Page Comparison

...

Files

os.h/os_sem.c

Prototype

void  OSSemSet (OS_SEM      *p_sem,
                OS_SEM_CTR   cnt,
                OS_ERR      *p_err)

Arguments

p_sem

is a pointer to the semaphore that is used as a signaling mechanism.

...

OS_ERR_NONE

If the count was changed or, not changed, because one or more tasks was waiting on the semaphore.

OS_ERR_OBJ_PTR_NULL

If OS_CFG_ARG_CHK_EN is set to 1 in DEF_ENABLED in os_cfg.h: if p_sem is a NULL pointer.

...

If OS_CFG_OBJ_TYPE_CHK_EN is set to 1 in DEF_ENABLED in os_cfg.h: if p_sem is not pointing to a semaphore.

...

If OS_CFG_CALLED_FROM_ISR_CHK_EN set to 1 in DEF_ENABLED in os_cfg.h: if this function was called from an ISR.

...

If tasks are waiting on the semaphore, the count is not changed.

Returned Value

None

Required Configuration

OS_CFG_SEM_EN and OS_CFG_SEM_SET_EN must be enabled in os_cfg.h. Refer to uCµC-OS-III Configuration Manual.

Callers

Application.

Notes/Warnings

1. Do not use this function if the semaphore is used to protect a shared resource.

Example Usage

          OS_SEM  SwSem;
           
           
          void  Task (void  *p_arg)
          {
              OS_ERR  err;
           
           
              (void)&p_arg;
              while (DEF_ON) {
                  OSSemSet(&SwSem,      /* Reset the semaphore count */
                            0,
                           &err);
                  /* Check "err" */
                  :
                  :
              }
          }