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_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¶
- •
- IO::Handle - Supply object methods for I/O handles
AUTHOR¶
Paul Evans <leonerd@leonerd.org.uk>