Base class for framed transport layers. More...

#include <erpc_framed_transport.hpp>

Inheritance diagram for erpc::FramedTransport:

Collaboration diagram for erpc::FramedTransport:

Classes
struct	Header
	Contents of the header that prefixes each message. More...

Public Member Functions
	FramedTransport (void)
	Constructor.

virtual	~FramedTransport (void)
	FramedTransport destructor.

virtual uint8_t	reserveHeaderSize (void) override
	Size of data placed in MessageBuffer before serializing eRPC data. More...

virtual erpc_status_t	receive (MessageBuffer *message) override
	Receives an entire message. More...

virtual erpc_status_t	send (MessageBuffer *message) override
	Function to send prepared message. More...

virtual void	setCrc16 (Crc16 *crcImpl) override
	This functions sets the CRC-16 implementation. More...

virtual Crc16 *	getCrc16 (void) override
	This functions gets the CRC-16 object. More...

Public Member Functions inherited from erpc::Transport
	Transport (void)
	Constructor.

virtual	~Transport (void)
	Transport destructor.

virtual bool	hasMessage (void)
	Poll for an incoming message. More...

Protected Member Functions
virtual erpc_status_t	underlyingSend (MessageBuffer *message, uint32_t size, uint32_t offset)
	Adds ability to framed transport to overwrite MessageBuffer when sending data. More...

virtual erpc_status_t	underlyingReceive (MessageBuffer *message, uint32_t size, uint32_t offset)
	Adds ability to framed transport to overwrite MessageBuffer when receiving data. More...

virtual erpc_status_t	underlyingSend (const uint8_t *data, uint32_t size)=0
	Subclasses must implement this function to send data. More...

virtual erpc_status_t	underlyingReceive (uint8_t *data, uint32_t size)=0
	Subclasses must implement this function to receive data. More...

Protected Attributes
Crc16 *	m_crcImpl

Mutex	m_sendLock
	Mutex protecting send.

Mutex	m_receiveLock
	Mutex protecting receive.

Detailed Description

Base class for framed transport layers.

This class adds simple framing to the data transmitted and received on the communications channel. This allows the transport to perform reads and writes of a size known in advance. Subclasses must implement the underlyingSend() and underlyingReceive() methods to actually transmit and receive data.

Frames have a maximum size of 64kB, as a 16-bit frame size is used.

Note: This implementation currently assumes both sides of the communications channel are the same endianness.

The frame header includes a CRC-16 over the data for integrity checking. This class includes a default CRC-16 implementation that is optimized for code size, but is relatively slow. If a faster implementation is desired, you can pass the new CRC function to setCRCFunction().

Class Documentation

struct erpc::FramedTransport::Header

Contents of the header that prefixes each message.

Class Members
uint16_t	m_crcHeader	CRC-16 over this header structure data.
uint16_t	m_messageSize	Size in bytes of the message, excluding the header.
uint16_t	m_crcBody	CRC-16 over the message data.

Member Function Documentation

uint8_t FramedTransport::reserveHeaderSize ( void )

overridevirtual

Size of data placed in MessageBuffer before serializing eRPC data.

Returns: uint8_t Amount of bytes, reserved before serialized data.

Reimplemented from erpc::Transport.

erpc_status_t FramedTransport::receive ( MessageBuffer * message )

overridevirtual

Receives an entire message.

The frame header and message data are received. The CRC-16 in the frame header is compared with the computed CRC. If the received CRC is invalid, kErpcStatus_Fail will be returned.

The message is only filled with the message data, not the frame header.

This function is blocking.

Parameters

[in] message Message buffer, to which will be stored incoming message.

Return values

kErpcStatus_Success	When receiving was successful.
kErpcStatus_CrcCheckFailed	When receiving failed.
other	Subclass may return other errors from the underlyingReceive() method.

Implements erpc::Transport.

erpc_status_t FramedTransport::send ( MessageBuffer * message )

overridevirtual

Function to send prepared message.

Parameters

[in] message Pass message buffer to send.

Return values

kErpcStatus_Success	When sending was successful.
other	Subclass may return other errors from the underlyingSend() method.

Implements erpc::Transport.

void FramedTransport::setCrc16 ( Crc16 * crcImpl )

overridevirtual

This functions sets the CRC-16 implementation.

Parameters

[in] crcImpl Object containing crc-16 compute function.

Reimplemented from erpc::Transport.

Crc16 * FramedTransport::getCrc16 ( void )

overridevirtual

This functions gets the CRC-16 object.

Returns: Crc16* Pointer to CRC-16 object containing crc-16 compute function.

Reimplemented from erpc::Transport.

erpc_status_t FramedTransport::underlyingSend	(	MessageBuffer *	message,
		uint32_t	size,
		uint32_t	offset
	)

protectedvirtual

Adds ability to framed transport to overwrite MessageBuffer when sending data.

Usually we don't want to do that.

Parameters

message	MessageBuffer to send.
size	size of message to send.
offset	data start address offset

Returns: erpc_status_t kErpcStatus_Success when it finished successful otherwise error.

Reimplemented in erpc::RPMsgTTYRTOSTransport.

erpc_status_t FramedTransport::underlyingReceive	(	MessageBuffer *	message,
		uint32_t	size,
		uint32_t	offset
	)

protectedvirtual

Adds ability to framed transport to overwrite MessageBuffer when receiving data.

Usually we don't want to do that.

Parameters

message	MessageBuffer to send.
size	size of message to send.
offset	data start address offset

Returns: erpc_status_t kErpcStatus_Success when it finished successful otherwise error.

Reimplemented in erpc::RPMsgTTYRTOSTransport.

virtual erpc_status_t erpc::FramedTransport::underlyingSend	(	const uint8_t *	data,
		uint32_t	size
	)

protectedpure virtual

Subclasses must implement this function to send data.

Parameters

[in]	data	Buffer to send.
[in]	size	Size of data to send.

Return values

kErpcStatus_Success	When data was written successfully.
kErpcStatus_Fail	When writing data ends with error.

Implemented in erpc::RPMsgTTYRTOSTransport, and erpc::TCPTransport.

virtual erpc_status_t erpc::FramedTransport::underlyingReceive	(	uint8_t *	data,
		uint32_t	size
	)

protectedpure virtual

Subclasses must implement this function to receive data.

Parameters

[in,out]	data	Preallocated buffer for receiving data.
[in]	size	Size of data to read.

Return values

kErpcStatus_Success	When data was read successfully.
kErpcStatus_Fail	When reading data ends with error.

Implemented in erpc::RPMsgTTYRTOSTransport, and erpc::TCPTransport.

Member Data Documentation

Crc16* erpc::FramedTransport::m_crcImpl

protected

CRC object.

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

erpc_framed_transport.hpp
erpc_framed_transport.cpp

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Class Documentation

Member Function Documentation

Member Data Documentation