cne_timer.h File Reference

#include <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <cne_common.h>
#include <cne_atomic.h>

Go to the source code of this file.

Data Structures
union	cne_timer_status
struct	cne_timer_debug_stats
struct	cne_timer

Macros
#define	CNE_TIMER_STOP   0
#define	CNE_TIMER_PENDING   1
#define	CNE_TIMER_RUNNING   2
#define	CNE_TIMER_CONFIG   3
#define	CNE_TIMER_NO_OWNER   -2
#define	CNE_TIMER_INITIALIZER

Typedefs
typedef void(*	cne_timer_cb_t) (struct cne_timer *, void *)

Enumerations
enum	cne_timer_type

Functions
void	cne_timer_subsystem_init (void)
void	cne_timer_init (struct cne_timer *tim)
int	cne_timer_reset (struct cne_timer *tim, uint64_t ticks, enum cne_timer_type type, unsigned tim_thread, cne_timer_cb_t fct, void *arg)
void	cne_timer_reset_sync (struct cne_timer *tim, uint64_t ticks, enum cne_timer_type type, unsigned tim_thread, cne_timer_cb_t fct, void *arg)
int	cne_timer_stop (struct cne_timer *tim)
void	cne_timer_stop_sync (struct cne_timer *tim)
int	cne_timer_pending (struct cne_timer *tim)
void	cne_timer_manage (void)
void	cne_timer_dump_stats (FILE *f)

Detailed Description

CNE Timer

This library provides a timer service to CNE Data Plane execution units that allows the execution of callback functions asynchronously.

• Timers can be periodic or single (one-shot).
• The timers can be loaded from one core and executed on another. This has to be specified in the call to cne_timer_reset().
• High precision is possible. NOTE: this depends on the call frequency to cne_timer_manage() that check the timer expiration for the local core.
• If not used in an application, for improved performance, it can be disabled at compilation time by not calling the cne_timer_manage() to improve performance.

This library provides an interface to add, delete and restart a timer. The API is based on the BSD callout(9) API with a few differences.

See the CNE architecture documentation for more information about the design of this library.

Definition in file cne_timer.h.

Macro Definition Documentation

CNE_TIMER_STOP

#define CNE_TIMER_STOP   0

State: timer is stopped.

Definition at line 43 of file cne_timer.h.

CNE_TIMER_PENDING

#define CNE_TIMER_PENDING   1

State: timer is scheduled.

Definition at line 44 of file cne_timer.h.

CNE_TIMER_RUNNING

#define CNE_TIMER_RUNNING   2

State: timer function is running.

Definition at line 45 of file cne_timer.h.

CNE_TIMER_CONFIG

#define CNE_TIMER_CONFIG   3

State: timer is being configured.

Definition at line 46 of file cne_timer.h.

CNE_TIMER_NO_OWNER

#define CNE_TIMER_NO_OWNER   -2

Timer has no owner.

Definition at line 47 of file cne_timer.h.

CNE_TIMER_INITIALIZER

#define CNE_TIMER_INITIALIZER

Value:

    {                                    \
        .status = {{                     \
            .state = CNE_TIMER_STOP,     \
            .owner = CNE_TIMER_NO_OWNER, \
        }},                              \
    }

A static initializer for a timer structure.

Definition at line 110 of file cne_timer.h.

Typedef Documentation

cne_timer_cb_t

typedef void(* cne_timer_cb_t) (struct cne_timer *, void *)

Callback function type for timer expiry.

Definition at line 82 of file cne_timer.h.

Enumeration Type Documentation

cne_timer_type

enum cne_timer_type

Timer type: Periodic or single (one-shot).

Definition at line 52 of file cne_timer.h.

Function Documentation

cne_timer_subsystem_init()

void cne_timer_subsystem_init

(

void

)

Initialize the timer library.

Initializes internal variables (list, locks and so on) for the CNE timer library.

Examples

examples/cnet-graph/cnet-graph.c, examples/cnet-quic/cnet-quic.c, and examples/timer/main.c.

cne_timer_init()

void cne_timer_init

(

struct cne_timer *

tim

)

Initialize a timer handle.

The cne_timer_init() function initializes the timer handle tim for use. No operations can be performed on a timer before it is initialized.

Parameters

tim	The timer to initialize.

