os::rtos::clock_rtc Class Reference

Real time clock. More...

#include <cmsis-plus/rtos/os.h>

Inheritance diagram for os::rtos::clock_rtc:

Public Types
Types & Constants
using	duration_t = port::clock::duration_t
	Type of variables holding clock durations.
using	timestamp_t = port::clock::timestamp_t
	Type of variables holding clock time stamps.
using	offset_t = port::clock::offset_t
	Type of variables holding clock offsets.

Public Member Functions
Constructors & Destructor
	clock_rtc ()
	Construct a real time clock object instance.
virtual	~clock_rtc () override
	Destruct the real time clock object instance.
Public Member Functions
virtual void	start (void) override
	Initialise and make the RTC tick.
Public Member Functions
virtual timestamp_t	now (void) override
	Tell the current time adjusted for epoch.
virtual result_t	sleep_until (timestamp_t timestamp) override
	Sleep until an absolute timestamp.
virtual offset_t	offset (void) override
	Get adjustment offset.
virtual offset_t	offset (offset_t value) override
	Set adjustment offset.
void	internal_check_timestamps (void)
Public Member Functions
timestamp_t	steady_now (void)
	Tell the current time since startup.
result_t	sleep_for (duration_t duration)
	Sleep for a relative duration.
result_t	wait_for (duration_t timeout)
	Timed wait for an event.
timestamp_t	update_for_slept_time (duration_t duration)
	Increase the internal count after a deep sleep.
Public Member Functions
const char *	name (void) const
	Get object name.

Static Public Attributes
Types & Constants
static constexpr uint32_t	frequency_hz = 1
	Real time clock frequency in Hz.

Detailed Description

Definition at line 590 of file os-clocks.h.

Constructor & Destructor Documentation

clock_rtc()

os::rtos::clock_rtc::clock_rtc

(

)

~clock_rtc()

virtual os::rtos::clock_rtc::~clock_rtc ( )

overridevirtual

Member Function Documentation

internal_check_timestamps()

void os::rtos::adjustable_clock::internal_check_timestamps ( void  )

inherited

Referenced by os_rtc_handler().

name()

const char * os::rtos::internal::object_named::name ( void  ) const

inlineinherited

Parameters

None.

Returns

A null terminated string.

All objects return a non-null string; anonymous objects return "-".

Note

Can be invoked from Interrupt Service Routines.

Definition at line 753 of file os-decls.h.

      {
        return name_;
      }

Referenced by os::memory::lifo::lifo(), os::memory::malloc_memory_resource::malloc_memory_resource(), os::rtos::message_queue_typed< T, Allocator >::message_queue_typed(), os::memory::block_pool::~block_pool(), os::rtos::event_flags::~event_flags(), os::memory::first_fit_top::~first_fit_top(), os::memory::lifo::~lifo(), os::memory::malloc_memory_resource::~malloc_memory_resource(), os::rtos::memory_pool::~memory_pool(), os::rtos::message_queue::~message_queue(), os::rtos::mutex::~mutex(), os::rtos::semaphore::~semaphore(), os::rtos::thread::~thread(), os::rtos::timer::~timer(), os::rtos::memory_pool::alloc(), os::rtos::thread::cancel(), os::rtos::event_flags::clear(), os::rtos::mutex::consistent(), os::rtos::thread::detach(), os::memory::new_delete_memory_resource::do_allocate(), os::memory::block_pool::do_allocate(), os::memory::first_fit_top::do_allocate(), os::memory::lifo::do_allocate(), os::memory::malloc_memory_resource::do_allocate(), os::rtos::thread::flags_raise(), os::rtos::memory_pool::free(), os::rtos::event_flags::get(), os::rtos::thread::interrupt(), os::rtos::thread::join(), os::rtos::thread::kill(), os::rtos::internal::terminated_threads_list::link(), os::rtos::mutex::lock(), os::rtos::memory::memory_resource::out_of_memory_handler(), os::rtos::semaphore::post(), os::rtos::mutex::prio_ceiling(), os::rtos::mutex::prio_ceiling(), os::rtos::thread::priority(), os::rtos::thread::priority_inherited(), os::rtos::event_flags::raise(), os::rtos::message_queue::receive(), os::rtos::memory_pool::reset(), os::rtos::message_queue::reset(), os::rtos::mutex::reset(), os::rtos::semaphore::reset(), os::rtos::thread::resume(), os::rtos::message_queue::send(), os::rtos::clock::sleep_for(), os::rtos::timer::start(), os::rtos::timer::stop(), os::rtos::memory_pool::timed_alloc(), os::rtos::mutex::timed_lock(), os::rtos::message_queue::timed_receive(), os::rtos::message_queue::timed_send(), os::rtos::semaphore::timed_wait(), os::rtos::event_flags::timed_wait(), os::rtos::memory::memory_resource::trace_print_statistics(), os::rtos::memory_pool::try_alloc(), os::rtos::mutex::try_lock(), os::rtos::message_queue::try_receive(), os::rtos::message_queue::try_send(), os::rtos::event_flags::try_wait(), os::rtos::semaphore::try_wait(), os::rtos::internal::ready_threads_list::unlink_head(), os::rtos::mutex::unlock(), os::rtos::event_flags::wait(), os::rtos::semaphore::wait(), and os::rtos::event_flags::waiting().

