libMesh::Threads Namespace Reference

Classes
class	atomic
class	BlockedRange
class	BoolAcquire
class	NonConcurrentThread
class	RangeBody
class	recursive_mutex
class	scalable_allocator
class	spin_mutex
class	split
class	task_scheduler_init

Typedefs
typedef NonConcurrentThread	Thread
typedef tbb::task_scheduler_init	task_scheduler_init
typedef tbb::split	split
typedef tbb::spin_mutex	spin_mutex
typedef tbb::recursive_mutex	recursive_mutex

Functions
template<typename Range , typename Body >
void	parallel_for (const Range &range, const Body &body)
template<typename Range , typename Body , typename Partitioner >
void	parallel_for (const Range &range, const Body &body, const Partitioner &)
template<typename Range , typename Body >
void	parallel_reduce (const Range &range, Body &body)
template<typename Range , typename Body , typename Partitioner >
void	parallel_reduce (const Range &range, Body &body, const Partitioner &)
template<typename Range >
unsigned int	num_pthreads (Range &range)
template<typename Range , typename Body >
void *	run_body (void *args)

Variables
bool	in_threads = false
spin_mutex	spin_mtx
recursive_mutex	recursive_mtx

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 216 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 209 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 79 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 73 of file threads_tbb.h.

Thread

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

Use the non-concurrent placeholder.

Use std::thread when available.

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

Definition at line 43 of file threads_none.h.

Function Documentation

num_pthreads()

template<typename Range >

unsigned int libMesh::Threads::num_pthreads

(

Range &

range

)

Definition at line 214 of file threads_pthread.h.

References std::min(), and 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(), libMesh::FEMSystem::postprocess(), libMesh::System::project_vector(), and libMesh::System::projection_matrix().

{
  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(), 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;
}

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 31 of file threads.C.

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

recursive_mtx

Threads::recursive_mutex libMesh::Threads::recursive_mtx

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

Definition at line 30 of file threads.C.

spin_mtx

Threads::spin_mutex libMesh::Threads::spin_mtx

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

Definition at line 29 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(), libMesh::ReferenceCounter::increment_constructor_count(), libMesh::ReferenceCounter::increment_destructor_count(), libMesh::VectorSetAction< Val >::insert(), libMesh::MatrixFillAction< ValIn, ValOut >::insert(), libMesh::WeightedPatchRecoveryErrorEstimator::EstimateError::operator()(), libMesh::PatchRecoveryErrorEstimator::EstimateError::operator()(), and libMesh::BoundaryProjectSolution::operator()().