libscheduler/libscheduler.c File Reference

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libscheduler.h"
#include "../libpriqueue/libpriqueue.h"

Data Structures
struct	job_t
	Stores information making up a job to be scheduled including any statistics. More...
Functions
void	scheduler_start_up (int cores, scheme_t scheme)
	Initalizes the scheduler.
int	scheduler_new_job (int job_number, int time, int running_time, int priority)
	Called when a new job arrives.
int	scheduler_job_finished (int core_id, int job_number, int time)
	Called when a job has completed execution.
int	scheduler_quantum_expired (int core_id, int time)
	When the scheme is set to RR, called when the quantum timer has expired on a core.
float	scheduler_average_waiting_time ()
	Returns the average waiting time of all jobs scheduled by your scheduler.
float	scheduler_average_turnaround_time ()
	Returns the average turnaround time of all jobs scheduled by your scheduler.
float	scheduler_average_response_time ()
	Returns the average response time of all jobs scheduled by your scheduler.
void	scheduler_clean_up ()
	Free any memory associated with your scheduler.
void	scheduler_show_queue ()
	This function may print out any debugging information you choose.

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Detailed Description

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Function Documentation

float scheduler_average_response_time

(

)

Returns the average response time of all jobs scheduled by your scheduler.

Assumptions:

• This function will only be called after all scheduling is complete (all jobs that have arrived will have finished and no new jobs will arrive).

  Returns:

  the average response time of all jobs scheduled.

float scheduler_average_turnaround_time

(

)

Returns the average turnaround time of all jobs scheduled by your scheduler.

Assumptions:

• This function will only be called after all scheduling is complete (all jobs that have arrived will have finished and no new jobs will arrive).

  Returns:

  the average turnaround time of all jobs scheduled.

float scheduler_average_waiting_time

(

)

Returns the average waiting time of all jobs scheduled by your scheduler.

Assumptions:

• This function will only be called after all scheduling is complete (all jobs that have arrived will have finished and no new jobs will arrive).

  Returns:

  the average waiting time of all jobs scheduled.

void scheduler_clean_up

(

)

Free any memory associated with your scheduler.

Assumptions:

• This function will be the last function called in your library.

int scheduler_job_finished	(	int	core_id,
		int	job_number,
		int	time
	)

Called when a job has completed execution.

The core_id, job_number and time parameters are provided for convenience. You may be able to calculate the values with your own data structure. If any job should be scheduled to run on the core free'd up by the finished job, return the job_number of the job that should be scheduled to run on core core_id.

Parameters:

core_id	the zero-based index of the core where the job was located.
job_number	a globally unique identification number of the job.
time	the current time of the simulator.

Returns:

job_number of the job that should be scheduled to run on core core_id

-1 if core should remain idle.

int scheduler_new_job	(	int	job_number,
		int	time,
		int	running_time,
		int	priority
	)

Called when a new job arrives.

If multiple cores are idle, the job should be assigned to the core with the lowest id. If the job arriving should be scheduled to run during the next time cycle, return the zero-based index of the core the job should be scheduled on. If another job is already running on the core specified, this will preempt the currently running job. Assumptions:

• You may assume that every job wil have a unique arrival time.

Parameters:

job_number	a globally unique identification number of the job arriving.
time	the current time of the simulator.
running_time	the total number of time units this job will run before it will be finished.
priority	the priority of the job. (The lower the value, the higher the priority.)

Returns:

index of core job should be scheduled on

-1 if no scheduling changes should be made.

int scheduler_quantum_expired	(	int	core_id,
		int	time
	)

When the scheme is set to RR, called when the quantum timer has expired on a core.

If any job should be scheduled to run on the core free'd up by the quantum expiration, return the job_number of the job that should be scheduled to run on core core_id.

Parameters:

core_id	the zero-based index of the core where the quantum has expired.
time	the current time of the simulator.

Returns:

job_number of the job that should be scheduled on core cord_id

-1 if core should remain idle

void scheduler_show_queue

(

)

This function may print out any debugging information you choose.

This function will be called by the simulator after every call the simulator makes to your scheduler. In our provided output, we have implemented this function to list the jobs in the order they are to be scheduled. Furthermore, we have also listed the current state of the job (either running on a given core or idle). For example, if we have a non-preemptive algorithm and job(id=4) has began running, job(id=2) arrives with a higher priority, and job(id=1) arrives with a lower priority, the output in our sample output will be:

2(-1) 4(0) 1(-1)

This function is not required and will not be graded. You may leave it blank if you do not find it useful.

void scheduler_start_up	(	int	cores,
		scheme_t	scheme
	)

Initalizes the scheduler.

Assumptions:

• You may assume this will be the first scheduler function called.
• You may assume this function will be called once once.
• You may assume that cores is a positive, non-zero number.
• You may assume that scheme is a valid scheduling scheme.

Parameters:

cores	the number of cores that is available by the scheduler. These cores will be known as core(id=0), core(id=1), ..., core(id=cores-1).
scheme	the scheduling scheme that should be used. This value will be one of the six enum values of scheme_t