CRT communication session management class. Assumes the following properties provided by the underlying transport: More...

#include <session.h>

Collaboration diagram for tvm::runtime::micro_rpc::Session:

Public Types
typedef void(*	MessageReceivedFunc) (void context, MessageType message_type, FrameBuffer buf)
	Callback invoked when a full message is received. More...

Public Member Functions
	Session (Framer framer, FrameBuffer receive_buffer, MessageReceivedFunc message_received_func, void *message_received_func_context)

tvm_crt_error_t	Initialize (uint8_t initial_session_nonce)
	Send a session terminate message, usually done at startup to interrupt a hanging remote. More...

tvm_crt_error_t	TerminateSession ()
	Terminate any previously-established session. More...

tvm_crt_error_t	StartSession ()
	Start a new session regardless of state. Sends kStartSessionMessage. More...

WriteStream *	Receiver ()
	Obtain a WriteStream implementation for use by the framing layer. More...

tvm_crt_error_t	SendMessage (MessageType message_type, const uint8_t *message_data, size_t message_size_bytes)
	Send a full message including header, payload, and CRC footer. More...

tvm_crt_error_t	StartMessage (MessageType message_type, size_t message_size_bytes)
	Send the framing and session layer headers. More...

tvm_crt_error_t	SendBodyChunk (const uint8_t *chunk_data, size_t chunk_size_bytes)
	Send a part of the message body. More...

tvm_crt_error_t	FinishMessage ()
	Finish sending the message by sending the framing layer footer. More...

bool	IsEstablished () const
	Returns true if the session is in the established state. More...

void	ClearReceiveBuffer ()
	Clear the receive buffer and prepare to receive next message. More...

Static Public Attributes
static constexpr const uint8_t	kInvalidNonce = 0
	An invalid nonce value that typically indicates an unknown nonce. More...

static constexpr const uint8_t	kVersion = 0x01
	A version number used to check compatibility of the remote session implementation. More...

Detailed Description

CRT communication session management class. Assumes the following properties provided by the underlying transport:

in-order delivery.
reliable delivery.

Specifically, designed for use with UARTs. Will probably work over semihosting, USB, and TCP; will probably not work reliably enough over UDP.

Member Typedef Documentation

◆ MessageReceivedFunc

typedef void(* tvm::runtime::micro_rpc::Session::MessageReceivedFunc) (void *context, MessageType message_type, FrameBuffer *buf)

Callback invoked when a full message is received.

This function is called in the following situations:

When a new session is established (this typically indicates the remote end reset). In this case, buf is NULL.
When a log message or normal traffic is received. In this case, buf points to a valid buffer containing the message content.

Parameters

context	The value of `message_received_func_context` passed to the constructor.
message_type	The type of session message received. Currently, this is always either kNormal or kLog.
buf	When message_type is not kStartSessionMessage, a FrameBuffer whose read cursor is at the first byte of the message payload. Otherwise, NULL.

Constructor & Destructor Documentation

◆ Session()

tvm::runtime::micro_rpc::Session::Session	(	Framer *	framer,
		FrameBuffer *	receive_buffer,
		MessageReceivedFunc	message_received_func,
		void *	message_received_func_context
	)

inline

Member Function Documentation

◆ ClearReceiveBuffer()

void tvm::runtime::micro_rpc::Session::ClearReceiveBuffer ( )

Clear the receive buffer and prepare to receive next message.

Call this function after MessageReceivedFunc is invoked. Any SessionReceiver::Write() calls made will return errors until this function is called to prevent them from corrupting the valid message in the receive buffer.

◆ FinishMessage()

tvm_crt_error_t tvm::runtime::micro_rpc::Session::FinishMessage ( )

Finish sending the message by sending the framing layer footer.

Returns: kTvmErrorNoError on success, or an error code otherwise.

◆ Initialize()

tvm_crt_error_t tvm::runtime::micro_rpc::Session::Initialize ( uint8_t initial_session_nonce )

Send a session terminate message, usually done at startup to interrupt a hanging remote.

Parameters

initial_session_nonce Initial nonce that should be used on the first session start message. Callers should ensure this is different across device resets.

Returns: kTvmErrorNoError on success, or an error code otherwise.

◆ IsEstablished()

bool tvm::runtime::micro_rpc::Session::IsEstablished ( ) const

inline

Returns true if the session is in the established state.

◆ Receiver()

WriteStream* tvm::runtime::micro_rpc::Session::Receiver ( )

inline

Obtain a WriteStream implementation for use by the framing layer.

Returns: A WriteStream to which received data should be written. Owned by this class.

◆ SendBodyChunk()

tvm_crt_error_t tvm::runtime::micro_rpc::Session::SendBodyChunk	(	const uint8_t *	chunk_data,
		size_t	chunk_size_bytes
	)

Send a part of the message body.

This function allows messages to be sent in pieces.

Parameters

chunk_data	The data contained in this message body chunk.
chunk_size_bytes	The number of valid bytes in chunk_data.

Returns: kTvmErrorNoError on success, or an error code otherwise.

◆ SendMessage()

tvm_crt_error_t tvm::runtime::micro_rpc::Session::SendMessage	(	MessageType	message_type,
		const uint8_t *	message_data,
		size_t	message_size_bytes
	)

Send a full message including header, payload, and CRC footer.

Parameters

message_type	One of MessageType; distinguishes the type of traffic at the session layer.
message_data	The data contained in the message.
message_size_bytes	The number of valid bytes in message_data.

Returns: kTvmErrorNoError on success, or an error code otherwise.

◆ StartMessage()

tvm_crt_error_t tvm::runtime::micro_rpc::Session::StartMessage	(	MessageType	message_type,
		size_t	message_size_bytes
	)

Send the framing and session layer headers.

This function allows messages to be sent in pieces.

Parameters

message_type	One of MessageType; distinguishes the type of traffic at the session layer.
message_size_bytes	The size of the message body, in bytes. Excludes the framing and session layer headers.

Returns: 0 on success, negative error code on failure.; kTvmErrorNoError on success, or an error code otherwise.

◆ StartSession()

tvm_crt_error_t tvm::runtime::micro_rpc::Session::StartSession ( )

Start a new session regardless of state. Sends kStartSessionMessage.

Generally speaking, this function should be called once per device reset by exactly one side in the system. No traffic can flow until this function is called.

Returns: kTvmErrorNoError on success, or an error code otherwise.

◆ TerminateSession()

tvm_crt_error_t tvm::runtime::micro_rpc::Session::TerminateSession ( )

Terminate any previously-established session.

Returns: kTvmErrorNoError on success, or an error code otherwise.

Member Data Documentation

◆ kInvalidNonce

constexpr const uint8_t tvm::runtime::micro_rpc::Session::kInvalidNonce = 0

staticconstexpr

An invalid nonce value that typically indicates an unknown nonce.

◆ kVersion

constexpr const uint8_t tvm::runtime::micro_rpc::Session::kVersion = 0x01

staticconstexpr

A version number used to check compatibility of the remote session implementation.

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

include/tvm/runtime/crt/rpc_common/session.h

Public Types

Public Member Functions

Static Public Attributes

Detailed Description

Member Typedef Documentation

◆ MessageReceivedFunc

Constructor & Destructor Documentation

◆ Session()

Member Function Documentation

◆ ClearReceiveBuffer()

◆ FinishMessage()

◆ Initialize()

◆ IsEstablished()

◆ Receiver()

◆ SendBodyChunk()

◆ SendMessage()

◆ StartMessage()

◆ StartSession()

◆ TerminateSession()

Member Data Documentation

◆ kInvalidNonce

◆ kVersion