Description
Deletes a mutex. This function should be used with care because multiple tasks may rely on the presence of the mutex. Generally speaking, before deleting a mutex, first delete all the tasks that access the mutex. However, as a general rule, do not delete kernel objects at run-time.
Files
os.h/os_mutex.c
Prototype
Arguments
p_mutex
is a pointer to the mutex to delete.
opt
specifies whether to delete the mutex only if there are no pending tasks (OS_OPT_DEL_NO_PEND), or whether to always delete the mutex regardless of whether tasks are pending or not (OS_OPT_DEL_ALWAYS). In this case, all pending tasks are readied.
p_err
is a pointer to a variable that is used to hold an error code:
OS_ERR_NONE
If the call is successful and the mutex has been deleted.
OS_ERR_DEL_ISR
If OS_CFG_CALLED_FROM_ISR_CHK_EN set to 1 in os_cfg.h: if attempting to delete a mutex from an ISR.
OS_ERR_OBJ_PTR_NULL
If OS_CFG_ARG_CHK_EN is set to 1 in os_cfg.h: if p_mutex is a NULL pointer.
OS_ERR_OBJ_TYPE
If OS_CFG_OBJ_TYPE_CHK_EN is set to 1 in os_cfg.h: if p_mutex is not pointing to a mutex.
OS_ERR_OPT_INVALID
If the user does not specify one of the two options mentioned in the opt argument.
OS_ERR_TASK_WAITING
If one or more task are waiting on the mutex and OS_OPT_DEL_NO_PEND is specified.
Returned Value
The number of tasks that were waiting for the mutex and 0 if an error occurred.
Required Configuration
OS_CFG_MUTEX_EN and OS_CFG_MUTEX_DEL_EN must be enabled in os_cfg.h. Refer to uC-OS-III Configuration Manual
Callers
Application.
Notes/Warnings
- Use this call with care as other tasks may expect the presence of the mutex.