X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=scpubgit%2FObject-Remote.git;a=blobdiff_plain;f=lib%2FObject%2FRemote%2FConnection.pm;h=136b065aac3284ed345cbe598a5e595b1ac155e2;hp=21bcec455061ad756157128644a3f72fc3b4d36b;hb=b0ec7e3b19d47b9ba5a864f5077d0dc8030834cc;hpb=12fb4a80d68ad14c18a35f60cc6d8a671f728ac9

diff --git a/lib/Object/Remote/Connection.pm b/lib/Object/Remote/Connection.pm
index 21bcec4..136b065 100644
--- a/lib/Object/Remote/Connection.pm
+++ b/lib/Object/Remote/Connection.pm
@@ -1,45 +1,64 @@
 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::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);
 
-our $DEBUG = !!$ENV{OBJECT_REMOTE_DEBUG};
+BEGIN { router()->exclude_forwarding }
+
+END {
+  log_debug { "Killing all child processes in the process group" };
+    
+  #send SIGINT to the process group for our children
+  kill(1, -2);
+}
+
+has _id => ( is => 'ro', required => 1, default => sub { our $NEXT_CONNECTION_ID++ } );
 
 has send_to_fh => (
   is => 'ro', required => 1,
-  trigger => sub { $_[1]->autoflush(1) },
+  trigger => sub {
+    my $self = $_[0];
+    $_[1]->autoflush(1);
+    Dlog_trace { my $id = $self->_id; "connection had send_to_fh set to $_"  } $_[1];
+  },
 );
 
 has read_channel => (
   is => 'ro', required => 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 $_" } $ch->fh;
     weaken($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 },
-  trigger => sub { 
-    my ($self, $f) = @_;
-    weaken($self);
-    $f->on_done(sub {
-      $self->_fail_outstanding("Connection lost: ".($f->get)[0]);
-    });
-  }
+  is => 'rw', default => sub { $_[0]->_install_future_handlers(CPS::Future->new) },
+  trigger => sub {
+    log_trace { "Installing handlers into future via trigger" };
+    $_[0]->_install_future_handlers($_[1])
+  },
 );
 
 has child_pid => (is => 'ro');
@@ -56,14 +75,6 @@ has remote_objects_by_id => (
 
 has outstanding_futures => (is => 'ro', default => sub { {} });
 
-sub _fail_outstanding {
-  my ($self, $error) = @_;
-  my $outstanding = $self->outstanding_futures;
-  $_->fail($error) for values %$outstanding;
-  %$outstanding = ();
-  return;
-}
-
 has _json => (
   is => 'lazy',
   handles => {
@@ -72,8 +83,77 @@ has _json => (
   },
 );
 
+after BUILD => sub {
+  my ($self) = @_;
+  my $pid = $self->child_pid;
+  
+  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) = @_;
+  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) = @_;
+    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'"
+        };
+      }
+    });
+    return $f; 
+};
+
 sub _id_to_remote_object {
   my ($self, $id) = @_;
+  Dlog_trace { "fetching proxy for remote object with id '$id' for connection $_" } $self->_id;
   return bless({}, 'Object::Remote::Null') if $id eq 'NULL';
   (
     $self->remote_objects_by_id->{$id}
@@ -104,24 +184,66 @@ sub _build__json {
       tie *$handle, 'Object::Remote::GlobProxy', $glob_container;
       return $handle;
     }
-  );
+  )->filter_json_single_key_object(
+    __local_object__ => sub {
+      $self->local_objects_by_id->{$_[0]}
+    }
+  )->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;
+    }
+  )->filter_json_single_key_object(
+    __remote_tied_array__ => sub {
+      my @tied_array;
+      tie @tied_array, 'Object::Remote::Tied', $self->_id_to_remote_object(@_);
+      return \@tied_array;
+    }
+  ); 
+}
+
+sub _load_if_possible {
+  my ($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 $spec;
+sub conn_from_spec {
+  my ($class, $spec, @args) = @_;
   foreach my $poss (do { our @Guess }) {
-    if (my $obj = $poss->($spec)) { return $obj }
+    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 {
@@ -133,6 +255,7 @@ sub remote_object {
 
 sub connect {
   my ($self, $to) = @_;
+  Dlog_debug { "Creating connection to remote node '$to' for connection $_" } $self->_id;
   return await_future(
     $self->send_class_call(0, 'Object::Remote', connect => $to)
   );
@@ -141,11 +264,13 @@ sub connect {
 sub remote_sub {
   my ($self, $sub) = @_;
   my ($pkg, $name) = $sub =~ m/^(.*)::([^:]+)$/;
+  Dlog_debug { "Invoking remote sub '$sub' for connection $_" } $self->_id;
   return await_future($self->send_class_call(0, $pkg, can => $name));
 }
 
 sub send_class_call {
   my ($self, $ctx, @call) = @_;
+  Dlog_trace { "Sending a class call for connection $_" } $self->_id;
   $self->send(call => class_call_handler => $ctx => call => @call);
 }
 
