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_debug { "CHLD signal handler is executing" };
42 $kid = waitpid(-1, WNOHANG);
43 log_trace { "waitpid() returned '$kid'" };
45 log_trace { "CHLD signal handler is done" };
50 log_debug { "Killing all child processes in the process group" };
52 #send SIGINT to the process group for our children
57 our $DEBUG = !!$ENV{OBJECT_REMOTE_DEBUG};
58 #numbering each connection allows it to be
59 #tracked along with file handles in
62 has _id => ( is => 'ro', required => 1, default => sub { our $NEXT_CONNECTION_ID++ } );
65 is => 'ro', required => 1,
69 Dlog_trace { my $id = $self->_id; "connection had send_to_fh set to $_" } $_[1];
73 #TODO see if this is another case of the same bug below
74 #where trigger never fires because the attribute isn't
75 #actually set at any time
77 is => 'ro', required => 1,
81 Dlog_trace { "trigger for read_channel has been invoked for connection $id; file handle is $_" } $ch->fh;
83 $ch->on_line_call(sub { $self->_receive(@_) });
84 $ch->on_close_call(sub {
85 log_trace { "invoking 'done' on on_close handler for connection id '$id'" };
86 $self->on_close->done(@_);
91 #TODO properly fix this bug -
92 #trigger can't ever be invoked with a default
93 #value and the on_close attribute is read only....
94 #the future never gets the on_done handler
98 $self->on_close(CPS::Future->new);
104 return unless defined $self->child_pid;
106 log_debug { "Setting process group of child process" };
108 setpgrp($self->child_pid, 1);
114 is => 'rw', default => sub { CPS::Future->new },
117 Dlog_trace { "trigger for on_close has been invoked for connection $_" } $self->_id;
120 Dlog_trace { "failing all of the outstanding futures for connection $_" } $self->_id;
121 $self->_fail_outstanding("Object::Remote connection lost: " . ($f->get)[0]);
126 has child_pid => (is => 'ro');
128 has local_objects_by_id => (
129 is => 'ro', default => sub { {} },
130 coerce => sub { +{ %{$_[0]} } }, # shallow clone on the way in
133 has remote_objects_by_id => (
134 is => 'ro', default => sub { {} },
135 coerce => sub { +{ %{$_[0]} } }, # shallow clone on the way in
138 has outstanding_futures => (is => 'ro', default => sub { {} });
140 sub _fail_outstanding {
141 my ($self, $error) = @_;
142 Dlog_debug { "Failing outstanding futures with '$error' for connection $_" } $self->_id;
143 my $outstanding = $self->outstanding_futures;
144 $_->fail($error) for values %$outstanding;
152 _deserialize => 'decode',
157 sub _id_to_remote_object {
158 my ($self, $id) = @_;
159 Dlog_trace { "fetching proxy for remote object with id '$id' for connection $_" } $self->_id;
160 return bless({}, 'Object::Remote::Null') if $id eq 'NULL';
162 $self->remote_objects_by_id->{$id}
163 or Object::Remote::Handle->new(connection => $self, id => $id)
168 weaken(my $self = shift);
169 JSON::PP->new->filter_json_single_key_object(
170 __remote_object__ => sub {
171 $self->_id_to_remote_object(@_);
173 )->filter_json_single_key_object(
174 __remote_code__ => sub {
175 my $code_container = $self->_id_to_remote_object(@_);
176 sub { $code_container->call(@_) };
178 )->filter_json_single_key_object(
179 __scalar_ref__ => sub {
183 )->filter_json_single_key_object(
184 __glob_ref__ => sub {
185 my $glob_container = $self->_id_to_remote_object(@_);
186 my $handle = Symbol::gensym;
187 tie *$handle, 'Object::Remote::GlobProxy', $glob_container;
190 )->filter_json_single_key_object(
191 __remote_tied_hash__ => sub {
193 tie %tied_hash, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
196 )->filter_json_single_key_object(
197 __remote_tied_array__ => sub {
199 tie @tied_array, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
