numam-dpdk/lib/librte_timer/rte_timer.h
Stephen Hemminger cd7c59dc04 timer: add API to query ticks until the next timer
It is useful to know when the next timer will expire when
using rte_epoll_wait (or sleep when idle). This experimental
API provides a hook to query the number of ticks remaining.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
2020-01-20 01:55:19 +01:00

544 lines
16 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2010-2014 Intel Corporation
*/
#ifndef _RTE_TIMER_H_
#define _RTE_TIMER_H_
/**
* @file
RTE Timer
*
* This library provides a timer service to RTE 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 rte_timer_reset().
* - High precision is possible. NOTE: this depends on the call frequency to
* rte_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 rte_timer_manage()
* to improve performance.
*
* The timer library uses the rte_get_hpet_cycles() function that
* uses the HPET, when available, to provide a reliable time reference. [HPET
* routines are provided by EAL, which falls back to using the chip TSC (time-
* stamp counter) as fallback when HPET is not available]
*
* 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 RTE architecture documentation for more information about the
* design of this library.
*/
#include <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <rte_common.h>
#include <rte_config.h>
#include <rte_spinlock.h>
#ifdef __cplusplus
extern "C" {
#endif
#define RTE_TIMER_STOP 0 /**< State: timer is stopped. */
#define RTE_TIMER_PENDING 1 /**< State: timer is scheduled. */
#define RTE_TIMER_RUNNING 2 /**< State: timer function is running. */
#define RTE_TIMER_CONFIG 3 /**< State: timer is being configured. */
#define RTE_TIMER_NO_OWNER -2 /**< Timer has no owner. */
/**
* Timer type: Periodic or single (one-shot).
*/
enum rte_timer_type {
SINGLE,
PERIODICAL
};
/**
* Timer status: A union of the state (stopped, pending, running,
* config) and an owner (the id of the lcore that owns the timer).
*/
union rte_timer_status {
RTE_STD_C11
struct {
uint16_t state; /**< Stop, pending, running, config. */
int16_t owner; /**< The lcore that owns the timer. */
};
uint32_t u32; /**< To atomic-set status + owner. */
};
#ifdef RTE_LIBRTE_TIMER_DEBUG
/**
* A structure that stores the timer statistics (per-lcore).
*/
struct rte_timer_debug_stats {
uint64_t reset; /**< Number of success calls to rte_timer_reset(). */
uint64_t stop; /**< Number of success calls to rte_timer_stop(). */
uint64_t manage; /**< Number of calls to rte_timer_manage(). */
uint64_t pending; /**< Number of pending/running timers. */
};
#endif
struct rte_timer;
/**
* Callback function type for timer expiry.
*/
typedef void (*rte_timer_cb_t)(struct rte_timer *, void *);
#define MAX_SKIPLIST_DEPTH 10
/**
* A structure describing a timer in RTE.
*/
struct rte_timer
{
uint64_t expire; /**< Time when timer expire. */
struct rte_timer *sl_next[MAX_SKIPLIST_DEPTH];
volatile union rte_timer_status status; /**< Status of timer. */
uint64_t period; /**< Period of timer (0 if not periodic). */
rte_timer_cb_t f; /**< Callback function. */
void *arg; /**< Argument to callback function. */
};
#ifdef __cplusplus
/**
* A C++ static initializer for a timer structure.
*/
#define RTE_TIMER_INITIALIZER { \
0, \
{NULL}, \
{{RTE_TIMER_STOP, RTE_TIMER_NO_OWNER}}, \
0, \
NULL, \
NULL, \
}
#else
/**
* A static initializer for a timer structure.
*/
#define RTE_TIMER_INITIALIZER { \
.status = {{ \
.state = RTE_TIMER_STOP, \
.owner = RTE_TIMER_NO_OWNER, \
}}, \
}
#endif
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Allocate a timer data instance in shared memory to track a set of pending
* timer lists.
*
* @param id_ptr
* Pointer to variable into which to write the identifier of the allocated
* timer data instance.
*
* @return
* - 0: Success
* - -ENOSPC: maximum number of timer data instances already allocated
*/
__rte_experimental
int rte_timer_data_alloc(uint32_t *id_ptr);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Deallocate a timer data instance.
*
* @param id
* Identifier of the timer data instance to deallocate.
