• 计时器是倒计时器，当计数器达到零时执行某个动作。用户通过回调函数提供这个动作。回调函数是用户声明的函数，在计时器到期时被调用。在回调函数中绝对不能进行阻塞调用（例如调用OSTimeDly()、OSTimeDlyHMSM()…或任何导致计时器任务阻塞或被删除的操作），这一点非常重要。

获取计时器的名字

#if OS_TMR_EN > 0u && OS_TMR_CFG_NAME_EN > 0u
INT8U  OSTmrNameGet (OS_TMR   *ptmr,INT8U   **pdest,INT8U    *perr)
{INT8U  len;
#ifdef OS_SAFETY_CRITICALif (perr == (INT8U *)0){OS_SAFETY_CRITICAL_EXCEPTION();return (0u);}#endif
#if OS_ARG_CHK_EN > 0uif (pdest == (INT8U **)0){*perr = OS_ERR_TMR_INVALID_DEST;return (0u);}if (ptmr == (OS_TMR *)0){*perr = OS_ERR_TMR_INVALID;return (0u);}#endifif (ptmr->OSTmrType != OS_TMR_TYPE)                /* Validate timer structure                                    */{*perr = OS_ERR_TMR_INVALID_TYPE;return (0u);}if (OSIntNesting > 0u)                             /* See if trying to call from an ISR                           */{*perr = OS_ERR_NAME_GET_ISR;return (0u);}OSSchedLock();switch (ptmr->OSTmrState){case OS_TMR_STATE_RUNNING:case OS_TMR_STATE_STOPPED:case OS_TMR_STATE_COMPLETED:*pdest = ptmr->OSTmrName;len    = OS_StrLen (*pdest);OSSchedUnlock();*perr = OS_ERR_NONE;return (len);case OS_TMR_STATE_UNUSED:                      /* Timer is not allocated                                      */OSSchedUnlock();*perr = OS_ERR_TMR_INACTIVE;return (0u);default:OSSchedUnlock();*perr = OS_ERR_TMR_INVALID_STATE;return (0u);}
}
#endif

获取计时器到期前剩余的时间

#if OS_TMR_EN > 0u
INT32U  OSTmrRemainGet (OS_TMR  *ptmr,INT8U   *perr)
{INT32U  remain;
#ifdef OS_SAFETY_CRITICALif (perr == (INT8U *)0){OS_SAFETY_CRITICAL_EXCEPTION();return (0u);}#endif
#if OS_ARG_CHK_EN > 0uif (ptmr == (OS_TMR *)0){*perr = OS_ERR_TMR_INVALID;return (0u);}#endifif (ptmr->OSTmrType != OS_TMR_TYPE)                /* Validate timer structure                                    */{*perr = OS_ERR_TMR_INVALID_TYPE;return (0u);}if (OSIntNesting > 0u)                             /* See if trying to call from an ISR                           */{*perr = OS_ERR_TMR_ISR;return (0u);}OSSchedLock();switch (ptmr->OSTmrState){case OS_TMR_STATE_RUNNING:remain = ptmr->OSTmrMatch - OSTmrTime;    /* Determine how much time is left to timeout                  */OSSchedUnlock();*perr  = OS_ERR_NONE;return (remain);case OS_TMR_STATE_STOPPED:                     /* It's assumed that the timer has not started yet             */switch (ptmr->OSTmrOpt){case OS_TMR_OPT_PERIODIC:if (ptmr->OSTmrDly == 0u){remain = ptmr->OSTmrPeriod;}else{remain = ptmr->OSTmrDly;}OSSchedUnlock();*perr  = OS_ERR_NONE;break;case OS_TMR_OPT_ONE_SHOT:default:remain = ptmr->OSTmrDly;OSSchedUnlock();*perr  = OS_ERR_NONE;break;}return (remain);case OS_TMR_STATE_COMPLETED:                   /* Only ONE-SHOT that timed out can be in this state           */OSSchedUnlock();*perr = OS_ERR_NONE;return (0u);case OS_TMR_STATE_UNUSED:OSSchedUnlock();*perr = OS_ERR_TMR_INACTIVE;return (0u);default:OSSchedUnlock();*perr = OS_ERR_TMR_INVALID_STATE;return (0u);}
}
#endif

查看计时器的状态

#if OS_TMR_EN > 0u
INT8U  OSTmrStateGet (OS_TMR  *ptmr,INT8U   *perr)
{INT8U  state;
#ifdef OS_SAFETY_CRITICALif (perr == (INT8U *)0){OS_SAFETY_CRITICAL_EXCEPTION();return (0u);}#endif
#if OS_ARG_CHK_EN > 0uif (ptmr == (OS_TMR *)0){*perr = OS_ERR_TMR_INVALID;return (0u);}#endifif (ptmr->OSTmrType != OS_TMR_TYPE)                /* Validate timer structure                                    */{*perr = OS_ERR_TMR_INVALID_TYPE;return (0u);}if (OSIntNesting > 0u)                             /* See if trying to call from an ISR                           */{*perr = OS_ERR_TMR_ISR;return (0u);}OSSchedLock();state = ptmr->OSTmrState;switch (state){case OS_TMR_STATE_UNUSED:case OS_TMR_STATE_STOPPED:case OS_TMR_STATE_COMPLETED:case OS_TMR_STATE_RUNNING:*perr = OS_ERR_NONE;break;default:*perr = OS_ERR_TMR_INVALID_STATE;break;}OSSchedUnlock();return (state);
}
#endif