Socket for interprocess communication between processes on the same controller. More...

#include <IpcSocket.hpp>

Public Types
typedef std::shared_ptr< IpcSocket >	Ptr
	Contextual definition of pointer type.

using	SelectMode = Arp::System::Commons::Net::SelectMode
	Contextual definition of available select modes.

using	PollMode = Arp::System::Commons::Net::PollMode
	Contextual definition of available poll modes.

using	ShutdownMode = Arp::System::Commons::Net::ShutdownMode
	Contextual definition of available poll modes.

Public Member Functions
	IpcSocket (bool blocking=true)
	Constructs a new socket for interprocess communication. More...

	IpcSocket (const IpcSocket &arg)=delete
	Copy constructor is deleted.

	IpcSocket (IpcSocket &&arg)=default
	Move constructor.

IpcSocket &	operator= (const IpcSocket &arg)=delete
	Assignment operator is deleted.

	~IpcSocket (void)
	Closes the socket and releases all ressources.

IpcSocketError	Bind (const Arp::String &path)
	Assigns an address to this socket so that other process can connect with it. More...

IpcSocketError	Listen (size_t backlog)
	Marks this socket as a passive socket that accepts incoming connection requests. More...

IpcSocketError	Connect (const Arp::String &path)
	Tries to connect with a remote socket. More...

bool	Select (SelectMode mode, Microseconds timeout, IpcSocketError &error)
	Checks if an i/o operation can be performed without blocking the calling thread. More...

int	Poll (PollMode mode, Milliseconds timeout, IpcSocketError &error)
	Checks if an i/o operation can be processed without blocking. More...

Ptr	Accept (IpcSocketError &error)
	Accepts a pending connection request. More...

IpcSocketError	Shutdown (void)
	Shuts down a connection. More...

IpcSocketError	Shutdown (ShutdownMode mode)
	Shuts down a connection. More...

IpcSocketError	Close (void)
	Closes the socket. This ends all communication on the socket. More...

int	Send (const void *pBuffer, size_t length, IpcSocketError &error)
	Transmit data over the socket that is in a connected state. More...

int	Receive (void *pBuffer, size_t length, IpcSocketError &error)
	Reads data from connected socket. More...

PeerCredentials	GetPeerCredentials (IpcSocketError &error)
	Reads peer credentials from connected socket. More...

Detailed Description

Socket for interprocess communication between processes on the same controller.

In contrast to instances of Arp::System::Commons::Net::Socket instances of this class can only be used to perform communication between processes on the same controller. The benefit of using an IpcSocket instead of a common Socket is that the API remains the same but the underlying mechanism is optimized for speed and performance by not using a complete network stack like TCP/IP and is thus much more lightweight.

IpcSockets can be used in a similar manner as normal TCP-sockets. A server needs a socket listening for incoming connection requests of clients. If such a request is processed a new socket instance is created that provides an endport for the communication between the server process and the client process. Server and client can then exchange data using binary read and write calls.

Constructor & Destructor Documentation

◆ IpcSocket()

Arp::System::Commons::Ipc::IpcSocket::IpcSocket ( bool blocking = true )

Constructs a new socket for interprocess communication.

Parameters

blocking Indicates if calls to accept and receive block until data is available or not.

Member Function Documentation

◆ Accept()

IpcSocket::Ptr Arp::System::Commons::Ipc::IpcSocket::Accept ( IpcSocketError & errorVal )

Accepts a pending connection request.

Before a socket can accept connection requests, it must be Bind with an address and must be set to Listen state.

If no connection request is pending and the socket is in

blocking mode, the call blocks until a remote peer sends a connection request
non-blocking mode, the call returns a nullptr and error is set to #SocketError::WouldBlock

Currently only ip v4 addresses are supported. The address must be encoded in a single 32 bit value. For an example how to encode the address see the example in the class description.

Parameters

error Holds error code in case the method returns nullptr.

Returns: Pointer to class instance representing accepted socket, nullptr otherwise.

◆ Bind()

IpcSocketError Arp::System::Commons::Ipc::IpcSocket::Bind ( const Arp::String & path )

Assigns an address to this socket so that other process can connect with it.

Parameters

path	to connect to.

Returns: See Arp::System::Commons::Ipc::IpcSocketError for more information on possible return values.

◆ Close()

IpcSocketError Arp::System::Commons::Ipc::IpcSocket::Close ( void )

Closes the socket. This ends all communication on the socket.

If this socket is bound to a file the file will be removed.

Returns: See Arp::System::Commons::Ipc::IpcSocketError more information on possible return values.

◆ Connect()

IpcSocketError Arp::System::Commons::Ipc::IpcSocket::Connect ( const Arp::String & path )

Tries to connect with a remote socket.

