THREADS: tools to create and manage a thread pool

Data Structures
struct	THREAD_POOL
	Structure of a thread 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 to run in an available thread inside a pool
int	destroy_threaded_pool (THREAD_POOL **thread_pool, unsigned int delay)
	destroy all running threads
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)
	allocate a new thread pool
int	refresh_thread_pool (THREAD_POOL *thread_pool)
	try to add some waiting process on some free thread slots, else do nothing
int	start_threaded_pool (THREAD_POOL *thread_pool)
	tell all the waiting threads to start their associated process
int	wait_for_synced_threaded_pool (THREAD_POOL *thread_pool)
	wait for all the threads in the pool to terminate processing, blocking but light on the CPU as there is no polling
int	wait_for_threaded_pool (THREAD_POOL *thread_pool)
	wait for the pool to become idle (no active threads, empty waiting list), blocking without polling

Detailed Description

---

Data Structure Documentation

THREAD_POOL

struct THREAD_POOL

Structure of a thread pool.

Examples

ex_accept_pool_client.c, ex_accept_pool_server.c, ex_fluid.c, ex_network.c, ex_network_ssl.c, ex_network_ssl_hardened.c, and ex_threads.c.

Definition at line 96 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 in the list, 0 for unlimited.
sem_t	nb_tasks	semaphore signaling pool idle state: value 0 = work in progress, value 1 = pool is idle (no active threads, empty waiting list). Used by wait_for_threaded_pool() to block until idle.
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 66 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 68 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 88 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_synced_threaded_pool().

param

void* THREAD_POOL_NODE::param

if not NULL , passed as argument

Definition at line 71 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 76 of file n_thread_pool.h.

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

th_end

sem_t THREAD_POOL_NODE::th_end

thread ending semaphore

Definition at line 85 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 83 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 80 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 91 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 78 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 74 of file n_thread_pool.h.

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

THREAD_WAITING_PROC

struct THREAD_WAITING_PROC

Structure of a waiting process item.

Definition at line 119 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 121 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 123 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, ex_network_ssl.c, and ex_network_ssl_hardened.c.

Definition at line 47 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 61 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 59 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 51 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 63 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 49 of file n_thread_pool.h.

NORMAL_PROC

#define NORMAL_PROC   1

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

Examples

ex_accept_pool_client.c, ex_accept_pool_server.c, and ex_threads.c.

Definition at line 43 of file n_thread_pool.h.

RUNNING_PROC

#define RUNNING_PROC   64

status of a thread which proc is currently running

Definition at line 55 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 57 of file n_thread_pool.h.

SYNCED_PROC

#define SYNCED_PROC   2

processing mode for added func, synced start, not queued

Examples

ex_threads.c.

Definition at line 45 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 53 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 to run in an available thread inside a pool

add a function to run in an available thread inside a 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 235 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, THREAD_POOL::nb_tasks, 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 dispatch_to_pool(), 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
	)

destroy all running threads

destroy all running threads

Parameters

pool	The THREAD_POOL *object to kill
delay	time in usec between each check

Returns

TRUE or FALSE

Definition at line 431 of file n_thread_pool.c.

References __n_assert, DONE, EXITED_THREAD, EXITING_THREAD, Free, IDLE_PROC, list_destroy(), pool, 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 44 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
	)

allocate a new thread pool

allocate a new thread pool

Parameters

nbmaxthr	number of active threads in the pool
nb_max_waiting	max number of waiting procs in the pool. Zero for no limit

Returns

NULL or a new thread pool object

Definition at line 132 of file n_thread_pool.c.

References EXITING_THREAD, Free, THREAD_POOL_NODE::func, IDLE_PROC, list_destroy(), 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 process on some free thread slots, else do nothing

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

Parameters

thread_pool

The thread pool to refresh

Returns

TRUE or FALSE

Definition at line 512 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, LIST::nb_items, 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, THREAD_POOL::waiting_list, and WAITING_PROC.

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

)

tell all the waiting threads to start their associated process

tell all the waiting threads to start their associated process

Parameters

thread_pool

The thread pool to launch

Returns

TRUE or FALSE

Definition at line 341 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 main(), and 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 threads in the pool to terminate processing, blocking but light on the CPU as there is no polling

wait for all the threads in the pool to terminate processing, 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 376 of file n_thread_pool.c.

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

Referenced by main(), and n_fluid_simulate_threaded().

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wait_for_threaded_pool()

int wait_for_threaded_pool

(

THREAD_POOL *

thread_pool

)

wait for the pool to become idle (no active threads, empty waiting list), blocking without polling

wait for the pool to become idle (no active threads, empty waiting list), blocking without polling

Parameters

thread_pool

The thread pool to wait on

Returns

TRUE or FALSE

Definition at line 405 of file n_thread_pool.c.

References __n_assert, LOG_ERR, n_log, THREAD_POOL::nb_tasks, refresh_thread_pool(), THREAD_POOL::thread_list, and thread_pool.

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

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