The Threads namespace is for wrapper functions for common general multithreading algorithms and tasks. More...

Classes
class	atomic
	Defines atomic operations which can only be executed on a single thread at a time. More...

class	BlockedRange
	Blocked range which can be subdivided and executed in parallel. More...

class	BoolAcquire
	We use a class to turn Threads::in_threads on and off, to be exception-safe. More...

class	DisablePerfLogInScope
	We use a class to turn perf logging off and on within threads, to be exception-safe and to avoid forcing indirect inclusion of libmesh_logging.h everywhere. More...

class	NonConcurrentThread
	Simple compatibility class for std::thread 'concurrent' execution. More...

class	RangeBody

class	recursive_mutex
	Recursive mutex. More...

class	scalable_allocator
	Scalable allocator to be used in multithreaded code chunks which allocate a lot of dynamic memory. More...

class	spin_mutex
	Spin mutex. More...

class	split
	Dummy "splitting object" used to distinguish splitting constructors from copy constructors. More...

class	task_scheduler_init
	Scheduler to manage threads. More...

Typedefs
typedef NonConcurrentThread	Thread
	Use the non-concurrent placeholder. More...

typedef tbb::task_scheduler_init	task_scheduler_init
	Scheduler to manage threads. More...

typedef tbb::split	split
	Dummy "splitting object" used to distinguish splitting constructors from copy constructors. More...

typedef tbb::spin_mutex	spin_mutex
	Spin mutex. More...

typedef tbb::recursive_mutex	recursive_mutex
	Recursive mutex. More...

Functions
void	lock_singleton_spin_mutex ()

void	unlock_singleton_spin_mutex ()

template<typename Range , typename Body >
void	parallel_for (const Range &range, const Body &body)
	Execute the provided function object in parallel on the specified range. More...

template<typename Range , typename Body , typename Partitioner >
void	parallel_for (const Range &range, const Body &body, const Partitioner &)
	Execute the provided function object in parallel on the specified range with the specified partitioner. More...

template<typename Range , typename Body >
void	parallel_reduce (const Range &range, Body &body)
	Execute the provided reduction operation in parallel on the specified range. More...

template<typename Range , typename Body , typename Partitioner >
void	parallel_reduce (const Range &range, Body &body, const Partitioner &)
	Execute the provided reduction operation in parallel on the specified range with the specified partitioner. More...

template<typename Range >
unsigned int	num_pthreads (Range &range)

template<typename Range , typename Body >
void *	run_body (void *args)

Variables
bool	in_threads = false
	A boolean which is true iff we are in a Threads:: function It may be useful to assert(!Threadsin_threads) in any code which is known to not be thread-safe. More...

spin_mutex	spin_mtx
	A convenient spin mutex object which can be used for obtaining locks. More...

recursive_mutex	recursive_mtx
	A convenient recursive mutex object which can be used for obtaining locks. More...

Detailed Description

The Threads namespace is for wrapper functions for common general multithreading algorithms and tasks.

Typedef Documentation

◆ recursive_mutex

typedef tbb::recursive_mutex libMesh::Threads::recursive_mutex

Recursive mutex.

Implements mutual exclusion by busy-waiting in user space for the lock to be acquired. The same thread can acquire the same lock multiple times

Definition at line 174 of file threads_tbb.h.

◆ spin_mutex

typedef tbb::spin_mutex libMesh::Threads::spin_mutex

Spin mutex.

Implements mutual exclusion by busy-waiting in user space for the lock to be acquired.

Definition at line 167 of file threads_tbb.h.

◆ split

typedef tbb::split libMesh::Threads::split

Dummy "splitting object" used to distinguish splitting constructors from copy constructors.

Definition at line 77 of file threads_tbb.h.

◆ task_scheduler_init

typedef tbb::task_scheduler_init libMesh::Threads::task_scheduler_init

Scheduler to manage threads.

Definition at line 71 of file threads_tbb.h.

◆ Thread

typedef tbb::tbb_thread libMesh::Threads::Thread

Use the non-concurrent placeholder.

Thread object abstraction that provides a basic constructor and support for join().

Use std::thread when available.

Definition at line 43 of file threads_none.h.

Function Documentation

◆ lock_singleton_spin_mutex()

void libMesh::Threads::lock_singleton_spin_mutex ( )

Definition at line 34 of file threads.C.

References libMesh::Threads::spin_mutex::lock(), and spin_mtx.

34 { spin_mtx.lock(); }

libMesh::Threads::spin_mutex::lock

void lock()

Definition: threads_none.h:131

libMesh::Threads::spin_mtx

spin_mutex spin_mtx

A convenient spin mutex object which can be used for obtaining locks.

Definition: threads.C:30

◆ num_pthreads()

template<typename Range >

unsigned int libMesh::Threads::num_pthreads ( Range & range )

Definition at line 214 of file threads_pthread.h.

References libMesh::n_threads().

 {
   std::size_t min = std::min((std::size_t)libMesh::n_threads(), range.size());
   return min > 0 ? cast_int<unsigned int>(min) : 1;
 }

◆ parallel_for() [1/2]

template<typename Range , typename Body >

void libMesh::Threads::parallel_for	(	const Range &	range,
		const Body &	body
	)

inline

Execute the provided function object in parallel on the specified range.

Definition at line 73 of file threads_none.h.

References in_threads.

Referenced by libMesh::FEMSystem::assemble_qoi_derivative(), libMesh::FEMSystem::assembly(), libMesh::MeshCommunication::assign_global_indices(), libMesh::System::boundary_project_vector(), libMesh::MeshCommunication::check_for_duplicate_global_indices(), libMesh::DofMap::create_dof_constraints(), libMesh::WeightedPatchRecoveryErrorEstimator::estimate_error(), libMesh::PatchRecoveryErrorEstimator::estimate_error(), and libMesh::FEMSystem::postprocess().