Currently only ip v4 addresses are supported. The address must be encoded in a single 32 bit value. For an example how to encode the address see the example in the class description.

Parameters

path	Name of socket to connect with.

Returns: See #SocketError for more information on possible return values.

◆ GetPeerCredentials()

PeerCredentials Arp::System::Commons::Ipc::IpcSocket::GetPeerCredentials ( IpcSocketError & error )

Reads peer credentials from connected socket.

Parameters

error Container variable holding error code after call returned.

Returns: Struct filled with peer credentials, -1 in case of failure.

◆ Listen()

IpcSocketError Arp::System::Commons::Ipc::IpcSocket::Listen ( size_t backlog )

Marks this socket as a passive socket that accepts incoming connection requests.

A socket in listening state features an internal queue where incoming connection requests are stored until they are processed by an Accept invocation. The maximal capacity of this queue is determined by the parameter backlog. If a connection request arrives while the queue is filled, the client may receive an error telling that the connection is refused or, if the utilized protocol allows retransmissions, the request may be ignored so that a consecutive reattempt to connnect may succeed.

Parameters

backlog Defines the maximum number of pending connection requests.

Returns: See Arp::System::Commons::Ipc::IpcSocketError for more information on possible return values.

◆ Poll()

int Arp::System::Commons::Ipc::IpcSocket::Poll	(	PollMode	mode,
		Milliseconds	timeout,
		IpcSocketError &	error
	)

Checks if an i/o operation can be processed without blocking.

Parameters

mode	Specifies the i/o operation to be checked.
timeout	Specifies the timeout to wait for the socket to get ready for the i/o operation. If set to zero, the call will return immediately. `Milliseconds(-1)` determines infinite.
error	The resulting socket error, if any error occur.

Returns: 1 if the specified i/o operation might be processed without blocking. 0 if this operation timed out. -1 if any error occurs. Check the error to get more infos about the error. If the socket was closed local or remote, the error is <cref name="SocketError::ConnectionReset" >.

◆ Receive()

int Arp::System::Commons::Ipc::IpcSocket::Receive	(	void *	pBuffer,
		size_t	length,
		IpcSocketError &	error
	)

Reads data from connected socket.

Parameters

pBuffer	Pointer to buffer where read data can be stored.
length	Capacity in bytes of buffer pBuffer.
error	Container variable holding error code after call returned.

Returns: Amount of bytes read from socket, -1 in case of failure.

◆ Select()

bool Arp::System::Commons::Ipc::IpcSocket::Select	(	SelectMode	mode,
		Microseconds	timeout,
		IpcSocketError &	error
	)

Checks if an i/o operation can be performed without blocking the calling thread.

Parameters

mode	Determines the i/o operation to be checked.
timeout	Specifies the time to wait for the socket to be ready for the i/o operation. If set to zero, the call will return immediately.
error	Container variable holding error code after call returned.

Returns: True if the specified i/o operation can be performed without blocking, otherwise false is returned.

◆ Send()

int Arp::System::Commons::Ipc::IpcSocket::Send	(	const void *	pBuffer,
		size_t	length,
		IpcSocketError &	error
	)

Transmit data over the socket that is in a connected state.

Parameters

pBuffer	Pointer to buffer containing serialized data to be send.
length	Amount of bytes to be send.
error	Container variable holding error code after call returned.

Returns: Amount of transmitted bytes, -1 in case of failure.

◆ Shutdown() [1/2]

IpcSocketError Arp::System::Commons::Ipc::IpcSocket::Shutdown ( ShutdownMode mode )

Shuts down a connection.

After the shutdown has been called, further reception and transmission on the socket is disallowed.

Returns: See Arp::System::Commons::Ipc::IpcSocketError for more information on possible return values.

◆ Shutdown() [2/2]

IpcSocketError Arp::System::Commons::Ipc::IpcSocket::Shutdown ( void )

Shuts down a connection.

After the shutdown has been called, further reception and transmission on the socket is disallowed.

Returns: See Arp::System::Commons::Ipc::IpcSocketError for more information on possible return values.

The documentation for this class was generated from the following files:

Arp/System/Commons/Ipc/IpcSocket.hpp
Arp/System/Commons/Ipc/IpcSocket.cpp

Public Types

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ IpcSocket()

Member Function Documentation

◆ Accept()

◆ Bind()

◆ Close()

◆ Connect()

◆ GetPeerCredentials()

◆ Listen()

◆ Poll()

◆ Receive()

◆ Select()

◆ Send()

◆ Shutdown() [1/2]

◆ Shutdown() [2/2]