Threads

Macros
#define	PJ_THREAD_DESC_SIZE   (64)
#define	PJ_CHECK_STACK()
#define	pj_thread_get_stack_max_usage(thread)   0
#define	pj_thread_get_stack_info(thread, f, l)   (*(f)="",*(l)=0)

Typedefs
typedef int()	pj_thread_proc(void *)
typedef long	pj_thread_desc[(64)]

Enumerations
enum	pj_thread_create_flags { PJ_THREAD_SUSPENDED = 1 }

Functions
pj_uint32_t	pj_getpid (void)
pj_status_t	pj_thread_create (pj_pool_t *pool, const char *thread_name, pj_thread_proc *proc, void *arg, pj_size_t stack_size, unsigned flags, pj_thread_t **thread)
pj_status_t	pj_thread_register (const char *thread_name, pj_thread_desc desc, pj_thread_t **thread)
pj_bool_t	pj_thread_is_registered (void)
int	pj_thread_get_prio (pj_thread_t *thread)
pj_status_t	pj_thread_set_prio (pj_thread_t *thread, int prio)
int	pj_thread_get_prio_min (pj_thread_t *thread)
int	pj_thread_get_prio_max (pj_thread_t *thread)
void *	pj_thread_get_os_handle (pj_thread_t *thread)
const char *	pj_thread_get_name (pj_thread_t *thread)
pj_status_t	pj_thread_resume (pj_thread_t *thread)
pj_thread_t *	pj_thread_this (void)
pj_status_t	pj_thread_join (pj_thread_t *thread)
pj_status_t	pj_thread_destroy (pj_thread_t *thread)
pj_status_t	pj_thread_sleep (unsigned msec)

Detailed Description

This module provides multithreading API.

Examples

For examples, please see:

• Test: Thread Test
• Test: Sleep, Time, and Timestamp

Macro Definition Documentation

PJ_CHECK_STACK

#define PJ_CHECK_STACK

(

)

PJ_CHECK_STACK() macro is used to check the sanity of the stack. The OS implementation may check that no stack overflow occurs, and it also may collect statistic about stack usage.

PJ_THREAD_DESC_SIZE

#define PJ_THREAD_DESC_SIZE   (64)

Size of thread struct.

pj_thread_get_stack_info

#define pj_thread_get_stack_info	(		thread,
			f,
			l
	)		(*(f)="",*(l)=0)

pj_thread_get_stack_info() for the thread

pj_thread_get_stack_max_usage

#define pj_thread_get_stack_max_usage

(

thread

)

0

pj_thread_get_stack_max_usage() for the thread

Typedef Documentation

pj_thread_desc

typedef long pj_thread_desc[(64)]

Thread structure, to thread's state when the thread is created by external or native API.

pj_thread_proc

typedef int() pj_thread_proc(void *)

Type of thread entry function.

Enumeration Type Documentation

pj_thread_create_flags

enum pj_thread_create_flags

Thread creation flags:

• PJ_THREAD_SUSPENDED: specify that the thread should be created suspended.

Function Documentation

pj_getpid()

pj_uint32_t pj_getpid

(

void

)

Get process ID.

Returns

process ID.

pj_thread_create()

pj_status_t pj_thread_create	(	pj_pool_t *	pool,
		const char *	thread_name,
		pj_thread_proc *	proc,
		void *	arg,
		pj_size_t	stack_size,
		unsigned	flags,
		pj_thread_t **	thread
	)

Create a new thread.

Parameters

pool	The memory pool from which the thread record will be allocated from.
thread_name	The optional name to be assigned to the thread.
proc	Thread entry function.
arg	Argument to be passed to the thread entry function.
stack_size	The size of the stack for the new thread, or ZERO or PJ_THREAD_DEFAULT_STACK_SIZE to let the library choose the reasonable size for the stack. For some systems, the stack will be allocated from the pool, so the pool must have suitable capacity.
flags	Flags for thread creation, which is bitmask combination from enum pj_thread_create_flags.
thread	Pointer to hold the newly created thread.