now()

virtual timestamp_t os::rtos::adjustable_clock::now ( void  )

overridevirtualinherited

Parameters

None.

Returns

The clock current timestamp (time units from startup plus the epoch offset).

Reimplemented from os::rtos::clock.

Referenced by __posix_gettimeofday(), and os::estd::chrono::realtime_clock::now().

offset() [1/2]

virtual offset_t os::rtos::adjustable_clock::offset ( offset_t  value )

overridevirtualinherited

Parameters

[in]

value

Integer representing the offset to epoch (positive).

Returns

Integer value representing the previous offset to epoch.

Reimplemented from os::rtos::clock.

offset() [2/2]

virtual offset_t os::rtos::adjustable_clock::offset ( void  )

overridevirtualinherited

Parameters

None.

Returns

Integer value representing the offset to epoch.

Reimplemented from os::rtos::clock.

sleep_for()

result_t os::rtos::clock::sleep_for ( duration_t  duration )

inherited

Parameters

[in]

duration

The number of clock units (ticks or seconds) to sleep.

Return values

ETIMEDOUT	The sleep lasted the entire duration.
EPERM	Cannot be invoked from an Interrupt Service Routines.
EINTR	The sleep was interrupted.

Warning

Cannot be invoked from Interrupt Service Routines.

Definition at line 175 of file os-clocks.cpp.

    {
#if defined(OS_TRACE_RTOS_CLOCKS)
 
#pragma GCC diagnostic push
#if defined(__clang__)
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wuseless-cast"
#endif
      trace::printf ("%s(%u) %p %s\n", __func__,
                     static_cast<unsigned int> (duration),
                     &this_thread::thread (), this_thread::thread ().name ());
#pragma GCC diagnostic pop
 
#endif // defined(OS_TRACE_RTOS_CLOCKS)
 
      // Don't call this from interrupt handlers.
      os_assert_err (!interrupts::in_handler_mode (), EPERM);
      // Don't call this from critical regions.
      os_assert_err (!scheduler::locked (), EPERM);
 
      clock::timestamp_t timestamp = steady_now () + duration;
      for (;;)
        {
          result_t res;
          res = internal_wait_until_ (timestamp, steady_list_);
 
          timestamp_t n = steady_now ();
          if (n >= timestamp)
            {
              return ETIMEDOUT;
            }
 
          if (this_thread::thread ().interrupted ())
            {
              return EINTR;
            }
 
          if (res != result::ok)
            {
              return res;
            }
        }
      return ENOTRECOVERABLE;
    }

References os::rtos::interrupts::in_handler_mode(), os::rtos::scheduler::locked(), os::rtos::internal::object_named::name(), os::rtos::result::ok, os_assert_err, os::trace::printf(), os::rtos::clock::steady_now(), and os::rtos::this_thread::thread().

