package Object::Remote::Connection;
+use Object::Remote::Logging qw (:log :dlog router);
use Object::Remote::Future;
use Object::Remote::Null;
use Object::Remote::Handle;
use Object::Remote::CodeContainer;
use Object::Remote::GlobProxy;
use Object::Remote::GlobContainer;
-use Object::Remote::Logging qw (:log :dlog);
use Object::Remote::Tied;
use Object::Remote;
use Symbol;
use IO::Handle;
+use POSIX ":sys_wait_h";
use Module::Runtime qw(use_module);
-use Scalar::Util qw(weaken blessed refaddr);
+use Scalar::Util qw(weaken blessed refaddr openhandle);
use JSON::PP qw(encode_json);
use Moo;
+use Carp qw(croak);
+
+BEGIN { router()->exclude_forwarding }
+
+END {
+ our %child_pids;
+
+ log_trace { "END handler is being invoked in " . __PACKAGE__ };
+
+ foreach(keys(%child_pids)) {
+ log_debug { "Killing child process '$_'" };
+ kill('TERM', $_);
+ }
+}
-our $DEBUG = !!$ENV{OBJECT_REMOTE_DEBUG};
-#numbering each connection allows it to be
-#tracked along with file handles in
-#the logs
-BEGIN { our $NEXT_CONNECTION_ID = 0 }
has _id => ( is => 'ro', required => 1, default => sub { our $NEXT_CONNECTION_ID++ } );
has send_to_fh => (
is => 'ro', required => 1,
trigger => sub {
- my $self = $_[0];
- $_[1]->autoflush(1);
- Dlog_trace { my $id = $self->_id; "connection had send_to_fh set to $_" } $_[1];
+ my $self = $_[0];
+ $_[1]->autoflush(1);
+ Dlog_trace { my $id = $self->_id; "connection had send_to_fh set to $_" } $_[1];
},
);
is => 'ro', required => 1,
trigger => sub {
my ($self, $ch) = @_;
- Dlog_trace { my $id = $self->_id; "trigger for read_channel has been invoked for connection $id; file handle is " } $ch->fh;
+ my $id = $self->_id;
+ Dlog_trace { "trigger for read_channel has been invoked for connection $id; file handle is $_" } $ch->fh;
weaken($self);
$ch->on_line_call(sub { $self->_receive(@_) });
- $ch->on_close_call(sub { $self->on_close->done(@_) });
+ $ch->on_close_call(sub {
+ log_trace { "invoking 'done' on on_close handler for connection id '$id'" };
+ $self->on_close->done(@_);
+ });
},
);
has on_close => (
- is => 'ro', default => sub { CPS::Future->new },
+ is => 'rw', default => sub { $_[0]->_install_future_handlers(CPS::Future->new) },
trigger => sub {
- my ($self, $f) = @_;
- Dlog_trace { "trigger for on_close has been invoked for connection $_" } $self->_id;
- weaken($self);
- $f->on_done(sub {
- $self->_fail_outstanding("Connection lost: ".($f->get)[0]);
- });
- }
+ log_trace { "Installing handlers into future via trigger" };
+ $_[0]->_install_future_handlers($_[1])
+ },
);
has child_pid => (is => 'ro');
has outstanding_futures => (is => 'ro', default => sub { {} });
-sub _fail_outstanding {
- my ($self, $error) = @_;
- Dlog_debug { "Failing outstanding futures with '$error' for connection $_" } $self->_id;
- my $outstanding = $self->outstanding_futures;
- $_->fail($error) for values %$outstanding;
- %$outstanding = ();
- return;
-}
-
has _json => (
is => 'lazy',
handles => {
},
);
+after BUILD => sub {
+ my ($self) = @_;
+ my $pid = $self->child_pid;
+ our %child_pids;
+ return unless defined $pid;
+ $child_pids{$pid} = 1;
+ return;
+};
+
+sub BUILD { }
+
+sub is_valid {
+ my ($self) = @_;
+ my $valid = ! $self->on_close->is_ready;
+
+ log_trace {
+ my $id = $self->_id;
+ my $text;
+ if ($valid) {
+ $text = 'yes';
+ } else {
+ $text = 'no';
+ }
+ "Connection '$id' is valid: '$text'"
+ };
+
+ return $valid;
+}
+
+sub _fail_outstanding {
+ my ($self, $error) = @_;
+ my $outstanding = $self->outstanding_futures;
+
+ Dlog_debug {
+ sprintf "Failing %i outstanding futures with '$error'", scalar(keys(%$outstanding))
+ };
+
+ foreach(keys(%$outstanding)) {
+ log_trace { "Failing future for $_" };
+ my $future = $outstanding->{$_};
+ $future->fail("$error\n");
+ }
+
+ %$outstanding = ();
+ return;
+}
+
+sub _install_future_handlers {
+ my ($self, $f) = @_;
+ our %child_pids;
+ Dlog_trace { "Installing handlers into future for connection $_" } $self->_id;
+ weaken($self);
+ $f->on_done(sub {
+ my $pid = $self->child_pid;
+ Dlog_trace { "Executing on_done handler in future for connection $_" } $self->_id;
+ $self->_fail_outstanding("Object::Remote connection lost: " . ($f->get)[0]);
+ return unless defined $pid;
