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rte_event_timer_adapter.h(3) DPDK rte_event_timer_adapter.h(3)

NAME

rte_event_timer_adapter.h

SYNOPSIS

#include 'rte_eventdev.h'
#include 'rte_eventdev_trace_fp.h'

Data Structures


struct rte_event_timer_adapter_conf
struct rte_event_timer_adapter_stats
struct rte_event_timer_adapter_info
struct rte_event_timer

Macros


#define RTE_EVENT_TIMER_ADAPTER_F_ADJUST_RES (1ULL << 0)
#define RTE_EVENT_TIMER_ADAPTER_F_SP_PUT (1ULL << 1)
#define RTE_EVENT_TIMER_ADAPTER_F_PERIODIC (1ULL << 2)

Typedefs


typedef int(* rte_event_timer_adapter_port_conf_cb_t) (uint16_t id, uint8_t event_dev_id, uint8_t *event_port_id, void *conf_arg)

Enumerations


enum rte_event_timer_adapter_clk_src { RTE_EVENT_TIMER_ADAPTER_CPU_CLK, RTE_EVENT_TIMER_ADAPTER_EXT_CLK0, RTE_EVENT_TIMER_ADAPTER_EXT_CLK1, RTE_EVENT_TIMER_ADAPTER_EXT_CLK2, RTE_EVENT_TIMER_ADAPTER_EXT_CLK3 }
enum rte_event_timer_state { RTE_EVENT_TIMER_NOT_ARMED = 0, RTE_EVENT_TIMER_ARMED = 1, RTE_EVENT_TIMER_CANCELED = 2, RTE_EVENT_TIMER_ERROR = -1, RTE_EVENT_TIMER_ERROR_TOOEARLY = -2, RTE_EVENT_TIMER_ERROR_TOOLATE = -3 }

Functions


struct rte_event_timer_adapter * rte_event_timer_adapter_create (const struct rte_event_timer_adapter_conf *conf)
struct rte_event_timer_adapter * rte_event_timer_adapter_create_ext (const struct rte_event_timer_adapter_conf *conf, rte_event_timer_adapter_port_conf_cb_t conf_cb, void *conf_arg)
int rte_event_timer_adapter_get_info (const struct rte_event_timer_adapter *adapter, struct rte_event_timer_adapter_info *adapter_info)
int rte_event_timer_adapter_start (const struct rte_event_timer_adapter *adapter)
int rte_event_timer_adapter_stop (const struct rte_event_timer_adapter *adapter)
struct rte_event_timer_adapter * rte_event_timer_adapter_lookup (uint16_t adapter_id)
int rte_event_timer_adapter_free (struct rte_event_timer_adapter *adapter)
int rte_event_timer_adapter_service_id_get (struct rte_event_timer_adapter *adapter, uint32_t *service_id)
int rte_event_timer_adapter_stats_get (struct rte_event_timer_adapter *adapter, struct rte_event_timer_adapter_stats *stats)
int rte_event_timer_adapter_stats_reset (struct rte_event_timer_adapter *adapter)
static uint16_t rte_event_timer_arm_burst (const struct rte_event_timer_adapter *adapter, struct rte_event_timer **evtims, uint16_t nb_evtims)
static uint16_t rte_event_timer_arm_tmo_tick_burst (const struct rte_event_timer_adapter *adapter, struct rte_event_timer **evtims, const uint64_t timeout_ticks, const uint16_t nb_evtims)
static uint16_t rte_event_timer_cancel_burst (const struct rte_event_timer_adapter *adapter, struct rte_event_timer **evtims, uint16_t nb_evtims)
__rte_experimental int rte_event_timer_remaining_ticks_get (const struct rte_event_timer_adapter *adapter, const struct rte_event_timer *evtim, uint64_t *ticks_remaining)

Detailed Description

RTE Event Timer Adapter

An event timer adapter has the following abstract working model:



