IO::Async::Socket(3pm) User Contributed Perl Documentation IO::Async::Socket(3pm)
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
",
$loop->stop;
},
on_recv_error => sub {
my ( $self, $errno ) = @_;
die "Cannot recv - $errno
";
},
);
$loop->add( $socket );
$socket->send( "A TEST DATAGRAM" );
},
on_resolve_error => sub { die "Cannot resolve - $_[0]
"; },
on_connect_error => sub { die "Cannot connect
"; },
);
$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_data" 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
o IO::Handle - Supply object methods for I/O handles
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.14.2 2012-10-24 IO::Async::Socket(3pm)