OSMutexCreate()

void  OSMutexCreate (OS_MUTEX    *p_mutex,

                     CPU_CHAR    *p_name,

                     OS_ERR      *p_err)

OSMutexCreate() is used to create and initialize a mutex. A mutex is used to gain exclusive access to a resource.

Arguments

p_mutex

is a pointer to a mutex control block that must be allocated in the application. The user will need to declare a “global” variable as follows, and pass a pointer to this variable to OSMutexCreate():

OS_MUTEX MyMutex;

p_name

is a pointer to an ASCII string used to assign a name to the mutual exclusion semaphore. The name may be displayed by debuggers or µC/Probe.

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 created.

OS_ERR_CREATE_ISR

if OS_CFG_CALLED_FROM_ISR_CHK_EN set to 1 in os_cfg.h: if attempting to create 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_ILLEGAL_CREATE_RUN_TIME

if OS_SAFETY_CRITICAL_IEC61508 is defined: you called this after calling OSSafetyCriticalStart() and thus you are no longer allowed to create additional kernel objects.

Returned Value

None

Notes/Warnings

Mutexes must be created before they are used.

Example