ITK  6.0.0
Insight Toolkit
Public Types | Public Member Functions | Static Public Member Functions | Protected Member Functions | Static Protected Member Functions | Private Member Functions | Static Private Member Functions | Private Attributes | Static Private Attributes | List of all members
itk::ThreadPool Class Reference

#include <itkThreadPool.h>

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:

Definition at line 55 of file itkThreadPool.h.

+ Inheritance diagram for itk::ThreadPool:
+ Collaboration diagram for itk::ThreadPool:

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)
ThreadIdType GetMaximumNumberOfThreads () const
const char * GetNameOfClass () const override
int GetNumberOfCurrentlyIdleThreads () const
template<class Function , class... Arguments>
auto AddWork (Function &&function, Arguments &&... arguments) -> std::future< std::invoke_result_t< Function, Arguments... >>
- Public Member Functions inherited from itk::Object
unsigned long AddObserver (const EventObject &event, Command *)
unsigned long AddObserver (const EventObject &event, Command *) const
unsigned long AddObserver (const EventObject &event, std::function< void(const EventObject &)> function) const
LightObject::Pointer CreateAnother () const override
virtual void DebugOff () const
virtual void DebugOn () const
CommandGetCommand (unsigned long tag)
bool GetDebug () const
MetaDataDictionaryGetMetaDataDictionary ()
const MetaDataDictionaryGetMetaDataDictionary () const
virtual ModifiedTimeType GetMTime () const
virtual const TimeStampGetTimeStamp () 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) const
void SetDebug (bool debugFlag) const
void SetReferenceCount (int) override
void UnRegister () const noexcept override
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
Pointer Clone () const
virtual void Delete ()
virtual int GetReferenceCount () const
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 val)
- Static Public Member Functions inherited from itk::LightObject
static void BreakOnError ()
static Pointer New ()

Protected Member Functions

void CleanUp ()
std::mutex & GetMutex () const
 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 &timeStamp)
 ~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 ()

Static Protected Member Functions

static void PrepareForFork ()
static void ResumeFromFork ()

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

◆ ConstPointer

Definition at line 64 of file itkThreadPool.h.

◆ Pointer

Definition at line 63 of file itkThreadPool.h.

◆ Self

Standard class type aliases.

Definition at line 61 of file itkThreadPool.h.

◆ Superclass

Definition at line 62 of file itkThreadPool.h.

Constructor & Destructor Documentation

◆ ThreadPool()

itk::ThreadPool::ThreadPool ( )

◆ ~ThreadPool()

itk::ThreadPool::~ThreadPool ( )

Definition at line 141 of file itkThreadPool.h.

Member Function Documentation

◆ AddThreads()

void itk::ThreadPool::AddThreads ( ThreadIdType  count)

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

◆ AddWork()

template<class Function , class... Arguments>
auto itk::ThreadPool::AddWork ( Function &&  function,
Arguments &&...  arguments 
) -> std::future<std::invoke_result_t<Function, Arguments...>>

Add this job to the thread pool queue.

This method returns an std::future, and calling get()
will block until the result is ready. Example usage:
auto result = pool->AddWork([](int param) { return param; }, 7);

std::cout << result.get() << std::endl;

Definition at line 87 of file itkThreadPool.h.

◆ CleanUp()

void itk::ThreadPool::CleanUp ( )

Stop the pool and release threads. To be called by the destructor and atfork.

◆ GetDoNotWaitForThreads()

static bool itk::ThreadPool::GetDoNotWaitForThreads ( )

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).

◆ GetInstance()

static Pointer itk::ThreadPool::GetInstance ( )

Returns the global singleton instance of the ThreadPool

◆ GetMaximumNumberOfThreads()

ThreadIdType itk::ThreadPool::GetMaximumNumberOfThreads ( ) const

Definition at line 109 of file itkThreadPool.h.

◆ GetMutex()

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

We need access to the mutex in AddWork, and the variable is only visible in the .cxx file, so this method returns it.

◆ GetNameOfClass()

const char* itk::ThreadPool::GetNameOfClass ( ) const
See also

Reimplemented from itk::Object.

◆ GetNumberOfCurrentlyIdleThreads()

int itk::ThreadPool::GetNumberOfCurrentlyIdleThreads ( ) const

The approximate number of idle threads.

◆ itkGetGlobalDeclarationMacro()

itk::ThreadPool::itkGetGlobalDeclarationMacro ( ThreadPoolGlobals  ,

Only used to synchronize the global variable across static libraries.

◆ New()

static Pointer itk::ThreadPool::New ( )

Returns the global instance

◆ PrepareForFork()

static void itk::ThreadPool::PrepareForFork ( )

◆ ResumeFromFork()

static void itk::ThreadPool::ResumeFromFork ( )

◆ SetDoNotWaitForThreads()

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

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).

◆ ThreadExecute()

static void itk::ThreadPool::ThreadExecute ( )

The continuously running thread function

Member Data Documentation

◆ m_Condition

std::condition_variable itk::ThreadPool::m_Condition

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

Definition at line 159 of file itkThreadPool.h.

◆ m_PimplGlobals

ThreadPoolGlobals* itk::ThreadPool::m_PimplGlobals

To lock on the internal variables

Definition at line 169 of file itkThreadPool.h.

◆ m_Stopping

bool itk::ThreadPool::m_Stopping { false }

Definition at line 166 of file itkThreadPool.h.

◆ m_Threads

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

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

Definition at line 163 of file itkThreadPool.h.

◆ m_WorkQueue

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

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 155 of file itkThreadPool.h.

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