/**
* Copyright (c) 2012 - 2017, 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
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* DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
#include "sdk_common.h"
#if NRF_MODULE_ENABLED(APP_SCHEDULER)
#include "app_scheduler.h"
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "nrf_soc.h"
#include "nrf_assert.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. */
#if APP_SCHEDULER_WITH_PROFILER
static uint16_t m_max_queue_utilization; /**< Maximum observed queue utilization. */
#endif
#if APP_SCHEDULER_WITH_PAUSE
static uint32_t m_scheduler_paused_counter = 0; /**< Counter storing the difference between pausing
and resuming the scheduler. */
#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;
#if APP_SCHEDULER_WITH_PROFILER
m_max_queue_utilization = 0;
#endif
return NRF_SUCCESS;
}
uint16_t app_sched_queue_space_get()
{
uint16_t start = m_queue_start_index;
uint16_t end = m_queue_end_index;
uint16_t free_space = m_queue_size - ((end >= start) ?
(end - start) : (m_queue_size + 1 - start + end));
return free_space;
}
#if 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 // APP_SCHEDULER_WITH_PROFILER
uint32_t app_sched_event_put(void const * 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);
#if 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;
}
#if APP_SCHEDULER_WITH_PAUSE
void app_sched_pause(void)
{
CRITICAL_REGION_ENTER();
if (m_scheduler_paused_counter < UINT32_MAX)
{
m_scheduler_paused_counter++;
}
CRITICAL_REGION_EXIT();
}
void app_sched_resume(void)
{
CRITICAL_REGION_ENTER();
if (m_scheduler_paused_counter > 0)
{
m_scheduler_paused_counter--;
}
CRITICAL_REGION_EXIT();
}
#endif //APP_SCHEDULER_WITH_PAUSE
/**@brief Function for checking if scheduler is paused which means that should break processing
* events.
*
* @return Boolean value - true if scheduler is paused, false otherwise.
*/
static __INLINE bool is_app_sched_paused(void)
{
#if APP_SCHEDULER_WITH_PAUSE
return (m_scheduler_paused_counter > 0);
#else
return false;
#endif
}
void app_sched_execute(void)
{
while (!is_app_sched_paused() && !APP_SCHED_QUEUE_EMPTY())
{
// Since this function is only called from the main loop, there is no
// need for a critical region here, however a special care must be taken
// regarding update of the queue start index (see the end of the loop).
uint16_t event_index = m_queue_start_index;
void * p_event_data;
uint16_t event_data_size;
app_sched_event_handler_t event_handler;
p_event_data = &m_queue_event_data[event_index * m_queue_event_size];
event_data_size = m_queue_event_headers[event_index].event_data_size;
event_handler = m_queue_event_headers[event_index].handler;
event_handler(p_event_data, event_data_size);
// Event processed, now it is safe to move the queue start index,
// so the queue entry occupied by this event can be used to store
// a next one.
m_queue_start_index = next_index(m_queue_start_index);
}
}
#endif //NRF_MODULE_ENABLED(APP_SCHEDULER)