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UAHCode/CPE435/Lab4/process2.c

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2022-08-28 21:12:16 +00:00
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include "info.h"
int main()
{
int id;
struct info *ctrl;
id = shmget( KEY,MSIZ, 0 );
// get the id of the already created shared memory segment
// .. function to create is same as getting id of the already created shared memory segment
if ( id < 0 )
{
//error … ;
exit(1) ;
}
// attach a local pointer to the shared memory
ctrl = (struct info *) shmat( id, 0, 0);
if ( ctrl <= (struct info *) (0) )
{
//error … ;
exit(1) ;
}
while (ctrl->flag!=-1)
{
// if flag is 1, add the numbers from shared memory, set flag to 0
if (ctrl->flag==1)
{
ctrl->sum = ctrl->value1+ctrl->value2;
printf("Sum: %f + %f = %f\n", ctrl->value1, ctrl->value2, ctrl->sum);
ctrl->flag = 0;
}
}
//detach the pointer from the shared memory
// .. we do not need to delete here, can be done in either of the process
shmdt(ctrl);
exit(0);
}