Ocean::ThreadPool Class Reference

This class implements a pool holding re-usable thread objects for individual use. More...

#include <ThreadPool.h>

Inheritance diagram for Ocean::ThreadPool:

Data Structures
class	PoolThread
	This class implements one thread of this thread pool. More...

Public Types
using	Function = std::function< void()>
	Definition of a caller function without return parameter.

Public Member Functions
	ThreadPool ()=default
	Creates a new thread pool object.
	~ThreadPool () override
	Destructs a thread pool.
size_t	capacity () const
	Returns the maximal number of thread objects allowed inside this pool.
size_t	size () const
	Returns the number of currently busy/active threads in this pool.
bool	setCapacity (const size_t capacity)
	Defines the maximal number of thread objects existing concurrently.
bool	invoke (Function &&function)
	Invokes a function on one of the free threads of this pool.
size_t	pending () const
	Returns the number of pending functions.
bool	isEmpty () const
	Returns whether the ThreadPool has completed all jobs that have been submitted.

Protected Types
using	UniquePoolThread = std::unique_ptr< PoolThread >
	Definition of a unique pointer holding a pool thread.
using	PoolThreads = std::vector< UniquePoolThread >
	Definition of a vector holding pool threads.
using	FunctionQueue = std::queue< Function >
	Definition of a queue holding functions.
Protected Types inherited from Ocean::Thread
typedef std::pair< pthread_t, bool >	TimedJoinPair
	Definition of a pair holding a thread id and a boolean state.
enum	ThreadPriority {   PRIORITY_IDLE , PRIORTY_BELOW_NORMAL , PRIORTY_NORMAL , PRIORTY_ABOVE_NORMAL ,   PRIORTY_HIGH , PRIORTY_REALTIME }
	Definition of different thread priority values. More...

Protected Member Functions
void	threadRun () override
	Thread run function.
Protected Member Functions inherited from Ocean::Thread
	Thread (const Thread &thread)=delete
	Disabled copy constructor.
void	createThread ()
	Creates the thread itself.
void	destroyThread ()
	Destroys the thread itself.
void	stopThreadExplicitly (const unsigned int timeout=5000u)
	Tries to stop the thread gracefully.
Thread &	operator= (const Thread &thread)=delete
	The disabled assign operator.
	Thread (const std::string &name=std::string())
	Creates a new thread object.
	Thread (const unsigned int randomNumberSeedValue, const std::string &name=std::string())
	Creates a new thread object.
virtual	~Thread ()
	Destructs a thread object.
bool	startThread ()
	Starts the thread.
void	stopThread ()
	Informs the thread to stop.
bool	terminateThread ()
	Terminates the thread.
bool	joinThread (const unsigned int timeout=(unsigned int)(-1))
	Waits until this thread has been stopped.
bool	shouldThreadStop () const
	Returns whether this thread should stop.
bool	isThreadInvokedToStart () const
	Returns whether this thread has been invoked to start immediately.
bool	isThreadActive () const
	Returns whether this thread is active.

Protected Attributes
PoolThreads	busyPoolThreads_
	The busy pool threads.
PoolThreads	idlePoolThreads_
	The idle pool threads.
FunctionQueue	pendingFunctions_
	The pending functions.
size_t	capacity_ = 2
	Maximal pool capacity, with range [1, infinity)
size_t	poolThreadIdCounter_ = 0
	The counter for pool thread ids.
Lock	lock_
	Pool lock.

