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一個(gè)簡(jiǎn)易的調(diào)度器
單片機(jī)源程序如下:
- #include <stc89c51.h>
- /****小小調(diào)度器開(kāi)始**********************************************/
- #define MAXTASKS 3
- volatile unsigned char timers[MAXTASKS];
- #define _SS static unsigned char _lc=0; switch(_lc){default:
- #define _EE ;}; _lc=0; return 255;
- #define WaitX(tickets)??do {_lc=(__LINE__+((__LINE__%256)==0))%256; return tickets ;} while(0); case (__LINE__+((__LINE__%256)==0))%256:
- #define RunTask(TaskName,TaskID) do { if (timers[TaskID]==0) timers[TaskID]=TaskName(); }??while(0);
- #define RunTaskA(TaskName,TaskID) { if (timers[TaskID]==0) {timers[TaskID]=TaskName(); continue;} }? ?//前面的任務(wù)優(yōu)先保證執(zhí)行
- #define CallSub(SubTaskName) do {unsigned char currdt; _lc=(__LINE__+((__LINE__%256)==0))%256; return 0; case (__LINE__+((__LINE__%256)==0))%256:??currdt=SubTaskName(); if(currdt!=255) return currdt;} while(0);
- #define InitTasks() {unsigned char i; for(i=MAXTASKS;i>0 ;i--) timers[i]=0; }
- #define UpdateTimers() {unsigned char i; for(i=MAXTASKS;i>0 ;i--){if((timers[i-1]!=0)&&(timers[i-1]!=255)) timers[i-1]--;}}
- #define SEM unsigned int
- //初始化信號(hào)量
- #define InitSem(sem) sem=0;
- //等待信號(hào)量
- #define WaitSem(sem) do{ sem=1; WaitX(0); if (sem>0) return 1;} while(0);
- //等待信號(hào)量或定時(shí)器溢出， 定時(shí)器tickets 最大為0xFFFE
- #define WaitSemX(sem,tickets)??do { sem=tickets+1; WaitX(0); if(sem>1){ sem--;??return 1;} } while(0);
- //發(fā)送信號(hào)量
- #define SendSem(sem)??do {sem=0;} while(0);
- /*****小小調(diào)度器結(jié)束*******************************************************/
- sbit LED1 = P2^1;
- sbit LED2 = P2^2;
- sbit LED0 = P2^5;
- unsigned char task0(){
- _SS
- while(1){
- WaitX(50);
- LED0=!LED0;
- }
- _EE
- }
- unsigned char??task1(){
- _SS
- while(1){
- WaitX(100);
- LED1=!LED1;
- }
- _EE
- }
- unsigned char??task2(){
- _SS
- while(1){
- WaitX(100);
- LED2=!LED2;
- }
- _EE
- }
- void InitT0()
- {
- TMOD = 0x21;
- IE |= 0x82;??// 12t
- TL0=0Xff;
- TH0=0XDB;
- TR0 = 1;
- }
- void INTT0(void) interrupt 1 using 1
- {
- TL0=0Xff;? ? //10ms 重裝
- TH0=0XDB;//b7;
- UpdateTimers();
- RunTask(task0,0);//任務(wù)0具有精確按時(shí)獲得執(zhí)行的權(quán)限，要求：task0每次執(zhí)行消耗時(shí)間<0.5個(gè) ticket
- }
- void main()
- {
- InitT0();
- InitTasks(); //初始化任務(wù)，實(shí)際上是給timers清零
- while(1){
- //? ?? ?? ???RunTask(task0,0);
- RunTaskA(task1,1);//任務(wù)1具有比任務(wù)2高的運(yùn)行權(quán)限
- RunTaskA(task2,2);//任務(wù)2具有低的運(yùn)行權(quán)限
- }
- }
所有資料51hei提供下載:
小小調(diào)度器.zip
(11.96 KB, 下載次數(shù): 40)
2019-5-11 08:44 上傳
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