*
* @return
* - 0: Success
* - -EINVAL: invalid timer data instance identifier
*/
__rte_experimental
int rte_timer_data_dealloc(uint32_t id);
/**
* Initialize the timer library.
*
* Initializes internal variables (list, locks and so on) for the RTE
* timer library.
*
* @note
* This function must be called in every process before using the library.
*
* @return
* - 0: Success
* - -ENOMEM: Unable to allocate memory needed to initialize timer
* subsystem
*/
int rte_timer_subsystem_init(void);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Free timer subsystem resources.
*/
__rte_experimental
void rte_timer_subsystem_finalize(void);
/**
* Initialize a timer handle.
*
* The rte_timer_init() function initializes the timer handle *tim*
* for use. No operations can be performed on a timer before it is
* initialized.
*
* @param tim
* The timer to initialize.
*/
void rte_timer_init(struct rte_timer *tim);
/**
* Reset and start the timer associated with the timer handle.
*
* The rte_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_lcore*.
*
* 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.
*
* @param tim
* The timer handle.
* @param ticks
* The number of cycles (see rte_get_hpet_hz()) before the callback
* function is called.
* @param 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.
* @param tim_lcore
* The ID of the lcore where the timer callback function has to be
* executed. If tim_lcore is LCORE_ID_ANY, the timer library will
* launch it on a different core for each call (round-robin).
* @param fct
* The callback function of the timer.
* @param arg
* The user argument of the callback function.
* @return
* - 0: Success; the timer is scheduled.
* - (-1): Timer is in the RUNNING or CONFIG state.
*/
int rte_timer_reset(struct rte_timer *tim, uint64_t ticks,
enum rte_timer_type type, unsigned tim_lcore,
rte_timer_cb_t fct, void *arg);
/**
* Loop until rte_timer_reset() succeeds.
*
* Reset and start the timer associated with the timer handle. Always
* succeed. See rte_timer_reset() for details.
*
* @param tim
* The timer handle.
* @param ticks
* The number of cycles (see rte_get_hpet_hz()) before the callback
* function is called.
* @param 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.
* @param tim_lcore
* The ID of the lcore where the timer callback function has to be
* executed. If tim_lcore is LCORE_ID_ANY, the timer library will
* launch it on a different core for each call (round-robin).
* @param fct
* The callback function of the timer.
* @param arg
* The user argument of the callback function.
*/
void
rte_timer_reset_sync(struct rte_timer *tim, uint64_t ticks,
enum rte_timer_type type, unsigned tim_lcore,
rte_timer_cb_t fct, void *arg);
/**
* Stop a timer.
*
* The rte_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 rte_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).
*
* @param tim
* The timer handle.
* @return
* - 0: Success; the timer is stopped.
* - (-1): The timer is in the RUNNING or CONFIG state.
*/
int rte_timer_stop(struct rte_timer *tim);
/**
* Loop until rte_timer_stop() succeeds.
*
* After a call to this function, the timer identified by *tim* is
* stopped. See rte_timer_stop() for details.
*
* @param tim
* The timer handle.
*/
void rte_timer_stop_sync(struct rte_timer *tim);
/**
* Test if a timer is pending.
*
* The rte_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.
*
* @param tim
* The timer handle.
* @return
* - 0: The timer is not pending.
* - 1: The timer is pending.
*/
int rte_timer_pending(struct rte_timer *tim);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Time until the next timer on the current lcore
* This function gives the ticks until the next timer will be active.
*
* @return
* - -EINVAL: invalid timer data instance identifier
* - -ENOENT: no timer pending
* - 0: a timer is pending and will run at next rte_timer_manage()
* - >0: ticks until the next timer is ready
*/
__rte_experimental
int64_t rte_timer_next_ticks(void);
/**
* Manage the timer list and execute callback functions.
*
* This function must be called periodically from EAL lcores
* 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.
*
* @return
* - 0: Success
* - -EINVAL: timer subsystem not yet initialized
*/
int rte_timer_manage(void);
/**
* Dump statistics about timers.
*
* @param f
* A pointer to a file for output
* @return
* - 0: Success
* - -EINVAL: timer subsystem not yet initialized
*/
int rte_timer_dump_stats(FILE *f);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* This function is the same as rte_timer_reset(), except that it allows a
* caller to specify the rte_timer_data instance containing the list to which
* the timer should be added.
*
* @see rte_timer_reset()
*
* @param timer_data_id
* An identifier indicating which instance of timer data should be used for
* this operation.
