THREADS: tools to create and manage a thread pool

Data Structures
struct	THREAD_POOL
	Structure of a trhead pool. More...
struct	THREAD_POOL_NODE
	A thread pool node. More...
struct	THREAD_WAITING_PROC
	Structure of a waiting process item. More...

Macros
#define	DIRECT_PROC   4
	processing mode for added func, direct start, not queued
#define	EXITED_THREAD   512
	indicate that the pool is off, all jobs have been consumed
#define	EXITING_THREAD   256
	indicate that the pool is exiting, unfinished jobs will finish and the pool will exit the threads and enter the EXITED state
#define	IDLE_PROC   16
	status of a thread which is waiting for some proc
#define	NO_LOCK   1024
	if passed to add_threaded_process, skip main table lock in case we are in a func which is already locking it
#define	NO_QUEUE   8
	special processing mode for waiting_list: do not add the work in queue since it' coming from the queue
#define	NORMAL_PROC   1
	processing mode for added func, synced start, can be queued
#define	RUNNING_PROC   64
	status of a thread which proc is currently running
#define	RUNNING_THREAD   128
	indicate that the pool is running and ready to use
#define	SYNCED_PROC   2
	processing mode for added func, synced start, not queued
#define	WAITING_PROC   32
	status of a thread who have proc waiting to be processed

Functions
int	add_threaded_process (THREAD_POOL *thread_pool, void *(*func_ptr)(void *param), void *param, int mode)
	add a function and params to a thread pool
int	destroy_threaded_pool (THREAD_POOL **thread_pool, unsigned int delay)
	delete a thread_pool, exit the threads and free the structs
long int	get_nb_cpu_cores ()
	get number of core of current system
THREAD_POOL *	new_thread_pool (size_t nbmaxthr, size_t nb_max_waiting)
	Create a new pool of nbmaxthr threads.
int	refresh_thread_pool (THREAD_POOL *thread_pool)
	try to add some waiting DIRECT_PROCs on some free thread slots, else do nothing
int	start_threaded_pool (THREAD_POOL *thread_pool)
	Launch the process waiting for execution in the thread pool.
int	wait_for_synced_threaded_pool (THREAD_POOL *thread_pool)
	wait for all the launched process, blocking but light on the CPU as there is no polling
int	wait_for_threaded_pool (THREAD_POOL *thread_pool, unsigned int delay)
	Wait for all the launched process in the thread pool to terminate.

Detailed Description

---

Data Structure Documentation

THREAD_POOL

struct THREAD_POOL

Structure of a trhead pool.

Examples

ex_fluid.c, ex_network.c, ex_network_ssl.c, and ex_threads.c.

Definition at line 78 of file n_thread_pool.h.

Collaboration diagram for THREAD_POOL:

Data Fields
pthread_mutex_t	lock	mutex to prevent mutual access of waiting_list parameters
size_t	max_threads	Maximum number of running threads in the list.
size_t	nb_actives	number of threads actually doing a proc
size_t	nb_max_waiting	Maximum number of waiting procedures int the list, 0 or -1 for unlimited.
sem_t	nb_tasks	semaphore to store the number of tasks
THREAD_POOL_NODE **	thread_list	Dynamically allocated but fixed size thread array.
LIST *	waiting_list	Waiting list handling.

THREAD_POOL_NODE

struct THREAD_POOL_NODE

A thread pool node.

Definition at line 48 of file n_thread_pool.h.

Collaboration diagram for THREAD_POOL_NODE:

Data Fields
void *(*	func )(void *param)
	function to call in the thread
pthread_mutex_t	lock
	mutex to prevent mutual access of node parameters
void *	param
	if not NULL , passed as argument
int	state
	state of the proc , RUNNING_PROC when it is busy processing func( param) , IDLE_PROC when it waits for some func and param to process , WAITING_PROC when it has things waiting to be processed
sem_t	th_end
	thread ending semaphore
sem_t	th_start
	thread starting semaphore
pthread_t	thr
	thread id
struct THREAD_POOL *	thread_pool
	pointer to assigned thread pool
int	thread_state
	state of the managing thread , RUNNING_THREAD, EXITING_THREAD, EXITED_THREAD
int	type
	SYNCED or DIRECT process start.

