1 package Object::Remote::Connection;
3 use Object::Remote::Logging qw (:log :dlog);
4 use Object::Remote::Future;
5 use Object::Remote::Null;
6 use Object::Remote::Handle;
7 use Object::Remote::CodeContainer;
8 use Object::Remote::GlobProxy;
9 use Object::Remote::GlobContainer;
10 use Object::Remote::Tied;
14 use POSIX ":sys_wait_h";
15 use Module::Runtime qw(use_module);
16 use Scalar::Util qw(weaken blessed refaddr openhandle);
17 use JSON::PP qw(encode_json);
21 #this will reap child processes as soon
22 #as they are done executing so the process
23 #table cleans up as fast as possible but
24 #anything that needs to call waitpid()
25 #in the future to get the exit value of
26 #a child will get trash results if
27 #the signal handler was running.
28 #If creating a child and getting the
29 #exit value is required then set
30 #a localized version of the signal
31 #handler for CHLD to be 'IGNORE'
32 #in the smallest block possible
33 #and outside the block send
34 #the process a CHLD signal
35 #to reap anything that may
36 #have exited while blocked
40 log_trace { "CHLD signal handler is executing" };
42 $kid = waitpid(-1, WNOHANG);
43 log_debug { "waitpid() returned '$kid'" };
45 log_trace { "CHLD signal handler is done" };
48 $SIG{PIPE} = sub { log_debug { "Got a PIPE signal" } };
52 log_debug { "Killing all child processes in the process group" };
54 #send SIGINT to the process group for our children
58 has _id => ( is => 'ro', required => 1, default => sub { our $NEXT_CONNECTION_ID++ } );
61 is => 'ro', required => 1,
65 Dlog_trace { my $id = $self->_id; "connection had send_to_fh set to $_" } $_[1];
70 is => 'ro', required => 1,
74 Dlog_trace { "trigger for read_channel has been invoked for connection $id; file handle is $_" } $ch->fh;
76 $ch->on_line_call(sub { $self->_receive(@_) });
77 $ch->on_close_call(sub {
78 log_trace { "invoking 'done' on on_close handler for connection id '$id'" };
79 $self->on_close->done(@_);
85 is => 'rw', default => sub { $_[0]->_install_future_handlers(CPS::Future->new) },
86 trigger => \&_install_future_handlers,
89 has child_pid => (is => 'ro');
91 has local_objects_by_id => (
92 is => 'ro', default => sub { {} },
93 coerce => sub { +{ %{$_[0]} } }, # shallow clone on the way in
96 has remote_objects_by_id => (
97 is => 'ro', default => sub { {} },
98 coerce => sub { +{ %{$_[0]} } }, # shallow clone on the way in
101 has outstanding_futures => (is => 'ro', default => sub { {} });
106 _deserialize => 'decode',
114 return unless defined $self->child_pid;
116 log_debug { "Setting process group of child process" };
118 setpgrp($self->child_pid, 1);
123 sub _fail_outstanding {
124 my ($self, $error) = @_;
125 Dlog_debug { "Failing outstanding futures with '$error' for connection $_" } $self->_id;
126 my $outstanding = $self->outstanding_futures;
127 $_->fail("$error\n") for values %$outstanding;
132 sub _install_future_handlers {
134 Dlog_trace { "trigger for on_close has been invoked for connection $_" } $self->_id;
137 Dlog_trace { "failing all of the outstanding futures for connection $_" } $self->_id;
138 $self->_fail_outstanding("Object::Remote connection lost: " . ($f->get)[0]);
143 sub _id_to_remote_object {
144 my ($self, $id) = @_;
145 Dlog_trace { "fetching proxy for remote object with id '$id' for connection $_" } $self->_id;
146 return bless({}, 'Object::Remote::Null') if $id eq 'NULL';
148 $self->remote_objects_by_id->{$id}
149 or Object::Remote::Handle->new(connection => $self, id => $id)
154 weaken(my $self = shift);
155 JSON::PP->new->filter_json_single_key_object(
156 __remote_object__ => sub {
157 $self->_id_to_remote_object(@_);
159 )->filter_json_single_key_object(
160 __remote_code__ => sub {
161 my $code_container = $self->_id_to_remote_object(@_);
162 sub { $code_container->call(@_) };
164 )->filter_json_single_key_object(
165 __scalar_ref__ => sub {
