 for ($i=0; $i<$evcount; $i++) {
261 my $ev = $events[$i];
263 # it's possible epoll_wait returned many events, including some at the end
264 # that ones in the front triggered unregister-interest actions. if we
265 # can't find the %sock entry, it's because we're no longer interested
267 my PublicInbox::DS $pob = $DescriptorMap{$ev->[0]};
269 my $state = $ev->[1];
271 DebugLevel >= 1 && $class->DebugMsg("Event: fd=%d (%s), state=%d \@ %s\n",
272 $ev->[0], ref($pob), $ev->[1], time);
274 # standard non-profiling codepat
275 $pob->event_read if $state & EPOLLIN && ! $pob->{closed};
276 $pob->event_write if $state & EPOLLOUT && ! $pob->{closed};
277 if ($state & (EPOLLERR|EPOLLHUP)) {
278 $pob->event_err if $state & EPOLLERR && ! $pob->{closed};
279 $pob->event_hup if $state & EPOLLHUP && ! $pob->{closed};
282 return unless PostEventLoop();
287 ### The fallback IO::Poll-based event loop. Gets installed as EventLoop if
288 ### IO::Epoll fails to load.
292 my PublicInbox::DS $pob;
295 my $timeout = RunTimers();
297 # the following sets up @poll as a series of ($poll,$event_mask)
298 # items, then uses IO::Poll::_poll, implemented in XS, which
299 # modifies the array in place with the even elements being
300 # replaced with the event masks that occured.
302 while ( my ($fd, $sock) = each %DescriptorMap ) {
303 push @poll, $fd, $sock->{event_watch};
306 # if nothing to poll, either end immediately (if no timeout)
307 # or just keep calling the callback
309 select undef, undef, undef, ($timeout / 1000);
310 return unless PostEventLoop();
314 my $count = IO::Poll::_poll($timeout, @poll);
315 unless ($count >= 0) {
316 return unless PostEventLoop();
320 # Fetch handles with read events
322 my ($fd, $state) = splice(@poll, 0, 2);
325 $pob = $DescriptorMap{$fd};
327 $pob->event_read if $state & POLLIN && ! $pob->{closed};
328 $pob->event_write if $state & POLLOUT && ! $pob->{closed};
329 $pob->event_err if $state & POLLERR && ! $pob->{closed};
330 $pob->event_hup if $state & POLLHUP && ! $pob->{closed};
333 return unless PostEventLoop();
339 ### The kqueue-based event loop. Gets installed as EventLoop if IO::KQueue works
341 sub KQueueEventLoop {
345 my $timeout = RunTimers();
346 my @ret = eval { $KQueue->kevent($timeout) };
348 # workaround https://rt.cpan.org/Ticket/Display.html?id=116615
349 if ($err =~ /Interrupted system call/) {
356 foreach my $kev (@ret) {
357 my ($fd, $filter, $flags, $fflags) = @$kev;
358 my PublicInbox::DS $pob = $DescriptorMap{$fd};
360 DebugLevel >= 1 && $class->DebugMsg("Event: fd=%d (%s), flags=%d \@ %s\n",
361 $fd, ref($pob), $flags, time);
363 $pob->event_read if $filter == IO::KQueue::EVFILT_READ() && !$pob->{closed};
364 $pob->event_write if $filter == IO::KQueue::EVFILT_WRITE() && !$pob->{closed};
365 if ($flags == IO::KQueue::EV_EOF() && !$pob->{closed}) {
373 return unless PostEventLoop();
379 =head2 C<< CLASS->SetPostLoopCallback( CODEREF ) >>
381 Sets post loop callback function. Pass a subref and it will be
382 called every time the event loop finishes.
384 Return 1 (or any true value) from the sub to make the loop continue, 0 or false
387 The callback function will be passed two parameters: \%DescriptorMap
390 sub SetPostLoopCallback {
391 my ($class, $ref) = @_;
394 # per-object callback
395 my PublicInbox::DS $self = $class;
396 if (defined $ref && ref $ref eq 'CODE') {
397 $PLCMap{$self->{fd}} = $ref;
399 delete $PLCMap{$self->{fd}};
403 $PostLoopCallback = (defined $ref && ref $ref eq 'CODE') ? $ref : undef;
407 # Internal function: run the post-event callback, send read events
408 # for pushed-back data, and close pending connections. returns 1
409 # if event loop should continue, or 0 to shut it all down.
