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=488794cf133aff53ce8a7698f650d65e804a5454;hb=b0ec7e3b19d47b9ba5a864f5077d0dc8030834cc;hpb=998ff9a49b1f18c9ec82212eda094c8261c0ef1c

diff --git a/lib/Object/Remote/Connection.pm b/lib/Object/Remote/Connection.pm
index 488794c..136b065 100644
--- a/lib/Object/Remote/Connection.pm
+++ b/lib/Object/Remote/Connection.pm
@@ -16,11 +16,9 @@ use Module::Runtime qw(use_module);
 use Scalar::Util qw(weaken blessed refaddr openhandle);
 use JSON::PP qw(encode_json);
 use Moo;
+use Carp qw(croak);
 
-BEGIN { 
-  router()->exclude_forwarding;
-  $SIG{PIPE} = sub { log_debug { "Got a PIPE signal" } };
-}
+BEGIN { router()->exclude_forwarding }
 
 END {
   log_debug { "Killing all child processes in the process group" };
@@ -34,9 +32,9 @@ 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];
   },
 );
 
@@ -58,8 +56,8 @@ has read_channel => (
 has on_close => (
   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])
+    log_trace { "Installing handlers into future via trigger" };
+    $_[0]->_install_future_handlers($_[1])
   },
 );
 
@@ -90,8 +88,8 @@ after BUILD => sub {
   my $pid = $self->child_pid;
   
   unless (defined $pid) {
-      log_trace { "After BUILD invoked for connection but there was no pid" };
-      return;
+    log_trace { "After BUILD invoked for connection but there was no pid" };
+    return;
   }
     
   log_trace { "Setting process group of child process '$pid'" };
@@ -101,11 +99,28 @@ after BUILD => sub {
 
 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;
 }
@@ -221,9 +236,9 @@ sub conn_from_spec {
 }
 
 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 $conn;
@@ -287,6 +302,9 @@ sub register_remote {
 sub send_free {
   my ($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 => $id ]);
 }
@@ -322,6 +340,11 @@ sub send_discard {
 sub _send {
   my ($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;
@@ -477,8 +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