int main(int argc, char* argv[]) {
if(argc < 3) {
printf("Incorrect number of arguments. Example usage: prog1 file.txt a b c\n");
exit(1);
}
// Get all the chars that will be searched for
char letters[argc - 2]; int i, j = 0;
for(i = START_LETTERS; i < argc; i++) {
letters[j++] = argv[i][0];
}
int occurences[argc - 2];
// Prepare structs for time logging
struct timeval start, finish;
gettimeofday(&start, NULL); // Get start time
// Open the file passed to program
FILE *fp;
fp = fopen(argv[1], "r");
// Get a count of each char using stdio file operations
for(i = 0; i < argc - 2; i++)
occurences[i] = countOccurences(fp, letters[i]);
fclose(fp);
gettimeofday(&finish, NULL); // Get finish time
// Print off occurences and elapsed time
for(i = 0; i < argc - 2; i++)
printf("%c count: %d\n", letters[i], occurences[i]);
printf("Elapsed time: %f seconds\n", computeElapsedTime(start, finish));
return 0;
}
main(int argc, char **argv)
{
int niter, nchild, policy;
double x, y;
int i, j,k, count = 0; /*# of points in the 1st quadrant of unit circle */
double z;
double pi;
pid_t pid;
struct sched_param param;
struct timeval start, finish;
double elapsedTime;
if (argc != 3){
perror("incorrect arguments");
exit(0);
}
niter = atoi(argv[1]);
nchild = atoi(argv[2]);
/*loop for the number of children*/
for (j = 0; j < nchild; j++){
/*set the schedule priority*/
k = j;
if(k % 2 == 0){
policy = SCHED_OTHER;
printf("Policy is sched other \n");
}
else{
policy = SCHED_FIFO;
printf("Policy is sched fifo \n");
}
param.sched_priority = sched_get_priority_max(policy);
if(sched_setscheduler(0, policy, ¶m)){
perror("Error setting scheduler policy");
exit(EXIT_FAILURE);
}
pid = fork();
if (pid < 0){
perror("Error forking.");
exit(pid);
}
/*parent process */
if (pid > 0){
// exit(0);
}
if (pid == 0){
/* initialize random numbers */
srand(SEED);
/*start timer*/
gettimeofday(&start, NULL);
count = 0;
for (i = 0; i<niter; i++) {
x = (double)rand() / RAND_MAX;
y = (double)rand() / RAND_MAX;
z = x*x + y*y;
if (z <= 1) count++;
}
pi = (double)count / niter * 4;
/*stop timer*/
gettimeofday(&finish, NULL);
/*compute elapsed time*/
elapsedTime = computeElapsedTime(start, finish);
printf("Elapsed time is %f \n", elapsedTime);
printf("# of trials= %d , estimate of pi is %g \n", niter, pi);
exit(0);
}
}
}
int main(int argc, char **argv)
{
int niter;
int nFork;
double x, y;
int count = 0; /* # of points in the 1st quadrant of unit circle */
double z;
double pi;
if (argc != 3)
{
perror("incorrect arguments\n");
exit(1);
}
niter = atoi(argv[1]);
nFork = atoi(argv[2]);
/* initialize random numbers */
for (int i = 0; i < nFork; i++)
{
if (fork() == 0)
{
int policy;
struct sched_param param;
// if i&1 == true (odd number) set SCHED_FIFO, else (even number) set SCHED_OTHER
policy = (i&1) ? SCHED_FIFO : SCHED_OTHER;
param.sched_priority = sched_get_priority_max(policy);
if (sched_setscheduler(0, policy, ¶m))
{
perror("Error setting scheduler policy");
exit(EXIT_FAILURE);
}
srand(SEED);
count = 0;
struct timeval start_time, finish_time;
double elapsed_time;
gettimeofday(&start_time, NULL);
for (int j = 0; j<niter; j++)
{
x = (double)rand()/RAND_MAX;
y = (double)rand()/RAND_MAX;
z = x*x+y*y;
if (z<=1) count++;
}
pi = (double)count/niter*4;
gettimeofday(&finish_time, NULL);
elapsed_time = computeElapsedTime(start_time, finish_time);
printf("\nchild %d, sched = %s, trials= %d , aprx. pi = %g, time [s] = %f\n",
i,
(policy == SCHED_FIFO) ? "fifo" : "other",
niter, pi, elapsed_time);
exit(EXIT_SUCCESS);
}
}
printf("completed execution\n");
}
