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Diffstat (limited to 'lib/PublicInbox/DS.pm')
-rw-r--r-- | lib/PublicInbox/DS.pm | 1052 |
1 files changed, 1052 insertions, 0 deletions
diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm new file mode 100644 index 00000000..779215c9 --- /dev/null +++ b/lib/PublicInbox/DS.pm @@ -0,0 +1,1052 @@ +# This library is free software; you can redistribute it and/or modify +# it under the same terms as Perl itself. +# +# This license differs from the rest of public-inbox +# +# 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 + +package PublicInbox::DS; +use strict; +use bytes; +use POSIX (); +use Time::HiRes (); + +use vars qw{$VERSION}; +$VERSION = "1.61"; + +use warnings; +no warnings qw(deprecated); + +use PublicInbox::Syscall qw(:epoll); + +use fields ('sock', # underlying socket + 'fd', # numeric file descriptor + '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.) + 'writer_func', # subref which does writing. must return bytes written (or undef) and set $! on errors + ); + +use Errno qw(EINPROGRESS EWOULDBLOCK EISCONN ENOTSOCK + EPIPE EAGAIN EBADF ECONNRESET ENOPROTOOPT); +use Socket qw(IPPROTO_TCP); +use Carp qw(croak confess); + +use constant DebugLevel => 0; + +use constant POLLIN => 1; +use constant POLLOUT => 4; +use constant POLLERR => 8; +use constant POLLHUP => 16; +use constant POLLNVAL => 32; + +our $HAVE_KQUEUE = eval { require IO::KQueue; 1 }; + +our ( + $HaveEpoll, # Flag -- is epoll available? initially undefined. + $HaveKQueue, + %DescriptorMap, # fd (num) -> PublicInbox::DS object + $Epoll, # Global epoll fd (for epoll mode only) + $KQueue, # Global kqueue fd (for kqueue mode only) + @ToClose, # sockets to close when event loop is done + %OtherFds, # A hash of "other" (non-PublicInbox::DS) file + # descriptors for the event loop to track. + + $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 + @Timers, # timers + ); + +# this may be set to zero with old kernels +our $EPOLLEXCLUSIVE = EPOLLEXCLUSIVE; +Reset(); + +##################################################################### +### C L A S S M E T H O D S +##################################################################### + +=head2 C<< CLASS->Reset() >> + +Reset all state + +=cut +sub Reset { + %DescriptorMap = (); + @ToClose = (); + %OtherFds = (); + $LoopTimeout = -1; # no timeout by default + @Timers = (); + + $PostLoopCallback = undef; + %PLCMap = (); + $DoneInit = 0; + + POSIX::close($Epoll) if defined $Epoll && $Epoll >= 0; + POSIX::close($KQueue) if defined $KQueue && $KQueue >= 0; + + *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->WatchedSockets() >> + +Returns the number of file descriptors which are registered with the global +poll object. + +=cut +sub WatchedSockets { + return scalar keys %DescriptorMap; +} +*watched_sockets = *WatchedSockets; + +=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->OtherFds( [%fdmap] ) >> + +Get/set the hash of file descriptors that need processing in parallel with +the registered PublicInbox::DS objects. + +=cut +sub OtherFds { + my $class = shift; + if ( @_ ) { %OtherFds = @_ } + return wantarray ? %OtherFds : \%OtherFds; +} + +=head2 C<< CLASS->AddOtherFds( [%fdmap] ) >> + +Add fds to the OtherFds hash for processing. + +=cut +sub AddOtherFds { + my $class = shift; + %OtherFds = ( %OtherFds, @_ ); # FIXME investigate what happens on dupe fds + return wantarray ? %OtherFds : \%OtherFds; +} + +=head2 C<< CLASS->SetLoopTimeout( $timeout ) >> + +Set the loop timeout for the event loop to some value in milliseconds. + +A timeout of 0 (zero) means poll forever. A timeout of -1 means poll and return +immediately. + +=cut +sub SetLoopTimeout { + return $LoopTimeout = $_[1] + 0; +} + +=head2 C<< CLASS->DebugMsg( $format, @args ) >> + +Print the debugging message specified by the C<sprintf>-style I<format> and +I<args> + +=cut +sub DebugMsg { + my ( $class, $fmt, @args ) = @_; + chomp $fmt; + printf STDERR ">>> $fmt\n", @args; +} + +=head2 C<< CLASS->AddTimer( $seconds, $coderef ) >> + +Add a timer to occur $seconds from now. $seconds may be fractional, but timers +are not guaranteed to fire at the exact time you ask for. + +Returns a timer object which you can call C<< $timer->cancel >> on if you need to. + +=cut +sub AddTimer { + my $class = shift; + my ($secs, $coderef) = @_; + + my $fire_time = Time::HiRes::time() + $secs; + + my $timer = bless [$fire_time, $coderef], "PublicInbox::DS::Timer"; + + if (!@Timers || $fire_time >= $Timers[-1][0]) { + push @Timers, $timer; + return $timer; + } + + # Now, where do we insert? (NOTE: this appears slow, algorithm-wise, + # but it was compared against calendar queues, heaps, naive push/sort, + # and a bunch of other versions, and found to be fastest with a large + # variety of datasets.) + for (my $i = 0; $i < @Timers; $i++) { + if ($Timers[$i][0] > $fire_time) { + splice(@Timers, $i, 0, $timer); + return $timer; + } + } + + die "Shouldn't get here."; +} + +=head2 C<< CLASS->DescriptorMap() >> + +Get the hash of PublicInbox::DS objects keyed by the file descriptor (fileno) they +are wrapping. + +Returns a hash in list context or a hashref in scalar context. + +=cut +sub DescriptorMap { + return wantarray ? %DescriptorMap : \%DescriptorMap; +} +*descriptor_map = *DescriptorMap; +*get_sock_ref = *DescriptorMap; + +sub _InitPoller +{ + return if $DoneInit; + $DoneInit = 1; + + if ($HAVE_KQUEUE) { + $KQueue = IO::KQueue->new(); + $HaveKQueue = $KQueue >= 0; + if ($HaveKQueue) { + *EventLoop = *KQueueEventLoop; + } + } + elsif (PublicInbox::Syscall::epoll_defined()) { + $Epoll = eval { epoll_create(1024); }; + $HaveEpoll = defined $Epoll && $Epoll >= 0; + if ($HaveEpoll) { + *EventLoop = *EpollEventLoop; + } + } + + if (!$HaveEpoll && !$HaveKQueue) { + require IO::Poll; + *EventLoop = *PollEventLoop; + } +} + +=head2 C<< CLASS->EventLoop() >> + +Start processing IO events. In most daemon programs this never exits. See +C<PostLoopCallback> below for how to exit the loop. + +=cut +sub FirstTimeEventLoop { + my $class = shift; + + _InitPoller(); + + if ($HaveEpoll) { + EpollEventLoop($class); + } elsif ($HaveKQueue) { + KQueueEventLoop($class); + } else { + PollEventLoop($class); + } +} + +# runs timers and returns milliseconds for next one, or next event loop +sub RunTimers { + return $LoopTimeout unless @Timers; + + my $now = Time::HiRes::time(); + + # Run expired timers + while (@Timers && $Timers[0][0] <= $now) { + my $to_run = shift(@Timers); + $to_run->[1]->($now) if $to_run->[1]; + } + + return $LoopTimeout unless @Timers; + + # convert time to an even number of milliseconds, adding 1 + # extra, otherwise floating point fun can occur and we'll + # call RunTimers like 20-30 times, each returning a timeout + # of 0.0000212 seconds + my $timeout = int(($Timers[0][0] - $now) * 1000) + 1; + + # -1 is an infinite timeout, so prefer a real timeout + return $timeout if $LoopTimeout == -1; + + # otherwise pick the lower of our regular timeout and time until + # the next timer + return $LoopTimeout if $LoopTimeout < $timeout; + return $timeout; +} + +### The epoll-based event loop. Gets installed as EventLoop if IO::Epoll loads +### okay. +sub EpollEventLoop { + my $class = shift; + + foreach my $fd ( keys %OtherFds ) { + if (epoll_ctl($Epoll, EPOLL_CTL_ADD, $fd, EPOLLIN) == -1) { + warn "epoll_ctl(): failure adding fd=$fd; $! (", $!