411 # now we can close sockets that wanted to close during our event processing.
412 # (we didn't want to close them during the loop, as we didn't want fd numbers
413 # being reused and confused during the event loop)
414 while (my $sock = shift @ToClose) {
415 my $fd = fileno($sock);
417 # close the socket. (not a PublicInbox::DS close)
420 # and now we can finally remove the fd from the map. see
421 # comment above in _cleanup.
422 delete $DescriptorMap{$fd};
426 # by default we keep running, unless a postloop callback (either per-object
427 # or global) cancels it
428 my $keep_running = 1;
430 # per-object post-loop-callbacks
431 for my $plc (values %PLCMap) {
432 $keep_running &&= $plc->(\%DescriptorMap);
435 # now we're at the very end, call callback if defined
436 if (defined $PostLoopCallback) {
437 $keep_running &&= $PostLoopCallback->(\%DescriptorMap);
440 return $keep_running;
443 #####################################################################
444 ### PublicInbox::DS-the-object code
445 #####################################################################
447 =head2 OBJECT METHODS
449 =head2 C<< CLASS->new( $socket ) >>
451 Create a new PublicInbox::DS subclass object for the given I<socket> which will
452 react to events on it during the C<EventLoop>.
454 This is normally (always?) called from your subclass via:
456 $class->SUPER::new($socket);
460 my ($self, $sock, $exclusive) = @_;
461 $self = fields::new($self) unless ref $self;
463 $self->{sock} = $sock;
464 my $fd = fileno($sock);
466 Carp::cluck("undef sock and/or fd in PublicInbox::DS->new. sock=" . ($sock || "") . ", fd=" . ($fd || ""))
470 $self->{write_buf} = [];
471 $self->{write_buf_offset} = 0;
472 $self->{write_buf_size} = 0;
475 my $ev = $self->{event_watch} = POLLERR|POLLHUP|POLLNVAL;
481 $ev = $self->{event_watch} = EPOLLIN|EPOLLERR|EPOLLHUP|$EPOLLEXCLUSIVE;
484 if (epoll_ctl($Epoll, EPOLL_CTL_ADD, $fd, $ev)) {
485 if ($!{EINVAL} && ($ev & $EPOLLEXCLUSIVE)) {
486 $EPOLLEXCLUSIVE = 0; # old kernel
487 $ev = $self->{event_watch} = EPOLLIN|EPOLLERR|EPOLLHUP;
490 die "couldn't add epoll watch for $fd: $!\n";
493 elsif ($HaveKQueue) {
494 # Add them to the queue but disabled for now
495 $KQueue->EV_SET($fd, IO::KQueue::EVFILT_READ(),
496 IO::KQueue::EV_ADD() | IO::KQueue::EV_DISABLE());
497 $KQueue->EV_SET($fd, IO::KQueue::EVFILT_WRITE(),
498 IO::KQueue::EV_ADD() | IO::KQueue::EV_DISABLE());
501 Carp::cluck("PublicInbox::DS::new blowing away existing descriptor map for fd=$fd ($DescriptorMap{$fd})")
502 if $DescriptorMap{$fd};
504 $DescriptorMap{$fd} = $self;
509 #####################################################################
510 ### I N S T A N C E M E T H O D S
511 #####################################################################
513 =head2 C<< $obj->steal_socket() >>
515 Basically returns our socket and makes it so that we don't try to close it,
516 but we do remove it from epoll handlers. THIS CLOSES $self. It is the same
517 thing as calling close, except it gives you the socket to use.