                          timer_tick_ns


                              +


                 +-------+    |


                 |       |    |


         +-------+ bkt 0 +----v---+


         |       |       |        |


         |       +-------+        |


     +---+---+                +---+---+  +---+---+---+---+


     |       |                |       |  |   |   |   |   |


     | bkt n |                | bkt 1 |<-> t0| t1| t2| tn|


     |       |                |       |  |   |   |   |   |


     +---+---+                +---+---+  +---+---+---+---+


         |     Timer adapter      |


     +---+---+                +---+---+


     |       |                |       |


     | bkt 4 |                | bkt 2 |<--- Current bucket


     |       |                |       |


     +---+---+                +---+---+


          |      +-------+       |


          |      |       |       |


          +------+ bkt 3 +-------+


                 |       |


                 +-------+
  • It has a virtual monotonically increasing 64-bit timer adapter clock based on enum rte_event_timer_adapter_clk_src clock source. The clock source could be a CPU clock, or a platform dependent external clock.
  • The application creates a timer adapter instance with given the clock source, the total number of event timers, and a resolution(expressed in ns) to traverse between the buckets.
  • Each timer adapter may have 0 to n buckets based on the configured max timeout(max_tmo_ns) and resolution(timer_tick_ns). Upon starting the timer adapter, the adapter starts ticking at timer_tick_ns resolution.
  • The application arms an event timer that will expire timer_tick_ns from now.
  • The application can cancel an armed timer and no timer expiry event will be generated.
  • If a timer expires then the library injects the timer expiry event in the designated event queue.
  • The timer expiry event will be received through rte_event_dequeue_burst.
  • The application frees the timer adapter instance.

Multiple timer adapters can be created with a varying level of resolution for various expiry use cases that run in parallel.

Before using the timer adapter, the application has to create and configure an event device along with the event port. Based on the event device capability it might require creating an additional event port to be used by the timer adapter.

The application creates the event timer adapter using the rte_event_timer_adapter_create(). The event device id is passed to this function, inside this function the event device capability is checked, and if an in-built port is absent the application uses the default function to create a new producer port.

The application may also use the function rte_event_timer_adapter_create_ext() to have granular control over producer port creation in a case where the in-built port is absent.

After creating the timer adapter, the application has to start it using rte_event_timer_adapter_start(). The buckets are traversed from 0 to n; when the adapter ticks, the next bucket is visited. Each time, the list per bucket is processed, and timer expiry events are sent to the designated event queue.

The application can arm one or more event timers using the rte_event_timer_arm_burst(). The timeout_ticks represents the number of timer_tick_ns after which the timer has to expire. The timeout at which the timers expire can be grouped or be independent of each event timer instance. rte_event_timer_arm_tmo_tick_burst() addresses the former case and rte_event_timer_arm_burst() addresses the latter case.

The application can cancel the timers from expiring using the rte_event_timer_cancel_burst().

On the secondary process, rte_event_timer_adapter_lookup() can be used to get the timer adapter pointer from its id and use it to invoke fastpath operations such as arm and cancel.

Some of the use cases of event timer adapter are Beacon Timers, Generic SW Timeout, Wireless MAC Scheduling, 3G Frame Protocols, Packet Scheduling, Protocol Retransmission Timers, Supervision Timers. All these use cases require high resolution and low time drift.

Definition in file rte_event_timer_adapter.h.

Macro Definition Documentation

#define RTE_EVENT_TIMER_ADAPTER_F_ADJUST_RES (1ULL << 0)

The event timer adapter implementation may have constraints on the resolution (timer_tick_ns) and maximum timer expiry timeout(max_tmo_ns) based on the given timer adapter or system. If this flag is set, the implementation adjusts the resolution and maximum timeout to the best possible configuration. On successful timer adapter creation, the application can get the configured resolution and max timeout with rte_event_timer_adapter_get_info().

See also

struct rte_event_timer_adapter_info::min_resolution_ns

struct rte_event_timer_adapter_info::max_tmo_ns

Definition at line 145 of file rte_event_timer_adapter.h.

#define RTE_EVENT_TIMER_ADAPTER_F_SP_PUT (1ULL << 1)

rte_event_timer_arm_burst() API to be used in single producer mode.

See also

struct rte_event_timer_adapter_conf::flags

Definition at line 150 of file rte_event_timer_adapter.h.