 {
   BoolAcquire b(in_threads);
   body(range);
 }

◆ parallel_for() [2/2]

template<typename Range , typename Body , typename Partitioner >

void libMesh::Threads::parallel_for	(	const Range &	range,
		const Body &	body,
		const Partitioner &	partitioner
	)

inline

Execute the provided function object in parallel on the specified range with the specified partitioner.

Definition at line 87 of file threads_none.h.

References in_threads.

 {
   BoolAcquire b(in_threads);
   body(range);
 }

◆ parallel_reduce() [1/2]

template<typename Range , typename Body >

void libMesh::Threads::parallel_reduce	(	const Range &	range,
		Body &	body
	)

inline

Execute the provided reduction operation in parallel on the specified range.

Definition at line 101 of file threads_none.h.

References in_threads.

Referenced by libMesh::FEMSystem::assemble_qoi(), libMesh::DofMap::build_sparsity(), libMesh::MeshTools::create_bounding_box(), libMesh::MeshTools::create_local_bounding_box(), libMesh::MeshTools::create_nodal_bounding_box(), libMesh::MeshTools::create_processor_bounding_box(), libMesh::MeshTools::create_subdomain_bounding_box(), main(), libMesh::GenericProjector< FFunctor, GFunctor, FValue, ProjectionAction >::project(), libMesh::System::project_vector(), libMesh::MeshTools::total_weight(), and libMesh::MeshTools::weight().

 {
   BoolAcquire b(in_threads);
   body(range);
 }

◆ parallel_reduce() [2/2]

template<typename Range , typename Body , typename Partitioner >

void libMesh::Threads::parallel_reduce	(	const Range &	range,
		Body &	body,
		const Partitioner &	partitioner
	)

inline

Execute the provided reduction operation in parallel on the specified range with the specified partitioner.

Definition at line 115 of file threads_none.h.

References in_threads.

 {
   BoolAcquire b(in_threads);
   body(range);
 }

◆ run_body()

template<typename Range , typename Body >

void* libMesh::Threads::run_body ( void * args )

Definition at line 229 of file threads_pthread.h.

References libMesh::Threads::RangeBody< Range, Body >::body, and libMesh::Threads::RangeBody< Range, Body >::range.

 {
   RangeBody<Range, Body> * range_body = (RangeBody<Range, Body> *)args;
 
   Body & body = *range_body->body;
   Range & range = *range_body->range;
 
   body(range);
 
   return nullptr;
 }

◆ unlock_singleton_spin_mutex()

void libMesh::Threads::unlock_singleton_spin_mutex ( )

Definition at line 35 of file threads.C.

References spin_mtx, and libMesh::Threads::spin_mutex::unlock().

35 { spin_mtx.unlock(); }

libMesh::Threads::spin_mutex::unlock

void unlock()

Definition: threads_none.h:132

libMesh::Threads::spin_mtx

spin_mutex spin_mtx

A convenient spin mutex object which can be used for obtaining locks.

Definition: threads.C:30

Variable Documentation

◆ in_threads

bool libMesh::Threads::in_threads = false

A boolean which is true iff we are in a Threads:: function It may be useful to assert(!Threadsin_threads) in any code which is known to not be thread-safe.

Definition at line 32 of file threads.C.

Referenced by parallel_for(), parallel_reduce(), libMesh::StaticCondensation::set_current_elem(), and libMesh::MeshBase::sub_point_locator().

◆ recursive_mtx

recursive_mutex libMesh::Threads::recursive_mtx

A convenient recursive mutex object which can be used for obtaining locks.

Definition at line 31 of file threads.C.

◆ spin_mtx

spin_mutex libMesh::Threads::spin_mtx

A convenient spin mutex object which can be used for obtaining locks.

Definition at line 30 of file threads.C.

Referenced by libMesh::FEAbstract::compute_node_constraints(), libMesh::FEGenericBase< FEOutputType< T >::type >::compute_periodic_constraints(), libMesh::FEAbstract::compute_periodic_node_constraints(), libMesh::FEGenericBase< FEOutputType< T >::type >::compute_proj_constraints(), libMesh::DofMap::constrain_p_dofs(), LaplaceSystem::element_postprocess(), libMesh::ReferenceCounter::increment_constructor_count(), libMesh::ReferenceCounter::increment_destructor_count(), libMesh::InfFE< Dim, T_radial, T_map >::inf_compute_constraints(), libMesh::VectorSetAction< Val >::insert(), libMesh::MatrixFillAction< ValIn, ValOut >::insert(), lock_singleton_spin_mutex(), libMesh::WeightedPatchRecoveryErrorEstimator::EstimateError::operator()(), libMesh::PatchRecoveryErrorEstimator::EstimateError::operator()(), libMesh::BoundaryProjectSolution::operator()(), LaplaceSystem::side_postprocess(), and unlock_singleton_spin_mutex().

Classes

Typedefs

Functions

Variables

Detailed Description

Typedef Documentation

◆ recursive_mutex

◆ spin_mutex

◆ split

◆ task_scheduler_init

◆ Thread

Function Documentation

◆ lock_singleton_spin_mutex()

◆ num_pthreads()

◆ parallel_for() [1/2]

◆ parallel_for() [2/2]

◆ parallel_reduce() [1/2]

◆ parallel_reduce() [2/2]

◆ run_body()

◆ unlock_singleton_spin_mutex()

Variable Documentation

◆ in_threads

◆ recursive_mtx

◆ spin_mtx