Socket Class Reference
[Netsocket]

Destroy a socket.

Closes socket if the socket is still open

Definition at line 34 of file Socket.h.

Accepts a connection on a socket.

The server socket must be bound and set to listen for connections. On a new connection, returns connected network socket which user is expected to call close() and that deallocates the resources. Referencing a returned pointer after a close() call is not allowed and leads to undefined behaviour.

By default, accept blocks until incomming connection occurs. If socket is set to non-blocking or times out, error is set to NSAPI_ERROR_WOULD_BLOCK.

Parameters:

error

pointer to storage of the error value or NULL

Returns:

pointer to a socket

Implemented in TCPSocket, and UDPSocket.

Bind a specific address to a socket.

Binding assigns a local address to a socket.

Parameters:

address

Local address to bind

Returns:

0 on success, negative error code on failure.

Implemented in InternetSocket.

Close the socket.

Closes any open connection and deallocates any memory associated with the socket. Called from destructor if socket is not closed.

Returns:

0 on success, negative error code on failure

Implemented in InternetSocket.

Connects socket to a remote address.

Attempt to make connection on connection-mode protocol or set or reset the peer address on connectionless protocol.

Also connectionless protocols use the connected address to filter incoming packets for recv() and recvfrom() calls.

To reset the peer address, zero initialised(default constructor) SocketAddress object have to be in the address parameter.

Parameters:

address

The SocketAddress of the remote peer

Returns:

0 on success, negative error code on failure

Implemented in TCPSocket, and UDPSocket.

Listen for incoming connections.

Marks the socket as a passive socket that can be used to accept incoming connections.

Parameters:

backlog

Number of pending connections that can be queued simultaneously, defaults to 1

Returns:

0 on success, negative error code on failure

Implemented in TCPSocket, and UDPSocket.

Receive data from a socket.

Receive data from connected socket or in case of connectionless socket this is equivalent of calling recvfrom(NULL, data, size).

If socket is connected, only packets coming from connected peer address are accepted.

Note:

recv() is allowed write to data buffer even if error occurs.

By default, recv blocks until some data is received. If socket is set to non-blocking or times out, NSAPI_ERROR_WOULD_BLOCK can be returned to indicate no data.

Parameters:

data	Destination buffer for data received from the host
size	Size of the buffer in bytes

Returns:

Number of received bytes on success, negative error code on failure. If no data is available to be received and the peer has performed an orderly shutdown, recv() returns 0.

Implemented in TCPSocket, and UDPSocket.

Receive a data from a socket.

Receives a data and stores the source address in address if address is not NULL. Returns the number of bytes written into the buffer.

If socket is connected, only packets coming from connected peer address are accepted.

Note:

recvfrom() is allowed write to address and data buffers even if error occurs.

By default, recvfrom blocks until a datagram is received. If socket is set to non-blocking or times out with no data, NSAPI_ERROR_WOULD_BLOCK is returned.

Parameters:

address	Destination for the source address or NULL
data	Destination buffer for datagram received from the host
size	Size of the buffer in bytes

Returns:

Number of received bytes on success, negative error code on failure

Implemented in TCPSocket, and UDPSocket.

Send data on a socket.

The socket must be connected to a remote host before send() call. Returns the number of bytes sent from the buffer. In case of connectionless socket, send data to pre-specified remote.

By default, send blocks until all data is sent. If socket is set to non-blocking or times out, a partial amount can be written. NSAPI_ERROR_WOULD_BLOCK is returned if no data was written.

Parameters:

data	Buffer of data to send to the host
size	Size of the buffer in bytes

Returns:

Number of sent bytes on success, negative error code on failure.

Implemented in TCPSocket, and UDPSocket.

Send a message on a socket.

The sendto() function shall send a message through a connection-mode or connectionless-mode socket. If the socket is connectionless-mode, the message shall be sent to the address specified. If the socket is connection-mode, address shall be ignored.

By default, sendto blocks until data is sent. If socket is set to non-blocking or times out, NSAPI_ERROR_WOULD_BLOCK is returned immediately.

Parameters:

address	Remote address
data	Buffer of data to send to the host
size	Size of the buffer in bytes

Returns:

Number of sent bytes on success, negative error code on failure

Implemented in TCPSocket, and UDPSocket.

Set blocking or non-blocking mode of the socket.

Initially all sockets are in blocking mode. In non-blocking mode blocking operations such as send/recv/accept return NSAPI_ERROR_WOULD_BLOCK if they can not continue.

set_blocking(false) is equivalent to set_timeout(-1) set_blocking(true) is equivalent to set_timeout(0)

Parameters:

blocking

true for blocking mode, false for non-blocking mode.

Implemented in InternetSocket.

Set timeout on blocking socket operations.

Initially all sockets have unbounded timeouts. NSAPI_ERROR_WOULD_BLOCK is returned if a blocking operation takes longer than the specified timeout. A timeout of 0 removes the timeout from the socket. A negative value give the socket an unbounded timeout.

set_timeout(0) is equivalent to set_blocking(false) set_timeout(-1) is equivalent to set_blocking(true)

Parameters:

timeout

Timeout in milliseconds

Implemented in InternetSocket.

Register a callback on state change of the socket.

The specified callback will be called on state changes such as when the socket can recv/send/accept successfully and on when an error occurs. The callback may also be called spuriously without reason.

The callback may be called in an interrupt context and should not perform expensive operations such as recv/send calls.

Note! This is not intended as a replacement for a poll or attach-like asynchronous api, but rather as a building block for constructing such functionality. The exact timing of when the registered function is called is not guaranteed and susceptible to change.

Parameters:

func	Function to call on state change

Implemented in InternetSocket.