comphelper::ThreadPool Class Reference

A very basic thread-safe thread pool implementation. More...

#include <threadpool.hxx>

Classes
class	ThreadWorker

Public Member Functions
	ThreadPool (std::size_t nWorkers)
	~ThreadPool ()
void	pushTask (std::unique_ptr< ThreadTask > pTask)
	push a new task onto the work queue More...
void	waitUntilDone (const std::shared_ptr< ThreadTaskTag > &, bool bJoin=true)
	Wait until all queued tasks associated with the tag are completed. More...
void	joinThreadsIfIdle ()
	join all threads if there are no tasks presently. More...
bool	isIdle () const
	return true if there are no queued or worked-on tasks More...
sal_Int32	getWorkerCount () const
	return the number of live worker threads More...
void	shutdown ()
	wait until all work is completed, then join all threads More...

Static Public Member Functions
static ThreadPool &	getSharedOptimalPool ()
	returns a pointer to a shared pool with optimal thread count for the CPU More...
static std::shared_ptr< ThreadTaskTag >	createThreadTaskTag ()
static bool	isTaskTagDone (const std::shared_ptr< ThreadTaskTag > &)
static std::size_t	getPreferredConcurrency ()
	returns a configurable max-concurrency limit to avoid spawning an unnecessarily large number of threads on high-core boxes. More...

Private Member Functions
	ThreadPool (const ThreadPool &)=delete
ThreadPool &	operator= (const ThreadPool &)=delete
std::unique_ptr< ThreadTask >	popWorkLocked (std::unique_lock< std::mutex > &rGuard, bool bWait)
	Pop a work task. More...
void	shutdownLocked (std::unique_lock< std::mutex > &)
void	incBusyWorker ()
void	decBusyWorker ()

Private Attributes
std::mutex	maMutex
	signalled when all in-progress tasks are complete More...
std::condition_variable	maTasksChanged
bool	mbTerminate
std::size_t const	mnMaxWorkers
std::size_t	mnBusyWorkers
std::vector< std::unique_ptr< ThreadTask > >	maTasks
std::vector< rtl::Reference< ThreadWorker > >	maWorkers

Friends
class	ThreadWorker

Detailed Description

A very basic thread-safe thread pool implementation.

Definition at line 44 of file threadpool.hxx.

Constructor & Destructor Documentation

ThreadPool() [1/2]

comphelper::ThreadPool::ThreadPool

(

std::size_t

nWorkers

)

Definition at line 96 of file threadpool.cxx.

~ThreadPool()

comphelper::ThreadPool::~ThreadPool

(

)

Definition at line 103 of file threadpool.cxx.

References maTasks, mbTerminate, and mnBusyWorkers.

ThreadPool() [2/2]

comphelper::ThreadPool::ThreadPool ( const ThreadPool &  )

privatedelete

Member Function Documentation

createThreadTaskTag()

std::shared_ptr< ThreadTaskTag > comphelper::ThreadPool::createThreadTaskTag ( )

static

Definition at line 301 of file threadpool.cxx.

decBusyWorker()

void comphelper::ThreadPool::decBusyWorker ( )

private

Definition at line 258 of file threadpool.cxx.

References mnBusyWorkers.

Referenced by comphelper::ThreadPool::ThreadWorker::execute().

getPreferredConcurrency()

std::size_t comphelper::ThreadPool::getPreferredConcurrency ( )

static

returns a configurable max-concurrency limit to avoid spawning an unnecessarily large number of threads on high-core boxes.

MAX_CONCURRENCY env. var. controls the cap.

Definition at line 134 of file threadpool.cxx.

getSharedOptimalPool()

ThreadPool & comphelper::ThreadPool::getSharedOptimalPool ( )

static

returns a pointer to a shared pool with optimal thread count for the CPU

Definition at line 129 of file threadpool.cxx.

getWorkerCount()

sal_Int32 comphelper::ThreadPool::getWorkerCount ( ) const

inline

return the number of live worker threads

Definition at line 79 of file threadpool.hxx.

incBusyWorker()

void comphelper::ThreadPool::incBusyWorker ( )

private

Definition at line 253 of file threadpool.cxx.

References mnBusyWorkers.

Referenced by comphelper::ThreadPool::ThreadWorker::execute().

isIdle()

bool comphelper::ThreadPool::isIdle ( ) const

inline

return true if there are no queued or worked-on tasks

Definition at line 76 of file threadpool.hxx.