Field Documentation

func

void *(* THREAD_POOL_NODE::func) (void *param)

function to call in the thread

Definition at line 50 of file n_thread_pool.h.

Referenced by add_threaded_process(), new_thread_pool(), and thread_pool_processing_function().

lock

pthread_mutex_t THREAD_POOL_NODE::lock

mutex to prevent mutual access of node parameters

Definition at line 70 of file n_thread_pool.h.

Referenced by add_threaded_process(), new_thread_pool(), refresh_thread_pool(), start_threaded_pool(), thread_pool_processing_function(), and wait_for_threaded_pool().

param

void* THREAD_POOL_NODE::param

if not NULL , passed as argument

Definition at line 53 of file n_thread_pool.h.

Referenced by add_threaded_process(), new_thread_pool(), and thread_pool_processing_function().

state

int THREAD_POOL_NODE::state

state of the proc , RUNNING_PROC when it is busy processing func( param) , IDLE_PROC when it waits for some func and param to process , WAITING_PROC when it has things waiting to be processed

Definition at line 58 of file n_thread_pool.h.

Referenced by add_threaded_process(), new_thread_pool(), refresh_thread_pool(), start_threaded_pool(), thread_pool_processing_function(), and wait_for_threaded_pool().

th_end

sem_t THREAD_POOL_NODE::th_end

thread ending semaphore

Definition at line 67 of file n_thread_pool.h.

Referenced by new_thread_pool(), thread_pool_processing_function(), and wait_for_synced_threaded_pool().

th_start

sem_t THREAD_POOL_NODE::th_start

thread starting semaphore

Definition at line 65 of file n_thread_pool.h.

Referenced by add_threaded_process(), new_thread_pool(), start_threaded_pool(), and thread_pool_processing_function().

thr

pthread_t THREAD_POOL_NODE::thr

thread id

Definition at line 62 of file n_thread_pool.h.

Referenced by new_thread_pool(), and thread_pool_processing_function().

thread_pool

struct THREAD_POOL* THREAD_POOL_NODE::thread_pool

pointer to assigned thread pool

Definition at line 73 of file n_thread_pool.h.

Referenced by new_thread_pool(), and thread_pool_processing_function().

thread_state

int THREAD_POOL_NODE::thread_state

state of the managing thread , RUNNING_THREAD, EXITING_THREAD, EXITED_THREAD

Definition at line 60 of file n_thread_pool.h.

Referenced by add_threaded_process(), new_thread_pool(), and thread_pool_processing_function().

type

int THREAD_POOL_NODE::type

SYNCED or DIRECT process start.

Definition at line 56 of file n_thread_pool.h.

Referenced by add_threaded_process(), new_thread_pool(), start_threaded_pool(), and thread_pool_processing_function().

THREAD_WAITING_PROC

struct THREAD_WAITING_PROC

Structure of a waiting process item.

Definition at line 101 of file n_thread_pool.h.

Collaboration diagram for THREAD_WAITING_PROC:

Data Fields
void *(*	func )(void *param)
	function to call in the thread
void *	param
	if not NULL , passed as argument

Field Documentation

func

void *(* THREAD_WAITING_PROC::func) (void *param)

function to call in the thread

Definition at line 103 of file n_thread_pool.h.

Referenced by add_threaded_process(), and refresh_thread_pool().

param

void* THREAD_WAITING_PROC::param

if not NULL , passed as argument

Definition at line 105 of file n_thread_pool.h.

Referenced by add_threaded_process(), and refresh_thread_pool().

Macro Definition Documentation

DIRECT_PROC

#define DIRECT_PROC   4

processing mode for added func, direct start, not queued

Examples

ex_network.c, and ex_network_ssl.c.

Definition at line 29 of file n_thread_pool.h.

EXITED_THREAD

#define EXITED_THREAD   512

indicate that the pool is off, all jobs have been consumed

Definition at line 43 of file n_thread_pool.h.

EXITING_THREAD

#define EXITING_THREAD   256

indicate that the pool is exiting, unfinished jobs will finish and the pool will exit the threads and enter the EXITED state

Definition at line 41 of file n_thread_pool.h.

