###########################################################################
=head1 NAME
Danga::Socket - Event loop and event-driven async socket base class
=head1 SYNOPSIS
package My::Socket
use Danga::Socket;
use base ('Danga::Socket');
use fields ('my_attribute');
sub new {
my My::Socket $self = shift;
$self = fields::new($self) unless ref $self;
$self->SUPER::new( @_ );
$self->{my_attribute} = 1234;
return $self;
}
sub event_err { ... }
sub event_hup { ... }
sub event_write { ... }
sub event_read { ... }
sub close { ... }
$my_sock->tcp_cork($bool);
# write returns 1 if all writes have gone through, or 0 if there
# are writes in queue
$my_sock->write($scalar);
$my_sock->write($scalarref);
$my_sock->write(sub { ... }); # run when previous data written
$my_sock->write(undef); # kick-starts
# read max $bytecount bytes, or undef on connection closed
$scalar_ref = $my_sock->read($bytecount);
# watch for writability. not needed with ->write(). write()
# will automatically turn on watch_write when you wrote too much
# and turn it off when done
$my_sock->watch_write($bool);
# watch for readability
$my_sock->watch_read($bool);
# if you read too much and want to push some back on
# readable queue. (not incredibly well-tested)
$my_sock->push_back_read($buf); # scalar or scalar ref
Danga::Socket->AddOtherFds(..);
Danga::Socket->SetLoopTimeout($millisecs);
Danga::Socket->DescriptorMap();
Danga::Socket->WatchedSockets(); # count of DescriptorMap keys
Danga::Socket->SetPostLoopCallback($code);
Danga::Socket->EventLoop();
=head1 DESCRIPTION
This is an abstract base class for objects backed by a socket which
provides the basic framework for event-driven asynchronous IO,
designed to be fast. Danga::Socket is both a base class for objects,
and an event loop.
Callers subclass Danga::Socket. Danga::Socket's constructor registers
itself with the Danga::Socket event loop, and invokes callbacks on the
object for readability, writability, errors, and other conditions.
Because Danga::Socket uses the "fields" module, your subclasses must
too.
=head1 MORE INFO
For now, see servers using Danga::Socket for guidance. For example:
perlbal, mogilefsd, or ddlockd.
=head1 API
Note where "C<CLASS>" is used below, normally you would call these methods as:
Danga::Socket->method(...);
However using a subclass works too.
The CLASS methods are all methods for the event loop part of Danga::Socket,
whereas the object methods are all used on your subclasses.
=cut
###########################################################################
package Danga::Socket;
use strict;
use bytes;
use POSIX ();
use Time::HiRes ();
my $opt_bsd_resource = eval "use BSD::Resource; 1;";
use vars qw{$VERSION};
$VERSION = "1.61";
use warnings;
no warnings qw(deprecated);
use Sys::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
'read_push_back', # arrayref of "pushed-back" read data the application didn't want
'closed', # bool: socket is closed
'corked', # bool: socket is corked
'event_watch', # bitmask of events the client is interested in (POLLIN,OUT,etc.)
'peer_v6', # bool: cached; if peer is an IPv6 address
'peer_ip', # cached stringified IP address of $sock
'peer_port', # cached port number of $sock
'local_ip', # cached stringified IP address of local end of $sock
'local_port', # cached port number of local end of $sock
'writer_func', # subref which does writing. must return bytes written (or undef) and set $! on errors
);
use Errno qw(EINPROGRESS EWOULDBLOCK EISCONN ENOTSOCK
EPIPE EAGAIN EBADF ECONNRESET ENOPROTOOPT);
use Socket qw(IPPROTO_TCP);
use Carp qw(croak confess);
use constant TCP_CORK => ($^O eq "linux" ? 3 : 0); # FIXME: not hard-coded (Linux-specific too)
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) -> Danga::Socket object
%PushBackSet, # fd (num) -> Danga::Socket (fds with pushed back read data)
$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-Danga::Socket) 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
$DoProfile, # if on, enable profiling
%Profiling, # what => [ utime, stime, calls ]
$DoneInit, # if we've done the one-time module init yet
@Timers, # timers
);
Reset();
#####################################################################
### C L A S S M E T H O D S
#####################################################################
=head2 C<< CLASS->Reset() >>
Reset all state
=cut
sub Reset {
%DescriptorMap = ();
%PushBackSet = ();
@ToClose = ();
%OtherFds = ();
$LoopTimeout = -1; # no timeout by default
$DoProfile = 0;
%Profiling = ();
@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 $HaveEpoll;
}
=head2 C<< CLASS->WatchedSockets() >>
Returns the number of file descriptors which are registered with the global
poll object.
