ardupilot/libraries/AP_HAL_ChibiOS/Scheduler.h

/*
 * This file is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This file is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * Code by Andrew Tridgell and Siddharth Bharat Purohit
 */
#pragma once

#include <AP_HAL/AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_CHIBIOS
#include "AP_HAL_ChibiOS_Namespace.h"

#define CHIBIOS_SCHEDULER_MAX_TIMER_PROCS 8

#define APM_MAIN_PRIORITY_BOOST 180 // same as normal for now
#define APM_MAIN_PRIORITY       180
#define APM_TIMER_PRIORITY      178
#define APM_RCIN_PRIORITY       177
#define APM_UART_PRIORITY        60
#define APM_STORAGE_PRIORITY     59
#define APM_IO_PRIORITY          58
#define APM_SHELL_PRIORITY       57
#define APM_STARTUP_PRIORITY     10

#ifndef APM_SPI_PRIORITY
#define APM_SPI_PRIORITY        179
#endif

#ifndef APM_UAVCAN_PRIORITY
#define APM_UAVCAN_PRIORITY     178
#endif

#ifndef APM_CAN_PRIORITY
#define APM_CAN_PRIORITY        177
#endif

#ifndef APM_I2C_PRIORITY
#define APM_I2C_PRIORITY        176
#endif

/* how long to boost priority of the main thread for each main
   loop. This needs to be long enough for all interrupt-level drivers
   (mostly SPI drivers) to run, and for the main loop of the vehicle
   code to start the AHRS update.

   Priority boosting of the main thread in delay_microseconds_boost()
   avoids the problem that drivers in hpwork all happen to run right
   at the start of the period where the main vehicle loop is calling
   wait_for_sample(). That causes main loop timing jitter, which
   reduces performance. Using the priority boost the main loop
   temporarily runs at a priority higher than hpwork and the timer
   thread, which results in much more consistent loop timing.
*/
#define APM_MAIN_PRIORITY_BOOST_USEC 150

#define APM_MAIN_THREAD_STACK_SIZE 8192

/* Scheduler implementation: */
class ChibiOS::Scheduler : public AP_HAL::Scheduler {
public:
    Scheduler();
    /* AP_HAL::Scheduler methods */


    void     init();
    void     delay(uint16_t ms);
    void     delay_microseconds(uint16_t us);
    void     delay_microseconds_boost(uint16_t us);
    void     register_delay_callback(AP_HAL::Proc, uint16_t min_time_ms);
    void     register_timer_process(AP_HAL::MemberProc);
    void     register_io_process(AP_HAL::MemberProc);
    void     register_timer_failsafe(AP_HAL::Proc, uint32_t period_us);
    void     suspend_timer_procs();
    void     resume_timer_procs();
    void     reboot(bool hold_in_bootloader);

    bool     in_main_thread() const override;
    void     system_initialized();
    void     hal_initialized() { _hal_initialized = true; }

private:
    bool _initialized;
    volatile bool _hal_initialized;
    AP_HAL::Proc _delay_cb;
    uint16_t _min_delay_cb_ms;
    AP_HAL::Proc _failsafe;

    volatile bool _timer_suspended;

    AP_HAL::MemberProc _timer_proc[CHIBIOS_SCHEDULER_MAX_TIMER_PROCS];
    uint8_t _num_timer_procs;
    volatile bool _in_timer_proc;

    AP_HAL::MemberProc _io_proc[CHIBIOS_SCHEDULER_MAX_TIMER_PROCS];
    uint8_t _num_io_procs;
    volatile bool _in_io_proc;

    volatile bool _timer_event_missed;

    thread_t* _timer_thread_ctx;
    thread_t* _rcin_thread_ctx;
    thread_t* _io_thread_ctx;
    thread_t* _storage_thread_ctx;
#if HAL_WITH_UAVCAN
    thread_t* _uavcan_thread_ctx;
#endif
    static void _timer_thread(void *arg);
    static void _rcin_thread(void *arg);
    static void _io_thread(void *arg);
    static void _storage_thread(void *arg);
    static void _uart_thread(void *arg);
#if HAL_WITH_UAVCAN
    static void _uavcan_thread(void *arg);
#endif
    void _run_timers(bool called_from_timer_thread);
    void _run_io(void);
};
#endif