Semaphore

UINT32 LOS_SemPend ( UINT32  uwSemHandle, UINT32  uwTimeout   ) Request a semaphore. Description: This API is used to request a semaphore based on the semaphore control structure ID specified by uwSemHandle and the parameter that specifies the timeout period. 注意: The specified sem id must be created first. 参数: 参数名称 描述 uwSemHandle  [IN] ID of the semaphore control structure to be requested. The ID of the semaphore control structure is obtained from semaphore creation. uwTimeout  [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: 返回值 描述 LOS_ERRNO_SEM_INVALID  The passed-in uwSemHandle 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_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 自从: Huawei LiteOS V100R001C00