* @param tim
* The timer handle.
* @param ticks
* The number of cycles (see rte_get_hpet_hz()) before the callback
* function is called.
* @param 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.
* @param tim_lcore
* The ID of the lcore where the timer callback function has to be
* executed. If tim_lcore is LCORE_ID_ANY, the timer library will
* launch it on a different core for each call (round-robin).
* @param fct
* The callback function of the timer. This parameter can be NULL if (and
* only if) rte_timer_alt_manage() will be used to manage this timer.
* @param arg
* The user argument of the callback function.
* @return
* - 0: Success; the timer is scheduled.
* - (-1): Timer is in the RUNNING or CONFIG state.
* - -EINVAL: invalid timer_data_id
*/
__rte_experimental
int
rte_timer_alt_reset(uint32_t timer_data_id, struct rte_timer *tim,
uint64_t ticks, enum rte_timer_type type,
unsigned int tim_lcore, rte_timer_cb_t fct, void *arg);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* This function is the same as rte_timer_stop(), except that it allows a
* caller to specify the rte_timer_data instance containing the list from which
* this timer should be removed.
*
* @see rte_timer_stop()
*
* @param timer_data_id
* An identifier indicating which instance of timer data should be used for
* this operation.
* @param tim
* The timer handle.
* @return
* - 0: Success; the timer is stopped.
* - (-1): The timer is in the RUNNING or CONFIG state.
* - -EINVAL: invalid timer_data_id
*/
__rte_experimental
int
rte_timer_alt_stop(uint32_t timer_data_id, struct rte_timer *tim);
/**
* Callback function type for rte_timer_alt_manage().
*/
typedef void (*rte_timer_alt_manage_cb_t)(struct rte_timer *tim);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Manage a set of timer lists and execute the specified callback function for
* all expired timers. This function is similar to rte_timer_manage(), except
* that it allows a caller to specify the timer_data instance that should
* be operated on, as well as a set of lcore IDs identifying which timer lists
* should be processed. Callback functions of individual timers are ignored.
*
* @see rte_timer_manage()
*
* @param timer_data_id
* An identifier indicating which instance of timer data should be used for
* this operation.
* @param poll_lcores
* An array of lcore ids identifying the timer lists that should be processed.
* NULL is allowed - if NULL, the timer list corresponding to the lcore
* calling this routine is processed (same as rte_timer_manage()).
* @param n_poll_lcores
* The size of the poll_lcores array. If 'poll_lcores' is NULL, this parameter
* is ignored.
* @param f
* The callback function which should be called for all expired timers.
* @return
* - 0: success
* - -EINVAL: invalid timer_data_id
*/
__rte_experimental
int
rte_timer_alt_manage(uint32_t timer_data_id, unsigned int *poll_lcores,
int n_poll_lcores, rte_timer_alt_manage_cb_t f);
/**
* Callback function type for rte_timer_stop_all().
*/
typedef void (*rte_timer_stop_all_cb_t)(struct rte_timer *tim, void *arg);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Walk the pending timer lists for the specified lcore IDs, and for each timer
* that is encountered, stop it and call the specified callback function to
* process it further.
*
* @param timer_data_id
* An identifier indicating which instance of timer data should be used for
* this operation.
* @param walk_lcores
* An array of lcore ids identifying the timer lists that should be processed.
* @param nb_walk_lcores
* The size of the walk_lcores array.
* @param f
* The callback function which should be called for each timers. Can be NULL.
* @param f_arg
* An arbitrary argument that will be passed to f, if it is called.
* @return
* - 0: success
* - EINVAL: invalid timer_data_id
*/
__rte_experimental
int
rte_timer_stop_all(uint32_t timer_data_id, unsigned int *walk_lcores,
int nb_walk_lcores, rte_timer_stop_all_cb_t f, void *f_arg);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* This function is the same as rte_timer_dump_stats(), except that it allows
* the caller to specify the rte_timer_data instance that should be used.
*
* @see rte_timer_dump_stats()
*
* @param timer_data_id
* An identifier indicating which instance of timer data should be used for
* this operation.
* @param f
* A pointer to a file for output
* @return
* - 0: success
* - -EINVAL: invalid timer_data_id
*/
__rte_experimental
int
rte_timer_alt_dump_stats(uint32_t timer_data_id, FILE *f);
#ifdef __cplusplus
}
#endif
#endif /* _RTE_TIMER_H_ */