+0, ")\n"; + } + } + + while (1) { + my @events; + my $i; + my $timeout = RunTimers(); + + # get up to 1000 events + my $evcount = epoll_wait($Epoll, 1000, $timeout, \@events); + EVENT: + for ($i=0; $i<$evcount; $i++) { + my $ev = $events[$i]; + + # it's possible epoll_wait returned many events, including some at the end + # that ones in the front triggered unregister-interest actions. if we + # can't find the %sock entry, it's because we're no longer interested + # in that event. + my PublicInbox::DS $pob = $DescriptorMap{$ev->[0]}; + 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) { + if (my $code = $OtherFds{$ev->[0]}) { + $code->($state); + } else { + 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); + + # standard non-profiling codepat + $pob->event_read if $state & EPOLLIN && ! $pob->{closed}; + $pob->event_write if $state & EPOLLOUT && ! $pob->{closed}; + if ($state & (EPOLLERR|EPOLLHUP)) { + $pob->event_err if $state & EPOLLERR && ! $pob->{closed}; + $pob->event_hup if $state & EPOLLHUP && ! $pob->{closed}; + } + } + return unless PostEventLoop(); + } + exit 0; +} + +### The fallback IO::Poll-based event loop. Gets installed as EventLoop if +### IO::Epoll fails to load. +sub PollEventLoop { + my $class = shift; + + my PublicInbox::DS $pob; + + while (1) { + my $timeout = RunTimers(); + + # the following sets up @poll as a series of ($poll,$event_mask) + # items, then uses IO::Poll::_poll, implemented in XS, which + # modifies the array in place with the even elements being + # replaced with the event masks that occured. + my @poll; + foreach my $fd ( keys %OtherFds ) { + push @poll, $fd, POLLIN; + } + while ( my ($fd, $sock) = each %DescriptorMap ) { + push @poll, $fd, $sock->{event_watch}; + } + + # if nothing to poll, either end immediately (if no timeout) + # or just keep calling the callback + unless (@poll) { + select undef, undef, undef, ($timeout / 1000); + return unless PostEventLoop(); + next; + } + + my $count = IO::Poll::_poll($timeout, @poll); + unless ($count >= 0) { + return unless PostEventLoop(); + next; + } + + # Fetch handles with read events + while (@poll) { + my ($fd, $state) = splice(@poll, 0, 2); + next unless $state; + + $pob = $DescriptorMap{$fd}; + + if (!$pob) { + if (my $code = $OtherFds{$fd}) { + $code->($state); + } + 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}; + $pob->event_hup if $state & POLLHUP && ! $pob->{closed}; + } + + return unless PostEventLoop(); + } + + exit 0; +} + +### The kqueue-based event loop. Gets installed as EventLoop if IO::KQueue works +### okay. +sub KQueueEventLoop { + my $class = shift; + + foreach my $fd (keys %OtherFds) { + $KQueue->EV_SET($fd, IO::KQueue::EVFILT_READ(), IO::KQueue::EV_ADD()); + } + + while (1) { + my $timeout = RunTimers(); + my @ret = eval { $KQueue->kevent($timeout) }; + if (my $err = $@) { + # workaround https://rt.cpan.org/Ticket/Display.html?id=116615 + if ($err =~ /Interrupted system call/) { + @ret = (); + } else { + die $err; + } + } + + foreach my $kev (@ret) { + my ($fd, $filter, $flags, $fflags) = @$kev; + my PublicInbox::DS $pob = $DescriptorMap{$fd}; + if (!$pob) { + if (my $code = $OtherFds{$fd}) { + $code->($filter); + } else { + 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); + + $pob->event_read if $filter == IO::KQueue::EVFILT_READ() && !$pob->{closed}; + $pob->event_write if $filter == IO::KQueue::EVFILT_WRITE() && !$pob->{closed}; + if ($flags == IO::KQueue::EV_EOF() && !