Linux epoll interface to CANopenNode. More...

Collaboration diagram for Epoll interface:

Files
file	CO_epoll_interface.h
	Helper functions for Linux epoll interface to CANopenNode.

Data Structures
struct	CO_epoll_t
	Object for epoll, timer and event API. More...

struct	CO_epoll_gtw_t
	Object for gateway. More...

Enumerations
enum	CO_commandInterface_t
	Command interface type for gateway-ascii.

Functions
CO_ReturnError_t	CO_epoll_create (CO_epoll_t *ep, uint32_t timerInterval_us)
	Create Linux epoll, timerfd and eventfd.

void	CO_epoll_close (CO_epoll_t *ep)
	Close epoll, timerfd and eventfd.

void	CO_epoll_wait (CO_epoll_t *ep)
	Wait for an epoll event.

void	CO_epoll_processLast (CO_epoll_t *ep)
	Closing function for an epoll event.

void	CO_epoll_initCANopenMain (CO_epoll_t ep, CO_t co)
	Initialization of functions in CANopen reset-communication section.

void	CO_epoll_processMain (CO_epoll_t ep, CO_t co, bool_t enableGateway, CO_NMT_reset_cmd_t *reset)
	Process CANopen mainline functions.

void	CO_epoll_processRT (CO_epoll_t ep, CO_t co, bool_t realtime)
	Process CAN receive and realtime functions.

CO_ReturnError_t	CO_epoll_createGtw (CO_epoll_gtw_t epGtw, int epoll_fd, int32_t commandInterface, uint32_t socketTimeout_ms, char localSocketPath)
	Create socket for gateway-ascii command interface and add it to epoll.

void	CO_epoll_closeGtw (CO_epoll_gtw_t *epGtw)
	Close gateway-ascii sockets.

void	CO_epoll_initCANopenGtw (CO_epoll_gtw_t epGtw, CO_t co)
	Initialization of gateway functions in CANopen reset-communication section.

void	CO_epoll_processGtw (CO_epoll_gtw_t epGtw, CO_t co, CO_epoll_t *ep)
	Process CANopen gateway functions.

Detailed Description

Linux epoll interface to CANopenNode.

The Linux epoll API performs a monitoring multiple file descriptors to see if I/O is possible on any of them.

CANopenNode uses epoll interface to provide an event based mechanism. Epoll waits for multiple different events, such as: interval timer event, notification event, CAN receive event or socket based event for gateway. CANopenNode non-blocking functions are processed after each event.

CANopenNode itself offers functionality for calculation of time, when next interval timer event should trigger the processing. It can also trigger notification events in case of multi-thread operation.

Function Documentation

◆ CO_epoll_create()

CO_ReturnError_t CO_epoll_create	(	CO_epoll_t *	ep,
		uint32_t	timerInterval_us )

Create Linux epoll, timerfd and eventfd.

Create and configure multiple Linux notification facilities, which trigger execution of the task. Epoll blocks and monitors multiple file descriptors, timerfd triggers in constant timer intervals and eventfd triggers on external signal.

Parameters

ep	This object
timerInterval_us	Timer interval in microseconds

Returns: CO_ReturnError_t CO_ERROR_NO, CO_ERROR_ILLEGAL_ARGUMENT or CO_ERROR_SYSCALL.

◆ CO_epoll_close()

void CO_epoll_close ( CO_epoll_t * ep )

Close epoll, timerfd and eventfd.

Parameters

ep	This object

◆ CO_epoll_wait()

void CO_epoll_wait ( CO_epoll_t * ep )

Wait for an epoll event.

This function blocks until event registered on epoll: timerfd, eventfd, or application specified event. Function also calculates timeDifference_us since last call and prepares timerNext_us.

Parameters

ep	This object

◆ CO_epoll_processLast()

void CO_epoll_processLast ( CO_epoll_t * ep )

Closing function for an epoll event.

This function must be called after CO_epoll_wait(). Between them should be application specified processing functions, which can check for own events and do own processing. Application may also lower timerNext_us variable. If lowered, then interval timer will be reconfigured and CO_epoll_wait() will be triggered earlier.