#define RTE_EVENT_TIMER_ADAPTER_F_PERIODIC (1ULL << 2)

Flag to configure an event timer adapter in periodic mode; non-periodic mode is the default. A timer will fire once or periodically until the timer is cancelled based on the adapter mode.

See also

struct rte_event_timer_adapter_conf::flags

Definition at line 158 of file rte_event_timer_adapter.h.

Typedef Documentation

typedef int(* rte_event_timer_adapter_port_conf_cb_t) (uint16_t id, uint8_t event_dev_id, uint8_t *event_port_id, void *conf_arg)

Callback function type for producer port creation.

Definition at line 205 of file rte_event_timer_adapter.h.

Enumeration Type Documentation

enum rte_event_timer_adapter_clk_src

Timer adapter clock source

Enumerator

Use CPU clock as the clock source.
Platform dependent external clock source 0.
Platform dependent external clock source 1.
Platform dependent external clock source 2.
Platform dependent external clock source 3.

Definition at line 121 of file rte_event_timer_adapter.h.

enum rte_event_timer_state

Event timer state.

Enumerator

Event timer not armed.
Event timer successfully armed.
Event timer successfully canceled.
Generic event timer error.
Event timer timeout tick value is too small for the adapter to handle, given its configured resolution.
Event timer timeout tick is greater than the maximum timeout.

Definition at line 455 of file rte_event_timer_adapter.h.

Function Documentation

struct rte_event_timer_adapter* rte_event_timer_adapter_create (const struct rte_event_timer_adapter_conf * conf)

Create an event timer adapter.

This function must be invoked first before any other function in the API.

When this API is used for creating adapter instance, rte_event_dev_config::nb_event_ports is automatically incremented, and the event device is reconfigured with additional event port during service initialization. This event device reconfigure logic also increments the rte_event_dev_config::nb_single_link_event_port_queues parameter if the adapter event port config is of type RTE_EVENT_PORT_CFG_SINGLE_LINK.

Application no longer needs to account for rte_event_dev_config::nb_event_ports and rte_event_dev_config::nb_single_link_event_port_queues parameters required for Timer adapter in event device configuration when the adapter is created with this API.

Parameters

conf The event timer adapter configuration structure.

Returns

A pointer to the new allocated event timer adapter on success. NULL on error with rte_errno set appropriately. Possible rte_errno values include:
  • ERANGE: timer_tick_ns is not in supported range.
  • ENOMEM: unable to allocate sufficient memory for adapter instances
  • EINVAL: invalid event device identifier specified in config
  • ENOSPC: maximum number of adapters already created
  • EIO: event device reconfiguration and restart error. The adapter reconfigures the event device with an additional port by default if it is required to use a service to manage timers. If the device had been started before this call, this error code indicates an error in restart following an error in reconfiguration, i.e., a combination of the two error codes.

struct rte_event_timer_adapter* rte_event_timer_adapter_create_ext (const struct rte_event_timer_adapter_conf * conf, rte_event_timer_adapter_port_conf_cb_t conf_cb, void * conf_arg)

Create a timer adapter with the supplied callback.

This function can be used to have a more granular control over the timer adapter creation. If a built-in port is absent, then the function uses the callback provided to create and get the port id to be used as a producer port.

Parameters

conf The timer adapter configuration structure
conf_cb The port config callback function.
conf_arg Opaque pointer to the argument for the callback function

Returns

A pointer to the new allocated event timer adapter on success. NULL on error with rte_errno set appropriately. Possible rte_errno values include:
  • ERANGE: timer_tick_ns is not in supported range.
  • ENOMEM: unable to allocate sufficient memory for adapter instances
  • EINVAL: invalid event device identifier specified in config
  • ENOSPC: maximum number of adapters already created

int rte_event_timer_adapter_get_info (const struct rte_event_timer_adapter * adapter, struct rte_event_timer_adapter_info * adapter_info)

Retrieve the contextual information of an event timer adapter.

Parameters

adapter A pointer to the event timer adapter structure.
adapter_info A pointer to a structure of type rte_event_timer_adapter_info to be filled with the contextual information of the adapter.