IDLE_PROC

#define IDLE_PROC   16

status of a thread which is waiting for some proc

Definition at line 33 of file n_thread_pool.h.

NO_LOCK

#define NO_LOCK   1024

if passed to add_threaded_process, skip main table lock in case we are in a func which is already locking it

Definition at line 45 of file n_thread_pool.h.

NO_QUEUE

#define NO_QUEUE   8

special processing mode for waiting_list: do not add the work in queue since it' coming from the queue

Definition at line 31 of file n_thread_pool.h.

NORMAL_PROC

#define NORMAL_PROC   1

processing mode for added func, synced start, can be queued

Examples

ex_threads.c.

Definition at line 25 of file n_thread_pool.h.

RUNNING_PROC

#define RUNNING_PROC   64

status of a thread which proc is currently running

Definition at line 37 of file n_thread_pool.h.

RUNNING_THREAD

#define RUNNING_THREAD   128

indicate that the pool is running and ready to use

Definition at line 39 of file n_thread_pool.h.

SYNCED_PROC

#define SYNCED_PROC   2

processing mode for added func, synced start, not queued

Definition at line 27 of file n_thread_pool.h.

WAITING_PROC

#define WAITING_PROC   32

status of a thread who have proc waiting to be processed

Definition at line 35 of file n_thread_pool.h.

Function Documentation

add_threaded_process()

int add_threaded_process	(	THREAD_POOL *	thread_pool,
		void *(*)(void *param)	func_ptr,
		void *	param,
		int	mode
	)

add a function and params to a thread pool

Parameters

thread_pool	The target thread pool
func_ptr	The function pointer to launch
param	Eventual parameter struct to pass to the function
mode	NORMAL_PROC: add to an available active thread or queue in the waiting list. SYNCED_PROC: add to an available thread and wait for a start call, no waiting list. DIRECT_PROC: add to an available thread, no waiting list.

Returns

TRUE or FALSE

Definition at line 180 of file n_thread_pool.c.

References DIRECT_PROC, THREAD_POOL_NODE::func, THREAD_WAITING_PROC::func, IDLE_PROC, list_push(), THREAD_POOL_NODE::lock, THREAD_POOL::lock, LOG_DEBUG, LOG_ERR, Malloc, mode, n_log, LIST::nb_items, THREAD_POOL::nb_max_waiting, NO_LOCK, NO_QUEUE, NORMAL_PROC, THREAD_POOL_NODE::param, THREAD_WAITING_PROC::param, RUNNING_THREAD, THREAD_POOL_NODE::state, SYNCED_PROC, THREAD_POOL_NODE::th_start, THREAD_POOL::thread_list, thread_pool, THREAD_POOL_NODE::thread_state, THREAD_POOL_NODE::type, THREAD_POOL::waiting_list, and WAITING_PROC.

Referenced by main(), main(), n_fluid_simulate_threaded(), n_vigenere_cypher(), and refresh_thread_pool().

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destroy_threaded_pool()

int destroy_threaded_pool	(	THREAD_POOL **	pool,
		unsigned int	delay
	)

delete a thread_pool, exit the threads and free the structs

Parameters

pool	The THREAD_POOL *object to kill
delay	The THREAD_POOL *object to kill

Returns

TRUE or FALSE

Definition at line 370 of file n_thread_pool.c.

References __n_assert, DONE, EXITING_THREAD, Free, IDLE_PROC, list_destroy(), and u_sleep().

Referenced by main(), main(), and n_vigenere_cypher().

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get_nb_cpu_cores()

long int get_nb_cpu_cores

(

)

get number of core of current system

Returns

The number of cores or 0 if the system command is not supported

Definition at line 26 of file n_thread_pool.c.

Referenced by main(), main(), and new_n_fluid().

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new_thread_pool()

THREAD_POOL * new_thread_pool	(	size_t	nbmaxthr,
		size_t	nb_max_waiting
	)

Create a new pool of nbmaxthr threads.

Parameters

nbmaxthr	number of active threads in the pool
nb_max_waiting	max number of waiting procs in the pool. Negative or zero value for no limit

Returns

NULL or a new trhead pool object

Definition at line 110 of file n_thread_pool.c.