@@ -169,12 +294,17 @@ sub new_class_call_handler {
 
 sub register_remote {
   my ($self, $remote) = @_;
+  Dlog_trace { my $i = $remote->id; "Registered a remote object with id of '$i' for connection $_" } $self->_id;
   weaken($self->remote_objects_by_id->{$remote->id} = $remote);
   return $remote;
 }
 
 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 ]);
 }
@@ -209,8 +339,33 @@ sub send_discard {
 
 sub _send {
   my ($self, $to_send) = @_;
-
-  print { $self->send_to_fh } $self->_serialize($to_send)."\n";
+  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;
+  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 {
@@ -218,7 +373,6 @@ 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 = $@; # won't get here if the eval doesn't die
@@ -241,12 +395,29 @@ sub _local_object_to_id {
 sub _deobjectify {
   my ($self, $data) = @_;
   if (blessed($data)) {
-    return +{ __remote_object__ => $self->_local_object_to_id($data) };
+    if (
+      $data->isa('Object::Remote::Proxy')
+      and $data->{remote}->connection == $self
+    ) {
+      return +{ __local_object__ => $data->{remote}->id };
+    } else {
+      return +{ __remote_object__ => $self->_local_object_to_id($data) };
+    }
   } elsif (my $ref = ref($data)) {
     if ($ref eq 'HASH') {
-      return +{ map +($_ => $self->_deobjectify($data->{$_})), keys %$data };
+      my $tied_to = tied(%$data);
+      if(defined($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') {
-      return [ map $self->_deobjectify($_), @$data ];
+      my $tied_to = tied(@$data);
+      if (defined($tied_to)) {
+        return +{__remote_tied_array__ => $self->_local_object_to_id($tied_to)}; 
+      } else {
+        return [ map $self->_deobjectify($_), @$data ];
+      }
     } elsif ($ref eq 'CODE') {
       my $id = $self->_local_object_to_id(
                  Object::Remote::CodeContainer->new(code => $data)
@@ -267,9 +438,10 @@ sub _deobjectify {
 
 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 };
+  Dlog_trace { "deserialization complete for connection $_" } $self->_id;
   eval { $self->${\"receive_${type}"}(@rest); 1 }
     or do { warn "Receive failed for ${flat}: $@"; return };
   return;
@@ -277,6 +449,7 @@ sub _receive {
 
 sub receive_free {
   my ($self, $id) = @_;
+  Dlog_trace { "got a receive_free for object '$id' for connection $_" } $self->_id;
   delete $self->local_objects_by_id->{$id}
     or warn "Free: no such object $id";
   return;
@@ -284,6 +457,7 @@ sub receive_free {
 
 sub receive_call {
   my ($self, $future_id, $id, @rest) = @_;
+  Dlog_trace { "got a receive_call for object '$id' for connection $_" } $self->_id;
   my $future = $self->_id_to_remote_object($future_id);
   $future->{method} = 'call_discard_free';
   my $local = $self->local_objects_by_id->{$id}
@@ -293,12 +467,14 @@ sub receive_call {
 
 sub receive_call_free {
   my ($self, $future, $id, @rest) = @_;
+  Dlog_trace { "got a receive_call_free for object '$id' for connection $_" } $self->_id;
   $self->receive_call($future, $id, undef, @rest);
   $self->receive_free($id);
 }
 
 sub _invoke {
   my ($self, $future, $local, $ctx, $method, @args) = @_;
+  Dlog_trace { "got _invoke for a method named '$method' for connection $_" } $self->_id;
   if ($method =~ /^start::/) {
     my $f = $local->$method(@args);
     $f->on_done(sub { undef($f); $future->done(@_) });
@@ -324,8 +500,82 @@ sub _invoke {
 
 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