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
59 our $DEBUG = !!$ENV{OBJECT_REMOTE_DEBUG};
60 #numbering each connection allows it to be
61 #tracked along with file handles in
64 has _id => ( is => 'ro', required => 1, default => sub { our $NEXT_CONNECTION_ID++ } );
67 is => 'ro', required => 1,
71 Dlog_trace { my $id = $self->_id; "connection had send_to_fh set to $_" } $_[1];
75 #TODO see if this is another case of the same bug below
76 #where trigger never fires because the attribute isn't
77 #actually set at any time
79 is => 'ro', required => 1,
83 Dlog_trace { "trigger for read_channel has been invoked for connection $id; file handle is $_" } $ch->fh;
85 $ch->on_line_call(sub { $self->_receive(@_) });
86 $ch->on_close_call(sub {
87 log_trace { "invoking 'done' on on_close handler for connection id '$id'" };
88 $self->on_close->done(@_);
93 #TODO properly fix this bug -
94 #trigger can't ever be invoked with a default
95 #value and the on_close attribute is read only....
96 #the future never gets the on_done handler
100 $self->on_close(CPS::Future->new);
106 return unless defined $self->child_pid;
108 log_debug { "Setting process group of child process" };
110 setpgrp($self->child_pid, 1);
115 is => 'rw', default => sub { CPS::Future->new },
118 Dlog_trace { "trigger for on_close has been invoked for connection $_" } $self->_id;
121 Dlog_trace { "failing all of the outstanding futures for connection $_" } $self->_id;
122 $self->_fail_outstanding("Object::Remote connection lost: " . ($f->get)[0]);
127 has child_pid => (is => 'ro');
129 has local_objects_by_id => (
130 is => 'ro', default => sub { {} },
131 coerce => sub { +{ %{$_[0]} } }, # shallow clone on the way in
134 has remote_objects_by_id => (
135 is => 'ro', default => sub { {} },
136 coerce => sub { +{ %{$_[0]} } }, # shallow clone on the way in
139 has outstanding_futures => (is => 'ro', default => sub { {} });
141 sub _fail_outstanding {
142 my ($self, $error) = @_;
143 Dlog_debug { "Failing outstanding futures with '$error' for connection $_" } $self->_id;
144 my $outstanding = $self->outstanding_futures;
145 $_->fail("$error\n") for values %$outstanding;
153 _deserialize => 'decode',
158 sub _id_to_remote_object {
159 my ($self, $id) = @_;
160 Dlog_trace { "fetching proxy for remote object with id '$id' for connection $_" } $self->_id;
161 return bless({}, 'Object::Remote::Null') if $id eq 'NULL';
163 $self->remote_objects_by_id->{$id}
164 or Object::Remote::Handle->new(connection => $self, id => $id)
169 weaken(my $self = shift);
170 JSON::PP->new->filter_json_single_key_object(
171 __remote_object__ => sub {
172 $self->_id_to_remote_object(@_);
174 )->filter_json_single_key_object(
175 __remote_code__ => sub {
176 my $code_container = $self->_id_to_remote_object(@_);
177 sub { $code_container->call(@_) };
179 )->filter_json_single_key_object(
180 __scalar_ref__ => sub {
184 )->filter_json_single_key_object(
185 __glob_ref__ => sub {
186 my $glob_container = $self->_id_to_remote_object(@_);
187 my $handle = Symbol::gensym;
188 tie *$handle, 'Object::Remote::GlobProxy', $glob_container;
191 )->filter_json_single_key_object(
192 __remote_tied_hash__ => sub {
194 tie %tied_hash, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
197 )->filter_json_single_key_object(
198 __remote_tied_array__ => sub {
200 tie @tied_array, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
206 sub _load_if_possible {
209 eval "require $class";
212 log_debug { "Attempt at loading '$class' failed with '$@'" };
218 unshift our @Guess, sub { blessed($_[0]) ? $_[0] : undef };
