Threads [System Information, Operating System Dependent Functionality.]

Defines
#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 long	pj_thread_desc [(64)]
Enumerations
enum	pj_thread_create_flags { PJ_THREAD_SUSPENDED = 1 }
Functions
typedef	int (PJ_THREAD_FUNC pj_thread_proc)(void *)
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

---

Define Documentation

#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.

#define PJ_THREAD_DESC_SIZE   (64)

Size of thread struct.

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

pj_thread_get_stack_info() for the thread

#define pj_thread_get_stack_max_usage

(

thread

)

0

pj_thread_get_stack_max_usage() for the thread

---

Typedef Documentation

typedef long pj_thread_desc[(64)]

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

---

Enumeration Type Documentation

enum pj_thread_create_flags

Thread creation flags:

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

---

Function Documentation

typedef int

(

PJ_THREAD_FUNC

pj_thread_proc

)

Type of thread entry function.

pj_uint32_t pj_getpid

(

void

)

Get process ID.

Returns:

process ID.

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_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.

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.

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.

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.

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.

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_bool_t pj_thread_is_registered

(

void

)

Check if this thread has been registered to PJLIB.

Returns:

Non-zero if it is registered.

pj_status_t pj_thread_join

(

pj_thread_t *

thread

)

Join thread, and block the caller thread until the specified thread exits. If the specified thread has already been dead, or it does not exist, the function will return immediately with successfull status.

Parameters:

thread

The thread handle.

Returns:

PJ_SUCCESS on success.

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_status_t pj_thread_resume

(

pj_thread_t *

thread

)

Resume a suspended thread.

Parameters:

thread

The thread handle.

Returns:

zero on success.

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.

Parameters:

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

Returns:

PJ_SUCCESS on success or the error code.

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_t* pj_thread_this

(

void

)

Get the current thread.

Returns:

Thread handle of current thread.