205 sub _load_if_possible {
208 eval "require $class";
211 log_debug { "Attempt at loading '$class' failed with '$@'" };
217 unshift our @Guess, sub { blessed($_[0]) ? $_[0] : undef };
218 map _load_if_possible($_), qw(
219 Object::Remote::Connector::Local
220 Object::Remote::Connector::LocalSudo
221 Object::Remote::Connector::SSH
222 Object::Remote::Connector::UNIX
227 my ($class, $spec, @args) = @_;
228 foreach my $poss (do { our @Guess }) {
229 if (my $conn = $poss->($spec, @args)) {
238 my ($class, $spec) = @_;
239 return $spec if blessed $spec;
240 my $conn = $class->conn_from_spec($spec);
242 die "Couldn't figure out what to do with ${spec}"
243 unless defined $conn;
245 return $conn->maybe::start::connect;
249 my ($self, @args) = @_;
250 Object::Remote::Handle->new(
251 connection => $self, @args
256 my ($self, $to) = @_;
257 Dlog_debug { "Creating connection to remote node '$to' for connection $_" } $self->_id;
259 $self->send_class_call(0, 'Object::Remote', connect => $to)
264 my ($self, $sub) = @_;
265 my ($pkg, $name) = $sub =~ m/^(.*)::([^:]+)$/;
266 Dlog_debug { "Invoking remote sub '$sub' for connection $_" } $self->_id;
267 return await_future($self->send_class_call(0, $pkg, can => $name));
270 sub send_class_call {
271 my ($self, $ctx, @call) = @_;
272 Dlog_trace { "Sending a class call for connection $_" } $self->_id;
273 $self->send(call => class_call_handler => $ctx => call => @call);
276 sub register_class_call_handler {
278 $self->local_objects_by_id->{'class_call_handler'} ||= do {
279 my $o = $self->new_class_call_handler;
280 $self->_local_object_to_id($o);
285 sub new_class_call_handler {
286 Object::Remote::CodeContainer->new(
288 my ($class, $method) = (shift, shift);
289 use_module($class)->$method(@_);
294 sub register_remote {
295 my ($self, $remote) = @_;
296 Dlog_trace { my $i = $remote->id; "Registered a remote object with id of '$i' for connection $_" } $self->_id;
297 weaken($self->remote_objects_by_id->{$remote->id} = $remote);
302 my ($self, $id) = @_;
303 Dlog_trace { "sending request to free object '$id' for connection $_" } $self->_id;
304 delete $self->remote_objects_by_id->{$id};
305 $self->_send([ free => $id ]);
309 my ($self, $type, @call) = @_;
311 my $future = CPS::Future->new;
312 my $remote = $self->remote_objects_by_id->{$call[0]};
314 unshift @call, $type => $self->_local_object_to_id($future);
316 my $outstanding = $self->outstanding_futures;
317 $outstanding->{$future} = $future;
318 $future->on_ready(sub {
320 delete $outstanding->{$future}
323 $self->_send(\@call);
329 my ($self, $type, @call) = @_;
331 unshift @call, $type => 'NULL';
333 $self->_send(\@call);
337 my ($self, $to_send) = @_;
338 my $fh = $self->send_to_fh;
339 Dlog_trace { "Starting to serialize data in argument to _send for connection $_" } $self->_id;
340 my $serialized = $self->_serialize($to_send)."\n";
341 Dlog_trace { my $l = length($serialized); "serialization is completed; sending '$l' characters of serialized data to $_" } $fh;
342 #TODO this is very risky for deadlocks unless it's set to non-blocking and then with out extra
343 #logic it could easily do short-writes to the remote side - how about taking this entire buffer
344 #and having the run loop send it to the file handle so this doesn't block while the sending
348 local($SIG{PIPE}) = 'IGNORE';
349 die "filehandle is not open" unless openhandle($fh);
350 log_trace { "file handle has passed openhandle() test; printing to it" };
351 $ret = print $fh $serialized;
352 die "print was not successful: $!" unless defined $ret
356 Dlog_debug { "exception encountered when trying to write to file handle $_: $@" } $fh;