+ log_debug { "Waiting for child '$pid' to exit" };
+ my $ret = waitpid($pid, 0);
+ if ($ret != $pid) {
+ log_debug { "Waited for pid $pid but waitpid() returned $ret" };
+ return;
+ } elsif ($? & 127) {
+ log_warn { "Remote interpreter did not exit cleanly" };
+ } else {
+ log_verbose {
+ my $exit_value = $? >> 8;
+ "Remote Perl interpreter exited with value '$exit_value'"
+ };
+ }
+
+ delete $child_pids{$pid};
+ });
+ return $f;
+};
+
sub _id_to_remote_object {
my ($self, $id) = @_;
Dlog_trace { "fetching proxy for remote object with id '$id' for connection $_" } $self->_id;
}
)->filter_json_single_key_object(
__remote_tied_hash__ => sub {
- my %tied_hash;
- tie %tied_hash, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
- return \%tied_hash;
+ my %tied_hash;
+ tie %tied_hash, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
+ return \%tied_hash;
}
)->filter_json_single_key_object(
__remote_tied_array__ => sub {
- my @tied_array;
- tie @tied_array, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
- return \@tied_array;
+ my @tied_array;
+ tie @tied_array, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
+ return \@tied_array;
}
);
}
+sub _load_if_possible {
+ my ($class) = @_;
+
+ use_module($class);
+
+ if ($@) {
+ log_debug { "Attempt at loading '$class' failed with '$@'" };
+ }
+
+}
+
BEGIN {
unshift our @Guess, sub { blessed($_[0]) ? $_[0] : undef };
- eval { require Object::Remote::Connector::Local };
- eval { require Object::Remote::Connector::LocalSudo };
- eval { require Object::Remote::Connector::SSH };
- eval { require Object::Remote::Connector::UNIX };
+ map _load_if_possible($_), qw(
+ Object::Remote::Connector::Local
+ Object::Remote::Connector::LocalSudo
+ Object::Remote::Connector::SSH
+ Object::Remote::Connector::UNIX
+ );
}
-sub new_from_spec {
- my ($class, $spec) = @_;
- return $spec if blessed $spec;
- Dlog_debug { "creating a new connection from spec" };
+sub conn_from_spec {
+ my ($class, $spec, @args) = @_;
foreach my $poss (do { our @Guess }) {
- if (my $conn = $poss->($spec)) {
- return $conn->maybe::start::connect;
+ if (my $conn = $poss->($spec, @args)) {
+ return $conn;
}
}
- die "Couldn't figure out what to do with ${spec}";
+
+ return undef;
+}
+
+sub new_from_spec {
+ my ($class, $spec, @args) = @_;
+ return $spec if blessed $spec;
+ my $conn = $class->conn_from_spec($spec, @args);
+
+ die "Couldn't figure out what to do with ${spec}"
+ unless defined $conn;
+
+ return $conn->maybe::start::connect;
}
sub remote_object {
sub remote_sub {
my ($self, $sub) = @_;
my ($pkg, $name) = $sub =~ m/^(.*)::([^:]+)$/;
- Dlog_debug { "Invoking remote sub '$sub' for connection $_" } $self->_id;
+ Dlog_debug { "Invoking remote sub '$sub' for connection '$_'" } $self->_id;
return await_future($self->send_class_call(0, $pkg, can => $name));
}
sub send_free {
my ($self, $id) = @_;
Dlog_trace { "sending request to free object '$id' for connection $_" } $self->_id;
+ #TODO this shows up some times when a remote side dies in the middle of a remote
+ #method invocation - possibly only when the object is being constructed?
+ #(in cleanup) Use of uninitialized value $id in delete at ../Object-Remote/lib/Object/Remote/Connection.
delete $self->remote_objects_by_id->{$id};
$self->_send([ free => $id ]);
}
sub _send {
my ($self, $to_send) = @_;
my $fh = $self->send_to_fh;
+
+ unless ($self->is_valid) {
+ croak "Attempt to invoke _send on a connection that is not valid";
+ }
+
Dlog_trace { "Starting to serialize data in argument to _send for connection $_" } $self->_id;
my $serialized = $self->_serialize($to_send)."\n";
Dlog_trace { my $l = length($serialized); "serialization is completed; sending '$l' characters of serialized data to $_" } $fh;
- #TODO this is very risky for deadlocks unless it's set to non-blocking and then with out extra
- #logic it could easily do short-writes to the remote side - how about taking this entire buffer
- #and having the run loop send it to the file handle so this doesn't block while the sending
- #is happening?
- my $ret = print $fh $serialized;
- Dlog_trace { my $r = defined $ret ? $ret : 'undef'; "print() returned $r with $_" } $fh;
- #TODO hrm reason print's return value was ignored?
