1、CPUTIMEALLTIME6STARTBLOCK-1BLOCKTIMESTATEREADY(5)为了清楚地观察诸进程的调度过程,程序应将每个时间片的进程的情况显示出来,参照的具体格式如下:RUNNING PROG: iREADY_QUEUE:-id1-id2BLOCK_QUEUE:id3-id4=ID 0 1 2 3 4PRIORITY P0 P1 P2 P3 P4CPUTIME C0 C1 C2 C3 C4ALLTIME A0 A1 A2 A3 A4STARTBLOCK T0 T1 T2 T3 T4BLOCKTIME B0 B1 B2 B3 B4STATE S0 S1 S2 S3 S4程序
2、代码:/A.4使用动态优先权的进程调度算法的模拟 /by YanQiwei#include #define N 5void init();void print();int getRunning();void sort();int run(int time);enum STATEReady,Run,Block,RunOut;struct PROCESS int ID; int Priority; int Cputime; int Alltime; int Startblock; int Blocktime; enum STATE State;ProcessN;int READYN;int BLO
3、CKN;int RUNOUTN2;int main() int Time=0; init(); printf(Time:%dn,Time); sort(); print(); while(1) Time+; getchar(); printf( if(run(Time) break; / sort(); /print(Time); return 0;void init() int i; /printf(Input properties of %d process(PRIORITY,ALLTIME,STARTBLOCK,BLOCKTIME):n, / N); for(i=0;i=0)tRUNNI
4、NG PROG: %dn,getRunning();tREADY_QUEUE:); if(READYi printf(%d,ProcessREADYi.ID); else ntBLOCK_QUEUE: if(BLOCKi,ProcessBLOCKi.ID); n=nIDtt%d,Processi.ID);nPRIORITY,Processi.Priority);nCPUTIMEt,Processi.Cputime);nALLTIMEt,Processi.Alltime);nSTARTBLOCK,Processi.Startblock);nBLOCKTIME,Processi.Blocktime
5、);nSTATEt switch(Processi.State) case 0:printf(tReadybreak; case 1:tRun if(Processi.Alltime=0) Processi.State=RunOut; else Processi.State=Ready; case 2:tBlock case 3:tRunOuttRUNOUT LIST: if(RUNOUTi0%d(%d),ProcessRUNOUTi0.ID,RUNOUTi1);int getRunning() if(Processi.State=Run) return i; if(Processi.Star
6、tblock=0) return -1;void sort() int i,j,k; if(Processi.State=Ready|Processi.State=Run) / Processi.State=Ready; continue; for(j=0;j+j) if(READYj0) READYj=i; break; else if(Processi.Priorityj;-k) READYk=READYk-1; else if(Processi.State=Block) if(BLOCKj=ProcessBLOCKj.Blocktime) BLOCKk=BLOCKk-1;int run(
7、int time) int i,runNum; runNum=READY0; if(runNum0&BLOCK0=0) ProcessrunNum.Priority-=3; ProcessrunNum.Alltime-=1; ProcessrunNum.Cputime+=1; ProcessrunNum.State=Run; for(i=0; if(i!=runNum) if(Processi.State=Ready) Processi.Priority+=1; else if(Processi.State=Block) Processi.Blocktime-=1; if(Processi.B
8、locktime=0) Processi.State=Ready; /print(); if(ProcessrunNum.Alltime=0) /ProcessrunNum.State=RunOut; for(i=0; if(RUNOUTi0 ProcessrunNum.Startblock-=1; if(ProcessrunNum.Startblock=0) ProcessrunNum.State=Block; /ProcessrunNum.Startblock-=1; else if(BLOCK0 if(Processi.State=Block) Processi.Startblock=-1; Processi.Blocktime-=1; if(Processi.Blocktime=0) Processi.State=Ready; / print();3、思考题(1)在实际的调度中,除了按调度算法选择下一个执行的进程外,还应处理哪些工作?答:1.记录系统中所有进程的执行情况作为进程调度的准备,进程管理模块必须将系统中各个进程的执行特征记录在各个进程的PCB表中。2.进行进程上下文交换一个进程的上下文包括进程的状态,有关变量和数据结构的值。机器寄存器的值和PCB以及有关程序,数据等。
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