text: 
  #ifndef __AP_HAL_VRBRAIN_SCHEDULER_H__
  #define __AP_HAL_VRBRAIN_SCHEDULER_H__
  
  #include <AP_HAL/AP_HAL.h>
  #if CONFIG_HAL_BOARD == HAL_BOARD_VRBRAIN
  #include "AP_HAL_VRBRAIN_Namespace.h"
  #include <sys/time.h>
  #include <signal.h>
  #include <pthread.h>
  #include <systemlib/perf_counter.h>
  
  #define VRBRAIN_SCHEDULER_MAX_TIMER_PROCS 8
  
  #define APM_MAIN_PRIORITY    180
  #define APM_TIMER_PRIORITY   181
  #define APM_UART_PRIORITY     60
  #define APM_IO_PRIORITY       59
  #define APM_OVERTIME_PRIORITY 10
  #define APM_STARTUP_PRIORITY  10
  
  /* Scheduler implementation: */
  class VRBRAIN::VRBRAINScheduler : public AP_HAL::Scheduler {
  public:
  	VRBRAINScheduler();
      /* AP_HAL::Scheduler methods */
  
      void     init(void *unused);
      void     delay(uint16_t ms);
      uint32_t millis();
      uint32_t micros();
      uint64_t millis64();
      uint64_t micros64();
      void     delay_microseconds(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);
      void     panic(const prog_char_t *errormsg, ...) FORMAT(2, 3) NORETURN;
  
      bool     in_timerprocess();
      bool     system_initializing();
      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_pending;
  
      volatile bool _timer_suspended;
  
      AP_HAL::MemberProc _timer_proc[VRBRAIN_SCHEDULER_MAX_TIMER_PROCS];
      uint8_t _num_timer_procs;
      volatile bool _in_timer_proc;
  
      AP_HAL::MemberProc _io_proc[VRBRAIN_SCHEDULER_MAX_TIMER_PROCS];
      uint8_t _num_io_procs;
      volatile bool _in_io_proc;
  
      volatile bool _timer_event_missed;
  
      pid_t _main_task_pid;
      pthread_t _timer_thread_ctx;
      pthread_t _io_thread_ctx;
      pthread_t _uart_thread_ctx;
  
      void *_timer_thread(void);
      void *_io_thread(void);
      void *_uart_thread(void);
  
      void _run_timers(bool called_from_timer_thread);
      void _run_io(void);
  
      void delay_microseconds_semaphore(uint16_t us);
  
      perf_counter_t  _perf_timers;
      perf_counter_t  _perf_io_timers;
      perf_counter_t  _perf_delay;
  };
  #endif
  #endif // __AP_HAL_VRBRAIN_SCHEDULER_H__
  
  
  