- die "could not write to filehandle: $!" unless $ret;
- return $ret;
+ my $ret;
+ eval {
+ #TODO this should be converted over to a non-blocking ::WriteChannel class
+ die "filehandle is not open" unless openhandle($fh);
+ log_trace { "file handle has passed openhandle() test; printing to it" };
+ $ret = print $fh $serialized;
+ die "print was not successful: $!" unless defined $ret
+ };
+
+ if ($@) {
+ Dlog_debug { "exception encountered when trying to write to file handle $_: $@" } $fh;
+ my $error = $@;
+ chomp($error);
+ $self->on_close->done("could not write to file handle: $error") unless $self->on_close->is_ready;
+ return;
+ }
+
+ return $ret;
}
sub _serialize {
local our @New_Ids = (-1);
return eval {
my $flat = $self->_encode($self->_deobjectify($data));
- warn "$$ >>> ${flat}\n" if $DEBUG;
$flat;
} || do {
my $err = $@; # won't get here if the eval doesn't die
if ($ref eq 'HASH') {
my $tied_to = tied(%$data);
if(defined($tied_to)) {
- return +{__remote_tied_hash__ => $self->_local_object_to_id($tied_to)};
+ return +{__remote_tied_hash__ => $self->_local_object_to_id($tied_to)};
} else {
return +{ map +($_ => $self->_deobjectify($data->{$_})), keys %$data };
}
} elsif ($ref eq 'ARRAY') {
my $tied_to = tied(@$data);
if (defined($tied_to)) {
- return +{__remote_tied_array__ => $self->_local_object_to_id($tied_to)};
+ return +{__remote_tied_array__ => $self->_local_object_to_id($tied_to)};
} else {
return [ map $self->_deobjectify($_), @$data ];
}
sub _receive {
my ($self, $flat) = @_;
- warn "$$ <<< $flat\n" if $DEBUG;
Dlog_trace { my $l = length($flat); "Starting to deserialize $l characters of data for connection $_" } $self->_id;
my ($type, @rest) = eval { @{$self->_deserialize($flat)} }
or do { warn "Deserialize failed for ${flat}: $@"; return };
Object::Remote::Connection - An underlying connection for L<Object::Remote>
-=head1 LAME
+ use Object::Remote;
+
+ my %opts = (
+ nice => '10', ulimit => '-v 400000',
+ watchdog_timeout => 120, stderr => \*STDERR,
+ );
+
+ my $local = Object::Remote->connect('-');
+ my $remote = Object::Remote->connect('myserver', nice => 5);
+ my $remote_user = Object::Remote->connect('user@myserver', %opts);
+ my $local_sudo = Object::Remote->connect('user@');
+
+ #$remote can be any other connection object
+ my $hostname = Sys::Hostname->can::on($remote, 'hostname');
+
+=head1 DESCRIPTION
+
+This is the class that supports connections to a Perl interpreter that is executed in a
+different process. The new Perl interpreter can be either on the local or a remote machine
+and is configurable via arguments passed to the constructor.
+
+=head1 ARGUMENTS
+
+=over 4
+
+=item nice
+
+If this value is defined then it will be used as the nice value of the Perl process when it
+is started. The default is the undefined value and will not nice the process.
+
+=item stderr
+
+If this value is defined then it will be used as the file handle that receives the output
+of STDERR from the Perl interpreter process and I/O will be performed by the run loop in a
+non-blocking way. If the value is undefined then STDERR of the remote process will be connected
+directly to STDERR of the local process with out the run loop managing I/O. The default value
+is undefined.
+
+There are a few ways to use this feature. By default the behavior is to form one unified STDERR
+across all of the Perl interpreters including the local one. For small scale and quick operation
+this offers a predictable and easy to use way to get at error messages generated anywhere. If
+the local Perl interpreter crashes then the remote Perl interpreters still have an active STDERR
+and it is possible to still receive output from them. This is generally a good thing but can
+cause issues.
+
+When using a file handle as the output for STDERR once the local Perl interpreter is no longer
+running there is no longer a valid STDERR for the remote interpreters to send data to. This means
+that it is no longer possible to receive error output from the remote interpreters and that the
+shell will start to kill off the child processes. Passing a reference to STDERR for the local
+interpreter (as the SYNOPSIS shows) causes the run loop to manage I/O, one unified STDERR for
+all Perl interpreters that ends as soon as the local interpreter process does, and the shell will
+start killing children when the local interpreter exits.
+
+It is also possible to pass in a file handle that has been opened for writing. This would be
+useful for logging the output of the remote interpreter directly into a dedicated file.
+
+=item ulimit
+
+If this string is defined then it will be passed unmodified as the arguments to ulimit when
+the Perl process is started. The default value is the undefined value and will not limit the
+process in any way.
+
+=item watchdog_timeout
+
+If this value is defined then it will be used as the number of seconds the watchdog will wait
+for an update before it terminates the Perl interpreter process. The default value is undefined
+and will not use the watchdog. See C<Object::Remote::Watchdog> for more information.
+
+=back
+
+=head1 SEE ALSO
+
+=over 4
+
+=item C<Object::Remote>
-Shipping prioritised over writing this part up. Blame mst.
+=back
=cut
projects / scpubgit/Object-Remote.git / blobdiff