521 my PublicInbox::DS $self = $_[0];
522 return if $self->{closed};
524 # cleanup does most of the work of closing this socket
527 # now undef our internal sock and fd structures so we don't use them
528 my $sock = $self->{sock};
529 $self->{sock} = undef;
533 =head2 C<< $obj->close( [$reason] ) >>
535 Close the socket. The I<reason> argument will be used in debugging messages.
539 my PublicInbox::DS $self = $_[0];
540 return if $self->{closed};
542 # print out debugging info for this close
544 my ($pkg, $filename, $line) = caller;
545 my $reason = $_[1] || "";
546 warn "Closing \#$self->{fd} due to $pkg/$filename/$line ($reason)\n";
549 # this does most of the work of closing us
552 # defer closing the actual socket until the event loop is done
553 # processing this round of events. (otherwise we might reuse fds)
555 push @ToClose, $self->{sock};
556 $self->{sock} = undef;
562 ### METHOD: _cleanup()
563 ### Called by our closers so we can clean internal data structures.
565 my PublicInbox::DS $self = $_[0];
567 # we're effectively closed; we have no fd and sock when we leave here
570 # we need to flush our write buffer, as there may
571 # be self-referential closures (sub { $client->close })
572 # preventing the object from being destroyed
573 $self->{write_buf} = [];
575 # if we're using epoll, we have to remove this from our epoll fd so we stop getting
576 # notifications about it
577 if ($HaveEpoll && $self->{fd}) {
578 if (epoll_ctl($Epoll, EPOLL_CTL_DEL, $self->{fd}, $self->{event_watch}) != 0) {
579 # dump_error prints a backtrace so we can try to figure out why this happened
580 $self->dump_error("epoll_ctl(): failure deleting fd=$self->{fd} during _cleanup(); $! (" . ($!+0) . ")");
584 # now delete from mappings. this fd no longer belongs to us, so we don't want
585 # to get alerts for it if it becomes writable/readable/etc.
586 delete $PLCMap{$self->{fd}};
588 # we explicitly don't delete from DescriptorMap here until we
589 # actually close the socket, as we might be in the middle of
590 # processing an epoll_wait/etc that returned hundreds of fds, one
591 # of which is not yet processed and is what we're closing. if we
592 # keep it in DescriptorMap, then the event harnesses can just
593 # looked at $pob->{closed} and ignore it. but if it's an
594 # un-accounted for fd, then it (understandably) freak out a bit
595 # and emit warnings, thinking their state got off.
597 # and finally get rid of our fd so we can't use it anywhere else
601 =head2 C<< $obj->sock() >>
603 Returns the underlying IO::Handle for the object.
607 my PublicInbox::DS $self = shift;
608 return $self->{sock};
611 =head2 C<< $obj->write( $data ) >>
613 Write the specified data to the underlying handle. I<data> may be scalar,
614 scalar ref, code ref (to run when there), or undef just to kick-start.
615 Returns 1 if writes all went through, or 0 if there are writes in queue. If
616 it returns 1, caller should stop waiting for 'writable' events)
620 my PublicInbox::DS $self;
624 # nobody should be writing to closed sockets, but caller code can
625 # do two writes within an event, have the first fail and
626 # disconnect the other side (whose destructor then closes the
627 # calling object, but it's still in a method), and then the
628 # now-dead object does its second write. that is this case. we
629 # just lie and say it worked. it'll be dead soon and won't be
631 return 1 if $self->{closed};
635 # just queue data if there's already a wait
639 $bref = ref $data ? $data : \$data;
640 if ($self->{write_buf_size}) {
641 push @{$self->{write_buf}}, $bref;
642 $self->{write_buf_size} += ref $bref eq "SCALAR" ? length($$bref) : 1;
646 # this flag says we're bypassing the queue system, knowing we're the
647 # only outstanding write, and hoping we don't ever need to use it.
648 # if so later, though, we'll need to queue
654 return 1 unless $bref ||= $self->{write_buf}[0];
658 $len = length($$bref); # this will die if $bref is a code ref, caught below
661 if (UNIVERSAL::isa($bref, "CODE")) {
662 unless ($need_queue) {
663 $self->{write_buf_size}--; # code refs are worth 1
664 shift @{$self->{write_buf}};
668 # code refs are just run and never get reenqueued
669 # (they're one-shot), so turn off the flag indicating the
670 # outstanding data needs queueing.
