/* Copyright (c) 2012 Nordic Semiconductor. All Rights Reserved. * * The information contained herein is property of Nordic Semiconductor ASA. * Terms and conditions of usage are described in detail in NORDIC * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT. * * Licensees are granted free, non-transferable use of the information. NO * WARRANTY of ANY KIND is provided. This heading must NOT be removed from * the file. * */ #include "app_scheduler.h" #include #include #include #include "nrf_soc.h" #include "nrf_assert.h" #include "app_util.h" #include "app_util_platform.h" /**@brief Structure for holding a scheduled event header. */ typedef struct { app_sched_event_handler_t handler; /**< Pointer to event handler to receive the event. */ uint16_t event_data_size; /**< Size of event data. */ } event_header_t; STATIC_ASSERT(sizeof(event_header_t) <= APP_SCHED_EVENT_HEADER_SIZE); static event_header_t * m_queue_event_headers; /**< Array for holding the queue event headers. */ static uint8_t * m_queue_event_data; /**< Array for holding the queue event data. */ static volatile uint8_t m_queue_start_index; /**< Index of queue entry at the start of the queue. */ static volatile uint8_t m_queue_end_index; /**< Index of queue entry at the end of the queue. */ static uint16_t m_queue_event_size; /**< Maximum event size in queue. */ static uint16_t m_queue_size; /**< Number of queue entries. */ #ifdef APP_SCHEDULER_WITH_PROFILER static uint16_t m_max_queue_utilization; /**< Maximum observed queue utilization. */ #endif /**@brief Function for incrementing a queue index, and handle wrap-around. * * @param[in] index Old index. * * @return New (incremented) index. */ static __INLINE uint8_t next_index(uint8_t index) { return (index < m_queue_size) ? (index + 1) : 0; } static __INLINE uint8_t app_sched_queue_full() { uint8_t tmp = m_queue_start_index; return next_index(m_queue_end_index) == tmp; } /**@brief Macro for checking if a queue is full. */ #define APP_SCHED_QUEUE_FULL() app_sched_queue_full() static __INLINE uint8_t app_sched_queue_empty() { uint8_t tmp = m_queue_start_index; return m_queue_end_index == tmp; } /**@brief Macro for checking if a queue is empty. */ #define APP_SCHED_QUEUE_EMPTY() app_sched_queue_empty() uint32_t app_sched_init(uint16_t event_size, uint16_t queue_size, void * p_event_buffer) { uint16_t data_start_index = (queue_size + 1) * sizeof(event_header_t); // Check that buffer is correctly aligned if (!is_word_aligned(p_event_buffer)) { return NRF_ERROR_INVALID_PARAM; } // Initialize event scheduler m_queue_event_headers = p_event_buffer; m_queue_event_data = &((uint8_t *)p_event_buffer)[data_start_index]; m_queue_end_index = 0; m_queue_start_index = 0; m_queue_event_size = event_size; m_queue_size = queue_size; #ifdef APP_SCHEDULER_WITH_PROFILER m_max_queue_utilization = 0; #endif return NRF_SUCCESS; } #ifdef APP_SCHEDULER_WITH_PROFILER static void queue_utilization_check(void) { uint16_t start = m_queue_start_index; uint16_t end = m_queue_end_index; uint16_t queue_utilization = (end >= start) ? (end - start) : (m_queue_size + 1 - start + end); if (queue_utilization > m_max_queue_utilization) { m_max_queue_utilization = queue_utilization; } } uint16_t app_sched_queue_utilization_get(void) { return m_max_queue_utilization; } #endif uint32_t app_sched_event_put(void * p_event_data, uint16_t event_data_size, app_sched_event_handler_t handler) { uint32_t err_code; if (event_data_size <= m_queue_event_size) { uint16_t event_index = 0xFFFF; CRITICAL_REGION_ENTER(); if (!APP_SCHED_QUEUE_FULL()) { event_index = m_queue_end_index; m_queue_end_index = next_index(m_queue_end_index); #ifdef APP_SCHEDULER_WITH_PROFILER // This function call must be protected with critical region because // it modifies 'm_max_queue_utilization'. queue_utilization_check(); #endif } CRITICAL_REGION_EXIT(); if (event_index != 0xFFFF) { // NOTE: This can be done outside the critical region since the event consumer will // always be called from the main loop, and will thus never interrupt this code. m_queue_event_headers[event_index].handler = handler; if ((p_event_data != NULL) && (event_data_size > 0)) { memcpy(&m_queue_event_data[event_index * m_queue_event_size], p_event_data, event_data_size); m_queue_event_headers[event_index].event_data_size = event_data_size; } else { m_queue_event_headers[event_index].event_data_size = 0; } err_code = NRF_SUCCESS; } else { err_code = NRF_ERROR_NO_MEM; } } else { err_code = NRF_ERROR_INVALID_LENGTH; } return err_code; } /**@brief Function for reading the next event from specified event queue. * * @param[out] pp_event_data Pointer to pointer to event data. * @param[out] p_event_data_size Pointer to size of event data. * @param[out] p_event_handler Pointer to event handler function pointer. * * @return NRF_SUCCESS if new event, NRF_ERROR_NOT_FOUND if event queue is empty. */ static uint32_t app_sched_event_get(void ** pp_event_data, uint16_t * p_event_data_size, app_sched_event_handler_t * p_event_handler) { uint32_t err_code = NRF_ERROR_NOT_FOUND; if (!APP_SCHED_QUEUE_EMPTY()) { uint16_t event_index; // NOTE: There is no need for a critical region here, as this function will only be called // from app_sched_execute() from inside the main loop, so it will never interrupt // app_sched_event_put(). Also, updating of (i.e. writing to) the start index will be // an atomic operation. event_index = m_queue_start_index; m_queue_start_index = next_index(m_queue_start_index); *pp_event_data = &m_queue_event_data[event_index * m_queue_event_size]; *p_event_data_size = m_queue_event_headers[event_index].event_data_size; *p_event_handler = m_queue_event_headers[event_index].handler; err_code = NRF_SUCCESS; } return err_code; } void app_sched_execute(void) { void * p_event_data; uint16_t event_data_size; app_sched_event_handler_t event_handler; // Get next event (if any), and execute handler while ((app_sched_event_get(&p_event_data, &event_data_size, &event_handler) == NRF_SUCCESS)) { event_handler(p_event_data, event_data_size); } }