Parameters

ep	This object

◆ CO_epoll_initCANopenMain()

void CO_epoll_initCANopenMain	(	CO_epoll_t *	ep,
		CO_t *	co )

Initialization of functions in CANopen reset-communication section.

Configure callbacks for CANopen objects.

Parameters

ep	This object
co	CANopen object

◆ CO_epoll_processMain()

void CO_epoll_processMain	(	CO_epoll_t *	ep,
		CO_t *	co,
		bool_t	enableGateway,
		CO_NMT_reset_cmd_t *	reset )

Process CANopen mainline functions.

This function calls CO_process(). It is non-blocking and should execute cyclically. It should be between CO_epoll_wait() and CO_epoll_processLast() functions.

Parameters

	ep	This object
	co	CANopen object
	enableGateway	If true, gateway to external world will be enabled.
[out]	reset	Return from CO_process().

◆ CO_epoll_processRT()

void CO_epoll_processRT	(	CO_epoll_t *	ep,
		CO_t *	co,
		bool_t	realtime )

Process CAN receive and realtime functions.

This function checks epoll for CAN receive event and processes CANopen realtime functions: CO_process_SYNC(), CO_process_RPDO() and CO_process_TPDO(). It is non-blocking and should execute cyclically. It should be between CO_epoll_wait() and CO_epoll_processLast() functions.

Function can be used in the mainline thread or in own realtime thread.

Processing of CANopen realtime functions is protected with CO_LOCK_OD. Also Node-Id must be configured and CANmodule must be in CANnormal for processing.

Parameters

ep	Pointer to CO_epoll_t object.
co	CANopen object
realtime	Set to true, if function is called from the own realtime thread, and is executed at short constant interval.

◆ CO_epoll_createGtw()

CO_ReturnError_t CO_epoll_createGtw	(	CO_epoll_gtw_t *	epGtw,
		int	epoll_fd,
		int32_t	commandInterface,
		uint32_t	socketTimeout_ms,
		char *	localSocketPath )

Create socket for gateway-ascii command interface and add it to epoll.

Depending on arguments function configures stdio interface or local socket or IP socket.

Parameters

epGtw	This object
epoll_fd	Already configured epoll file descriptor
commandInterface	Command interface type from CO_commandInterface_t
socketTimeout_ms	Timeout for established socket connection in [ms]
localSocketPath	File path, if commandInterface is local socket

Returns: CO_ReturnError_t CO_ERROR_NO, CO_ERROR_ILLEGAL_ARGUMENT or CO_ERROR_SYSCALL.

◆ CO_epoll_closeGtw()

void CO_epoll_closeGtw ( CO_epoll_gtw_t * epGtw )

Close gateway-ascii sockets.

Parameters

epGtw This object

◆ CO_epoll_initCANopenGtw()

void CO_epoll_initCANopenGtw	(	CO_epoll_gtw_t *	epGtw,
		CO_t *	co )

Initialization of gateway functions in CANopen reset-communication section.

Parameters

epGtw	This object
co	CANopen object

◆ CO_epoll_processGtw()

void CO_epoll_processGtw	(	CO_epoll_gtw_t *	epGtw,
		CO_t *	co,
		CO_epoll_t *	ep )

Process CANopen gateway functions.

This function checks for epoll events and verifies socket connection timeout. It is non-blocking and should execute cyclically. It should be between CO_epoll_wait() and CO_epoll_processLast() functions.

Parameters

epGtw	This object
co	CANopen object
ep	Pointer to CO_epoll_t object.

Files

Data Structures

Enumerations

Functions

Detailed Description

Function Documentation

◆ CO_epoll_create()

◆ CO_epoll_close()

◆ CO_epoll_wait()

◆ CO_epoll_processLast()

◆ CO_epoll_initCANopenMain()

◆ CO_epoll_processMain()

◆ CO_epoll_processRT()

◆ CO_epoll_createGtw()

◆ CO_epoll_closeGtw()

◆ CO_epoll_initCANopenGtw()

◆ CO_epoll_processGtw()