Referenced by joinThreadsIfIdle().

isTaskTagDone()

bool comphelper::ThreadPool::isTaskTagDone ( const std::shared_ptr< ThreadTaskTag > &  pTag )

static

Definition at line 306 of file threadpool.cxx.

joinThreadsIfIdle()

void comphelper::ThreadPool::joinThreadsIfIdle

(

)

join all threads if there are no tasks presently.

Definition at line 292 of file threadpool.cxx.

References isIdle(), maMutex, and shutdownLocked().

Referenced by waitUntilDone().

operator=()

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

privatedelete

popWorkLocked()

std::unique_ptr< ThreadTask > comphelper::ThreadPool::popWorkLocked ( std::unique_lock< std::mutex > &  rGuard, bool  bWait  )

private

Pop a work task.

Parameters

bWait

- if set wait until task present or termination

Returns

a new task to perform, or NULL if list empty or terminated

Definition at line 233 of file threadpool.cxx.

References maTasks, maTasksChanged, and mbTerminate.

Referenced by comphelper::ThreadPool::ThreadWorker::execute(), shutdownLocked(), and waitUntilDone().

pushTask()

void comphelper::ThreadPool::pushTask

(

std::unique_ptr< ThreadTask >

pTask

)

push a new task onto the work queue

Definition at line 214 of file threadpool.cxx.

References maMutex, maTasks, maTasksChanged, maWorkers, mbTerminate, mnBusyWorkers, mnMaxWorkers, and ThreadWorker.

shutdown()

void comphelper::ThreadPool::shutdown

(

)

wait until all work is completed, then join all threads

Definition at line 157 of file threadpool.cxx.

References maMutex, and shutdownLocked().

shutdownLocked()

void comphelper::ThreadPool::shutdownLocked ( std::unique_lock< std::mutex > &  aGuard )

private

Definition at line 166 of file threadpool.cxx.

References find(), maTasks, maTasksChanged, maWorkers, mbTerminate, and popWorkLocked().

Referenced by joinThreadsIfIdle(), and shutdown().

waitUntilDone()

void comphelper::ThreadPool::waitUntilDone	(	const std::shared_ptr< ThreadTaskTag > &	rTag,
		bool	bJoin = true
	)

Wait until all queued tasks associated with the tag are completed.

Parameters

bJoin

- if set call joinThreadsIfIdle() at the end

Definition at line 264 of file threadpool.cxx.

References comphelper::gbIsWorkerThread, joinThreadsIfIdle(), maMutex, maWorkers, and popWorkLocked().

Friends And Related Function Documentation

ThreadWorker

friend class ThreadWorker

friend

Definition at line 89 of file threadpool.hxx.

Referenced by pushTask().

Member Data Documentation

maMutex

std::mutex comphelper::ThreadPool::maMutex

private

signalled when all in-progress tasks are complete

Definition at line 101 of file threadpool.hxx.

Referenced by comphelper::ThreadPool::ThreadWorker::execute(), joinThreadsIfIdle(), pushTask(), shutdown(), and waitUntilDone().

maTasks

std::vector< std::unique_ptr<ThreadTask> > comphelper::ThreadPool::maTasks

private

Definition at line 106 of file threadpool.hxx.

Referenced by popWorkLocked(), pushTask(), shutdownLocked(), and ~ThreadPool().

maTasksChanged

std::condition_variable comphelper::ThreadPool::maTasksChanged

private

Definition at line 102 of file threadpool.hxx.

Referenced by popWorkLocked(), pushTask(), and shutdownLocked().

maWorkers

std::vector< rtl::Reference< ThreadWorker > > comphelper::ThreadPool::maWorkers

private

Definition at line 107 of file threadpool.hxx.

Referenced by pushTask(), shutdownLocked(), and waitUntilDone().

mbTerminate

bool comphelper::ThreadPool::mbTerminate

private

Definition at line 103 of file threadpool.hxx.

Referenced by comphelper::ThreadPool::ThreadWorker::execute(), popWorkLocked(), pushTask(), shutdownLocked(), and ~ThreadPool().

mnBusyWorkers

std::size_t comphelper::ThreadPool::mnBusyWorkers

private

Definition at line 105 of file threadpool.hxx.

Referenced by decBusyWorker(), incBusyWorker(), pushTask(), and ~ThreadPool().

mnMaxWorkers

std::size_t const comphelper::ThreadPool::mnMaxWorkers

private

Definition at line 104 of file threadpool.hxx.

Referenced by pushTask().

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

• threadpool.hxx
• threadpool.cxx