169 )->filter_json_single_key_object(
170 __glob_ref__ => sub {
171 my $glob_container = $self->_id_to_remote_object(@_);
172 my $handle = Symbol::gensym;
173 tie *$handle, 'Object::Remote::GlobProxy', $glob_container;
176 )->filter_json_single_key_object(
177 __local_object__ => sub {
178 $self->local_objects_by_id->{$_[0]}
180 )->filter_json_single_key_object(
181 __remote_tied_hash__ => sub {
183 tie %tied_hash, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
186 )->filter_json_single_key_object(
187 __remote_tied_array__ => sub {
189 tie @tied_array, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
195 sub _load_if_possible {
201 log_debug { "Attempt at loading '$class' failed with '$@'" };
207 unshift our @Guess, sub { blessed($_[0]) ? $_[0] : undef };
208 map _load_if_possible($_), qw(
209 Object::Remote::Connector::Local
210 Object::Remote::Connector::LocalSudo
211 Object::Remote::Connector::SSH
212 Object::Remote::Connector::UNIX
217 my ($class, $spec, @args) = @_;
218 foreach my $poss (do { our @Guess }) {
219 if (my $conn = $poss->($spec, @args)) {
228 my ($class, $spec) = @_;
229 return $spec if blessed $spec;
230 my $conn = $class->conn_from_spec($spec);
232 die "Couldn't figure out what to do with ${spec}"
233 unless defined $conn;
235 return $conn->maybe::start::connect;
239 my ($self, @args) = @_;
240 Object::Remote::Handle->new(
241 connection => $self, @args
246 my ($self, $to) = @_;
247 Dlog_debug { "Creating connection to remote node '$to' for connection $_" } $self->_id;
249 $self->send_class_call(0, 'Object::Remote', connect => $to)
254 my ($self, $sub) = @_;
255 my ($pkg, $name) = $sub =~ m/^(.*)::([^:]+)$/;
256 Dlog_debug { "Invoking remote sub '$sub' for connection $_" } $self->_id;
257 return await_future($self->send_class_call(0, $pkg, can => $name));
260 sub send_class_call {
261 my ($self, $ctx, @call) = @_;
262 Dlog_trace { "Sending a class call for connection $_" } $self->_id;
263 $self->send(call => class_call_handler => $ctx => call => @call);
266 sub register_class_call_handler {
268 $self->local_objects_by_id->{'class_call_handler'} ||= do {
269 my $o = $self->new_class_call_handler;
270 $self->_local_object_to_id($o);
275 sub new_class_call_handler {
276 Object::Remote::CodeContainer->new(
278 my ($class, $method) = (shift, shift);
279 use_module($class)->$method(@_);
284 sub register_remote {
285 my ($self, $remote) = @_;
286 Dlog_trace { my $i = $remote->id; "Registered a remote object with id of '$i' for connection $_" } $self->_id;
287 weaken($self->remote_objects_by_id->{$remote->id} = $remote);
292 my ($self, $id) = @_;
293 Dlog_trace { "sending request to free object '$id' for connection $_" } $self->_id;
294 delete $self->remote_objects_by_id->{$id};
295 $self->_send([ free => $id ]);
299 my ($self, $type, @call) = @_;
301 my $future = CPS::Future->new;
302 my $remote = $self->remote_objects_by_id->{$call[0]};
304 unshift @call, $type => $self->_local_object_to_id($future);
306 my $outstanding = $self->outstanding_futures;
307 $outstanding->{$future} = $future;
308 $future->on_ready(sub {
310 delete $outstanding->{$future}
313 $self->_send(\@call);
319 my ($self, $type, @call) = @_;
321 unshift @call, $type => 'NULL';
323 $self->_send(\@call);
327 my ($self, $to_send) = @_;
328 my $fh = $self->send_to_fh;
329 Dlog_trace { "Starting to serialize data in argument to _send for connection $_" } $self->_id;
330 my $serialized = $self->_serialize($to_send)."\n";
331 Dlog_trace { my $l = length($serialized); "serialization is completed; sending '$l' characters of serialized data to $_" } $fh;
334 #TODO this should be converted over to a non-blocking ::WriteChannel class
335 die "filehandle is not open" unless openhandle($fh);
336 log_trace { "file handle has passed openhandle() test; printing to it" };
337 $ret = print $fh $serialized;