Returns

  • 0: Success, driver updates the contextual information of the timer adapter
  • <0: Error code returned by the driver info get function.
  • -EINVAL: adapter identifier invalid

See also

RTE_EVENT_TIMER_ADAPTER_F_ADJUST_RES, struct rte_event_timer_adapter_info

int rte_event_timer_adapter_start (const struct rte_event_timer_adapter * adapter)

Start a timer adapter.

The adapter start step is the last one and consists of setting the timer adapter to start accepting the timers and schedules to event queues.

On success, all basic functions exported by the API (timer arm, timer cancel and so on) can be invoked.

Parameters

adapter A pointer to the event timer adapter structure.

Returns

  • 0: Success, adapter started.
  • <0: Error code returned by the driver start function.
  • -EINVAL if adapter identifier invalid
  • -ENOENT if software adapter but no service core mapped
  • -ENOTSUP if software adapter and more than one service core mapped
  • -EALREADY if adapter has already been started

Note

The eventdev to which the event_timer_adapter is connected needs to be started before calling rte_event_timer_adapter_start().

int rte_event_timer_adapter_stop (const struct rte_event_timer_adapter * adapter)

Stop an event timer adapter.

The adapter can be restarted with a call to rte_event_timer_adapter_start().

Parameters

adapter A pointer to the event timer adapter structure.

Returns

  • 0: Success, adapter stopped.
  • <0: Error code returned by the driver stop function.
  • -EINVAL if adapter identifier invalid

struct rte_event_timer_adapter* rte_event_timer_adapter_lookup (uint16_t adapter_id)

Lookup an event timer adapter using its identifier.

If an event timer adapter was created in another process with the same identifier, this function will locate its state and set up access to it so that it can be used in this process.

Parameters

adapter_id The event timer adapter identifier.

Returns

A pointer to the event timer adapter matching the identifier on success. NULL on error with rte_errno set appropriately. Possible rte_errno values include:
•
ENOENT - requested entry not available to return.

int rte_event_timer_adapter_free (struct rte_event_timer_adapter * adapter)

Free an event timer adapter.

Destroy an event timer adapter, freeing all resources.

Before invoking this function, the application must wait for all the armed timers to expire or cancel the outstanding armed timers.

Parameters

adapter A pointer to an event timer adapter structure.

Returns

  • 0: Successfully freed the event timer adapter resources.
  • <0: Failed to free the event timer adapter resources.
  • -EAGAIN: adapter is busy; timers outstanding
  • -EBUSY: stop hasn't been called for this adapter yet
  • -EINVAL: adapter id invalid, or adapter invalid

int rte_event_timer_adapter_service_id_get (struct rte_event_timer_adapter * adapter, uint32_t * service_id)

Retrieve the service ID of the event timer adapter. If the adapter doesn't use an rte_service function, this function returns -ESRCH.

Parameters

adapter A pointer to an event timer adapter.
service_id A pointer to a uint32_t, to be filled in with the service id.

Returns

  • 0: Success
  • <0: Error code on failure
  • -ESRCH: the adapter does not require a service to operate

int rte_event_timer_adapter_stats_get (struct rte_event_timer_adapter * adapter, struct rte_event_timer_adapter_stats * stats)

Retrieve statistics for an event timer adapter instance.

Parameters

adapter A pointer to an event timer adapter structure.
stats A pointer to a structure to fill with statistics.

Returns

  • 0: Successfully retrieved.
  • <0: Failure; error code returned.

int rte_event_timer_adapter_stats_reset (struct rte_event_timer_adapter * adapter)

Reset statistics for an event timer adapter instance.

Parameters

adapter A pointer to an event timer adapter structure.

Returns

  • 0: Successfully reset;
  • <0: Failure; error code returned.

static uint16_t rte_event_timer_arm_burst (const struct rte_event_timer_adapter * adapter, struct rte_event_timer ** evtims, uint16_t nb_evtims) [inline], [static]

Arm a burst of event timers with separate expiration timeout tick for each event timer.