676 die "Write error: $@ <$bref>";
679 my $to_write = $len - $self->{write_buf_offset};
680 my $written = syswrite($self->{sock}, $$bref, $to_write,
681 $self->{write_buf_offset});
683 if (! defined $written) {
685 return $self->close("EPIPE");
686 } elsif ($! == EAGAIN) {
687 # since connection has stuff to write, it should now be
688 # interested in pending writes:
690 push @{$self->{write_buf}}, $bref;
691 $self->{write_buf_size} += $len;
693 $self->{write_set_watch} = 1 unless $self->{event_watch} & POLLOUT;
694 $self->watch_write(1);
696 } elsif ($! == ECONNRESET) {
697 return $self->close("ECONNRESET");
700 DebugLevel >= 1 && $self->debugmsg("Closing connection ($self) due to write error: $!\n");
702 return $self->close("write_error");
703 } elsif ($written != $to_write) {
704 DebugLevel >= 2 && $self->debugmsg("Wrote PARTIAL %d bytes to %d",
705 $written, $self->{fd});
707 push @{$self->{write_buf}}, $bref;
708 $self->{write_buf_size} += $len;
710 # since connection has stuff to write, it should now be
711 # interested in pending writes:
712 $self->{write_buf_offset} += $written;
713 $self->{write_buf_size} -= $written;
714 $self->on_incomplete_write;
716 } elsif ($written == $to_write) {
717 DebugLevel >= 2 && $self->debugmsg("Wrote ALL %d bytes to %d (nq=%d)",
718 $written, $self->{fd}, $need_queue);
719 $self->{write_buf_offset} = 0;
721 if ($self->{write_set_watch}) {
722 $self->watch_write(0);
723 $self->{write_set_watch} = 0;
726 # this was our only write, so we can return immediately
727 # since we avoided incrementing the buffer size or
728 # putting it in the buffer. we also know there
729 # can't be anything else to write.
730 return 1 if $need_queue;
732 $self->{write_buf_size} -= $written;
733 shift @{$self->{write_buf}};
740 sub on_incomplete_write {
741 my PublicInbox::DS $self = shift;
742 $self->{write_set_watch} = 1 unless $self->{event_watch} & POLLOUT;
743 $self->watch_write(1);
746 =head2 C<< $obj->read( $bytecount ) >>
748 Read at most I<bytecount> bytes from the underlying handle; returns scalar
749 ref on read, or undef on connection closed.
753 my PublicInbox::DS $self = shift;
754 return if $self->{closed};
757 my $sock = $self->{sock};
759 # if this is too high, perl quits(!!). reports on mailing lists
760 # don't seem to point to a universal answer. 5MB worked for some,
761 # crashed for others. 1MB works for more people. let's go with 1MB
763 my $req_bytes = $bytes > 1048576 ? 1048576 : $bytes;
765 my $res = sysread($sock, $buf, $req_bytes, 0);
