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is a pointer to a variable used to hold an error code. The error code may be one of the following:
OS_ERR_NONE
if If the call is successful and the semaphore has been deleted.
OS_ERR_DEL_ISR
if If OS_CFG_CALLED_FROM_ISR_CHK_EN set to 1 in os_cfg.h: if attempting to delete the semaphore from an ISR.
OS_ERR_OBJ_PTR_NULL
if If OS_CFG_ARG_CHK_EN is set to 1 in os_cfg.h: if p_sem is a NULL pointer.
OS_ERR_OBJ_TYPE
if If OS_CFG_OBJ_TYPE_CHK_EN is set to 1 in os_cfg.h: if p_sem is not pointing to a semaphore.
OS_ERR_OPT_INVALID
if If OS_CFG_ARG_CHK_EN is set to 1 in os_cfg.h: if one of the two options mentioned in the opt argument is not specified.
OS_ERR_TASK_WAITING
if If one or more tasks are waiting on the semaphore.
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