Semaphore 的协作图:

宏定义
#define	LOS_SEM_COUNT_MAX 0xFFFE

#define	LOS_ERRNO_SEM_NO_MEMORY LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x00)

#define	LOS_ERRNO_SEM_INVALID LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x01)

#define	LOS_ERRNO_SEM_PTR_NULL LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x02)

#define	LOS_ERRNO_SEM_ALL_BUSY LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x03)

#define	LOS_ERRNO_SEM_UNAVAILABLE LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x04)

#define	LOS_ERRNO_SEM_PEND_INTERR LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x05)

#define	LOS_ERRNO_SEM_PEND_IN_LOCK LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x06)

#define	LOS_ERRNO_SEM_TIMEOUT LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x07)

#define	LOS_ERRNO_SEM_OVERFLOW LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x08)

#define	LOS_ERRNO_SEM_PENDED LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x09)

#define	LOS_ERRNO_SEM_PEND_IN_SYSTEM_TASK LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x0A)

函数
UINT32	LOS_SemCreate (UINT16 count, UINT32 *semHandle)
	Create a semaphore.

UINT32	LOS_BinarySemCreate (UINT16 count, UINT32 *semHandle)
	Create a binary semaphore.

UINT32	LOS_SemDelete (UINT32 semHandle)
	Delete a semaphore.

UINT32	LOS_SemPend (UINT32 semHandle, UINT32 timeout)
	Request a semaphore.

UINT32	LOS_SemPost (UINT32 semHandle)
	Release a semaphore.

详细描述

宏定义说明

◆ LOS_ERRNO_SEM_ALL_BUSY

#define LOS_ERRNO_SEM_ALL_BUSY LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x03)

Semaphore error code: No semaphore control structure is available.

Value: 0x02000703.

Solution: Perform corresponding operations based on the requirements in the code context.

◆ LOS_ERRNO_SEM_INVALID

#define LOS_ERRNO_SEM_INVALID LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x01)

Semaphore error code: Invalid parameter.

Value: 0x02000701.

Solution: Change the passed-in invalid parameter value to a valid value.

◆ LOS_ERRNO_SEM_NO_MEMORY

#define LOS_ERRNO_SEM_NO_MEMORY LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x00)

Semaphore error code: The memory is insufficient.

Value: 0x02000700.

Solution: Allocate more memory.

◆ LOS_ERRNO_SEM_OVERFLOW

#define LOS_ERRNO_SEM_OVERFLOW LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x08)

Semaphore error code: The times of semaphore release exceed the maximum times permitted.

Value: 0x02000708.

Solution: Perform corresponding operations based on the requirements in the code context.

◆ LOS_ERRNO_SEM_PEND_IN_LOCK

#define LOS_ERRNO_SEM_PEND_IN_LOCK LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x06)

Semaphore error code: The task is unable to request a semaphore because task scheduling is locked.

Value: 0x02000706.

Solution: Do not call LOS_SemPend when task scheduling is locked.

◆ LOS_ERRNO_SEM_PEND_IN_SYSTEM_TASK

#define LOS_ERRNO_SEM_PEND_IN_SYSTEM_TASK LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x0A)

Semaphore error code: The API is called in system-level callback, which is forbidden. old usage: The API is called in software timer callback, which is forbidden (LOS_ERRNO_SEM_PEND_SWTERR).

Value: 0x0200070A.

Solution: Do not call the API in the system-level callback.

弃用:: This error code is obsolete since LiteOS 5.0.0.

◆ LOS_ERRNO_SEM_PEND_INTERR

#define LOS_ERRNO_SEM_PEND_INTERR LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x05)

Semaphore error code: The API is called during an interrupt, which is forbidden.

Value: 0x02000705.

Solution: Do not call the API during an interrupt.

◆ LOS_ERRNO_SEM_PENDED

#define LOS_ERRNO_SEM_PENDED LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x09)

Semaphore error code: The queue of the tasks that are waiting on the semaphore control structure is not null.

Value: 0x02000709.

Solution: Delete the semaphore after awaking all tasks that are waiting on the semaphore.

◆ LOS_ERRNO_SEM_PTR_NULL

#define LOS_ERRNO_SEM_PTR_NULL LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x02)

Semaphore error code: Null pointer.

Value: 0x02000702.

Solution: Change the passed-in null pointer to a valid non-null pointer.

◆ LOS_ERRNO_SEM_TIMEOUT

#define LOS_ERRNO_SEM_TIMEOUT LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x07)

Semaphore error code: The request for a semaphore times out.

Value: 0x02000707.

Solution: Change the passed-in parameter value to the value within the valid range.

◆ LOS_ERRNO_SEM_UNAVAILABLE

#define LOS_ERRNO_SEM_UNAVAILABLE LOS_ERRNO_OS_ERROR(LOS_MOD_SEM, 0x04)

Semaphore error code: Invalid parameter that specifies the timeout interval.

Value: 0x02000704.

Solution: Change the passed-in parameter value to a valid nonzero value.

◆ LOS_SEM_COUNT_MAX

#define LOS_SEM_COUNT_MAX 0xFFFE

Max count of counting semaphores

函数说明

◆ LOS_BinarySemCreate()

UINT32 LOS_BinarySemCreate	(	UINT16	count,
		UINT32 *	semHandle
	)

extern

Create a binary semaphore.