$pob->{closed}) { + if ($fflags) { + $pob->event_err; + } else { + $pob->event_hup; + } + } + } + return unless PostEventLoop(); + } + + exit(0); +} + +=head2 C<< CLASS->SetPostLoopCallback( CODEREF ) >> + +Sets post loop callback function. Pass a subref and it will be +called every time the event loop finishes. + +Return 1 (or any true value) from the sub to make the loop continue, 0 or false +and it will exit. + +The callback function will be passed two parameters: \%DescriptorMap, \%OtherFds. + +=cut +sub SetPostLoopCallback { + my ($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; + } +} + +# Internal function: run the post-event callback, send read events +# for pushed-back data, and close pending connections. returns 1 +# if event loop should continue, or 0 to shut it all down. +sub PostEventLoop { + # now we can close sockets that wanted to close during our event processing. + # (we didn't want to close them during the loop, as we didn't want fd numbers + # being reused and confused during the event loop) + while (my $sock = shift @ToClose) { + my $fd = fileno($sock); + + # close the socket. (not a PublicInbox::DS close) + $sock->close; + + # and now we can finally remove the fd from the map. see + # comment above in _cleanup. + delete $DescriptorMap{$fd}; + } + + + # by default we keep running, unless a postloop callback (either per-object + # or global) cancels it + my $keep_running = 1; + + # per-object post-loop-callbacks + for my $plc (values %PLCMap) { + $keep_running &&= $plc->(\%DescriptorMap, \%OtherFds); + } + + # now we're at the very end, call callback if defined + if (defined $PostLoopCallback) { + $keep_running &&= $PostLoopCallback->(\%DescriptorMap, \%OtherFds); + } + + return $keep_running; +} + +##################################################################### +### PublicInbox::DS-the-object code +##################################################################### + +=head2 OBJECT METHODS + +=head2 C<< CLASS->new( $socket ) >> + +Create a new PublicInbox::DS subclass object for the given I<socket> which will +react to events on it during the C<EventLoop>. + +This is normally (always?) called from your subclass via: + + $class->SUPER::new($socket); + +=cut +sub new { + my ($self, $sock, $exclusive) = @_; + $self = fields::new($self) unless ref $self; + + $self->{sock} = $sock; + my $fd = fileno($sock); + + Carp::cluck("undef sock and/or fd in PublicInbox::DS->new. sock=" . ($sock || "") . ", fd=" . ($fd || "")) + unless $sock && $fd; + + $self->{fd} = $fd; + $self->{write_buf} = []; + $self->{write_buf_offset} = 0; + $self->{write_buf_size} = 0; + $self->{closed} = 0; + + my $ev = $self->{event_watch} = POLLERR|POLLHUP|POLLNVAL; + + _InitPoller(); + + if ($HaveEpoll) { + if ($exclusive) { + $ev = $self->{event_watch} = EPOLLIN|EPOLLERR|EPOLLHUP|$EPOLLEXCLUSIVE; + } +retry: + if (epoll_ctl($Epoll, EPOLL_CTL_ADD, $fd, $ev)) { + if ($!{EINVAL} && ($ev & $EPOLLEXCLUSIVE)) { + $EPOLLEXCLUSIVE = 0; # old kernel + $ev = $self->{event_watch} = EPOLLIN|EPOLLERR|EPOLLHUP; + goto retry; + } + die "couldn't add epoll watch for $fd: $!\n"; + } + } + elsif ($HaveKQueue) { + # Add them to the queue but disabled for now + $KQueue->EV_SET($fd, IO::KQueue::EVFILT_READ(), + IO::KQueue::EV_ADD() | IO::KQueue::EV_DISABLE()); + $KQueue->EV_SET($fd, IO::KQueue::EVFILT_WRITE(), + IO::KQueue::EV_ADD() | IO::KQueue::EV_DISABLE()); + } + + Carp::cluck("PublicInbox::DS::new blowing away existing descriptor map for fd=$fd ($DescriptorMap{$fd})") + if $DescriptorMap{$fd}; + + $DescriptorMap{$fd} = $self; + return $self; +} + + +##################################################################### +### I N S T A N C E M E T H O D S +##################################################################### + +=head2 C<< $obj->steal_socket() >> + +Basically returns our socket and makes it so that we don't try to close it, +but we do remove it