Group PJ_THREAD

group PJ_THREAD

This module provides multithreading API.

Examples

For examples, please see:

  • Test: Thread Test

  • Test: Sleep, Time, and Timestamp

Defines

PJ_THREAD_DESC_SIZE

Size of thread struct.

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_get_stack_max_usage(thread)

pj_thread_get_stack_max_usage() for the thread

pj_thread_get_stack_info(thread, f, l)

pj_thread_get_stack_info() for the thread

Typedefs

typedef long pj_thread_desc[(64)]

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

Enums

enum pj_thread_create_flags

Thread creation flags:

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

Values:

enumerator PJ_THREAD_SUSPENDED

Functions

typedef int (PJ_THREAD_FUNC pj_thread_proc)(void *)

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_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_bool_t pj_thread_is_registered(void)

Check if this thread has been registered to PJLIB.

Returns

Non-zero if it is registered.

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_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.

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.

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.

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.

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_status_t pj_thread_resume(pj_thread_t *thread)

Resume a suspended thread.

Parameters

thread – The thread handle.

Returns

zero on success.

pj_thread_t *pj_thread_this(void)

Get the current thread.

Returns

Thread handle of current thread.

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_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_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.