=cut
sub WatchedSockets {
return scalar keys %DescriptorMap;
}
*watched_sockets = *WatchedSockets;
=head2 C<< CLASS->EnableProfiling() >>
Turns profiling on, clearing current profiling data.
=cut
sub EnableProfiling {
if ($opt_bsd_resource) {
%Profiling = ();
$DoProfile = 1;
return 1;
}
return 0;
}
=head2 C<< CLASS->DisableProfiling() >>
Turns off profiling, but retains data up to this point
=cut
sub DisableProfiling {
$DoProfile = 0;
}
=head2 C<< CLASS->ProfilingData() >>
Returns reference to a hash of data in format:
ITEM => [ utime, stime, #calls ]
=cut
sub ProfilingData {
return \%Profiling;
}
=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 Danga::Socket 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], "Danga::Socket::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 Danga::Socket 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 (Sys::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);
}
}
## profiling-related data/functions
our ($Prof_utime0, $Prof_stime0);
sub _pre_profile {
($Prof_utime0, $Prof_stime0) = getrusage();
}
sub _post_profile {
# get post information
my ($autime, $astime) = getrusage();
# calculate differences
my $utime = $autime - $Prof_utime0;
my $stime = $astime - $Prof_stime0;
foreach my $k (@_) {
$Profiling{$k} ||= [ 0.0, 0.0, 0 ];
$Profiling{$k}->[0] += $utime;
$Profiling{$k}->[1] += $stime;
$Profiling{$k}->[2]++;
}
}
# 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 Danga::Socket $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 $state for which we have no mapping. removing.\n";
POSIX::close($fd);
epoll_ctl($Epoll, EPOLL_CTL_DEL, $fd, 0);
}
next;
}
DebugLevel >= 1 && $class->DebugMsg("Event: fd=%d (%s), state=%d \@ %s\n",
$ev->[0], ref($pob), $ev->[1], time);
if ($DoProfile) {
my $class = ref $pob;
# call profiling action on things that need to be done
if ($state & EPOLLIN && ! $pob->{closed}) {
_pre_profile();
$pob->event_read;
_post_profile("$class-read");
}
if ($state & EPOLLOUT && ! $pob->{closed}) {
_pre_profile();
$pob->event_write;
_post_profile("$class-write");
}
if ($state & (EPOLLERR|EPOLLHUP)) {
if ($state & EPOLLERR && ! $pob->{closed}) {
_pre_profile();
$pob->event_err;
_post_profile("$class-err");
}
if ($state & EPOLLHUP && ! $pob->{closed}) {
_pre_profile();
$pob->event_hup;
_post_profile("$class-hup");
}
}
next;
}
# 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 Danga::Socket $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 ($count) {
return unless PostEventLoop();
next;
}
# Fetch handles with read events
while (@poll) {
my ($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 = $KQueue->kevent($timeout);
foreach my $kev (@ret) {
my ($fd, $filter, $flags, $fflags) = @$kev;
my Danga::Socket $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 Danga::Socket $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 {
# fire read events for objects with pushed-back read data
my $loop = 1;
while ($loop) {
$loop = 0;
foreach my $fd (keys %PushBackSet) {
my Danga::Socket $pob = $PushBackSet{$fd};
