项目板和nxp培训b221ucos课件rtos3iii任务调度

飞 单片机应 Gong

Page态，使当前最重要的任务优先运行。

Page OSTaskCreate((OS_TCB*)&App_TaskStartTCB,...);

PagestructOS_TCB{

//指向堆栈*NextPtr;//指向任务就绪表中后一个任务的*PrevPtr;//指向任务就绪表中前一个任务的TCBTaskEntryAddr;//指向任务代码的 *TaskEntryArg

TickCtrMatch

}

Page{

OSTaskCreate..

..OS_TaskInitTCB(p_tcb);//包含p_tcb->TaskState=..p_spOSTaskStkInit(...);//....}

Page

Page typedefCPU_INT32U#define ((OS_CFG_PRIO_MAX-1)/32+1

PagevoidOS_PrioInsert(OS_PRIOvoidOS_PrioRemove(OS_PRIOOS_PRIOOS_PrioGetHighest

PagePrio=Prio=voidOS_PrioInsert(OS_PRIO{

bit_nbr=ix=bit_nbr=ix==prio==31-&bit=1<<OSPrioTbl[ix]bit=1<<}

OSPrioTbl[1]|=

Page11级

PagevoidOS_PrioRemove(OS_PRIO{

//注：如下代码已针对32=prio/=(CPU_DATA)prio&=31-}

Page00000000000000000000000000000000000000000000000000000000000000000100000000000000100000000000000000000000000000000000000

prio=prio=

OS_PrioGetHighest

while(*p_tbl==(CPU_DATA)0){prio+=DEF_INT_CPU_NBR_BITS;指向指向

}prio+=(OS_PRIO) return(prio);}

PageOS_PRIOOS_PrioGetHighest{OS_PRIOif(OSPrioTbl[0]!={prio }{prio tLeadZeros(OSPrioTbl[1])+}return}

Page LeadingZero）指令，用来实现前导零计算功

R0,R0

Page tLeadZeros32(CPU_INT32U CPU_DATAix,nbr_lead_zeros;if(val>0x0000FFFF){if(val>0x00FFFFFF){/*Chkbits[31:24]*/ix=(CPU_DATA)(val>>24);nbr_lead_zeros= tLeadZerosTbl[ix]+0);else=/*Chkbits[23:16](CPU_DATA)(val>>= +elseif(val>0x000000FF){/*Chkbits[15:08] =(CPU_DATA)(val>>nbr_lead_zeros= +}else /*Chkbits[07:00] =(CPU_DATA)(val>>nbr_lead_zeros= +return

Pageconst tLeadZerosTbl[256]=0123456789ABCDEF0

Page

PageOS_RDY_LIST

Pagestruct{

PageOS_RDY_LISTOther

0000000OtherOtherOther

Page。。

Page

0OtherOtherOtherTask3_TCBOther0

PagevoidOS_RdyListInsertTail(OS_TCB OS_RDY_LIST*p_rdy_list; p_rdy_list=&OSRdyList[p_tcb-if(p_rdy_list-/*CASE0:==whenthereare{== = =p_tcb;}else{/*CASE1:=AFTERthetaillist = ====}}

Page00

0Other0OtherOther =OSTCBHighRdyPtr=

PageμC/OS-III是一个可型内核，这意味着，当一个使一个优先级更高的任务进入就绪态μC/OS-III会当前运行任务的CPUμC/OS-III的可型任务调度＋时间片轮转调

PageOSTimeDlyOSTaskSuspend()等，会调用OSSched()。OSSemPost()OSTaskCreate()OSTaskResume()等也会调

PagevoidOSSched{if(OSIntNestingCtr> }/*中断嵌套?if(OSSchedLockNestingCtr>0)

}/*调度器上锁 =OSTCBHighRdyPtr=if(OSTCBHighRdyPtrOSTCBCurPtr)/*是否有优先级更高的任务就绪{return;}}

/*任务切换计数加 /*任务切换

Pagevoid{

OS_ERR}

PagevoidOSIntExit{if(OSIntNestingCtr==0){return;}//中断嵌套层数为0？OSIntNestingCtr--;//中断嵌套层数减1if(OSIntNestingCtr>0){ }//if(OSSchedLockNestingCtr>0) }// =OS_PrioGetHighest();OSTCBHighRdyPtr=OSRdyList[OSPrioHighRdy].HeadPtr;if(OSTCBHighRdyPtr==OSTCBCurPtr){return;} /*中断级任务切换}

PagevoidOS_SchedRoundRobin(OS_RDY_LIST p_tcb=p_rdy_list-if(p_tcb- >0){p_tcb->TimeQuantaCtr--;if(p_tcb->TimeQuantaCtr >0){CPU_CRITICAL_EXIT();return; if(p_rdy_list->NbrEntries <2){CPU_CRITICAL_EXIT();return;}if(OSSchedLockNestingCtr>0){CPU_CRITICAL_EXIT();return;}p_tcb=p_rdy_list->HeadPtr;if(p_tcb->TimeQuanta==0)p_tcb->