from epoll handlers. THIS CLOSES $self. It is the same +thing as calling close, except it gives you the socket to use. + +=cut +sub steal_socket { + my PublicInbox::DS $self = $_[0]; + return if $self->{closed}; + + # cleanup does most of the work of closing this socket + $self->_cleanup(); + + # now undef our internal sock and fd structures so we don't use them + my $sock = $self->{sock}; + $self->{sock} = undef; + return $sock; +} + +=head2 C<< $obj->close( [$reason] ) >> + +Close the socket. The I<reason> argument will be used in debugging messages. + +=cut +sub close { + my PublicInbox::DS $self = $_[0]; + return if $self->{closed}; + + # print out debugging info for this close + if (DebugLevel) { + my ($pkg, $filename, $line) = caller; + my $reason = $_[1] || ""; + warn "Closing \#$self->{fd} due to $pkg/$filename/$line ($reason)\n"; + } + + # this does most of the work of closing us + $self->_cleanup(); + + # defer closing the actual socket until the event loop is done + # processing this round of events. (otherwise we might reuse fds) + if ($self->{sock}) { + push @ToClose, $self->{sock}; + $self->{sock} = undef; + } + + return 0; +} + +### METHOD: _cleanup() +### Called by our closers so we can clean internal data structures. +sub _cleanup { + my PublicInbox::DS $self = $_[0]; + + # we're effectively closed; we have no fd and sock when we leave here + $self->{closed} = 1; + + # we need to flush our write buffer, as there may + # be self-referential closures (sub { $client->close }) + # preventing the object from being destroyed + $self->{write_buf} = []; + + # if we're using epoll, we have to remove this from our epoll fd so we stop getting + # notifications about it + if ($HaveEpoll && $self->{fd}) { + if (epoll_ctl($Epoll, EPOLL_CTL_DEL, $self->{fd}, $self->{event_watch}) != 0) { + # dump_error prints a backtrace so we can try to figure out why this happened + $self->dump_error("epoll_ctl(): failure deleting fd=$self->{fd} during _cleanup(); $! (" . ($!+0) . ")"); + } + } + + # 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 + # of which is not yet processed and is what we're closing. if we + # keep it in DescriptorMap, then the event harnesses can just + # looked at $pob->{closed} and ignore it. but if it's an + # un-accounted for fd, then it (understandably) freak out a bit + # and emit warnings, thinking their state got off. + + # and finally get rid of our fd so we can't use it anywhere else + $self->{fd} = undef; +} + +=head2 C<< $obj->sock() >> + +Returns the underlying IO::Handle for the object. + +=cut +sub sock { + my PublicInbox::DS $self = shift; + 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, +scalar ref, code ref (to run when there), or undef just to kick-start. +Returns 1 if writes all went through, or 0 if there are writes in queue. If +it returns 1, caller should stop waiting for 'writable' events) + +=cut +sub write { + my PublicInbox::DS $self; + my $data; + ($self, $data) = @_; + + # nobody should be writing to closed sockets, but caller code can + # do two writes within an event, have the first fail and + # disconnect the other side (whose destructor then closes the + # calling object, but it's still in a method), and then the + # now-dead object does its second write. that is this case. we + # just lie and say it worked. it'll be dead soon and won't be + # hurt by this lie. + return 1 if $self->{closed}; + + my $bref; + + # just queue data if there's already a wait + my $need_queue; + + if (defined $data) { + $bref = ref $data ? $data : \$data; + if ($self->{write_buf_size}) { + push @{$self->{write_buf}}, $bref; + $self->{write_buf_size} += ref $bref eq "SCALAR" ? length($$bref) : 