357 my $error = $@; chomp($error);
358 $self->on_close->done("could not write to file handle: $error") unless $self->on_close->is_ready;
366 my ($self, $data) = @_;
367 local our @New_Ids = (-1);
369 my $flat = $self->_encode($self->_deobjectify($data));
370 warn "$$ >>> ${flat}\n" if $DEBUG;
373 my $err = $@; # won't get here if the eval doesn't die
374 # don't keep refs to new things
375 delete @{$self->local_objects_by_id}{@New_Ids};
376 die "Error serializing: $err";
380 sub _local_object_to_id {
381 my ($self, $object) = @_;
382 my $id = refaddr($object);
383 $self->local_objects_by_id->{$id} ||= do {
384 push our(@New_Ids), $id if @New_Ids;
391 my ($self, $data) = @_;
392 if (blessed($data)) {
393 return +{ __remote_object__ => $self->_local_object_to_id($data) };
394 } elsif (my $ref = ref($data)) {
395 if ($ref eq 'HASH') {
396 my $tied_to = tied(%$data);
397 if(defined($tied_to)) {
398 return +{__remote_tied_hash__ => $self->_local_object_to_id($tied_to)};
400 return +{ map +($_ => $self->_deobjectify($data->{$_})), keys %$data };
402 } elsif ($ref eq 'ARRAY') {
403 my $tied_to = tied(@$data);
404 if (defined($tied_to)) {
405 return +{__remote_tied_array__ => $self->_local_object_to_id($tied_to)};
407 return [ map $self->_deobjectify($_), @$data ];
409 } elsif ($ref eq 'CODE') {
410 my $id = $self->_local_object_to_id(
411 Object::Remote::CodeContainer->new(code => $data)
413 return +{ __remote_code__ => $id };
414 } elsif ($ref eq 'SCALAR') {
415 return +{ __scalar_ref__ => $$data };
416 } elsif ($ref eq 'GLOB') {
417 return +{ __glob_ref__ => $self->_local_object_to_id(
418 Object::Remote::GlobContainer->new(handle => $data)
421 die "Can't collapse reftype $ref";
424 return $data; # plain scalar
428 my ($self, $flat) = @_;
429 warn "$$ <<< $flat\n" if $DEBUG;
430 Dlog_trace { my $l = length($flat); "Starting to deserialize $l characters of data for connection $_" } $self->_id;
431 my ($type, @rest) = eval { @{$self->_deserialize($flat)} }
432 or do { warn "Deserialize failed for ${flat}: $@"; return };
433 Dlog_trace { "deserialization complete for connection $_" } $self->_id;
434 eval { $self->${\"receive_${type}"}(@rest); 1 }
435 or do { warn "Receive failed for ${flat}: $@"; return };
440 my ($self, $id) = @_;
441 Dlog_trace { "got a receive_free for object '$id' for connection $_" } $self->_id;
442 delete $self->local_objects_by_id->{$id}
443 or warn "Free: no such object $id";
448 my ($self, $future_id, $id, @rest) = @_;
449 Dlog_trace { "got a receive_call for object '$id' for connection $_" } $self->_id;
450 my $future = $self->_id_to_remote_object($future_id);
451 $future->{method} = 'call_discard_free';
452 my $local = $self->local_objects_by_id->{$id}
453 or do { $future->fail("No such object $id"); return };
454 $self->_invoke($future, $local, @rest);
457 sub receive_call_free {
458 my ($self, $future, $id, @rest) = @_;
459 Dlog_trace { "got a receive_call_free for object '$id' for connection $_" } $self->_id;
460 $self->receive_call($future, $id, undef, @rest);
461 $self->receive_free($id);
465 my ($self, $future, $local, $ctx, $method, @args) = @_;
466 Dlog_trace { "got _invoke for a method named '$method' for connection $_" } $self->_id;
467 if ($method =~ /^start::/) {
468 my $f = $local->$method(@args);
469 $f->on_done(sub { undef($f); $future->done(@_) });
471 $f->on_fail(sub { undef($f); $future->fail(@_) });
474 my $do = sub { $local->$method(@args) };
478 ? ($ctx ? $do->() : scalar($do->()))
482 } or do { $future->fail($@); return; };
490 Object::Remote::Connection - An underlying connection for L<Object::Remote>
494 Shipping prioritised over writing this part up. Blame mst.