219 map _load_if_possible($_), qw(
220 Object::Remote::Connector::Local
221 Object::Remote::Connector::LocalSudo
222 Object::Remote::Connector::SSH
223 Object::Remote::Connector::UNIX
228 my ($class, $spec, @args) = @_;
229 foreach my $poss (do { our @Guess }) {
230 if (my $conn = $poss->($spec, @args)) {
239 my ($class, $spec) = @_;
240 return $spec if blessed $spec;
241 my $conn = $class->conn_from_spec($spec);
243 die "Couldn't figure out what to do with ${spec}"
244 unless defined $conn;
246 return $conn->maybe::start::connect;
250 my ($self, @args) = @_;
251 Object::Remote::Handle->new(
252 connection => $self, @args
257 my ($self, $to) = @_;
258 Dlog_debug { "Creating connection to remote node '$to' for connection $_" } $self->_id;
260 $self->send_class_call(0, 'Object::Remote', connect => $to)
265 my ($self, $sub) = @_;
266 my ($pkg, $name) = $sub =~ m/^(.*)::([^:]+)$/;
267 Dlog_debug { "Invoking remote sub '$sub' for connection $_" } $self->_id;
268 return await_future($self->send_class_call(0, $pkg, can => $name));
271 sub send_class_call {
272 my ($self, $ctx, @call) = @_;
273 Dlog_trace { "Sending a class call for connection $_" } $self->_id;
274 $self->send(call => class_call_handler => $ctx => call => @call);
277 sub register_class_call_handler {
279 $self->local_objects_by_id->{'class_call_handler'} ||= do {
280 my $o = $self->new_class_call_handler;
281 $self->_local_object_to_id($o);
286 sub new_class_call_handler {
287 Object::Remote::CodeContainer->new(
289 my ($class, $method) = (shift, shift);
290 use_module($class)->$method(@_);
295 sub register_remote {
296 my ($self, $remote) = @_;
297 Dlog_trace { my $i = $remote->id; "Registered a remote object with id of '$i' for connection $_" } $self->_id;
298 weaken($self->remote_objects_by_id->{$remote->id} = $remote);
303 my ($self, $id) = @_;
304 Dlog_trace { "sending request to free object '$id' for connection $_" } $self->_id;
305 delete $self->remote_objects_by_id->{$id};
306 $self->_send([ free => $id ]);
310 my ($self, $type, @call) = @_;
312 my $future = CPS::Future->new;
313 my $remote = $self->remote_objects_by_id->{$call[0]};
315 unshift @call, $type => $self->_local_object_to_id($future);
317 my $outstanding = $self->outstanding_futures;
318 $outstanding->{$future} = $future;
319 $future->on_ready(sub {
321 delete $outstanding->{$future}
324 $self->_send(\@call);
330 my ($self, $type, @call) = @_;
332 unshift @call, $type => 'NULL';
334 $self->_send(\@call);
338 my ($self, $to_send) = @_;
339 my $fh = $self->send_to_fh;
340 Dlog_trace { "Starting to serialize data in argument to _send for connection $_" } $self->_id;
341 my $serialized = $self->_serialize($to_send)."\n";
342 Dlog_trace { my $l = length($serialized); "serialization is completed; sending '$l' characters of serialized data to $_" } $fh;
343 #TODO this is very risky for deadlocks unless it's set to non-blocking and then with out extra
344 #logic it could easily do short-writes to the remote side - how about taking this entire buffer
345 #and having the run loop send it to the file handle so this doesn't block while the sending
349 local($SIG{PIPE}) = 'IGNORE';
350 die "filehandle is not open" unless openhandle($fh);
351 log_trace { "file handle has passed openhandle() test; printing to it" };
352 $ret = print $fh $serialized;
353 die "print was not successful: $!" unless defined $ret
357 Dlog_debug { "exception encountered when trying to write to file handle $_: $@" } $fh;
358 my $error = $@; chomp($error);
359 $self->on_close->done("could not write to file handle: $error") unless $self->on_close->is_ready;
