/** * Copyright (c) 2012 - 2019, Nordic Semiconductor ASA * * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form, except as embedded into a Nordic * Semiconductor ASA integrated circuit in a product or a software update for * such product, must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other * materials provided with the distribution. * * 3. Neither the name of Nordic Semiconductor ASA nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * 4. This software, with or without modification, must only be used with a * Nordic Semiconductor ASA integrated circuit. * * 5. Any software provided in binary form under this license must not be reverse * engineered, decompiled, modified and/or disassembled. * * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ /** @file * * @defgroup app_scheduler Scheduler * @{ * @ingroup app_common * * @brief The scheduler is used for transferring execution from the interrupt context to the main * context. * * @details See @ref seq_diagrams_sched for sequence diagrams illustrating the flow of events * when using the Scheduler. * * @section app_scheduler_req Requirements: * * @subsection main_context_logic Logic in main context: * * - Define an event handler for each type of event expected. * - Initialize the scheduler by calling the APP_SCHED_INIT() macro before entering the * application main loop. * - Call app_sched_execute() from the main loop each time the application wakes up because of an * event (typically when sd_app_evt_wait() returns). * * @subsection int_context_logic Logic in interrupt context: * * - In the interrupt handler, call app_sched_event_put() * with the appropriate data and event handler. This will insert an event into the * scheduler's queue. The app_sched_execute() function will pull this event and call its * handler in the main context. * * @if (PERIPHERAL) * For an example usage of the scheduler, see the implementations of * @ref ble_sdk_app_hids_mouse and @ref ble_sdk_app_hids_keyboard. * @endif * * @image html scheduler_working.svg The high level design of the scheduler */ #ifndef APP_SCHEDULER_H__ #define APP_SCHEDULER_H__ #include "sdk_config.h" #include #include "app_error.h" #include "app_util.h" #ifdef __cplusplus extern "C" { #endif #define APP_SCHED_EVENT_HEADER_SIZE 8 /**< Size of app_scheduler.event_header_t (only for use inside APP_SCHED_BUF_SIZE()). */ /**@brief Compute number of bytes required to hold the scheduler buffer. * * @param[in] EVENT_SIZE Maximum size of events to be passed through the scheduler. * @param[in] QUEUE_SIZE Number of entries in scheduler queue (i.e. the maximum number of events * that can be scheduled for execution). * * @return Required scheduler buffer size (in bytes). */ #define APP_SCHED_BUF_SIZE(EVENT_SIZE, QUEUE_SIZE) \ (((EVENT_SIZE) + APP_SCHED_EVENT_HEADER_SIZE) * ((QUEUE_SIZE) + 1)) /**@brief Scheduler event handler type. */ typedef void (*app_sched_event_handler_t)(void * p_event_data, uint16_t event_size); /**@brief Macro for initializing the event scheduler. * * @details It will also handle dimensioning and allocation of the memory buffer required by the * scheduler, making sure the buffer is correctly aligned. * * @param[in] EVENT_SIZE Maximum size of events to be passed through the scheduler. * @param[in] QUEUE_SIZE Number of entries in scheduler queue (i.e. the maximum number of events * that can be scheduled for execution). * * @note Since this macro allocates a buffer, it must only be called once (it is OK to call it * several times as long as it is from the same location, e.g. to do a reinitialization). */ #define APP_SCHED_INIT(EVENT_SIZE, QUEUE_SIZE) \ do \ { \ static uint32_t APP_SCHED_BUF[CEIL_DIV(APP_SCHED_BUF_SIZE((EVENT_SIZE), (QUEUE_SIZE)), \ sizeof(uint32_t))]; \ uint32_t ERR_CODE = app_sched_init((EVENT_SIZE), (QUEUE_SIZE), APP_SCHED_BUF); \ APP_ERROR_CHECK(ERR_CODE); \ } while (0) /**@brief Function for initializing the Scheduler. * * @details It must be called before entering the main loop. * * @param[in] max_event_size Maximum size of events to be passed through the scheduler. * @param[in] queue_size Number of entries in scheduler queue (i.e. the maximum number of * events that can be scheduled for execution). * @param[in] p_evt_buffer Pointer to memory buffer for holding the scheduler queue. It must * be dimensioned using the APP_SCHED_BUFFER_SIZE() macro. The buffer * must be aligned to a 4 byte boundary. * * @note Normally initialization should be done using the APP_SCHED_INIT() macro, as that will both * allocate the scheduler buffer, and also align the buffer correctly. * * @retval NRF_SUCCESS Successful initialization. * @retval NRF_ERROR_INVALID_PARAM Invalid parameter (buffer not aligned to a 4 byte * boundary). */ uint32_t app_sched_init(uint16_t max_event_size, uint16_t queue_size, void * p_evt_buffer); /**@brief Function for executing all scheduled events. * * @details This function must be called from within the main loop. It will execute all events * scheduled since the last time it was called. */ void app_sched_execute(void); /**@brief Function for scheduling an event. * * @details Puts an event into the event queue. * * @param[in] p_event_data Pointer to event data to be scheduled. * @param[in] event_size Size of event data to be scheduled. * @param[in] handler Event handler to receive the event. * * @return NRF_SUCCESS on success, otherwise an error code. */ uint32_t app_sched_event_put(void const * p_event_data, uint16_t event_size, app_sched_event_handler_t handler); /**@brief Function for getting the maximum observed queue utilization. * * Function for tuning the module and determining QUEUE_SIZE value and thus module RAM usage. * * @note @ref APP_SCHEDULER_WITH_PROFILER must be enabled to use this functionality. * * @return Maximum number of events in queue observed so far. */ uint16_t app_sched_queue_utilization_get(void); /**@brief Function for getting the current amount of free space in the queue. * * @details The real amount of free space may be less if entries are being added from an interrupt. * To get the sxact value, this function should be called from the critical section. * * @return Amount of free space in the queue. */ uint16_t app_sched_queue_space_get(void); /**@brief A function to pause the scheduler. * * @details When the scheduler is paused events are not pulled from the scheduler queue for * processing. The function can be called multiple times. To unblock the scheduler the * function @ref app_sched_resume has to be called the same number of times. * * @note @ref APP_SCHEDULER_WITH_PAUSE must be enabled to use this functionality. */ void app_sched_pause(void); /**@brief A function to resume a scheduler. * * @details To unblock the scheduler this function has to be called the same number of times as * @ref app_sched_pause function. * * @note @ref APP_SCHEDULER_WITH_PAUSE must be enabled to use this functionality. */ void app_sched_resume(void); #ifdef __cplusplus } #endif #endif // APP_SCHEDULER_H__ /** @} */