itk::ThreadPool Class Reference

#include <itkThreadPool.h>

Inheritance diagram for itk::ThreadPool:

Collaboration diagram for itk::ThreadPool:

Detailed Description

Thread pool maintains a constant number of threads.

Thread pool is called and initialized from within the PoolMultiThreader. Initially the thread pool is started with GlobalDefaultNumberOfThreads. The jobs are submitted via AddWork method.

This implementation heavily borrows from: https://github.com/progschj/ThreadPool

Definition at line 55 of file itkThreadPool.h.

Public Types
using	ConstPointer = SmartPointer< const Self >
using	Pointer = SmartPointer< Self >
using	Self = ThreadPool
using	Superclass = Object
Public Types inherited from itk::Object
using	ConstPointer = SmartPointer< const Self >
using	Pointer = SmartPointer< Self >
using	Self = Object
using	Superclass = LightObject
Public Types inherited from itk::LightObject
using	ConstPointer = SmartPointer< const Self >
using	Pointer = SmartPointer< Self >
using	Self = LightObject

Public Member Functions
void	AddThreads (ThreadIdType count)
m_WorkQueue	emplace_back ([task](){(*task)();})
ThreadIdType	GetMaximumNumberOfThreads () const
virtual const char *	GetNameOfClass () const
int	GetNumberOfCurrentlyIdleThreads () const
m_Condition	notify_one ()
Public Member Functions inherited from itk::Object
unsigned long	AddObserver (const EventObject &event, Command *)
unsigned long	AddObserver (const EventObject &event, Command *) const
LightObject::Pointer	CreateAnother () const override
virtual void	DebugOff () const
virtual void	DebugOn () const
Command *	GetCommand (unsigned long tag)
bool	GetDebug () const
MetaDataDictionary &	GetMetaDataDictionary ()
const MetaDataDictionary &	GetMetaDataDictionary () const
virtual ModifiedTimeType	GetMTime () const
virtual const TimeStamp &	GetTimeStamp () const
bool	HasObserver (const EventObject &event) const
void	InvokeEvent (const EventObject &)
void	InvokeEvent (const EventObject &) const
virtual void	Modified () const
void	Register () const override
void	RemoveAllObservers ()
void	RemoveObserver (unsigned long tag)
void	SetDebug (bool debugFlag) const
void	SetReferenceCount (int) override
void	UnRegister () const noexceptoverride
void	SetMetaDataDictionary (const MetaDataDictionary &rhs)
void	SetMetaDataDictionary (MetaDataDictionary &&rrhs)
virtual void	SetObjectName (std::string _arg)
virtual const std::string &	GetObjectName () const
Public Member Functions inherited from itk::LightObject
virtual void	Delete ()
virtual int	GetReferenceCount () const
	itkCloneMacro (Self)
void	Print (std::ostream &os, Indent indent=0) const

Static Public Member Functions
static Pointer	GetInstance ()
static Pointer	New ()
static bool	GetDoNotWaitForThreads ()
static void	SetDoNotWaitForThreads (bool doNotWaitForThreads)
Static Public Member Functions inherited from itk::Object
static bool	GetGlobalWarningDisplay ()
static void	GlobalWarningDisplayOff ()
static void	GlobalWarningDisplayOn ()
static Pointer	New ()
static void	SetGlobalWarningDisplay (bool flag)
Static Public Member Functions inherited from itk::LightObject
static void	BreakOnError ()
static Pointer	New ()

Public Attributes
std::future< return_type >	res = task->get_future()
return	res
auto	task

Protected Member Functions
std::mutex &	GetMutex ()
	ThreadPool ()
	~ThreadPool () override
Protected Member Functions inherited from itk::Object
	Object ()
bool	PrintObservers (std::ostream &os, Indent indent) const
void	PrintSelf (std::ostream &os, Indent indent) const override
virtual void	SetTimeStamp (const TimeStamp &time)
	~Object () override
Protected Member Functions inherited from itk::LightObject
virtual LightObject::Pointer	InternalClone () const
	LightObject ()
virtual void	PrintHeader (std::ostream &os, Indent indent) const
virtual void	PrintTrailer (std::ostream &os, Indent indent) const
virtual	~LightObject ()

Private Member Functions
	itkGetGlobalDeclarationMacro (ThreadPoolGlobals, PimplGlobals)

Static Private Member Functions
static void	ThreadExecute ()

