trusty (3) IO::Async::Socket.3pm.gz

NAME

       "IO::Async::Socket" - event callbacks and send buffering for a socket filehandle

SYNOPSIS

        use IO::Async::Socket;

        use IO::Async::Loop;
        my $loop = IO::Async::Loop->new;

        $loop->connect(
           host     => "some.host.here",
           service  => "echo",
           socktype => 'dgram',

           on_connected => sub {
              my ( $sock ) = @_;

              my $socket = IO::Async::Socket->new(
                 handle => $sock,
                 on_recv => sub {
                    my ( $self, $dgram, $addr ) = @_;

                    print "Received reply: $dgram\n",
                    $loop->stop;
                 },
                 on_recv_error => sub {
                    my ( $self, $errno ) = @_;
                    die "Cannot recv - $errno\n";
                 },
              );

              $loop->add( $socket );

              $socket->send( "A TEST DATAGRAM" );
           },

           on_resolve_error => sub { die "Cannot resolve - $_[0]\n"; },
           on_connect_error => sub { die "Cannot connect\n"; },
        );

        $loop->run;

DESCRIPTION

       This subclass of IO::Async::Handle contains a socket filehandle. It provides a queue of outgoing data. It
       invokes the "on_recv" handler when new data is received from the filehandle. Data may be sent to the
       filehandle by calling the "send" method.

       It is primarily intended for "SOCK_DGRAM" or "SOCK_RAW" sockets; for "SOCK_STREAM" sockets an instance of
       IO::Async::Stream is probably more appropriate.

EVENTS

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

   on_recv $data, $addr
       Invoke on receipt of a packet, datagram, or stream segment.

       The "on_recv" handler is invoked once for each packet, datagram, or stream segment that is received. It
       is passed the data itself, and the sender's address.

   on_recv_error $errno
       Optional. Invoked when the "recv" method on the receiving handle fails.

   on_send_error $errno
       Optional. Invoked when the "send" method on the sending handle fails.

       The "on_recv_error" and "on_send_error" handlers are passed the value of $! at the time the error
       occured. (The $! variable itself, by its nature, may have changed from the original error by the time
       this handler runs so it should always use the value passed in).

       If an error occurs when the corresponding error callback is not supplied, and there is not a subclass
       method for it, then the "close" method is called instead.

   on_outgoing_empty
       Optional. Invoked when the sending data buffer becomes empty.

PARAMETERS

       The following named parameters may be passed to "new" or "configure":

       read_handle => IO
               The IO handle to receive from. Must implement "fileno" and "recv" methods.

       write_handle => IO
               The IO handle to send to. Must implement "fileno" and "send" methods.

       handle => IO
               Shortcut to specifying the same IO handle for both of the above.

       on_recv => CODE
       on_recv_error => CODE
       on_outgoing_empty => CODE
       on_send_error => CODE
       autoflush => BOOL
               Optional. If true, the "send" method will atempt to send data to the operating system
               immediately, without waiting for the loop to indicate the filehandle is write-ready.

       recv_len => INT
               Optional. Sets the buffer size for "recv" calls. Defaults to 64 KiB.

       recv_all => BOOL
               Optional. If true, repeatedly call "recv" when the receiving handle first becomes read-ready. By
               default this is turned off, meaning at most one fixed-size buffer is received. If there is still
               more data in the kernel's buffer, the handle will stil be readable, and will be received from
               again.

               This behaviour allows multiple streams and sockets to be multiplexed simultaneously, meaning that
               a large bulk transfer on one cannot starve other filehandles of processing time. Turning this
               option on may improve bulk data transfer rate, at the risk of delaying or stalling processing on
               other filehandles.

       send_all => INT
               Optional. Analogous to the "recv_all" option, but for sending. When "autoflush" is enabled, this
               option only affects deferred sending if the initial attempt failed.

       The condition requiring an "on_recv" handler is checked at the time the object is added to a Loop; it is
       allowed to create a "IO::Async::Socket" object with a read handle but without a "on_recv" handler,
       provided that one is later given using "configure" before the stream is added to its containing Loop,
       either directly or by being a child of another Notifier already in a Loop, or added to one.

METHODS

   $socket->send( $data, $flags, $addr )
       This method adds a segment of data to be sent, or sends it immediately, according to the "autoflush"
       parameter. $flags and $addr are optional.

       If the "autoflush" option is set, this method will try immediately to send the data to the underlying
       filehandle, optionally using the given flags and destination address. If this completes successfully then
       it will have been sent by the time this method returns. If it fails to send, then the data is queued as
       if "autoflush" were not set, and will be flushed as normal.

SEE ALSO

       •   IO::Handle - Supply object methods for I/O handles

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>