itk::ThreadPool Class Reference

#include <itkThreadPool.h>

Inheritance diagram for itk::ThreadPool:

Collaboration diagram for itk::ThreadPool:

Detailed Description

Thread pool manages the threads for itk.

Thread pool is called and initialized from within the MultiThreader. Initially the thread pool is started with zero threads. Threads are added as job(s) are submitted to the thread pool and if it cannot be executed right away. For example : If the thread pool has three threads and all are busy. If a new job is submitted to the thread pool, the thread pool checks to see if any threads are free. If not, it adds a new thread and executed the job right away. The ThreadJob class is used to submit jobs to the thread pool. The ThreadJob's necessary members need to be set and then the ThreadJob can be passed to the ThreaadPool by calling its AssignWork Method which returns the thread id on which the job is being executed. One can then wait for the job using the thread id and calling the WaitForJob method on the thread pool.

Definition at line 72 of file itkThreadPool.h.

Classes
class	ThreadProcessIdentifiers
class	ThreadSemaphorePair

Public Types
typedef SmartPointer< const Self >	ConstPointer
typedef SmartPointer< Self >	Pointer
typedef ThreadPool	Self
typedef Object	Superclass
typedef unsigned int	ThreadCountType
typedef ThreadJob::JobIdType	ThreadJobIdType
typedef int	ThreadTimeType
Public Types inherited from itk::Object
typedef SmartPointer< const Self >	ConstPointer
typedef SmartPointer< Self >	Pointer
typedef Object	Self
typedef LightObject	Superclass
Public Types inherited from itk::LightObject
typedef SmartPointer< const Self >	ConstPointer
typedef SmartPointer< Self >	Pointer
typedef LightObject	Self

Public Member Functions
ThreadProcessIdType	AssignWork (ThreadJob worker)
virtual const char *	GetNameOfClass () const
void	InitializeThreads (ThreadCountType maxThreads)
bool	WaitForJobOnThreadHandle (ThreadProcessIdType handle)
Public Member Functions inherited from itk::Object
unsigned long	AddObserver (const EventObject &event, Command *)
unsigned long	AddObserver (const EventObject &event, Command *) const
virtual 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
virtual void	Register () const override
void	RemoveAllObservers ()
void	RemoveObserver (unsigned long tag)
void	SetDebug (bool debugFlag) const
void	SetMetaDataDictionary (const MetaDataDictionary &rhs)
virtual void	SetReferenceCount (int) override
virtual void	UnRegister () const noexceptoverride
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 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 ()

Protected Member Functions
	ThreadPool ()
virtual	~ThreadPool ()
Protected Member Functions inherited from itk::Object
	Object ()
bool	PrintObservers (std::ostream &os, Indent indent) const
virtual void	PrintSelf (std::ostream &os, Indent indent) const override
virtual void	SetTimeStamp (const TimeStamp &time)
virtual	~Object ()
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 Types
enum	{   JOB_THREADHANDLE_JUST_ADDED =-3,   JOB_THREADHANDLE_IS_FREE =-2,   JOB_THREADHANDLE_IS_DONE =-1 }
typedef std::pair < ThreadJobIdType, ThreadJob >	ThreadJobContainerPairType
typedef std::map < ThreadJobIdType, ThreadJob >	ThreadJobContainerType
typedef std::set< ThreadJobIdType >	ThreadJobIdsContainerType
typedef std::set < ThreadProcessIdType >	ThreadProcessIdContainerType

Private Member Functions
ThreadPool &	operator= (ThreadPool const &)
	ThreadPool (ThreadPool const &)

Private Attributes
bool	m_ExceptionOccurred
unsigned int	m_IdCounter
bool	m_ScheduleForDestruction
ThreadCountType	m_ThreadCount
ThreadProcessIdContainerType	m_ThreadHandles
ThreadJobContainerType	m_WorkerQueue