338 die "print was not successful: $!" unless defined $ret
342 Dlog_debug { "exception encountered when trying to write to file handle $_: $@" } $fh;
343 my $error = $@; chomp($error);
344 $self->on_close->done("could not write to file handle: $error") unless $self->on_close->is_ready;
352 my ($self, $data) = @_;
353 local our @New_Ids = (-1);
355 my $flat = $self->_encode($self->_deobjectify($data));
358 my $err = $@; # won't get here if the eval doesn't die
359 # don't keep refs to new things
360 delete @{$self->local_objects_by_id}{@New_Ids};
361 die "Error serializing: $err";
365 sub _local_object_to_id {
366 my ($self, $object) = @_;
367 my $id = refaddr($object);
368 $self->local_objects_by_id->{$id} ||= do {
369 push our(@New_Ids), $id if @New_Ids;
376 my ($self, $data) = @_;
377 if (blessed($data)) {
379 $data->isa('Object::Remote::Proxy')
380 and $data->{remote}->connection == $self
382 return +{ __local_object__ => $data->{remote}->id };
384 return +{ __remote_object__ => $self->_local_object_to_id($data) };
386 } elsif (my $ref = ref($data)) {
387 if ($ref eq 'HASH') {
388 my $tied_to = tied(%$data);
389 if(defined($tied_to)) {
390 return +{__remote_tied_hash__ => $self->_local_object_to_id($tied_to)};
392 return +{ map +($_ => $self->_deobjectify($data->{$_})), keys %$data };
394 } elsif ($ref eq 'ARRAY') {
395 my $tied_to = tied(@$data);
396 if (defined($tied_to)) {
397 return +{__remote_tied_array__ => $self->_local_object_to_id($tied_to)};
399 return [ map $self->_deobjectify($_), @$data ];
401 } elsif ($ref eq 'CODE') {
402 my $id = $self->_local_object_to_id(
403 Object::Remote::CodeContainer->new(code => $data)
405 return +{ __remote_code__ => $id };
406 } elsif ($ref eq 'SCALAR') {
407 return +{ __scalar_ref__ => $$data };
408 } elsif ($ref eq 'GLOB') {
409 return +{ __glob_ref__ => $self->_local_object_to_id(
410 Object::Remote::GlobContainer->new(handle => $data)
413 die "Can't collapse reftype $ref";
416 return $data; # plain scalar
420 my ($self, $flat) = @_;
421 Dlog_trace { my $l = length($flat); "Starting to deserialize $l characters of data for connection $_" } $self->_id;
422 my ($type, @rest) = eval { @{$self->_deserialize($flat)} }
423 or do { warn "Deserialize failed for ${flat}: $@"; return };
424 Dlog_trace { "deserialization complete for connection $_" } $self->_id;
425 eval { $self->${\"receive_${type}"}(@rest); 1 }
426 or do { warn "Receive failed for ${flat}: $@"; return };
431 my ($self, $id) = @_;
432 Dlog_trace { "got a receive_free for object '$id' for connection $_" } $self->_id;
433 delete $self->local_objects_by_id->{$id}
434 or warn "Free: no such object $id";
439 my ($self, $future_id, $id, @rest) = @_;
440 Dlog_trace { "got a receive_call for object '$id' for connection $_" } $self->_id;
441 my $future = $self->_id_to_remote_object($future_id);
442 $future->{method} = 'call_discard_free';
443 my $local = $self->local_objects_by_id->{$id}
444 or do { $future->fail("No such object $id"); return };
445 $self->_invoke($future, $local, @rest);
448 sub receive_call_free {
449 my ($self, $future, $id, @rest) = @_;
450 Dlog_trace { "got a receive_call_free for object '$id' for connection $_" } $self->_id;
451 $self->receive_call($future, $id, undef, @rest);
452 $self->receive_free($id);
456 my ($self, $future, $local, $ctx, $method, @args) = @_;
457 Dlog_trace { "got _invoke for a method named '$method' for connection $_" } $self->_id;
458 if ($method =~ /^start::/) {
459 my $f = $local->$method(@args);
460 $f->on_done(sub { undef($f); $future->done(@_) });
462 $f->on_fail(sub { undef($f); $future->fail(@_) });
465 my $do = sub { $local->$method(@args) };
469 ? ($ctx ? $do->() : scalar($do->()))
473 } or do { $future->fail($@); return; };
481 Object::Remote::Connection - An underlying connection for L<Object::Remote>
485 Shipping prioritised over writing this part up. Blame mst.