Before calling this function, the application allocates struct rte_event_timer objects from mempool or huge page backed application buffers of desired size. On successful allocation, application updates the struct rte_event_timer` attributes such as expiry event attributes, timeout ticks from now. This function submits the event timer arm requests to the event timer adapter and on expiry, the events will be injected to designated event queue. Timer expiry events will be generated once or periodically until cancellation based on the adapter mode.

Parameters

adapter A pointer to an event timer adapter structure.
evtims Pointer to an array of objects of type rte_event_timer structure.
nb_evtims Number of event timers in the supplied array.

Returns

The number of successfully armed event timers. The return value can be less than the value of the nb_evtims parameter. If the return value is less than nb_evtims, the remaining event timers at the end of evtims are not consumed, and the caller has to take care of them, and rte_errno is set accordingly. Possible errno values include:
  • EINVAL Invalid timer adapter, expiry event queue ID is invalid, or an expiry event's sched type doesn't match the capabilities of the destination event queue.
  • EAGAIN Specified timer adapter is not running
  • EALREADY A timer was encountered that was already armed

See also

RTE_EVENT_TIMER_ADAPTER_F_PERIODIC

Definition at line 598 of file rte_event_timer_adapter.h.

static uint16_t rte_event_timer_arm_tmo_tick_burst (const struct rte_event_timer_adapter * adapter, struct rte_event_timer ** evtims, const uint64_t timeout_ticks, const uint16_t nb_evtims) [inline], [static]

Arm a burst of event timers with same expiration timeout tick.

Provides the same functionality as rte_event_timer_arm_burst(), except that application can use this API when all the event timers have the same timeout expiration tick. This specialized function can provide the additional hint to the adapter implementation and optimize if possible.

Parameters

adapter A pointer to an event timer adapter structure.
evtims Points to an array of objects of type rte_event_timer structure.
timeout_ticks The number of ticks in which the timers should expire.
nb_evtims Number of event timers in the supplied array.

Returns

The number of successfully armed event timers. The return value can be less than the value of the nb_evtims parameter. If the return value is less than nb_evtims, the remaining event timers at the end of evtims are not consumed, and the caller has to take care of them, and rte_errno is set accordingly. Possible errno values include:
  • EINVAL Invalid timer adapter, expiry event queue ID is invalid, or an expiry event's sched type doesn't match the capabilities of the destination event queue.
  • EAGAIN Specified event timer adapter is not running
  • EALREADY A timer was encountered that was already armed

Definition at line 641 of file rte_event_timer_adapter.h.

static uint16_t rte_event_timer_cancel_burst (const struct rte_event_timer_adapter * adapter, struct rte_event_timer ** evtims, uint16_t nb_evtims) [inline], [static]

Cancel a burst of event timers from being scheduled to the event device.

Parameters

adapter A pointer to an event timer adapter structure.
evtims Points to an array of objects of type rte_event_timer structure
nb_evtims Number of event timer instances in the supplied array.

Returns

The number of successfully canceled event timers. The return value can be less than the value of the nb_evtims parameter. If the return value is less than nb_evtims, the remaining event timers at the end of evtims are not consumed, and the caller has to take care of them, and rte_errno is set accordingly. Possible errno values include:
  • EINVAL Invalid timer adapter identifier
  • EAGAIN Specified timer adapter is not running
  • EALREADY A timer was encountered that was already canceled

Definition at line 678 of file rte_event_timer_adapter.h.

__rte_experimental int rte_event_timer_remaining_ticks_get (const struct rte_event_timer_adapter * adapter, const struct rte_event_timer * evtim, uint64_t * ticks_remaining)

Get the number of ticks remaining until event timer expiry.

Parameters

adapter A pointer to an event timer adapter structure
evtim A pointer to an rte_event_timer structure
ticks_remaining Pointer to variable into which to write the number of ticks remaining until event timer expiry

Returns

  • 0: Success
  • -EINVAL Invalid timer adapter identifier or the event timer is not in the armed state or ticks_remaining is NULL
  • -ENOTSUP The timer adapter implementation does not support this API.

Author

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Fri Dec 15 2023 Version 23.11.0