# a previous event_read invocation could've closed a
# connection that we already evaluated in "keys
# %PushBackSet", so skip ones that seem to have
# disappeared. this is expected.
next unless $pob;
die "ASSERT: the $pob socket has no read_push_back" unless @{$pob->{read_push_back}};
next unless (! $pob->{closed} &&
$pob->{event_watch} & POLLIN);
$loop = 1;
$pob->event_read;
}
}
# 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 Danga::Socket 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;
}
#####################################################################
### Danga::Socket-the-object code
#####################################################################
=head2 OBJECT METHODS
=head2 C<< CLASS->new( $socket ) >>
Create a new Danga::Socket 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 Danga::Socket $self = shift;
$self = fields::new($self) unless ref $self;
my $sock = shift;
$self->{sock} = $sock;
my $fd = fileno($sock);
Carp::cluck("undef sock and/or fd in Danga::Socket->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;
$self->{corked} = 0;
$self->{read_push_back} = [];
$self->{event_watch} = POLLERR|POLLHUP|POLLNVAL;
_InitPoller();
if ($HaveEpoll) {
epoll_ctl($Epoll, EPOLL_CTL_ADD, $fd, $self->{event_watch})
and 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("Danga::Socket::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->tcp_cork( $boolean ) >>
Turn TCP_CORK on or off depending on the value of I<boolean>.
=cut
sub tcp_cork {
my Danga::Socket $self = $_[0];
my $val = $_[1];
# make sure we have a socket
return unless $self->{sock};
return if $val == $self->{corked};
my $rv;
if (TCP_CORK) {
$rv = setsockopt($self->{sock}, IPPROTO_TCP, TCP_CORK,
pack("l", $val ? 1 : 0));
} else {
# FIXME: implement freebsd *PUSH sockopts
$rv = 1;
}
# if we failed, close (if we're not already) and warn about the error
if ($rv) {
$self->{corked} = $val;
} else {
if ($! == EBADF || $! == ENOTSOCK) {
# internal state is probably corrupted; warn and then close if
# we're not closed already
warn "setsockopt: $!";
$self->close('tcp_cork_failed');
} elsif ($! == ENOPROTOOPT || $!{ENOTSOCK} || $!{EOPNOTSUPP}) {
# TCP implementation doesn't support corking, so just ignore it
# or we're trying to tcp-cork a non-socket (like a socketpair pipe
# which is acting like a socket, which Perlbal does for child
# processes acting like inetd-like web servers)
} else {
# some other error; we should never hit here, but if we do, die
die "setsockopt: $!";
}
}
}
=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 Danga::Socket $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 Danga::Socket $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 Danga::Socket $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} = [];
# uncork so any final data gets sent. only matters if the person closing
# us forgot to do it, but we do it to be safe.
$self->tcp_cork(0);
# if we're using epoll, we have to remove this from our epoll fd so we stop getting
# notifications about it
if ($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 $PushBackSet{$self->{fd}};
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 Danga::Socket $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 Danga::Socket $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 Danga::Socket $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 Danga::Socket $self = shift;
$self->{write_set_watch} = 1 unless $self->{event_watch} & POLLOUT;
$self->watch_write(1);
}
=head2 C<< $obj->push_back_read( $buf ) >>
Push back I<buf> (a scalar or scalarref) into the read stream. Useful if you read
more than you need to and want to return this data on the next "read".
