.. SPDX-FileCopyrightText: 2019-2021 Intel Corporation .. .. SPDX-License-Identifier: CC-BY-4.0

================ tick_count class

[timing.tick_count]

A tick_count is an absolute wall clock timestamp. Two tick_count objects can be subtracted to compute wall clock duration tick_count::interval_t, which can be converted to seconds.

.. code:: cpp

namespace oneapi { namespace tbb {

   class tick_count {
   public:
       class interval_t;
       tick_count();
       tick_count( const tick_count& );
       ~tick_count();
       tick_count& operator=( const tick_count& );
       static tick_count now();
       static double resolution();
   };

} // namespace tbb } // namespace oneapi

tick_count() Constructs tick_count with an unspecified wall clock timestamp.

tick_count( const tick_count& ) Constructs tick_count with the timestamp of the given tick_count.

~tick_count() Destructor.

tick_count& operator=( const tick_count& ) Assigns the timestamp of one tick_count to another.

static tick_count now() Returns a tick_count object that represents the current wall clock timestamp.

static double resolution() Returns the resolution of the clock used by tick_count, in seconds.

============================ tick_count::interval_t class

[timing.tick_count.interval_t]

A tick_count::interval_t represents wall clock duration.

.. code:: cpp

namespace oneapi { namespace tbb {

   class tick_count::interval_t {
   public:
       interval_t();
       explicit interval_t( double );
       ~interval_t();
       interval_t& operator=( const interval_t& );
       interval_t& operator+=( const interval_t& );
       interval_t& operator-=( const interval_t& );
       double seconds() const;
   };

} // namespace tbb } // namespace oneapi

interval_t() Constructs interval_t representing zero time duration.

explicit interval_t( double ) Constructs interval_t representing the specified number of seconds.

~interval_t() Destructor.

interval_t& operator=( const interval_t& ) Assigns the wall clock duration of one interval_t to another.

interval_t& operator+=( const interval_t& ) Increases the duration to the given interval_t, and returns *this.

interval_t& operator-=( const interval_t& ) Decreases the duration to the given interval_t, and returns *this.

double seconds() const Returns the duration measured in seconds.

==================== Non-member functions

[timing.tick_count.nonmember]

These functions provide arithmetic binary operations with wall clock timestamps and durations.

.. code:: cpp

oneapi::tbb::tick_count::interval_t operator-( const oneapi::tbb::tick_count&, const oneapi::tbb::tick_count& ); oneapi::tbb::tick_count::interval_t operator+( const oneapi::tbb::tick_count::interval_t&, const oneapi::tbb::tick_count::interval_t& ); oneapi::tbb::tick_count::interval_t operator-( const oneapi::tbb::tick_count::interval_t&, const oneapi::tbb::tick_count::interval_t& );

The namespace where these functions are defined is unspecified as long as they may be used in respective binary operation expressions on tick_count and tick_count::interval_t objects. For example, an implementation may define the classes and functions in the same unspecified internal namespace, and define oneapi::tbb::tick_count as a type alias for which the non-member functions are reachable only via argument-dependent lookup.

oneapi::tbb::tick_count::interval_t operator-( const oneapi::tbb::tick_count&, const oneapi::tbb::tick_count& ) Returns interval_t representing the duration between two given wall clock timestamps.

oneapi::tbb::tick_count::interval_t operator+( const oneapi::tbb::tick_count::interval_t&, const oneapi::tbb::tick_count::interval_t& ) Returns interval_t representing the sum of two given intervals.

oneapi::tbb::tick_count::interval_t operator-( const oneapi::tbb::tick_count::interval_t&, const oneapi::tbb::tick_count::interval_t& ) Returns interval_t representing the difference of two given intervals.