1; + return 0; + } + + # this flag says we're bypassing the queue system, knowing we're the + # only outstanding write, and hoping we don't ever need to use it. + # if so later, though, we'll need to queue + $need_queue = 1; + } + + WRITE: + while (1) { + return 1 unless $bref ||= $self->{write_buf}[0]; + + my $len; + eval { + $len = length($$bref); # this will die if $bref is a code ref, caught below + }; + if ($@) { + if (UNIVERSAL::isa($bref, "CODE")) { + unless ($need_queue) { + $self->{write_buf_size}--; # code refs are worth 1 + shift @{$self->{write_buf}}; + } + $bref->(); + + # code refs are just run and never get reenqueued + # (they're one-shot), so turn off the flag indicating the + # outstanding data needs queueing. + $need_queue = 0; + + undef $bref; + next WRITE; + } + die "Write error: $@ <$bref>"; + } + + 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}); + } + + if (! defined $written) { + if ($! == EPIPE) { + return $self->close("EPIPE"); + } elsif ($! == EAGAIN) { + # since connection has stuff to write, it should now be + # interested in pending writes: + if ($need_queue) { + push @{$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) { + return $self->close("ECONNRESET"); + } + + DebugLevel >= 1 && $self->debugmsg("Closing connection ($self) due to write error: $!\n"); + + return $self->close("write_error"); + } elsif ($written != $to_write) { + DebugLevel >= 2 && $self->debugmsg("Wrote PARTIAL %d bytes to %d", + $written, $self->{fd}); + if ($need_queue) { + push @{$self->{write_buf}}, $bref; + $self->{write_buf_size} += $len; + } + # since connection has stuff to write, it should now be + # interested in pending writes: + $self->{write_buf_offset} += $written; + $self->{write_buf_size} -= $written; + $self->on_incomplete_write; + return 0; + } elsif ($written == $to_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; + } + + # this was our only write, so we can return immediately + # since we avoided incrementing the buffer size or + # putting it in the buffer. we also know there + # can't be anything else to write. + return 1 if $need_queue; + + $self->{write_buf_size} -= $written; + shift @{$self->{write_buf}}; + undef $bref; + next WRITE; + } + } +} + +sub on_incomplete_write { + my PublicInbox::DS $self = shift; + $self->{write_set_watch} = 1 unless $self->{event_watch} & POLLOUT; + $self->watch_write(1); +} + +=head2 C<< $obj->read( $bytecount ) >> + +Read at most I<bytecount> bytes from the underlying handle; returns scalar +ref on read, or undef on connection closed. + +=cut +sub read { + my PublicInbox::DS $self = shift; + return if $self->{closed}; + my $bytes = shift; + my $buf; + my $sock = $self->{sock}; + + # if this is too high, perl quits(!!). reports on mailing lists + # don't seem to point to a universal answer. 5MB worked for some, + # crashed for others. 1MB works for more people. let's go with 1MB + # for now. :/ + my $req_bytes = $bytes > 1048576 ? 1048576 : $bytes; + + my $res = sysread($sock, $buf, $req_bytes, 0); + DebugLevel >= 2 && $self->debugmsg("sysread = %d; \$! = %d", $res, $!); + + if (! $res && $! != EWOULDBLOCK) { + # catches 0=conn closed or undef=error + DebugLevel >= 2 && $self->debugmsg("Fd \#%d read hit the end of the road.", $self->{fd}); + return undef; + } + + return \$buf; +} + +=head2 (VIRTUAL) C<< $obj->event_read() >> + +Readable event handler. Concrete deriviatives of PublicInbox::DS should +provide an implementation of this. The default implementation will die if +called. + +=cut +sub event_read { die "Base class event_read called for $_[0]\n"; } + +=head2 (VIRTUAL) C<< $obj->event_err() >> + +Error event handler. Concrete deriviatives of