fcfs.c

#include "algorithms.h"
#include <time.h>
//The algorithm return total running time 
Result* FCFSA(process* parray[],int nump){
	srand(time(NULL));
	heap* ready;//"ready" heap is sorted by using getting time
	process** standby = (process**)malloc(sizeof(process*)*(nump+1));
	int first=0,last=0;
	Running* running = init_Running(0);
	Running* fake = init_Running(0);
	Result* result = init_Result();
	stack* finished = result->finished;
	int idle=-1;
	int time=0;

	//initialize heap
	//first, make heap with key value 1(getting time)
	//second, insert all processes in parray into heap
	ready=init_heap(1,nump);
	for(time=0;time<nump;time++){
		if(parray[time]->arrivalT==0)
			standby[last++]=parray[time];
		else
			heap_insert(ready,parray[time]);
	}
	
	for(time=0;/*infinitely*/;time++){
		while(IsAvailProcess(ready,1,time)){
			ChangeRunning(fake,ready);
			standby[last]=fake->Process;
			last++;
			last%=nump+1;
		}
		if(running->Process==NULL){
			idle++;
			if(last!=first){
				running->Process=standby[first];
				first++;
				first%=nump+1;
			}
		}

		else if(RunningFinished(running)){
			int i=0;
			FinishProcess(running,time,finished);
			if(last!=first){
				running->Process=standby[first];
				first++;
				first%=nump+1;
			}
		}

		else if(RunningInterrupted(running,BYIO)){
			interrupt_process(running->Process,BYIO,time);
			heap_insert(ready,running->Process);
			if(last!=first){
				running->Process=standby[first];
				first++;
				first%=nump+1;
			}
			else{
				running->Process=NULL;
			}
		}
	
		if(AllFinished(running,ready,ready)){
		break;
		}
		
		checkingList(result,running,time);
		SpendTime(running);
	}
	result->totaltime=time;
	result->idle=idle;
	printf("finished algorithm!!!\n");
	return result;
}