Returns

PJ_SUCCESS on success, or the error code.

pj_thread_destroy()

pj_status_t pj_thread_destroy

(

pj_thread_t *

thread

)

Destroy thread and release resources allocated for the thread. However, the memory allocated for the pj_thread_t itself will only be released when the pool used to create the thread is destroyed.

Parameters

thread

The thread handle.

Returns

zero on success.

pj_thread_get_name()

const char * pj_thread_get_name

(

pj_thread_t *

thread

)

Get thread name.

Parameters

thread

The thread handle.

Returns

Thread name as null terminated string.

pj_thread_get_os_handle()

void * pj_thread_get_os_handle

(

pj_thread_t *

thread

)

Return native handle from pj_thread_t for manipulation using native OS APIs.

Parameters

thread

PJLIB thread descriptor.

Returns

Native thread handle. For example, when the backend thread uses pthread, this function will return pointer to pthread_t, and on Windows, this function will return HANDLE.

pj_thread_get_prio()

int pj_thread_get_prio

(

pj_thread_t *

thread

)

Get thread priority value for the thread.

Parameters

thread

Thread handle.

Returns

Thread priority value, or -1 on error.

pj_thread_get_prio_max()

int pj_thread_get_prio_max

(

pj_thread_t *

thread

)

Get the highest priority value available for this thread.

Parameters

thread

Thread handle.

Returns

Minimum thread priority value, or -1 on error.

pj_thread_get_prio_min()

int pj_thread_get_prio_min

(

pj_thread_t *

thread

)

Get the lowest priority value available for this thread.

Parameters

thread

Thread handle.

Returns

Minimum thread priority value, or -1 on error.

pj_thread_is_registered()

pj_bool_t pj_thread_is_registered

(

void

)

Check if this thread has been registered to PJLIB.

Returns

Non-zero if it is registered.

pj_thread_join()

pj_status_t pj_thread_join

(

pj_thread_t *

thread

)

Join thread, and block the caller thread until the specified thread exits. If it is called from within the thread itself, it will return immediately with failure status. If the specified thread has already been dead, or it does not exist, the function will return immediately with successful status.

Parameters

thread

The thread handle.

Returns

PJ_SUCCESS on success.

pj_thread_register()

pj_status_t pj_thread_register	(	const char *	thread_name,
		pj_thread_desc	desc,
		pj_thread_t **	thread
	)

Register a thread that was created by external or native API to PJLIB. This function must be called in the context of the thread being registered. When the thread is created by external function or API call, it must be 'registered' to PJLIB using pj_thread_register(), so that it can cooperate with PJLIB's framework. During registration, some data needs to be maintained, and this data must remain available during the thread's lifetime.

Parameters

thread_name	The optional name to be assigned to the thread.
desc	Thread descriptor, which must be available throughout the lifetime of the thread.
thread	Pointer to hold the created thread handle.

Returns

PJ_SUCCESS on success, or the error code.

pj_thread_resume()

pj_status_t pj_thread_resume

(

pj_thread_t *

thread

)

Resume a suspended thread.

Parameters

thread

The thread handle.

Returns

zero on success.

pj_thread_set_prio()

pj_status_t pj_thread_set_prio	(	pj_thread_t *	thread,
		int	prio
	)

Set the thread priority. The priority value must be in the priority value range, which can be retrieved with pj_thread_get_prio_min() and pj_thread_get_prio_max() functions.

For Android, this function will only set the priority of the calling thread (the thread param must be set to NULL or the calling thread handle).

Parameters

thread	Thread handle.
prio	New priority to be set to the thread.

Returns

PJ_SUCCESS on success or the error code.

pj_thread_sleep()

pj_status_t pj_thread_sleep

(

unsigned

msec

)

Put the current thread to sleep for the specified miliseconds.

Parameters

msec	Miliseconds delay.

Returns

zero if successfull.

pj_thread_this()

pj_thread_t * pj_thread_this

(

void

)

Get the current thread.

Returns

Thread handle of current thread.