List of OpenMP* Runtime Library Routines

Function

Description

SUBROUTINE omp_set_num_threads(num_threads)

Sets the number of threads to use for subsequent parallel regions.

INTEGER FUNCTION omp_get_num_threads()

Returns the number of threads that are being used in the current parallel region.

INTEGER FUNCTION omp_get_max_threads()

Returns the maximum number of threads that are available for parallel execution.

INTEGER FUNCTION omp_get_thread_num()

Determines the unique thread number of the thread currently executing this section of code.

INTEGER FUNCTION omp_get_num_procs()

Determines the number of processors on the current machine.

LOGICAL FUNCTION omp_in_parallel()

Returns .TRUE. if called within the dynamic extent of a parallel region executing in parallel, otherwise returns .FALSE. .

SUBROUTINE omp_set_dynamic(dynamic_threads) INTEGER dynamic_threads

Enables or disables dynamic adjustment of the number of threads used to execute a parallel region. If dynamic_threads is non-zero, dynamic threads are enabled. If dynamic_threads is zero, dynamic threads are disabled.

LOGICAL FUNCTION omp_get_dynamic()

Returns .TRUE. if dynamic thread adjustment is enabled, otherwise returns .FALSE. .

SUBROUTINE omp_set_nested(nested)
INTEGER nested

Enables or disables nested parallelism. If parameter is non-zero, enable. Default is disabled.

LOGICAL FUNCTION omp_get_nested()

Determines whether nested parallelism is currently enabled or disabled. Function returns non-zero if nested parallelism is supported, zero otherwise. Always returns .FALSE. in the current version of compiler.

SUBROUTINE omp_init_lock(lock) INTEGER lock

Initializes a unique lock and set lock to its value.

SUBROUTINE omp_destroy_lock(lock)
INTEGER lock

 Disassociates lock from any locks.

SUBROUTINE omp_set_lock(lock)
INTEGER lock

Forces the executing thread to wait until the lock associated with lock is available. The thread is granted ownership of the lock when it becomes available.

SUBROUTINE omp_unset_lock(lock)
INTEGER lock

Releases executing thread from ownership of lock associated with lock. The lock argument must be initialized via omp_init_lock(), and behavior undefined if executing thread does not own the lock associated with lock.

INTEGER omp_test_lock(lock)

Attempts to set lock associated with lock. If successful, returns non-zero. lock must be initialized via omp_init_lock(lock).

SUBROUTINE omp_init_nest_lock(lock)
INTEGER lock

 Initializes a unique nested lock and set lock to its value.

SUBROUTINE omp_destroy_nest_lock(lock)
INTEGER lock

Disassociates the nested lock "lock" from any locks.

SUBROUTINE omp_set_nest_lock(lock)
INTEGER lock

Forces the executing thread to wait until the lock associated with lock is available. The thread is granted ownership of the lock when it becomes available.

SUBROUTINE omp_unset_nest_lock(lock)
INTEGER lock

Releases executing thread from ownership of lock associated with lock if count is zero. lock must be initialized via omp_init_nest_lock(). Behavior is undefined if executing thread does not own the lock associated with lock.

INTEGER omp_test_nest_lock(lock)

Attempts to set lock associated with lock. If successful, returns nesting count, otherwise returns zero. lock must be initialized via omp_init_lock().