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 __local_object__ => sub {
192 $self->local_objects_by_id->{$_[0]}
194 )->filter_json_single_key_object(
195 __remote_tied_hash__ => sub {
197 tie %tied_hash, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
200 )->filter_json_single_key_object(
201 __remote_tied_array__ => sub {
203 tie @tied_array, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
209 sub _load_if_possible {
212 eval "require $class";
215 log_debug { "Attempt at loading '$class' failed with '$@'" };
221 unshift our @Guess, sub { blessed($_[0]) ? $_[0] : undef };
222 map _load_if_possible($_), qw(
223 Object::Remote::Connector::Local
224 Object::Remote::Connector::LocalSudo
225 Object::Remote::Connector::SSH
226 Object::Remote::Connector::UNIX
231 my ($class, $spec, @args) = @_;
232 foreach my $poss (do { our @Guess }) {
233 if (my $conn = $poss->($spec, @args)) {
242 my ($class, $spec) = @_;
243 return $spec if blessed $spec;
244 my $conn = $class->conn_from_spec($spec);
246 die "Couldn't figure out what to do with ${spec}"
247 unless defined $conn;
249 return $conn->maybe::start::connect;
253 my ($self, @args) = @_;
254 Object::Remote::Handle->new(
255 connection => $self, @args
260 my ($self, $to) = @_;
261 Dlog_debug { "Creating connection to remote node '$to' for connection $_" } $self->_id;
263 $self->send_class_call(0, 'Object::Remote', connect => $to)
268 my ($self, $sub) = @_;
269 my ($pkg, $name) = $sub =~ m/^(.*)::([^:]+)$/;
270 Dlog_debug { "Invoking remote sub '$sub' for connection $_" } $self->_id;
271 return await_future($self->send_class_call(0, $pkg, can => $name));
274 sub send_class_call {
275 my ($self, $ctx, @call) = @_;
276 Dlog_trace { "Sending a class call for connection $_" } $self->_id;
277 $self->send(call => class_call_handler => $ctx => call => @call);
280 sub register_class_call_handler {
282 $self->local_objects_by_id->{'class_call_handler'} ||= do {
283 my $o = $self->new_class_call_handler;
284 $self->_local_object_to_id($o);
289 sub new_class_call_handler {
290 Object::Remote::CodeContainer->new(
292 my ($class, $method) = (shift, shift);
293 use_module($class)->$method(@_);
298 sub register_remote {
299 my ($self, $remote) = @_;
300 Dlog_trace { my $i = $remote->id; "Registered a remote object with id of '$i' for connection $_" } $self->_id;
301 weaken($self->remote_objects_by_id->{$remote->id} = $remote);
306 my ($self, $id) = @_;
307 Dlog_trace { "sending request to free object '$id' for connection $_" } $self->_id;
308 delete $self->remote_objects_by_id->{$id};
309 $self->_send([ free => $id ]);
313 my ($self, $type, @call) = @_;
315 my $future = CPS::Future->new;
316 my $remote = $self->remote_objects_by_id->{$call[0]};
318 unshift @call, $type => $self->_local_object_to_id($future);
320 my $outstanding = $self->outstanding_futures;
321 $outstanding->{$future} = $future;
322 $future->on_ready(sub {
324 delete $outstanding->{$future}
327 $self->_send(\@call);
333 my ($self, $type, @call) = @_;
335 unshift @call, $type => 'NULL';
337 $self->_send(\@call);
341 my ($self, $to_send) = @_;
342 my $fh = $self->send_to_fh;
343 Dlog_trace { "Starting to serialize data in argument to _send for connection $_" } $self->_id;
344 my $serialized = $self->_serialize($to_send)."\n";
345 Dlog_trace { my $l = length($serialized); "serialization is completed; sending '$l' characters of serialized data to $_" } $fh;
346 #TODO this is very risky for deadlocks unless it's set to non-blocking and then with out extra
347 #logic it could easily do short-writes to the remote side - how about taking this entire buffer
348 #and having the run loop send it to the file handle so this doesn't block while the sending
352 local($SIG{PIPE}) = 'IGNORE';
353 die "filehandle is not open" unless openhandle($fh);
354 log_trace { "file handle has passed openhandle() test; printing to it" };
355 $ret = print $fh $serialized;