Referenced by os_sysclock_sleep_for(), and osDelay().

sleep_until()

virtual result_t os::rtos::adjustable_clock::sleep_until ( timestamp_t  timestamp )

overridevirtualinherited

Parameters

[in]

timestamp

The absolute moment in time, in clock units.

Return values

ETIMEDOUT	The sleep lasted the entire duration.
EPERM	Cannot be invoked from an Interrupt Service Routines.
EINTR	The sleep was interrupted.

Reimplemented from os::rtos::clock.

start()

virtual void os::rtos::clock_rtc::start ( void  )

overridevirtual

Parameters

None.

Returns

Nothing.

Implements os::rtos::clock.

Referenced by os::rtos::scheduler::start().

steady_now()

clock::timestamp_t os::rtos::clock::steady_now ( void  )

inherited

Parameters

None.

Returns

The clock current steady timestamp (time units from startup).

Note

Can be invoked from Interrupt Service Routines.

Definition at line 161 of file os-clocks.cpp.

    {
      // ----- Enter critical section -----------------------------------------
      interrupts::critical_section ics;
 
      // Prevent inconsistent values using the critical section.
      return steady_count_;
      // ----- Exit critical section ------------------------------------------
    }

Referenced by os::rtos::clock::sleep_for(), and os::rtos::clock::wait_for().

update_for_slept_time()

clock::timestamp_t os::rtos::clock::update_for_slept_time ( duration_t  duration )

inherited

Parameters

duration

Number of ticks lost during sleep.

Returns

The clock current steady timestamp (time units from startup).

During deep sleep the interrupts used to count clock ticks are usually disabled and an external RTC is configured to wake-up the device, so a number of clock ticks are lost.

To keep the clocks accurate, it is recommended to sample the external RTC before entering deep sleep and again when the device is back to life, compute the time slept as difference, and use this function to update the internal clock counter.

Definition at line 315 of file os-clocks.cpp.

    {
      // ----- Enter critical section -----------------------------------------
      interrupts::critical_section ics;
 
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wdeprecated-volatile"
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wvolatile"
#endif
      steady_count_ += duration;
#pragma GCC diagnostic pop
 
      internal_check_timestamps ();
      return steady_count_;
      // ----- Exit critical section ------------------------------------------
    }

wait_for()

result_t os::rtos::clock::wait_for ( duration_t  timeout )

inherited

Parameters

[in]

timeout

The timeout in clock units.

Return values

result::ok	An event occurred before the timeout.
ETIMEDOUT	The wait lasted the entire duration.
EPERM	Cannot be invoked from an Interrupt Service Routines.
EINTR	The sleep was interrupted.

Warning

Cannot be invoked from Interrupt Service Routines.

Definition at line 264 of file os-clocks.cpp.

    {
#if defined(OS_TRACE_RTOS_CLOCKS)
 
#pragma GCC diagnostic push
#if defined(__clang__)
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wuseless-cast"
#endif
      trace::printf ("%s(%u)\n", __func__,
                     static_cast<unsigned int> (timeout));
#pragma GCC diagnostic pop
 
#endif // defined(OS_TRACE_RTOS_CLOCKS)
 
      // Don't call this from interrupt handlers.
      os_assert_err (!interrupts::in_handler_mode (), EPERM);
      // Don't call this from critical regions.
      os_assert_err (!scheduler::locked (), EPERM);
 
      clock::timestamp_t timestamp = steady_now () + timeout;
 
      result_t res;
      res = internal_wait_until_ (timestamp, steady_list_);
 
      timestamp_t nw = steady_now ();
      if (nw >= timestamp)
        {
          return ETIMEDOUT;
        }
 
      if (this_thread::thread ().interrupted ())
        {
          return EINTR;
        }
 
      return res;
    }

References os::rtos::interrupts::in_handler_mode(), os::rtos::scheduler::locked(), os_assert_err, os::trace::printf(), os::rtos::clock::steady_now(), and os::rtos::this_thread::thread().

Referenced by os_sysclock_wait_for().

Member Data Documentation

frequency_hz

constexpr uint32_t os::rtos::clock_rtc::frequency_hz = 1

staticconstexpr

Definition at line 601 of file os-clocks.h.

---

The documentation for this class was generated from the following file:

• os-clocks.h