[thirdparty/gcc.git] / libgomp / doc / openmp-runtime-library-routines / ompgetnumthreads.rst

..
  Copyright 1988-2022 Free Software Foundation, Inc.
  This is part of the GCC manual.
  For copying conditions, see the copyright.rst file.

.. _omp_get_num_threads:

omp_get_num_threads -- Size of the active team
**********************************************

Description:
  Returns the number of threads in the current team.  In a sequential section of
  the program ``omp_get_num_threads`` returns 1.

  The default team size may be initialized at startup by the
  :envvar:`OMP_NUM_THREADS` environment variable.  At runtime, the size
  of the current team may be set either by the ``NUM_THREADS``
  clause or by ``omp_set_num_threads``.  If none of the above were
  used to define a specific value and :envvar:`OMP_DYNAMIC` is disabled,
  one thread per CPU online is used.

C/C++:
  .. list-table::

     * - *Prototype*:
       - ``int omp_get_num_threads(void);``

Fortran:
  .. list-table::

     * - *Interface*:
       - ``integer function omp_get_num_threads()``

See also:
  :ref:`omp_get_max_threads`, :ref:`omp_set_num_threads`, :ref:`OMP_NUM_THREADS`

Reference:
  :openmp:`4.5`, Section 3.2.2.
Commit	Line	Data
c63539ff ML	1	..
	2	Copyright 1988-2022 Free Software Foundation, Inc.
	3	This is part of the GCC manual.
	4	For copying conditions, see the copyright.rst file.
	5
	6	.. _omp_get_num_threads:
	7
	8	omp_get_num_threads -- Size of the active team
	9	**********************************************
	10
	11	Description:
	12	Returns the number of threads in the current team. In a sequential section of
	13	the program ``omp_get_num_threads`` returns 1.
	14
	15	The default team size may be initialized at startup by the
	16	:envvar:`OMP_NUM_THREADS` environment variable. At runtime, the size
	17	of the current team may be set either by the ``NUM_THREADS``
	18	clause or by ``omp_set_num_threads``. If none of the above were
	19	used to define a specific value and :envvar:`OMP_DYNAMIC` is disabled,
	20	one thread per CPU online is used.
	21
	22	C/C++:
	23	.. list-table::
	24
	25	* - Prototype:
	26	- ``int omp_get_num_threads(void);``
	27
	28	Fortran:
	29	.. list-table::
	30
	31	* - Interface:
	32	- ``integer function omp_get_num_threads()``
	33
	34	See also:
	35	:ref:`omp_get_max_threads`, :ref:`omp_set_num_threads`, :ref:`OMP_NUM_THREADS`
	36
	37	Reference:
3ed1b4ce	38	:openmp:`4.5`, Section 3.2.2.