367 my ($self, $data) = @_;
368 local our @New_Ids = (-1);
370 my $flat = $self->_encode($self->_deobjectify($data));
371 warn "$$ >>> ${flat}\n" if $DEBUG;
374 my $err = $@; # won't get here if the eval doesn't die
375 # don't keep refs to new things
376 delete @{$self->local_objects_by_id}{@New_Ids};
377 die "Error serializing: $err";
381 sub _local_object_to_id {
382 my ($self, $object) = @_;
383 my $id = refaddr($object);
384 $self->local_objects_by_id->{$id} ||= do {
385 push our(@New_Ids), $id if @New_Ids;
392 my ($self, $data) = @_;
393 if (blessed($data)) {
394 return +{ __remote_object__ => $self->_local_object_to_id($data) };
395 } elsif (my $ref = ref($data)) {
396 if ($ref eq 'HASH') {
397 my $tied_to = tied(%$data);
398 if(defined($tied_to)) {
399 return +{__remote_tied_hash__ => $self->_local_object_to_id($tied_to)};
401 return +{ map +($_ => $self->_deobjectify($data->{$_})), keys %$data };
403 } elsif ($ref eq 'ARRAY') {
404 my $tied_to = tied(@$data);
405 if (defined($tied_to)) {
406 return +{__remote_tied_array__ => $self->_local_object_to_id($tied_to)};
408 return [ map $self->_deobjectify($_), @$data ];
410 } elsif ($ref eq 'CODE') {
411 my $id = $self->_local_object_to_id(
412 Object::Remote::CodeContainer->new(code => $data)
414 return +{ __remote_code__ => $id };
415 } elsif ($ref eq 'SCALAR') {
416 return +{ __scalar_ref__ => $$data };
417 } elsif ($ref eq 'GLOB') {
418 return +{ __glob_ref__ => $self->_local_object_to_id(
419 Object::Remote::GlobContainer->new(handle => $data)
422 die "Can't collapse reftype $ref";
425 return $data; # plain scalar
429 my ($self, $flat) = @_;
430 warn "$$ <<< $flat\n" if $DEBUG;
431 Dlog_trace { my $l = length($flat); "Starting to deserialize $l characters of data for connection $_" } $self->_id;
432 my ($type, @rest) = eval { @{$self->_deserialize($flat)} }
433 or do { warn "Deserialize failed for ${flat}: $@"; return };
434 Dlog_trace { "deserialization complete for connection $_" } $self->_id;
435 eval { $self->${\"receive_${type}"}(@rest); 1 }
436 or do { warn "Receive failed for ${flat}: $@"; return };
441 my ($self, $id) = @_;
442 Dlog_trace { "got a receive_free for object '$id' for connection $_" } $self->_id;
443 delete $self->local_objects_by_id->{$id}
444 or warn "Free: no such object $id";
449 my ($self, $future_id, $id, @rest) = @_;
450 Dlog_trace { "got a receive_call for object '$id' for connection $_" } $self->_id;
451 my $future = $self->_id_to_remote_object($future_id);
452 $future->{method} = 'call_discard_free';
453 my $local = $self->local_objects_by_id->{$id}
454 or do { $future->fail("No such object $id"); return };
455 $self->_invoke($future, $local, @rest);
458 sub receive_call_free {
459 my ($self, $future, $id, @rest) = @_;
460 Dlog_trace { "got a receive_call_free for object '$id' for connection $_" } $self->_id;
461 $self->receive_call($future, $id, undef, @rest);
462 $self->receive_free($id);
466 my ($self, $future, $local, $ctx, $method, @args) = @_;
467 Dlog_trace { "got _invoke for a method named '$method' for connection $_" } $self->_id;
468 if ($method =~ /^start::/) {
469 my $f = $local->$method(@args);
470 $f->on_done(sub { undef($f); $future->done(@_) });
472 $f->on_fail(sub { undef($f); $future->fail(@_) });
475 my $do = sub { $local->$method(@args) };
479 ? ($ctx ? $do->() : scalar($do->()))
483 } or do { $future->fail($@); return; };
491 Object::Remote::Connection - An underlying connection for L<Object::Remote>
495 Shipping prioritised over writing this part up. Blame mst.