References Free, THREAD_POOL_NODE::func, IDLE_PROC, THREAD_POOL_NODE::lock, THREAD_POOL::lock, LOG_ERR, Malloc, MAX_LIST_ITEMS, THREAD_POOL::max_threads, n_log, THREAD_POOL::nb_actives, THREAD_POOL::nb_max_waiting, THREAD_POOL::nb_tasks, new_generic_list(), THREAD_POOL_NODE::param, RUNNING_THREAD, THREAD_POOL_NODE::state, THREAD_POOL_NODE::th_end, THREAD_POOL_NODE::th_start, THREAD_POOL_NODE::thr, THREAD_POOL::thread_list, thread_pool, THREAD_POOL_NODE::thread_pool, thread_pool_processing_function(), THREAD_POOL_NODE::thread_state, THREAD_POOL_NODE::type, and THREAD_POOL::waiting_list.

Referenced by main(), main(), and n_vigenere_cypher().

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refresh_thread_pool()

int refresh_thread_pool

(

THREAD_POOL *

thread_pool

)

try to add some waiting DIRECT_PROCs on some free thread slots, else do nothing

Parameters

thread_pool

The thread pool to refresh

Returns

TRUE or FALSE

Definition at line 427 of file n_thread_pool.c.

References __n_assert, add_threaded_process(), Free, THREAD_WAITING_PROC::func, THREAD_POOL_NODE::lock, THREAD_POOL::lock, LOG_DEBUG, LOG_ERR, THREAD_POOL::max_threads, n_log, THREAD_POOL::nb_actives, THREAD_POOL::nb_tasks, LIST_NODE::next, NO_LOCK, NO_QUEUE, NORMAL_PROC, THREAD_WAITING_PROC::param, LIST_NODE::ptr, remove_list_node, RUNNING_PROC, LIST::start, THREAD_POOL_NODE::state, THREAD_POOL::thread_list, thread_pool, and THREAD_POOL::waiting_list.

Referenced by main(), n_fluid_simulate_threaded(), n_vigenere_cypher(), thread_pool_processing_function(), and wait_for_threaded_pool().

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start_threaded_pool()

int start_threaded_pool

(

THREAD_POOL *

thread_pool

)

Launch the process waiting for execution in the thread pool.

Parameters

thread_pool

The thread pool to launche

Returns

TRUE or FALSE

Definition at line 269 of file n_thread_pool.c.

References THREAD_POOL_NODE::lock, THREAD_POOL::lock, LOG_ERR, THREAD_POOL::max_threads, n_log, THREAD_POOL_NODE::state, SYNCED_PROC, THREAD_POOL_NODE::th_start, THREAD_POOL::thread_list, thread_pool, THREAD_POOL_NODE::type, and WAITING_PROC.

Referenced by n_fluid_simulate_threaded().

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wait_for_synced_threaded_pool()

int wait_for_synced_threaded_pool

(

THREAD_POOL *

thread_pool

)

wait for all the launched process, blocking but light on the CPU as there is no polling

Parameters

thread_pool

The thread pool to wait

Returns

TRUE or FALSE

Definition at line 304 of file n_thread_pool.c.

References __n_assert, LOG_ERR, THREAD_POOL::max_threads, n_log, THREAD_POOL_NODE::th_end, THREAD_POOL::thread_list, and thread_pool.

Referenced by n_fluid_simulate_threaded().

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wait_for_threaded_pool()

int wait_for_threaded_pool	(	THREAD_POOL *	thread_pool,
		unsigned int	delay
	)

Wait for all the launched process in the thread pool to terminate.

Parameters

thread_pool	The thread pool to wait
delay	time between each check

Returns

TRUE or FALSE

Definition at line 325 of file n_thread_pool.c.

References DONE, IDLE_PROC, THREAD_POOL_NODE::lock, THREAD_POOL::max_threads, LIST::nb_items, refresh_thread_pool(), THREAD_POOL_NODE::state, THREAD_POOL::thread_list, thread_pool, u_sleep(), and THREAD_POOL::waiting_list.

Referenced by main(), main(), and n_vigenere_cypher().

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