356 die "print was not successful: $!" unless defined $ret
360 Dlog_debug { "exception encountered when trying to write to file handle $_: $@" } $fh;
361 my $error = $@; chomp($error);
362 $self->on_close->done("could not write to file handle: $error") unless $self->on_close->is_ready;
370 my ($self, $data) = @_;
371 local our @New_Ids = (-1);
373 my $flat = $self->_encode($self->_deobjectify($data));
374 warn "$$ >>> ${flat}\n" if $DEBUG;
377 my $err = $@; # won't get here if the eval doesn't die
378 # don't keep refs to new things
379 delete @{$self->local_objects_by_id}{@New_Ids};
380 die "Error serializing: $err";
384 sub _local_object_to_id {
385 my ($self, $object) = @_;
386 my $id = refaddr($object);
387 $self->local_objects_by_id->{$id} ||= do {
388 push our(@New_Ids), $id if @New_Ids;
395 my ($self, $data) = @_;
396 if (blessed($data)) {
398 $data->isa('Object::Remote::Proxy')
399 and $data->{remote}->connection == $self
401 return +{ __local_object__ => $data->{remote}->id };
403 return +{ __remote_object__ => $self->_local_object_to_id($data) };
405 } elsif (my $ref = ref($data)) {
406 if ($ref eq 'HASH') {
407 my $tied_to = tied(%$data);
408 if(defined($tied_to)) {
409 return +{__remote_tied_hash__ => $self->_local_object_to_id($tied_to)};
411 return +{ map +($_ => $self->_deobjectify($data->{$_})), keys %$data };
413 } elsif ($ref eq 'ARRAY') {
414 my $tied_to = tied(@$data);
415 if (defined($tied_to)) {
416 return +{__remote_tied_array__ => $self->_local_object_to_id($tied_to)};
418 return [ map $self->_deobjectify($_), @$data ];
420 } elsif ($ref eq 'CODE') {
421 my $id = $self->_local_object_to_id(
422 Object::Remote::CodeContainer->new(code => $data)
424 return +{ __remote_code__ => $id };
425 } elsif ($ref eq 'SCALAR') {
426 return +{ __scalar_ref__ => $$data };
427 } elsif ($ref eq 'GLOB') {
428 return +{ __glob_ref__ => $self->_local_object_to_id(
429 Object::Remote::GlobContainer->new(handle => $data)
432 die "Can't collapse reftype $ref";
435 return $data; # plain scalar
439 my ($self, $flat) = @_;
440 warn "$$ <<< $flat\n" if $DEBUG;
441 Dlog_trace { my $l = length($flat); "Starting to deserialize $l characters of data for connection $_" } $self->_id;
442 my ($type, @rest) = eval { @{$self->_deserialize($flat)} }
443 or do { warn "Deserialize failed for ${flat}: $@"; return };
444 Dlog_trace { "deserialization complete for connection $_" } $self->_id;
445 eval { $self->${\"receive_${type}"}(@rest); 1 }
446 or do { warn "Receive failed for ${flat}: $@"; return };
451 my ($self, $id) = @_;
452 Dlog_trace { "got a receive_free for object '$id' for connection $_" } $self->_id;
453 delete $self->local_objects_by_id->{$id}
454 or warn "Free: no such object $id";
459 my ($self, $future_id, $id, @rest) = @_;
460 Dlog_trace { "got a receive_call for object '$id' for connection $_" } $self->_id;
461 my $future = $self->_id_to_remote_object($future_id);
462 $future->{method} = 'call_discard_free';
463 my $local = $self->local_objects_by_id->{$id}
464 or do { $future->fail("No such object $id"); return };
465 $self->_invoke($future, $local, @rest);
468 sub receive_call_free {
469 my ($self, $future, $id, @rest) = @_;
470 Dlog_trace { "got a receive_call_free for object '$id' for connection $_" } $self->_id;
471 $self->receive_call($future, $id, undef, @rest);
472 $self->receive_free($id);
476 my ($self, $future, $local, $ctx, $method, @args) = @_;
477 Dlog_trace { "got _invoke for a method named '$method' for connection $_" } $self->_id;
478 if ($method =~ /^start::/) {
479 my $f = $local->$method(@args);
480 $f->on_done(sub { undef($f); $future->done(@_) });
482 $f->on_fail(sub { undef($f); $future->fail(@_) });
485 my $do = sub { $local->$method(@args) };
489 ? ($ctx ? $do->() : scalar($do->()))
493 } or do { $future->fail($@); return; };
501 Object::Remote::Connection - An underlying connection for L<Object::Remote>
505 Shipping prioritised over writing this part up. Blame mst.