thread_pool Class Reference

The thread_pool class. More...

#include <thread_pool.h>

Public Types
typedef std::function< int(void)>	FunctionPointer
	Pointer to thread pool function. More...

Public Member Functions
	thread_pool (unsigned int num_threads=std::thread::hardware_concurrency() *4)
	Construct a thread_pool object. More...
virtual	~thread_pool ()
	Object destructor. Ends all threads and cleans up resources. More...
int	init (unsigned int num_threads=0)
	Initialise thread pool. Initialise the thread pool. Does nothing if called more than once. More...
void	tear_down (bool silent=false)
	Shut down the thread pool. More...
bool	schedule_thread (FunctionPointer &&func)
	Schedule a new thread from pool. More...
unsigned int	current_running () const
	Get number of currently running threads. More...
unsigned int	current_queued ()
	Get number of currently queued threads. More...
unsigned int	pool_size () const
	Get current pool size. More...

Protected Attributes
std::vector< std::thread >	m_thread_pool
std::mutex	m_queue_mutex
std::condition_variable	m_queue_cond
std::queue< FunctionPointer >	m_thread_queue
std::atomic_bool	m_queue_shutdown
unsigned int	m_num_threads
unsigned int	m_cur_threads
std::atomic_uint32_t	m_threads_running

Private Member Functions
void	loop_function ()
	Start loop function. More...

Static Private Member Functions
static void	loop_function_starter (thread_pool &tp)
	Start loop function. More...

Detailed Description

The thread_pool class.

Definition at line 54 of file thread_pool.h.

Member Typedef Documentation

FunctionPointer

typedef std::function<int(void)> thread_pool::FunctionPointer

Pointer to thread pool function.

Definition at line 57 of file thread_pool.h.

Constructor & Destructor Documentation

thread_pool()

thread_pool::thread_pool ( unsigned int  num_threads = std::thread::hardware_concurrency() * 4 )

explicit

Construct a thread_pool object.

Parameters

[in]

num_threads

- Optional: number of threads to create in pool. Defaults to Defaults to 4 x number of CPU cores.

Definition at line 36 of file thread_pool.cc.

~thread_pool()

thread_pool::~thread_pool ( )

virtual

Object destructor. Ends all threads and cleans up resources.

Definition at line 44 of file thread_pool.cc.

References tear_down().

Member Function Documentation

current_queued()

unsigned int thread_pool::current_queued

(

)

Get number of currently queued threads.

Returns

Returns number of currently queued threads.

Definition at line 109 of file thread_pool.cc.

References m_queue_mutex, and m_thread_queue.

current_running()

unsigned int thread_pool::current_running

(

)

const

Get number of currently running threads.

Returns

Returns number of currently running threads.

Definition at line 104 of file thread_pool.cc.

References m_threads_running.

init()

int thread_pool::init

(

unsigned int

num_threads = 0

)

Initialise thread pool. Initialise the thread pool. Does nothing if called more than once.

Parameters

[in]

num_threads

- Optional: number of threads to create in pool. Defaults to Defaults to 4x number of CPU cores.

Returns

Number of threads created on success; on error or if called more than once, returns 0.

Definition at line 121 of file thread_pool.cc.

References Logging::info(), loop_function_starter(), m_num_threads, m_thread_pool, and Logging::warning().

loop_function()

void thread_pool::loop_function ( )

private

Start loop function.

Definition at line 54 of file thread_pool.cc.

References m_cur_threads, m_queue_cond, m_queue_mutex, m_queue_shutdown, m_thread_queue, and Logging::trace().

loop_function_starter()

void thread_pool::loop_function_starter ( thread_pool &  tp )

staticprivate

Start loop function.

Parameters

[in]

tp

- Thread pool object of caller.

Definition at line 49 of file thread_pool.cc.

References tp.

Referenced by init().

pool_size()

unsigned int thread_pool::pool_size

(

)

const

Get current pool size.

Returns

Return current pool size.

Definition at line 116 of file thread_pool.cc.

References m_thread_pool.

schedule_thread()

bool thread_pool::schedule_thread

(

FunctionPointer &&

func

)

Schedule a new thread from pool.

Parameters

[in]

func

- std::function object to call

Returns

Returns true if thread was successfully scheduled, false if not.

Definition at line 82 of file thread_pool.cc.

References m_queue_cond, m_queue_mutex, m_queue_shutdown, m_thread_pool, m_thread_queue, and Logging::trace().

tear_down()

void thread_pool::tear_down

(

bool

silent = false

)

Shut down the thread pool.

Parameters

[in]

silent

- If true, no log messages will be issued.

Definition at line 144 of file thread_pool.cc.

References Logging::debug(), m_queue_cond, m_queue_mutex, m_queue_shutdown, m_thread_pool, and m_thread_queue.

Referenced by ~thread_pool().

Member Data Documentation

m_cur_threads

unsigned int thread_pool::m_cur_threads

protected

Current number of threads.

Definition at line 122 of file thread_pool.h.

Referenced by loop_function().

m_num_threads

unsigned int thread_pool::m_num_threads

protected

Max. number of threads. Defaults to 4x number of CPU cores.

Definition at line 121 of file thread_pool.h.

Referenced by init().

m_queue_cond

std::condition_variable thread_pool::m_queue_cond

protected

Condition for critical section

Definition at line 118 of file thread_pool.h.

Referenced by loop_function(), schedule_thread(), and tear_down().

m_queue_mutex

std::mutex thread_pool::m_queue_mutex

protected

Mutex for critical section

Definition at line 117 of file thread_pool.h.

Referenced by current_queued(), loop_function(), schedule_thread(), and tear_down().

m_queue_shutdown

std::atomic_bool thread_pool::m_queue_shutdown

protected

If true all threads have been shut down

Definition at line 120 of file thread_pool.h.

Referenced by loop_function(), schedule_thread(), and tear_down().

m_thread_pool

std::vector<std::thread> thread_pool::m_thread_pool

protected

Thread pool

Definition at line 116 of file thread_pool.h.

Referenced by init(), pool_size(), schedule_thread(), and tear_down().

m_thread_queue

std::queue<FunctionPointer> thread_pool::m_thread_queue

protected

Thread queue parameters

Definition at line 119 of file thread_pool.h.

Referenced by current_queued(), loop_function(), schedule_thread(), and tear_down().

m_threads_running

std::atomic_uint32_t thread_pool::m_threads_running

protected

Currently running threads.

Definition at line 123 of file thread_pool.h.

Referenced by current_running().

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

• src/thread_pool.h
• src/thread_pool.cc