Examples

examples/timer/main.c.

cne_timer_reset()

int cne_timer_reset	(	struct cne_timer *	tim,
		uint64_t	ticks,
		enum cne_timer_type	type,
		unsigned	tim_thread,
		cne_timer_cb_t	fct,
		void *	arg
	)

Reset and start the timer associated with the timer handle.

The cne_timer_reset() function resets and starts the timer associated with the timer handle tim. When the timer expires after ticks HPET cycles, the function specified by fct will be called with the argument arg on core tim_thread.

If the timer associated with the timer handle is already running (in the RUNNING state), the function will fail. The user has to check the return value of the function to see if there is a chance that the timer is in the RUNNING state.

If the timer is being configured on another core (the CONFIG state), it will also fail.

If the timer is pending or stopped, it will be rescheduled with the new parameters.

Parameters

tim	The timer handle.
ticks	The number of cycles (see cne_get_hpet_hz()) before the callback function is called.
type	The type can be either: PERIODICAL: The timer is automatically reloaded after execution (returns to the PENDING state) SINGLE: The timer is one-shot, that is, the timer goes to a STOPPED state after execution.
tim_thread	The ID of the thread where the timer callback function has to be executed.
fct	The callback function of the timer.
arg	The user argument of the callback function.

Returns

• 0: Success; the timer is scheduled.
• (-1): Timer is in the RUNNING or CONFIG state.

Examples

examples/timer/main.c.

cne_timer_reset_sync()

void cne_timer_reset_sync	(	struct cne_timer *	tim,
		uint64_t	ticks,
		enum cne_timer_type	type,
		unsigned	tim_thread,
		cne_timer_cb_t	fct,
		void *	arg
	)

Loop until cne_timer_reset() succeeds.

Reset and start the timer associated with the timer handle. Always succeed. See cne_timer_reset() for details.

Parameters

tim	The timer handle.
ticks	The number of cycles (see cne_get_hpet_hz()) before the callback function is called.
type	The type can be either: PERIODICAL: The timer is automatically reloaded after execution (returns to the PENDING state) SINGLE: The timer is one-shot, that is, the timer goes to a STOPPED state after execution.
tim_thread	The ID of the thread where the timer callback function has to be executed.
fct	The callback function of the timer.
arg	The user argument of the callback function.

cne_timer_stop()

int cne_timer_stop

(

struct cne_timer *

tim

)

Stop a timer.

The cne_timer_stop() function stops the timer associated with the timer handle tim. It may fail if the timer is currently running or being configured.

If the timer is pending or stopped (for instance, already expired), the function will succeed. The timer handle tim must have been initialized using cne_timer_init(), otherwise, undefined behavior will occur.

This function can be called safely from a timer callback. If it succeeds, the timer is not referenced anymore by the timer library and the timer structure can be freed (even in the callback function).

Parameters

tim	The timer handle.

Returns

• 0: Success; the timer is stopped.
• (-1): The timer is in the RUNNING or CONFIG state.

Examples

examples/timer/main.c.

cne_timer_stop_sync()

void cne_timer_stop_sync

(

struct cne_timer *

tim

)

Loop until cne_timer_stop() succeeds.

After a call to this function, the timer identified by tim is stopped. See cne_timer_stop() for details.

Parameters

tim	The timer handle.

cne_timer_pending()

int cne_timer_pending

(

struct cne_timer *

tim

)

Test if a timer is pending.

The cne_timer_pending() function tests the PENDING status of the timer handle tim. A PENDING timer is one that has been scheduled and whose function has not yet been called.

Parameters

tim	The timer handle.

Returns

• 0: The timer is not pending.
• 1: The timer is pending.

cne_timer_manage()

void cne_timer_manage

(

void

)

Manage the timer list and execute callback functions.

This function must be called periodically from CNE threads main_loop(). It browses the list of pending timers and runs all timers that are expired.

The precision of the timer depends on the call frequency of this function. However, the more often the function is called, the more CPU resources it will use.

Examples

examples/cnet-graph/cnet-graph.c, and examples/timer/main.c.

cne_timer_dump_stats()

void cne_timer_dump_stats

(

FILE *

f

)

Dump statistics about timers.

Parameters

f	A pointer to a file for output

Examples

examples/timer/main.c.