Description:: This API is used to create a binary semaphore control structure according to the initial number of available semaphores specified by count and return the ID of this semaphore control structure.

注意: None.

参数

count	[IN] Initial number of available semaphores. The value range is [0, 1].
semHandle	[OUT] ID of the semaphore control structure that is initialized.

返回值

LOS_ERRNO_SEM_PTR_NULL	The passed-in semHandle value is NULL.
LOS_ERRNO_SEM_OVERFLOW	The passed-in count value is greater than the maximum number of available semaphores.
LOS_ERRNO_SEM_ALL_BUSY	No semaphore control structure is available.
LOS_OK	The semaphore is successfully created.

Dependency:

los_sem.h: the header file that contains the API declaration.

参见: LOS_SemCreate | LOS_SemDelete

自从: Huawei LiteOS V100R001C00

◆ LOS_SemCreate()

UINT32 LOS_SemCreate	(	UINT16	count,
		UINT32 *	semHandle
	)

extern

Create a semaphore.

Description:: This API is used to create a semaphore control structure according to the initial number of available semaphores specified by count and return the ID of this semaphore control structure.

注意: None.

参数

count	[IN] Initial number of available semaphores. The value range is [0, LOS_SEM_COUNT_MAX).
semHandle	[OUT] ID of the semaphore control structure that is initialized.

返回值

LOS_ERRNO_SEM_PTR_NULL	The passed-in semHandle value is NULL.
LOS_ERRNO_SEM_OVERFLOW	The passed-in count value is greater than the maximum number of available semaphores.
LOS_ERRNO_SEM_ALL_BUSY	No semaphore control structure is available.
LOS_OK	The semaphore is successfully created.

Dependency:

los_sem.h: the header file that contains the API declaration.

参见: LOS_SemDelete | LOS_BinarySemCreate

自从: Huawei LiteOS V100R001C00

◆ LOS_SemDelete()

UINT32 LOS_SemDelete ( UINT32 semHandle )

extern

Delete a semaphore.

Description:: This API is used to delete a semaphore control structure that has an ID specified by semHandle.

注意: The specified sem id must be created first before deleting it.

参数

semHandle [IN] ID of the semaphore control structure to be deleted. The ID of the semaphore control structure is obtained from semaphore creation.

返回值

LOS_ERRNO_SEM_INVALID	The passed-in semHandle value is invalid.
LOS_ERRNO_SEM_PENDED	The queue of the tasks that are waiting on the semaphore control structure is not null.
LOS_OK	The semaphore control structure is successfully deleted.

Dependency:

los_sem.h: the header file that contains the API declaration.

参见: LOS_SemCreate | LOS_BinarySemCreate

自从: Huawei LiteOS V100R001C00

◆ LOS_SemPend()

UINT32 LOS_SemPend	(	UINT32	semHandle,
		UINT32	timeout
	)

extern

Request a semaphore.

Description:: This API is used to request a semaphore based on the semaphore control structure ID specified by semHandle and the parameter that specifies the timeout period.

注意

Do not pend sem during an interrupt.
Do not pend sem in a system task, such as idle or swtmr task.
The specified sem id must be created first.
Do not recommend to use this API in software timer callback.

参数

semHandle	[IN] ID of the semaphore control structure to be requested. The ID of the semaphore control structure is obtained from semaphore creation.
timeout	[IN] Timeout interval for waiting on the semaphore. The value range is [0, 0xFFFFFFFF]. If the value is set to 0, the semaphore is not waited on. If the value is set to 0xFFFFFFFF, the semaphore is waited on forever(unit: Tick).

返回值

LOS_ERRNO_SEM_INVALID	The passed-in semHandle value is invalid.
LOS_ERRNO_SEM_UNAVAILABLE	There is no available semaphore resource.
LOS_ERRNO_SEM_PEND_INTERR	The API is called during an interrupt, which is forbidden.
LOS_ERRNO_SEM_PEND_IN_LOCK	The task is unable to request a semaphore because task scheduling is locked.
LOS_ERRNO_SEM_PEND_IN_SYSTEM_TASK	The API is called in a system task, such as idle task or software timer, which is forbidden.
LOS_ERRNO_SEM_TIMEOUT	The request for the semaphore times out.
LOS_OK	The semaphore request succeeds.

Dependency:

los_sem.h: the header file that contains the API declaration.

参见: LOS_SemPost | LOS_SemCreate | LOS_BinarySemCreate

自从: Huawei LiteOS V100R001C00

◆ LOS_SemPost()

UINT32 LOS_SemPost ( UINT32 semHandle )

extern

Release a semaphore.

Description:: This API is used to release a semaphore that has a semaphore control structure ID specified by semHandle.

注意: The specified sem id must be created first.

参数

semHandle [IN] ID of the semaphore control structure to be released.The ID of the semaphore control structure is obtained from semaphore creation.

返回值

LOS_ERRNO_SEM_INVALID	The passed-in semHandle value is invalid.
LOS_ERRNO_SEM_OVERFLOW	The times of semaphore release exceed the maximum times permitted.
LOS_OK	The semaphore is successfully released.

Dependency:

los_sem.h: the header file that contains the API declaration.

参见: LOS_SemPend | LOS_SemCreate | LOS_BinarySemCreate

自从: Huawei LiteOS V100R001C00