int main() {
int result, child_pid, tmp_errno, policy;
int min_priority, new_priority, old_priority;
struct sched_param param;
/* Create a child process which wait SIGUSR1 */
child_pid = fork();
if (child_pid == -1) {
perror("An error occurs when calling fork()");
return PTS_UNRESOLVED;
} else if (child_pid == 0) {
child_proc();
}
if (sched_getparam(child_pid, ¶m) != 0) {
perror("An error occurs when calling sched_getparam()");
kill(child_pid, SIGUSR1);
return PTS_UNRESOLVED;
}
/* Assume that the process have permission to change priority of
its child */
old_priority = param.sched_priority;
policy = sched_getscheduler(0);
if (policy == -1) {
perror("An error occurs when calling sched_getscheduler()");
return PTS_UNRESOLVED;
}
min_priority = sched_get_priority_min(policy);
new_priority = param.sched_priority == min_priority ?
(param.sched_priority = sched_get_priority_max(policy)) :
(param.sched_priority = min_priority);
result = sched_setparam(child_pid, ¶m);
tmp_errno = errno;
if (sched_getparam(child_pid, ¶m) != 0) {
perror("An error occurs when calling sched_getparam()");
kill(child_pid, SIGUSR1);
return PTS_UNRESOLVED;
}
if (result == 0 && param.sched_priority == new_priority) {
printf("Test PASSED\n");
kill(child_pid, SIGUSR1);
return PTS_PASS;
} else if (result == 0 && param.sched_priority == old_priority) {
printf("The param does not change.\n");
kill(child_pid, SIGUSR1);
return PTS_FAIL;
} else if (result == -1 && tmp_errno == EPERM) {
printf("The process have not permission to change the param of its child.\n");
kill(child_pid, SIGUSR1);
return PTS_UNRESOLVED;
} else if (result == -1 && tmp_errno == EINVAL) {
/* the new priority may be to big */
/* test with a new priority lower than the old one */
param.sched_priority = (new_priority -= 2);
result = sched_setparam(child_pid, ¶m);
if (result == 0 && param.sched_priority == new_priority) {
printf("Test PASSED");
kill(child_pid, SIGUSR1);
return PTS_PASS;
}
}
perror("Unknow error");
kill(child_pid, SIGUSR1);
return PTS_FAIL;
}
int main_proc(void)
{
int syserr = -1;
int fd = -1;
void* data = MAP_FAILED;
fd = open("/home/iret/video.dat", O_RDONLY);
if (fd == -1)
{
perror("open");
goto EXIT_LABEL;
}
struct stat st = { 0 };
syserr = fstat(fd, &st);
if (syserr)
{
perror("fstat");
goto EXIT_LABEL;
}
off_t data_len = st.st_size;
data = mmap(NULL, data_len, PROT_READ, MAP_PRIVATE, fd, 0);
if (data == MAP_FAILED)
{
perror("mmap");
goto EXIT_LABEL;
}
srand(time(NULL));
for (int i=0; i<CHILDS_NUM; i++)
{
int start = rand() % ((int)st.st_size / 2);
pid_t pid = fork();
assert(pid != -1);
if (! pid)
{
child_proc(data, start);
}
}
munmap(data, data_len);
data = MAP_FAILED;
close(fd);
fd = -1;
int suc = 0;
while (1)
{
int status = 0;
pid_t pid = wait(&status);
if (pid == -1)
{
break;
}
if (WIFEXITED(status))
{
suc += WEXITSTATUS(status);
}
}
fprintf(stderr, "DONE suc=%d\n", suc);
EXIT_LABEL:
if (data != MAP_FAILED)
{
munmap(data, data_len);
data = MAP_FAILED;
}
if (fd != -1)
{
close(fd);
fd = -1;
}
return 0;
}