Additional Inherited Members
Static Protected Member Functions inherited from Ocean::Thread
static void	sleep (unsigned int ms)
	Sleeps the calling thread for a given time.
static void	giveUp ()
	Gives up the remaining thread time.
static ThreadId	currentThreadId ()
	Returns the thread id of the current (calling) thread.
static ThreadPriority	threadPriority ()
	Returns the priority of the current thread.
static bool	setThreadPriority (const ThreadPriority priority)
	Sets the priority of the current thread.
template<typename TObject , typename TExpectedValue >
static bool	waitForValue (TObject &object, const TExpectedValue &expectedValue, const double timeout=-1.0)
	Waits until an object/variable has an expected value.
template<typename TObject , typename TExpectedValue >
static bool	waitForValue (TObject &object, const TExpectedValue &expectedValue, TemporaryScopedLock &temporaryScopedLock, const double timeout=-1.0)
	Waits until an object/variable has an expected value.
static int	pthread_timedjoin_np (pthread_t thread, void **retval, const struct timespec *abstime)
	Implements a thread join function with timeout value.

Detailed Description

This class implements a pool holding re-usable thread objects for individual use.

This class is not a singleton, use ThreadPoolSingleton in case a singleton is sufficient.

See also

ThreadPoolSingleton, Scheduler, TaskQueue.

Member Typedef Documentation

Function

using Ocean::ThreadPool::Function = std::function<void()>

Definition of a caller function without return parameter.

FunctionQueue

using Ocean::ThreadPool::FunctionQueue = std::queue<Function>

protected

Definition of a queue holding functions.

PoolThreads

using Ocean::ThreadPool::PoolThreads = std::vector<UniquePoolThread>

protected

Definition of a vector holding pool threads.

UniquePoolThread

using Ocean::ThreadPool::UniquePoolThread = std::unique_ptr<PoolThread>

protected

Definition of a unique pointer holding a pool thread.

Constructor & Destructor Documentation

ThreadPool()

Ocean::ThreadPool::ThreadPool ( )

default

Creates a new thread pool object.

~ThreadPool()

Ocean::ThreadPool::~ThreadPool ( )

override

Destructs a thread pool.

Member Function Documentation

capacity()

size_t Ocean::ThreadPool::capacity ( ) const

inline

Returns the maximal number of thread objects allowed inside this pool.

Returns

Maximal thread capacity, with range [1, infinity); 2 by default

invoke()

bool Ocean::ThreadPool::invoke

(

Function &&

function

)

Invokes a function on one of the free threads of this pool.

Parameters

function

The function that will be invoked by a free thread

Returns

True, if the function will be invoked by a free thread, otherwise no free thread was available

isEmpty()

bool Ocean::ThreadPool::isEmpty ( ) const

inline

Returns whether the ThreadPool has completed all jobs that have been submitted.

Returns

True, if the results of size() and pending() are atomically both 0

pending()

size_t Ocean::ThreadPool::pending ( ) const

inline

Returns the number of pending functions.

Returns

The number of pending functions which have not been executed yet as the pool is at capacity, with range [0, infinity)

setCapacity()

bool Ocean::ThreadPool::setCapacity

(

const size_t

capacity

)

Defines the maximal number of thread objects existing concurrently.

Parameters

capacity

Maximal number of thread objects to be allowed inside this pool, with range (1, infinity)

Returns

True, if succeeded

size()

size_t Ocean::ThreadPool::size ( ) const

inline

Returns the number of currently busy/active threads in this pool.

Returns

Thread number, with range [0, infinity)

threadRun()

void Ocean::ThreadPool::threadRun ( )

overrideprotectedvirtual

Thread run function.

Implements Ocean::Thread.

Field Documentation

busyPoolThreads_

PoolThreads Ocean::ThreadPool::busyPoolThreads_

protected

The busy pool threads.

capacity_

size_t Ocean::ThreadPool::capacity_ = 2

protected

Maximal pool capacity, with range [1, infinity)

idlePoolThreads_

PoolThreads Ocean::ThreadPool::idlePoolThreads_

protected

The idle pool threads.

lock_

Lock Ocean::ThreadPool::lock_

mutableprotected

Pool lock.

pendingFunctions_

FunctionQueue Ocean::ThreadPool::pendingFunctions_

protected

The pending functions.

poolThreadIdCounter_

size_t Ocean::ThreadPool::poolThreadIdCounter_ = 0

protected

The counter for pool thread ids.

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

• ThreadPool.h