Thread: problem with the scheduler

Attached my code for a scheduler that schedules a task periodical. But in my code i have taken different periods and need to set the timer for those periods and i should use single timer for this . (means set the timer for only one time) how i can achieve this please help me soon.

I might be missing something here but wouldn't your task need to consist of something more than a string? Say a struct with a timestamp, which you add to the end of a queue. Then periodically check the front of the queue if the timestamp of that struct has passed current time. BTW, it's probably better if you paste the code in code tags directly in the forum.

Code:

#include<sys/time.h>
#include<stdio.h>
#include<time.h>
#include<string.h>
#include"stdlib.h"
//extern int g_stop_application;
int SetTimer(struct timeval *, int);
int CheckTimer(struct timeval *, int);
int SetTimer(struct timeval *tv, int usec)
{
int msec;
gettimeofday(tv,NULL);
msec=(tv->tv_usec)*1000;
msec +=(usec*1000);
return 1;
}
int CheckTimer(struct timeval *tv, int usec)
{
struct timeval ctv;
gettimeofday(&ctv,NULL);
int msec;
if(((ctv.tv_usec)*1000 >= (tv->tv_usec)*1000) || ((ctv.tv_sec)*0.001 >= (tv->tv_sec)*0.001))
{
gettimeofday(tv,NULL);
msec=(tv->tv_usec)*1000;
msec +=(usec*1000);
return 1;
}
else
return 0;
}
int main()
{
int i,j,temp,check;
struct timeval tv;
char Task[5][8]={ "task_1","task_2","task_3","task_4","task_5" },temp1[5][8];
int msec[5]={60,40,10,50,80};
for(i=0;i<5;i++)
{
printf("The Tasks in scheduler is %s with period %d\n",Task[i],msec[i]);
}
for(i=0;i<5;i++)
{
for(j=i+1;j<5;j++)
{
if(msec[i]>msec[j])
{
temp=msec[i];
msec[i]=msec[j];
msec[j]=temp;
strcpy(temp1[i],Task[i]);
strcpy(Task[i],Task[j]);
strcpy(Task[j],temp1[i]);
}
}
}
for(i=0;i<5;i++)
{
printf("The scheduled tasks in scheduler is %s with period %d\n\n",Task[i],msec[i]);
}

SetTimer(&tv,10);

while(1)
{
for(i=0;i<5;i++)
{
check=CheckTimer(&tv,10);
if (check==1)
{
printf("%s starting at %d milli sec\n",Task[i],msec[i]);
}
}
/*if(g_stop_application ==1)
{
break;
}
}
return 0;
}

-- here is my code..
ya i agree with you that a task contain more than a string but here i am developing a application stub so i took string as the reference. and i want my code to be periodic and run the task periodically for different periods setted by the timer this is my requirement and i am failing to do this.

I believe a naive implementation would be to create a polling loop, get current time compare it to your tasks, sleep for a bit.

Code:

while(1) {
     //get current time

     //compare you time stamp to your tasks

     //sleep
}