766 DebugLevel >= 2 && $self->debugmsg("sysread = %d; \$! = %d", $res, $!);
768 if (! $res && $! != EWOULDBLOCK) {
769 # catches 0=conn closed or undef=error
770 DebugLevel >= 2 && $self->debugmsg("Fd \#%d read hit the end of the road.", $self->{fd});
777 =head2 (VIRTUAL) C<< $obj->event_read() >>
779 Readable event handler. Concrete deriviatives of PublicInbox::DS should
780 provide an implementation of this. The default implementation will die if
784 sub event_read { die "Base class event_read called for $_[0]\n"; }
786 =head2 (VIRTUAL) C<< $obj->event_err() >>
788 Error event handler. Concrete deriviatives of PublicInbox::DS should
789 provide an implementation of this. The default implementation will die if
793 sub event_err { die "Base class event_err called for $_[0]\n"; }
795 =head2 (VIRTUAL) C<< $obj->event_hup() >>
797 'Hangup' event handler. Concrete deriviatives of PublicInbox::DS should
798 provide an implementation of this. The default implementation will die if
802 sub event_hup { die "Base class event_hup called for $_[0]\n"; }
804 =head2 C<< $obj->event_write() >>
806 Writable event handler. Concrete deriviatives of PublicInbox::DS may wish to
807 provide an implementation of this. The default implementation calls
808 C<write()> with an C<undef>.
816 =head2 C<< $obj->watch_read( $boolean ) >>
818 Turn 'readable' event notification on or off.
822 my PublicInbox::DS $self = shift;
823 return if $self->{closed} || !$self->{sock};
826 my $event = $self->{event_watch};
828 $event &= ~POLLIN if ! $val;
829 $event |= POLLIN if $val;
831 # If it changed, set it
832 if ($event != $self->{event_watch}) {
834 $KQueue->EV_SET($self->{fd}, IO::KQueue::EVFILT_READ(),
835 $val ? IO::KQueue::EV_ENABLE() : IO::KQueue::EV_DISABLE());
838 epoll_ctl($Epoll, EPOLL_CTL_MOD, $self->{fd}, $event)
839 and $self->dump_error("couldn't modify epoll settings for $self->{fd} " .
840 "from $self->{event_watch} -> $event: $! (" . ($!+0) . ")");
842 $self->{event_watch} = $event;
846 =head2 C<< $obj->watch_write( $boolean ) >>
848 Turn 'writable' event notification on or off.
852 my PublicInbox::DS $self = shift;
853 return if $self->{closed} || !$self->{sock};
856 my $event = $self->{event_watch};
858 $event &= ~POLLOUT if ! $val;
859 $event |= POLLOUT if $val;
861 if ($val && caller ne __PACKAGE__) {
862 # A subclass registered interest, it's now responsible for this.
863 $self->{write_set_watch} = 0;
866 # If it changed, set it
867 if ($event != $self->{event_watch}) {
869 $KQueue->EV_SET($self->{fd}, IO::KQueue::EVFILT_WRITE(),
870 $val ? IO::KQueue::EV_ENABLE() : IO::KQueue::EV_DISABLE());
873 epoll_ctl($Epoll, EPOLL_CTL_MOD, $self->{fd}, $event)
874 and $self->dump_error("couldn't modify epoll settings for $self->{fd} " .
875 "from $self->{event_watch} -> $event: $! (" . ($!+0) . ")");
877 $self->{event_watch} = $event;
881 =head2 C<< $obj->dump_error( $message ) >>
883 Prints to STDERR a backtrace with information about this socket and what lead
884 up to the dump_error call.
890 while (my ($file, $line, $sub) = (caller($i++))[1..3]) {
891 push @list, "\t$file:$line called $sub\n";
894 warn "ERROR: $_[1]\n" .
895 "\t$_[0] = " . $_[0]->as_string . "\n" .
899 =head2 C<< $obj->debugmsg( $format, @args ) >>
901 Print the debugging message specified by the C<sprintf>-style I<format> and
906 my ( $self, $fmt, @args ) = @_;
907 confess "Not an object" unless ref $self;
910 printf STDERR ">>> $fmt\n", @args;
913 =head2 C<< $obj->as_string() >>
915 Returns a string describing this socket.
919 my PublicInbox::DS $self = shift;
920 my $rw = "(" . ($self->{event_watch} & POLLIN ? 'R' : '') .
921 ($self->{event_watch} & POLLOUT ? 'W' : '') . ")";
922 my $ret = ref($self) . "$rw: " . ($self->{closed} ? "closed" : "open");
926 package PublicInbox::DS::Timer;
927 # [$abs_float_firetime, $coderef];
934 =head1 AUTHORS (Danga::Socket)
936 Brad Fitzpatrick <brad@danga.com> - author
938 Michael Granger <ged@danga.com> - docs, testing
940 Mark Smith <junior@danga.com> - contributor, heavy user, testing
942 Matt Sergeant <matt@sergeant.org> - kqueue support, docs, timers, other bits