ucos V2.52

OSTimeTick()函数解析

调用处：os_cpu_a.asm里_OSTickISR

函数所有源文件：os_core.c

代码：

void  OSTimeTick (void)
{
#if OS_CRITICAL_METHOD == 3           /* Allocate storage for CPU status register */
OS_CPU_SR  cpu_sr;
#endif    
OS_TCB    *ptcb;

OSTimeTickHook();                 /* Call user definable hook                 */
#if OS_TIME_GET_SET_EN > 0   
OS_ENTER_CRITICAL();             /* Update the 32-bit tick counter           */
OSTime++;                                                             //(1)
OS_EXIT_CRITICAL();
#endif
if (OSRunning == TRUE) {           //(2)
ptcb = OSTCBList;            /* Point at first TCB in TCB list           */     
while (ptcb->OSTCBPrio != OS_IDLE_PRIO) 
{    /* Go through all TCBs in TCB list          */   //(3)
OS_ENTER_CRITICAL();           //(4)
if (ptcb->OSTCBDly != 0) 
{       /* Delayed or waiting for event with TO     */    //(5)
if (--ptcb->OSTCBDly == 0) 
{      /* Decrement nbr of ticks to end of delay   */    //(6)
if ((ptcb->OSTCBStat & OS_STAT_SUSPEND) == OS_STAT_RDY) 
{ /* Is task suspended?    */    //(7)
/* No, Make task R-to-R (timed out)*/
OSRdyGrp |= ptcb->OSTCBBitY;
OSRdyTbl[ptcb->OSTCBY] |= ptcb->OSTCBBitX;      //(8)
} else {            /* Yes, Leave 1 tick to prevent loosing the task when the suspension is removed.*/
ptcb->OSTCBDly = 1;  //(9)
} 
}
}
ptcb = ptcb->OSTCBNext;  /* Point at next TCB in TCB list   */    //(10)
OS_EXIT_CRITICAL();          //(11)
}
}
}