Static Private Attributes
static SimpleFastMutexLock	m_NumberOfPendingJobsToBeRunMutex
static SimpleFastMutexLock	m_WorkerQueueMutex
typedef std::vector < ThreadProcessIdentifiers >	ThreadProcessIdentifiersVecType
typedef std::vector < ThreadSemaphorePair * >	ThreadSemHandlePairingQueueType
ThreadProcessIdentifiersVecType	m_ThreadProcessIdentifiersVector
ThreadSemHandlePairingQueueType	m_ThreadSemHandlePairingQueue
ThreadSemHandlePairingQueueType	m_ThreadSemHandlePairingForWaitQueue
static SimpleFastMutexLock	m_ThreadProcessIdentifiersVectorMutex
static Pointer	m_ThreadPoolInstance
static SimpleFastMutexLock	m_ThreadPoolInstanceMutex
const ThreadJob &	FetchWork (ThreadProcessIdType t)
void	RemoveActiveId (ThreadJobIdType id)
void	AddThread ()
ThreadProcessIdentifiers *	FindThreadToRun ()
ThreadSemaphorePair *	GetSemaphore (ThreadSemHandlePairingQueueType &q, ThreadProcessIdType threadHandle)
ThreadSemaphorePair *	GetSemaphoreForThread (ThreadProcessIdType threadHandle)
ThreadSemaphorePair *	GetSemaphoreForThreadWait (ThreadProcessIdType threadHandle)
void	DeallocateThreadSemSet (ThreadSemHandlePairingQueueType &q)
ThreadProcessIdType	GetThreadHandleForThreadId (ThreadIdType id)
static void *	ThreadExecute (void *param)
static bool	CompareThreadHandles (ThreadProcessIdType t1, ThreadProcessIdType t2)

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

Member Typedef Documentation

typedef SmartPointer<const Self> itk::ThreadPool::ConstPointer

Definition at line 80 of file itkThreadPool.h.

typedef SmartPointer< Self > itk::ThreadPool::Pointer

Definition at line 79 of file itkThreadPool.h.

typedef ThreadPool itk::ThreadPool::Self

Standard class typedefs.

Definition at line 77 of file itkThreadPool.h.

typedef Object itk::ThreadPool::Superclass

Definition at line 78 of file itkThreadPool.h.

typedef unsigned int itk::ThreadPool::ThreadCountType

Definition at line 84 of file itkThreadPool.h.

typedef std::pair<ThreadJobIdType,ThreadJob> itk::ThreadPool::ThreadJobContainerPairType

private

Definition at line 157 of file itkThreadPool.h.

typedef std::map<ThreadJobIdType,ThreadJob> itk::ThreadPool::ThreadJobContainerType

private

Definition at line 155 of file itkThreadPool.h.

typedef std::set<ThreadJobIdType> itk::ThreadPool::ThreadJobIdsContainerType

private

Definition at line 159 of file itkThreadPool.h.

typedef ThreadJob::JobIdType itk::ThreadPool::ThreadJobIdType

Definition at line 85 of file itkThreadPool.h.

typedef std::set<ThreadProcessIdType> itk::ThreadPool::ThreadProcessIdContainerType

private

Definition at line 161 of file itkThreadPool.h.

typedef std::vector<ThreadProcessIdentifiers> itk::ThreadPool::ThreadProcessIdentifiersVecType

private

To lock on the vectors

Definition at line 226 of file itkThreadPool.h.

typedef std::vector<ThreadSemaphorePair *> itk::ThreadPool::ThreadSemHandlePairingQueueType

private

To lock on the vectors

Definition at line 230 of file itkThreadPool.h.

typedef int itk::ThreadPool::ThreadTimeType

local class typedefs.

Definition at line 83 of file itkThreadPool.h.

Member Enumeration Documentation

anonymous enum

private

Vector of pairs that hold job ids and their corresponding thread handles

Enumerator
JOB_THREADHANDLE_JUST_ADDED
JOB_THREADHANDLE_IS_FREE
JOB_THREADHANDLE_IS_DONE

Definition at line 178 of file itkThreadPool.h.

Constructor & Destructor Documentation

itk::ThreadPool::ThreadPool ( )

protected

virtual itk::ThreadPool::~ThreadPool ( )

protectedvirtual

itk::ThreadPool::ThreadPool ( ThreadPool const &  )

private

Member Function Documentation

void itk::ThreadPool::AddThread ( )

private

Called to add a thread to the thread pool. This method add a thread to the thread pool and pushes the thread handle into the m_ThreadHandles set

ThreadProcessIdType itk::ThreadPool::AssignWork

(

ThreadJob

worker

)

This method is called to assign a job to the thread pool

static bool itk::ThreadPool::CompareThreadHandles ( ThreadProcessIdType  t1, ThreadProcessIdType  t2  )

staticprivate

Method to compare thread handles - true for same false for different

void itk::ThreadPool::DeallocateThreadSemSet ( ThreadSemHandlePairingQueueType &  q )

private

To lock on the vectors

const ThreadJob& itk::ThreadPool::FetchWork ( ThreadProcessIdType  t )

private

This function is called by the threads to get jobs to be executed. This method is the "first" call from the threads in the thread pool. Now this method blocks the thread until a job is available for the thread to execute. Once a job is available(known from m_ThreadProcessIdentifiersVector), it gets it from the worker queue and returns it

ThreadProcessIdentifiers* itk::ThreadPool::FindThreadToRun ( )

private

To check if the thread pool has to add a thread. This method checks if any threads in the thread pool are free. If so, it returns false else returns true

static Pointer itk::ThreadPool::GetInstance ( )

static

Returns the global singleton instance of the ThreadPool

This method is a Singleton and does not have a New method.

