Process Dynamic Priority scheduling

1 /*******************************************2 *3 * FILE:PRO.C4 * Describe: Operating system process scheduling, dynamic priority algorithm5 * Author: Ah q6 * iime:2016.11.197 *8 *******************************************/9#include <stdio.h>Ten #defineP 5 One #defineprintf (proprety) printf ("%s\t", proprety) A structPCB {//Define Process Structure -     intpid//Process ID -     structPCB *next;//point to Next process the     intTime//the time required for the process to execute -     intPriority//Process Priority -     intState//the status of the process execution, only 0, 1 states. 0 Not executed, 1 executed - }; + structPCB pro[p]= {//Initialize 5 processes -{0,1,6,3,0}, +{1,2,4,4,0}, A{2,3,4,3,0}, at{3,4,4,2,0}, -{4,0,1,0,0}, - }; -  - /******************************************* - * in * Function: Shows the status of all Processes - * to *******************************************/ + voiddisplay () { -     intI=0, property=5; thePrintF ("\npid"); *      for(i=0; i<p; i++) { $printf"%d\t", pro[i].pid);Panax Notoginseng     } -PrintF ("\nnext"); the      for(i=0; i<p; i++) { +printf"%d\t", pro[i].next); A     } thePrintF ("\ntime"); +      for(i=0; i<p; i++) { -printf"%d\t", pro[i].time); $     } $PrintF ("\npri"); -      for(i=0; i<p; i++) { -printf"%d\t", pro[i].priority); the     } -PrintF ("\nstate");Wuyi      for(i=0; i<p; i++) { theprintf"%d\t", pro[i].state); -     } Wuprintf"\ n"); - } About  $ /******************************************* - * - * Function: Sort the structure, descending by priority * Time Ascending - * A *******************************************/ + intcmpConst void*a,Const void*b) { the     structPCB *aa= (structPCB *) A; -     structPCB *bb= (structPCB *) b; $  the     //returns the status directly if the process execution finishes the     if(aa->time==0|| aa->state==1)return 1; the     Else if(bb->time==0|| bb->state==1)return-1; the  -     if(bb->priority!=aa->Priority ) in         return(bb->priority-aa->Priority ); the     Else the         return(aa->time-bb->Time ); About } the  the /******************************************* the * + * Function: Process sequencing requires sub-function cmp () - * the *******************************************/Bayi voidReSort () { theQsort (Pro,p,sizeof(pro[0]), CMP); the } -  - /******************************************* the * the * Function: Check if there are any programs that have not finished executing the * the *******************************************/ - intCheck () { the     intI=0; the      for(i=0; i<p; i++) { the         if(!pro[i].state)return 1;94     } the     return 0; the } the 98 /******************************************* About * - * Function: Modify pointer to point101 *102 *******************************************/103 voidRepoint () {104     intI=0; the      for(; i<p; i++) {106         if(pro[i].state&&i>0) {107pro[i-1].next=0;108         }109         if(i< (P-1)) thepro[i].next=pro[i+1].pid;111     } the }113  the intMain () { the     intf=0, i=1; theprintf"the initial state is:");117 display ();118      while(check ()) {//after each execution, test if there are still processes not finished119printf"after the first%d run:", i++); -         //Pro[0] is the first process, which is considered to be a process executed in the cup. Each execution time is reduced by one, and priority is reduced by one. 121pro[0].time-=1;//perform a process execution time minus one122pro[0].priority-=1;//dynamic priority, minus one priority per execution123 124         if(pro[0].time==0) pro[0].state=1, pro[0].priority=-1, pro[0].next=0;//If the process finishes, and the execution time is 0, the status is 1, the priority is adjusted, and the pointer is modulated to 0 theReSort ();//Reflow Process126Repoint ();//Rearrange pointers127Display ();//Output -     }129printf"The process is complete. \ n"); the     return 0;131}

Process Dynamic Priority scheduling