Private Attributes
std::condition_variable	m_Condition
bool	m_Stopping { false }
std::vector< std::thread >	m_Threads
std::deque< std::function < void() > >	m_WorkQueue

Static Private Attributes
static ThreadPoolGlobals *	m_PimplGlobals

Additional Inherited Members
Protected Attributes inherited from itk::LightObject
std::atomic< int >	m_ReferenceCount

Member Typedef Documentation

using itk::ThreadPool::ConstPointer = SmartPointer<const Self>

Definition at line 64 of file itkThreadPool.h.

using itk::ThreadPool::Pointer = SmartPointer< Self >

Definition at line 63 of file itkThreadPool.h.

using itk::ThreadPool::Self = ThreadPool

Standard class type aliases.

Definition at line 61 of file itkThreadPool.h.

using itk::ThreadPool::Superclass = Object

Definition at line 62 of file itkThreadPool.h.

Constructor & Destructor Documentation

itk::ThreadPool::ThreadPool ( )

protected

itk::ThreadPool::~ThreadPool ( )

overrideprotected

Member Function Documentation

void itk::ThreadPool::AddThreads

(

ThreadIdType

count

)

Can call this method if we want to add extra threads to the pool.

m_WorkQueue itk::ThreadPool::emplace_back

(

[task] (){(*task)();}

)

static bool itk::ThreadPool::GetDoNotWaitForThreads ( )

static

Set/Get wait for threads. This function should be used carefully, probably only during static initialization phase to disable waiting for threads when ITK is built as a static library and linked into a shared library (Windows only).

static Pointer itk::ThreadPool::GetInstance ( )

static

Returns the global singleton instance of the ThreadPool

ThreadIdType itk::ThreadPool::GetMaximumNumberOfThreads ( ) const

inline

Definition at line 104 of file itkThreadPool.h.

std::mutex& itk::ThreadPool::GetMutex ( )

protected

virtual const char* itk::ThreadPool::GetNameOfClass ( ) const

virtual

Run-time type information (and related methods).

Reimplemented from itk::Object.

int itk::ThreadPool::GetNumberOfCurrentlyIdleThreads

(

)

const

The approximate number of idle threads.

itk::ThreadPool::itkGetGlobalDeclarationMacro ( ThreadPoolGlobals  , PimplGlobals    )

private

Only used to synchronize the global variable across static libraries.

static Pointer itk::ThreadPool::New ( )

static

Returns the global instance

m_Condition itk::ThreadPool::notify_one

(

)

static void itk::ThreadPool::SetDoNotWaitForThreads ( bool  doNotWaitForThreads )

static

Set/Get wait for threads. This function should be used carefully, probably only during static initialization phase to disable waiting for threads when ITK is built as a static library and linked into a shared library (Windows only).

static void itk::ThreadPool::ThreadExecute ( )

staticprivate

The continuously running thread function

Member Data Documentation

std::condition_variable itk::ThreadPool::m_Condition

private

When a thread is idle, it is waiting on m_Condition. AddWork signals it to resume a (random) thread.

Definition at line 141 of file itkThreadPool.h.

ThreadPoolGlobals* itk::ThreadPool::m_PimplGlobals

staticprivate

To lock on the internal variables

Definition at line 151 of file itkThreadPool.h.

bool itk::ThreadPool::m_Stopping { false }

private

Definition at line 148 of file itkThreadPool.h.

std::vector< std::thread > itk::ThreadPool::m_Threads

private

Vector to hold all thread handles. Thread handles are used to delete (join) the threads.

Definition at line 145 of file itkThreadPool.h.

std::deque< std::function< void() > > itk::ThreadPool::m_WorkQueue

private

This is a list of jobs submitted to the thread pool. This is the only place where the jobs are submitted. Filled by AddWork, emptied by ThreadExecute.

Definition at line 137 of file itkThreadPool.h.

std::future< return_type > itk::ThreadPool::res = task->get_future()

Definition at line 92 of file itkThreadPool.h.

return itk::ThreadPool::res

Definition at line 98 of file itkThreadPool.h.

auto itk::ThreadPool::task

Initial value:

= std::make_shared< std::packaged_task< return_type() > >(
      std::bind( std::forward< Function >( function ), std::forward< Arguments >( arguments )... ) )

Definition at line 89 of file itkThreadPool.h.

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The documentation for this class was generated from the following file:

• itkThreadPool.h