PublicInbox::DS should +provide an implementation of this. The default implementation will die if +called. + +=cut +sub event_err { die "Base class event_err called for $_[0]\n"; } + +=head2 (VIRTUAL) C<< $obj->event_hup() >> + +'Hangup' event handler. Concrete deriviatives of PublicInbox::DS should +provide an implementation of this. The default implementation will die if +called. + +=cut +sub event_hup { die "Base class event_hup called for $_[0]\n"; } + +=head2 C<< $obj->event_write() >> + +Writable event handler. Concrete deriviatives of PublicInbox::DS may wish to +provide an implementation of this. The default implementation calls +C<write()> with an C<undef>. + +=cut +sub event_write { + my $self = shift; + $self->write(undef); +} + +=head2 C<< $obj->watch_read( $boolean ) >> + +Turn 'readable' event notification on or off. + +=cut +sub watch_read { + my PublicInbox::DS $self = shift; + return if $self->{closed} || !$self->{sock}; + + my $val = shift; + my $event = $self->{event_watch}; + + $event &= ~POLLIN if ! $val; + $event |= POLLIN if $val; + + # If it changed, set it + if ($event != $self->{event_watch}) { + if ($HaveKQueue) { + $KQueue->EV_SET($self->{fd}, IO::KQueue::EVFILT_READ(), + $val ? IO::KQueue::EV_ENABLE() : IO::KQueue::EV_DISABLE()); + } + elsif ($HaveEpoll) { + epoll_ctl($Epoll, EPOLL_CTL_MOD, $self->{fd}, $event) + and $self->dump_error("couldn't modify epoll settings for $self->{fd} " . + "from $self->{event_watch} -> $event: $! (" . ($!+0) . ")"); + } + $self->{event_watch} = $event; + } +} + +=head2 C<< $obj->watch_write( $boolean ) >> + +Turn 'writable' event notification on or off. + +=cut +sub watch_write { + my PublicInbox::DS $self = shift; + return if $self->{closed} || !$self->{sock}; + + my $val = shift; + my $event = $self->{event_watch}; + + $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) { + $KQueue->EV_SET($self->{fd}, IO::KQueue::EVFILT_WRITE(), + $val ? IO::KQueue::EV_ENABLE() : IO::KQueue::EV_DISABLE()); + } + elsif ($HaveEpoll) { + epoll_ctl($Epoll, EPOLL_CTL_MOD, $self->{fd}, $event) + and $self->dump_error("couldn't modify epoll settings for $self->{fd} " . + "from $self->{event_watch} -> $event: $! (" . ($!+0) . ")"); + } + $self->{event_watch} = $event; + } +} + +=head2 C<< $obj->dump_error( $message ) >> + +Prints to STDERR a backtrace with information about this socket and what lead +up to the dump_error call. + +=cut +sub dump_error { + my $i = 0; + my @list; + while (my ($file, $line, $sub) = (caller($i++))[1..3]) { + push @list, "\t$file:$line called $sub\n"; + } + + warn "ERROR: $_[1]\n" . + "\t$_[0] = " . $_[0]->as_string . "\n" . + join('', @list); +} + +=head2 C<< $obj->debugmsg( $format, @args ) >> + +Print the debugging message specified by the C<sprintf>-style I<format> and +I<args>. + +=cut +sub debugmsg { + my ( $self, $fmt, @args ) = @_; + confess "Not an object" unless ref $self; + + chomp $fmt; + printf STDERR ">>> $fmt\n", @args; +} + +=head2 C<< $obj->as_string() >> + +Returns a string describing this socket. + +=cut +sub as_string { + my PublicInbox::DS $self = shift; + my $rw = "(" . ($self->{event_watch} & POLLIN ? 'R' : '') . + ($self->{event_watch} & POLLOUT ? 'W' : '') . ")"; + my $ret = ref($self) . "$rw: " . ($self->{closed} ? "closed" : "open"); + return $ret; +} + +package PublicInbox::DS::Timer; +# [$abs_float_firetime, $coderef]; +sub cancel { + $_[0][1] = undef; +} + +1; + +=head1 AUTHORS (Danga::Socket) + +Brad Fitzpatrick <brad@danga.com> - author + +Michael Granger <ged@danga.com> - docs, testing + +Mark Smith <junior@danga.com> - contributor, heavy user, testing + +Matt Sergeant <matt@sergeant.org> - kqueue support, docs, timers, other bits |