Experimental three-process scheduling simulation program

Experimental three- process Scheduling simulation program

Internet of Things 201306104112 Jianfeng

1. Purpose and Requirements

Experimental purpose

A process scheduler is completed in a high-level language to deepen the understanding of process concepts and process scheduling algorithms.

Experimental requirements

Design a process scheduling simulator with N (n not less than 5) processes executing concurrently.

Process scheduling algorithm:" time slice Rotation method " scheduling algorithm to N processes.  

2. Content

The design, coding and debugging of two algorithms (Simple time slice rotation method and multistage feedback queue scheduling algorithm ) are completed, and the experimental report is completed.

1) Each process has a Process control block (PCB) representation. The Process Control block contains the following information: Process name, priority, arrival time, required run time, elapsed CPU time, process state, and so on.  

2) the status of each process can be ready, run R(Running), or complete F(finished ) One of three states.

3) The ready process can only run one time slice after acquiring the CPU. Represented by the elapsed CPU time plus 1 .

4) If the elapsed CPU time of the process has reached the required run time after a time slice is run, the process is undone if the elapsed CPU time of the process after running a time slice has not reached the required run time, that is, the process needs to continue running , you should insert it into the ready queue for the next schedule.

5) Each time the schedule is scheduled , the program prints a run process, the PCB of each process in the ready queue for inspection.  　　

6) Repeat the process until the process is complete.

3. Code

#pragma COMMENT (linker, "/subsystem:console") #include <stdio.h> #include <stdlib.h> #include <conio.h   > #include <dos.h> #define GETPCH (Type) (type*) malloc (sizeof (type)) #define NULL 0 struct pcb{/* Define Process Control block PCB */  Char name[10];  Char state;  int super;  int ntime;  int rtime;  struct pcb* link;  } *ready=null,*p;  typedef struct PCB PCB;  Sort ()/* Establish prioritization functions for processes */{PCB *first, *second;  int insert=0; if ((ready==null) | | | ((P->super) > (ready->super)))  /* Priority Max, insert team First */{p->link=ready;  Ready=p;  } else/* Process Compare priority, insert the appropriate location */{first=ready;  second=first->link;  while (Second!=null) {if (P->super > (second->super))/* If the insert process is larger than the current process precedence, */{* * is inserted in front of the current process */p->link=second;  first->link=p;  Second=null;  Insert=1;  } else/* Inserts a process with the lowest priority number, insert to the end of the queue */{first=first->link;  second=second->link;  }} if (insert==0) first->link=p;  }} input ()/* Establish the Process Control block function */{int i,num; printf ("\ n Please enter the process number:"); scanf ("%d", &num); num=num++; for (I=1; i<num;i++) {printf ("\ n process number no.%d:\n", i);  P=GETPCH (PCB); printf ("\ n input process name:");  scanf ("%s", p->name); printf ("\ n Input process priority number:");  scanf ("%d", &p->super); printf ("\ n input process run time:");  scanf ("%d", &p->ntime);  printf ("\ n");  P->rtime=0;p->state= ' W ';  p->link=null; Sort (); /* Call the Sort function */}} int space () {int l=0;  pcb* Pr=ready;  while (pr!=null) {l++;  pr=pr->link;  } return (L);  } disp (PCB * PR)/* Establish a process display function to display the current process */{printf ("\ QName \ t state \ t super \ ndtime \ t runtime \ n");  printf ("|%s\t", pr->name);  printf ("|%c\t", pr->state);  printf ("|%d\t", pr->super);  printf ("|%d\t", pr->ntime);  printf ("|%d\t", pr->rtime);  printf ("\ n");  } check ()/* Establish process view function */{pcb* PR; printf ("\ n * * * * Currently running process is:%s", p->name);  /* Displays the current running process */disp (P);  Pr=ready; printf ("\ n * * * Current ready queue status: \ n");  /* Show ready queue status */while (pr!=null) {disp (PR);  pr=pr->link;  }} Destroy ()/* Establish the process undo function (Process run end, undo process) */{printf ("\ n process [%s] completed. \ n", p->name);  Free (p); } running ()/* Establish the process-ready function (process run time to, set ready state */{(p->rtime) + +); if (P->rtime==p->ntime) destroy ();  /* Call the Destroy function */else {(p->super)--; P->state= ' W '; Sort ();  /* Call the Sort function */}} main ()/*/main function */{int len,h=0;  Char ch;  Input ();  Len=space ();  while ((len!=0) && (ready!=null)) {Ch=getchar ();  h++;  printf ("\ n the execute number:%d \ n", h);  P=ready;  ready=p->link;  p->link=null;  P->state= ' R ';  Check ();  Running (); printf ("\ n Press any key to continue ...");  Ch=getchar ();  } printf ("\ n \ nthe process has completed. \ n");  Ch=getchar ();  }

4. Summary

This test is also a multi-reference, the realization of the understanding is not too deep, but also in the class to see more to learn.

Experimental three-process scheduling simulation program