=cut
sub push_back_read {
my Danga::Socket $self = shift;
my $buf = shift;
push @{$self->{read_push_back}}, ref $buf ? $buf : \$buf;
$PushBackSet{$self->{fd}} = $self;
}
=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 Danga::Socket $self = shift;
return if $self->{closed};
my $bytes = shift;
my $buf;
my $sock = $self->{sock};
if (@{$self->{read_push_back}}) {
$buf = shift @{$self->{read_push_back}};
my $len = length($$buf);
if ($len <= $bytes) {
delete $PushBackSet{$self->{fd}} unless @{$self->{read_push_back}};
return $buf;
} else {
# if the pushed back read is too big, we have to split it
my $overflow = substr($$buf, $bytes);
$buf = substr($$buf, 0, $bytes);
unshift @{$self->{read_push_back}}, \$overflow;
return \$buf;
}
}
# 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 Danga::Socket 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 Danga::Socket 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 Danga::Socket 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 Danga::Socket 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 Danga::Socket $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 Danga::Socket $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->peer_ip_string() >>
Returns the string describing the peer's IP
=cut
sub peer_ip_string {
my Danga::Socket $self = shift;
return _undef("peer_ip_string undef: no sock") unless $self->{sock};
return $self->{peer_ip} if defined $self->{peer_ip};
my $pn = getpeername($self->{sock});
return _undef("peer_ip_string undef: getpeername") unless $pn;
my ($port, $iaddr) = eval {
if (length($pn) >= 28) {
return Socket6::unpack_sockaddr_in6($pn);
} else {
return Socket::sockaddr_in($pn);
}
};
if ($@) {
$self->{peer_port} = "[Unknown peerport '$@']";
return "[Unknown peername '$@']";
}
$self->{peer_port} = $port;
if (length($iaddr) == 4) {
return $self->{peer_ip} = Socket::inet_ntoa($iaddr);
} else {
$self->{peer_v6} = 1;
return $self->{peer_ip} = Socket6::inet_ntop(Socket6::AF_INET6(),
$iaddr);
}
}
=head2 C<< $obj->peer_addr_string() >>
Returns the string describing the peer for the socket which underlies this
object in form "ip:port"
=cut
sub peer_addr_string {
my Danga::Socket $self = shift;
my $ip = $self->peer_ip_string
or return undef;
return $self->{peer_v6} ?
"[$ip]:$self->{peer_port}" :
"$ip:$self->{peer_port}";
}
=head2 C<< $obj->local_ip_string() >>
Returns the string describing the local IP
=cut
sub local_ip_string {
my Danga::Socket $self = shift;
return _undef("local_ip_string undef: no sock") unless $self->{sock};
return $self->{local_ip} if defined $self->{local_ip};
my $pn = getsockname($self->{sock});
return _undef("local_ip_string undef: getsockname") unless $pn;
my ($port, $iaddr) = Socket::sockaddr_in($pn);
$self->{local_port} = $port;
return $self->{local_ip} = Socket::inet_ntoa($iaddr);
}
=head2 C<< $obj->local_addr_string() >>
Returns the string describing the local end of the socket which underlies this
object in form "ip:port"
=cut
sub local_addr_string {
my Danga::Socket $self = shift;
my $ip = $self->local_ip_string;
return $ip ? "$ip:$self->{local_port}" : undef;
}
=head2 C<< $obj->as_string() >>
Returns a string describing this socket.
=cut
sub as_string {
my Danga::Socket $self = shift;
my $rw = "(" . ($self->{event_watch} & POLLIN ? 'R' : '') .
($self->{event_watch} & POLLOUT ? 'W' : '') . ")";
my $ret = ref($self) . "$rw: " . ($self->{closed} ? "closed" : "open");
my $peer = $self->peer_addr_string;
if ($peer) {
$ret .= " to " . $self->peer_addr_string;
}
return $ret;
}
sub _undef {
return undef unless $ENV{DS_DEBUG};
my $msg = shift || "";
warn "Danga::Socket: $msg\n";
return undef;
}
package Danga::Socket::Timer;
# [$abs_float_firetime, $coderef];
sub cancel {
$_[0][1] = undef;
}
=head1 AUTHORS
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
=head1 BUGS
Not documented enough (but isn't that true of every project?).
tcp_cork only works on Linux for now. No BSD push/nopush support.
=head1 LICENSE
License is granted to use and distribute this module under the same
terms as Perl itself.
=cut
1;
# Local Variables:
# mode: perl
# c-basic-indent: 4
# indent-tabs-mode: nil
# End: