Acme-Sort-Sleep

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local/lib/perl5/IO/Async.pm  view on Meta::CPAN

=head2 Child Processes

The L<IO::Async::Loop> object provides a number of methods to facilitate the
running of child processes. C<spawn_child> is primarily a wrapper around the
typical C<fork(2)>/C<exec(2)> style of starting child processes, and
C<run_child> provide a method similar to perl's C<readpipe> (which is used
to implement backticks C<``>).

=head2 File Change Watches

The L<IO::Async::File> object observes changes to C<stat(2)> properties of a
file, directory, or other filesystem object. It invokes callbacks when
properties change. This is used by L<IO::Async::FileStream> which presents
the same events as a L<IO::Async::Stream> but operates on a regular file on
the filesystem, observing it for updates.

=head2 Asynchronous Co-routines and Functions

The C<IO::Async> framework generally provides mechanisms for multiplexing IO
tasks between different handles, so there aren't many occasions when it is
necessary to run code in another thread or process. Two cases where this does

local/lib/perl5/IO/Async/File.pm  view on Meta::CPAN

    }
 );

 $loop->add( $file );

 $loop->run;

=head1 DESCRIPTION

This subclass of L<IO::Async::Notifier> watches an open filehandle or named
filesystem entity for changes in its C<stat()> fields. It invokes various
events when the values of these fields change. It is most often used to watch
a file for size changes; for this task see also L<IO::Async::FileStream>.

While called "File", it is not required that the watched filehandle be a
regular file. It is possible to watch anything that C<stat(2)> may be called
on, such as directories or other filesystem entities.

=cut

=head1 EVENTS

The following events are invoked, either using subclass methods or CODE
references in parameters.

=head2 on_dev_changed $new_dev, $old_dev

=head2 on_ino_changed $new_ino, $old_ino

=head2 ...

=head2 on_ctime_changed $new_ctime, $old_ctime

Invoked when each of the individual C<stat()> fields have changed. All the
C<stat()> fields are supported apart from C<blocks> and C<blksize>. Each is
passed the new and old values of the field.

=head2 on_devino_changed $new_stat, $old_stat

Invoked when either of the C<dev> or C<ino> fields have changed. It is passed
two L<File::stat> instances containing the complete old and new C<stat()>
fields. This can be used to observe when a named file is renamed; it will not
be observed to happen on opened filehandles.

=head2 on_stat_changed $new_stat, $old_stat

Invoked when any of the C<stat()> fields have changed. It is passed two
L<File::stat> instances containing the old and new C<stat()> fields.

=cut

=head1 PARAMETERS

The following named parameters may be passed to C<new> or C<configure>.

=head2 handle => IO

The opened filehandle to watch for C<stat()> changes if C<filename> is not
supplied.

=head2 filename => STRING

Optional. If supplied, watches the named file rather than the filehandle given
in C<handle>. The file will be opened for reading and then watched for
renames. If the file is renamed, the new filename is opened and tracked
similarly after closing the previous file.

=head2 interval => NUM

Optional. The interval in seconds to poll the filehandle using C<stat(2)>
looking for size changes. A default of 2 seconds will be applied if not
defined.

=cut

sub _init
{
   my $self = shift;
   my ( $params ) = @_;

local/lib/perl5/IO/Async/File.pm  view on Meta::CPAN

   open $self->{handle}, "<", $path or croak "Cannot open $path for reading - $!";

   $self->{last_stat} = stat $self->{handle};
}

sub on_tick
{
   my $self = shift;

   my $old = $self->{last_stat};
   my $new = stat( defined $self->{filename} ? $self->{filename} : $self->{handle} );

   my $any_changed;
   foreach my $stat ( @STATS ) {
      next if $old->$stat == $new->$stat;

      $any_changed++;
      $self->maybe_invoke_event( "on_${stat}_changed", $new->$stat, $old->$stat );
   }

   if( $old->dev != $new->dev or $old->ino != $new->ino ) {

local/lib/perl5/IO/Async/FileStream.pm  view on Meta::CPAN

=head2 filename => STRING

Optional. If supplied, watches the named file rather than the filehandle given
in C<read_handle>. The file will be opened by the constructor, and then
watched for renames. If the file is renamed, the new filename is opened and
tracked similarly after closing the previous file.

=head2 interval => NUM

Optional. The interval in seconds to poll the filehandle using C<stat(2)>
looking for size changes. A default of 2 seconds will be applied if not
defined.

=cut

sub configure
{
   my $self = shift;
   my %params = @_;

local/lib/perl5/IO/Async/Loop/Select.pm  view on Meta::CPAN

   my $fileno = $params{handle}->fileno;

   vec( $self->{rvec}, $fileno, 1 ) = 1 if $params{on_read_ready};
   vec( $self->{wvec}, $fileno, 1 ) = 1 if $params{on_write_ready};

   # MSWin32 does not indicate writeready for connect() errors, HUPs, etc
   # but it does indicate exceptional
   vec( $self->{evec}, $fileno, 1 ) = 1 if SELECT_CONNECT_EVEC and $params{on_write_ready};

   vec( $self->{avec}, $fileno, 1 ) = 1 if FAKE_ISREG_READY and stat( $params{handle} ) and -f _;
}

sub unwatch_io
{
   my $self = shift;
   my %params = @_;

   $self->__unwatch_io( %params );

   my $fileno = $params{handle}->fileno;

   vec( $self->{rvec}, $fileno, 1 ) = 0 if $params{on_read_ready};
   vec( $self->{wvec}, $fileno, 1 ) = 0 if $params{on_write_ready};

   vec( $self->{evec}, $fileno, 1 ) = 0 if SELECT_CONNECT_EVEC and $params{on_write_ready};

   vec( $self->{avec}, $fileno, 1 ) = 0 if FAKE_ISREG_READY and stat( $params{handle} ) and -f _;

   # vec will grow a bit vector as needed, but never shrink it. We'll trim
   # trailing null bytes
   $_ =~s/\0+\z// for $self->{rvec}, $self->{wvec}, $self->{evec}, $self->{avec};
}

=head1 SEE ALSO

=over 4