package Object::Remote::Connection;
-use Object::Remote::Logging qw (:log :dlog);
+use Object::Remote::Logging qw (:log :dlog router);
use Object::Remote::Future;
use Object::Remote::Null;
use Object::Remote::Handle;
use Scalar::Util qw(weaken blessed refaddr openhandle);
use JSON::PP qw(encode_json);
use Moo;
+use Carp qw(croak);
-BEGIN {
- #this will reap child processes as soon
- #as they are done executing so the process
- #table cleans up as fast as possible but
- #anything that needs to call waitpid()
- #in the future to get the exit value of
- #a child will get trash results if
- #the signal handler was running.
- #If creating a child and getting the
- #exit value is required then set
- #a localized version of the signal
- #handler for CHLD to be 'IGNORE'
- #in the smallest block possible
- #and outside the block send
- #the process a CHLD signal
- #to reap anything that may
- #have exited while blocked
- #in waitpid()
- $SIG{CHLD} = sub {
- my $kid;
- log_trace { "CHLD signal handler is executing" };
- do {
- $kid = waitpid(-1, WNOHANG);
- log_debug { "waitpid() returned '$kid'" };
- } while $kid > 0;
- log_trace { "CHLD signal handler is done" };
- };
-
- $SIG{PIPE} = sub { log_debug { "Got a PIPE signal" } };
-}
+BEGIN { router()->exclude_forwarding }
END {
log_debug { "Killing all child processes in the process group" };
kill(1, -2);
}
-our $DEBUG = !!$ENV{OBJECT_REMOTE_DEBUG};
-
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 $_" } $_[1];
},
);
trigger => sub {
my ($self, $ch) = @_;
my $id = $self->_id;
- Dlog_trace { "trigger for read_channel has been invoked for connection $id; file handle is $_" } $ch->fh;
+ 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(@_) });
$ch->on_close_call(sub {
- log_trace { "invoking 'done' on on_close handler for connection id '$id'" };
+ log_trace { "invoking 'done' on on_close handler for connection id '$id'" };
$self->on_close->done(@_);
});
},
has on_close => (
is => 'rw', default => sub { $_[0]->_install_future_handlers(CPS::Future->new) },
- trigger => \&_install_future_handlers,
+ trigger => sub {
+ log_trace { "Installing handlers into future via trigger" };
+ $_[0]->_install_future_handlers($_[1])
+ },
);
has child_pid => (is => 'ro');
);
after BUILD => sub {
- my ($self) = @_;
-
- return unless defined $self->child_pid;
+ my ($self) = @_;
+ my $pid = $self->child_pid;
- log_debug { "Setting process group of child process" };
+ unless (defined $pid) {
+ log_trace { "After BUILD invoked for connection but there was no pid" };
+ return;
+ }
+
+ log_trace { "Setting process group of child process '$pid'" };
setpgrp($self->child_pid, 1);
};
sub BUILD { }
+sub is_valid {
+ my ($self) = @_;
+ my $closed = $self->on_close->is_ready;
+
+ log_trace { "Connection closed: $closed" };
+ return ! $closed;
+}
+
sub _fail_outstanding {
my ($self, $error) = @_;
- Dlog_debug { "Failing outstanding futures with '$error' for connection $_" } $self->_id;
my $outstanding = $self->outstanding_futures;
- $_->fail("$error\n") for values %$outstanding;
+
+ Dlog_debug {
+ sprintf "Failing %i outstanding futures with '$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) = @_;
- Dlog_trace { "trigger for on_close has been invoked for connection $_" } $self->_id;
+ Dlog_trace { "Installing handlers into future for connection $_" } $self->_id;
weaken($self);
$f->on_done(sub {
- Dlog_trace { "failing all of the outstanding futures for connection $_" } $self->_id;
+ 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'"
+ };
+ }
});
return $f;
};
sub _load_if_possible {
my ($class) = @_;
- eval "require $class";
+ use_module($class);
if ($@) {
log_debug { "Attempt at loading '$class' failed with '$@'" };
}
sub new_from_spec {
- my ($class, $spec) = @_;
+ my ($class, $spec, @args) = @_;
return $spec if blessed $spec;
- my $conn = $class->conn_from_spec($spec);
+ my $conn = $class->conn_from_spec($spec, @args);
die "Couldn't figure out what to do with ${spec}"
unless defined $conn;
sub send_free {
my ($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 $_" } $fh;
if ($@) {
Dlog_debug { "exception encountered when trying to write to file handle $_: $@" } $fh;
- my $error = $@; chomp($error);
+ my $error = $@;
+ chomp($error);
$self->on_close->done("could not write to file handle: $error") unless $self->on_close->is_ready;
return;
}
local our @New_Ids = (-1);
return eval {
my $flat = $self->_encode($self->_deobjectify($data));
- warn "$$ >>> ${flat}\n" if $DEBUG;
$flat;
} || do {
my $err = $@; # won't get here if the eval doesn't die
sub _receive {
my ($self, $flat) = @_;
- warn "$$ <<< $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