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

virtual

Run-time type information (and related methods).

Reimplemented from itk::Object.

ThreadSemaphorePair* itk::ThreadPool::GetSemaphore ( ThreadSemHandlePairingQueueType &  q, ThreadProcessIdType  threadHandle  )

private

To lock on the vectors

ThreadSemaphorePair* itk::ThreadPool::GetSemaphoreForThread ( ThreadProcessIdType  threadHandle )

private

To lock on the vectors

ThreadSemaphorePair* itk::ThreadPool::GetSemaphoreForThreadWait ( ThreadProcessIdType  threadHandle )

private

To lock on the vectors

ThreadProcessIdType itk::ThreadPool::GetThreadHandleForThreadId ( ThreadIdType  id )

private

Used under windows - gets the thread handle associated with thread id

void itk::ThreadPool::InitializeThreads

(

ThreadCountType

maxThreads

)

Can call this method if we want to pre-start maxThreads in the thread pool

static Pointer itk::ThreadPool::New ( )

static

Returns the global instance of the ThreadPool

ThreadPool& itk::ThreadPool::operator= ( ThreadPool const &  )

private

void itk::ThreadPool::RemoveActiveId ( ThreadJobIdType  id )

private

Used to remove an active job id from the queue because it is done. This method is called by the threads once they are done with the job. This method removes the job id from m_ActiveJobIds, marks the thread as free by setting appropriate values in the m_ThreadProcessIdentifiersVector vector and removes the job from m_WorkerQueue

static void* itk::ThreadPool::ThreadExecute ( void *  param )

staticprivate

thread function

bool itk::ThreadPool::WaitForJobOnThreadHandle

(

ThreadProcessIdType

handle

)

This method blocks until the given (job) id has finished executing

Member Data Documentation

bool itk::ThreadPool::m_ExceptionOccurred

private

set if exception occurs

Definition at line 153 of file itkThreadPool.h.

unsigned int itk::ThreadPool::m_IdCounter

private

counter to assign job ids

Definition at line 150 of file itkThreadPool.h.

SimpleFastMutexLock itk::ThreadPool::m_NumberOfPendingJobsToBeRunMutex

staticprivate

To lock on m_NumberOfPendingJobsToBeRun

Definition at line 147 of file itkThreadPool.h.

bool itk::ThreadPool::m_ScheduleForDestruction

private

Set when the thread pool is to be stopped

Definition at line 141 of file itkThreadPool.h.

ThreadCountType itk::ThreadPool::m_ThreadCount

private

Maintains count of threads

Definition at line 144 of file itkThreadPool.h.

ThreadProcessIdContainerType itk::ThreadPool::m_ThreadHandles

private

Vector to hold all active thread handles

Definition at line 174 of file itkThreadPool.h.

Pointer itk::ThreadPool::m_ThreadPoolInstance

staticprivate

To lock on the vectors

Definition at line 262 of file itkThreadPool.h.

SimpleFastMutexLock itk::ThreadPool::m_ThreadPoolInstanceMutex

staticprivate

To lock on m_ThreadPoolInstance

Definition at line 264 of file itkThreadPool.h.

ThreadProcessIdentifiersVecType itk::ThreadPool::m_ThreadProcessIdentifiersVector

private

To lock on the vectors

Definition at line 227 of file itkThreadPool.h.

SimpleFastMutexLock itk::ThreadPool::m_ThreadProcessIdentifiersVectorMutex

staticprivate

To lock on the vectors

Definition at line 236 of file itkThreadPool.h.

ThreadSemHandlePairingQueueType itk::ThreadPool::m_ThreadSemHandlePairingForWaitQueue

private

To lock on the vectors

Definition at line 233 of file itkThreadPool.h.

ThreadSemHandlePairingQueueType itk::ThreadPool::m_ThreadSemHandlePairingQueue

private

To lock on the vectors

Definition at line 232 of file itkThreadPool.h.

ThreadJobContainerType itk::ThreadPool::m_WorkerQueue

private

this is a list of jobs(ThreadJob) submitted to the thread pool this is the only place where the jobs are submitted. We need a worker queue because the thread pool assigns work to a thread which is free. So when a job is submitted, it has to be stored somewhere

Definition at line 168 of file itkThreadPool.h.

SimpleFastMutexLock itk::ThreadPool::m_WorkerQueueMutex

staticprivate

To lock on m_WorkerQueue

Definition at line 171 of file itkThreadPool.h.

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

• itkThreadPool.h