Files
allwpilib/hal/src/main/native/include/wpi/hal/Notifier.h
2025-11-07 23:09:21 -08:00

125 lines
3.8 KiB
C

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.
#pragma once
#include <stdint.h>
#include "wpi/hal/Types.h"
#include "wpi/util/nodiscard.h"
/**
* @defgroup hal_notifier Notifier Functions
* @ingroup hal_capi
* @{
*/
#ifdef __cplusplus
extern "C" {
#endif
/**
* Initializes a notifier.
*
* A notifier is an FPGA controller timer that triggers at requested intervals
* based on the FPGA time. This can be used to make precise control loops.
*
* @param[out] status Error status variable. 0 on success.
* @return the created notifier
*/
HAL_NotifierHandle HAL_InitializeNotifier(int32_t* status);
/**
* Sets the HAL notifier thread priority.
*
* The HAL notifier thread is responsible for managing the FPGA's notifier
* interrupt and waking up user's Notifiers when it's their time to run.
* Giving the HAL notifier thread real-time priority helps ensure the user's
* real-time Notifiers, if any, are notified to run in a timely manner.
*
* @param[in] realTime Set to true to set a real-time priority, false for
* standard priority.
* @param[in] priority Priority to set the thread to. For real-time, this is
* 1-99 with 99 being highest. For non-real-time, this is
* forced to 0. See "man 7 sched" for more details.
* @param[out] status Error status variable. 0 on success.
* @return True on success.
*/
HAL_Bool HAL_SetNotifierThreadPriority(HAL_Bool realTime, int32_t priority,
int32_t* status);
/**
* Sets the name of a notifier.
*
* @param[in] notifierHandle the notifier handle
* @param[in] name name
* @param[out] status Error status variable. 0 on success.
*/
void HAL_SetNotifierName(HAL_NotifierHandle notifierHandle, const char* name,
int32_t* status);
/**
* Stops a notifier from running.
*
* This will cause any call into HAL_WaitForNotifierAlarm to return with time =
* 0.
*
* @param[in] notifierHandle the notifier handle
* @param[out] status Error status variable. 0 on success.
*/
void HAL_StopNotifier(HAL_NotifierHandle notifierHandle, int32_t* status);
/**
* Cleans a notifier.
*
* Note this also stops a notifier if it is already running.
*
* @param[in] notifierHandle the notifier handle
*/
void HAL_CleanNotifier(HAL_NotifierHandle notifierHandle);
/**
* Updates the trigger time for a notifier.
*
* Note that this time is an absolute time relative to HAL_GetFPGATime()
*
* @param[in] notifierHandle the notifier handle
* @param[in] triggerTime the updated trigger time
* @param[out] status Error status variable. 0 on success.
*/
void HAL_UpdateNotifierAlarm(HAL_NotifierHandle notifierHandle,
uint64_t triggerTime, int32_t* status);
/**
* Cancels the next notifier alarm.
*
* This does not cause HAL_WaitForNotifierAlarm to return.
*
* @param[in] notifierHandle the notifier handle
* @param[out] status Error status variable. 0 on success.
*/
void HAL_CancelNotifierAlarm(HAL_NotifierHandle notifierHandle,
int32_t* status);
/**
* Waits for the next alarm for the specific notifier.
*
* This is a blocking call until either the time elapses or HAL_StopNotifier
* gets called. If the latter occurs, this function will return zero and any
* loops using this function should exit. Failing to do so can lead to
* use-after-frees.
*
* @param[in] notifierHandle the notifier handle
* @param[out] status Error status variable. 0 on success.
* @return the FPGA time the notifier returned
*/
WPI_NODISCARD
uint64_t HAL_WaitForNotifierAlarm(HAL_NotifierHandle notifierHandle,
int32_t* status);
#ifdef __cplusplus
} // extern "C"
#endif
/** @} */