int child_fn(int priority, int id)
{
sem_t *sem, *sem_1;
if (set_my_prio(priority) == -1)
exit(-1);
sem = sem_open(semname, 0);
if( sem == SEM_FAILED || sem == NULL ) {
perror(ERROR_PREFIX "sem_open: sem");
return -1;
}
sem_1 = sem_open(semname_1, 0);
if( sem_1 == SEM_FAILED || sem_1 == NULL ) {
perror(ERROR_PREFIX "sem_open: sem_1");
return -1;
}
sem_wait(sem_1);
fprintf(stderr, "child %d try to get lock, prio: %d\n",
id, get_my_prio());
if (sem_wait(sem) == -1)
{
perror("Error at sem_wait");
fprintf(stderr, "Child %d: Cannot get lock", id);
exit(-1);
}
fprintf(stderr, "child %d got lock\n", id);
exit(0);
}
int main()
{
#ifndef _POSIX_PRIORITY_SCHEDULING
printf("_POSIX_PRIORITY_SCHEDULING not defined\n");
return PTS_UNTESTED;
#endif
sem_t *sem, *sem_1;
int val = 3; /* for sem_1 to track the child state */
int priority;
pid_t c_1, c_2, c_3, ret_pid;
int retval = PTS_UNRESOLVED;
int status;
snprintf(semname, 20, "/" TEST "_%d", getpid());
/* Initial value of Semaphore is 1 */
sem = sem_open(semname, O_CREAT, 0777, 1);
if( sem == SEM_FAILED || sem == NULL ) {
perror(ERROR_PREFIX "sem_open");
return PTS_UNRESOLVED;
}
snprintf(semname_1, 20, "/" TEST "_%d_1", getpid());
sem_1 = sem_open(semname_1, O_CREAT, 0777, val);
if( sem_1 == SEM_FAILED || sem_1 == NULL ) {
perror(ERROR_PREFIX "sem_open: sem_1");
sem_unlink(semname);
return PTS_UNRESOLVED;
}
/* The parent has highest priority */
priority = sched_get_priority_min(SCHED_FIFO) + 3;
if (set_my_prio(priority) == -1) {
retval = PTS_UNRESOLVED;
goto clean_up;
}
/* Lock Semaphore */
if( sem_wait(sem) == -1 ) {
perror(ERROR_PREFIX "sem_wait");
retval = PTS_UNRESOLVED;
goto clean_up;
}
c_1 = fork();
if (c_1 == 0)
{
/* Child 1, should block */
child_fn(priority - 2, 1);
}
else if (c_1 < 0)
{
perror("Error at fork");
retval = PTS_UNRESOLVED;
goto clean_up;
}
fprintf(stderr, "P: child_1:%d forked\n", c_1);
sleep(1);
c_2 = fork();
if (c_2 == 0)
{
/* Child 2 */
child_fn(priority - 1, 2);
}
else if (c_2 < 0)
{
perror("Error at fork");
retval = PTS_UNRESOLVED;
goto clean_up;
}
fprintf(stderr, "P: child_2: %d forked\n", c_2);
/* Make sure the two children has been waiting */
/* do {
sleep(1);
sem_getvalue(sem_1, &val);
//printf("val = %d\n", val);
} while (val != 1);
*/
c_3 = fork();
if (c_3 == 0)
{
/* Child 3 */
child_fn(priority - 1, 3);
}
fprintf(stderr, "P: child_3: %d forked\n", c_3);
/* Make sure child 3 has been waiting for the lock */
/* do {
sleep(1);
sem_getvalue(sem_1, &val);
//printf("val = %d\n", val);
} while (val != 0);
*/
/* Ok, let's release the lock */
fprintf(stderr, "P: release lock\n");
sem_post(sem);
ret_pid = wait(&status);
if (ret_pid == c_2 && WIFEXITED(status)
&& WEXITSTATUS(status) == 0)
{
fprintf(stderr, "P: release lock\n");
sem_post(sem);
ret_pid = wait(&status);
if (ret_pid == c_3 && WIFEXITED(status)
&& WEXITSTATUS(status) == 0)
{
fprintf(stderr, "P: release lock\n");
sem_post(sem);
ret_pid = wait(&status);
if (ret_pid == c_1 && WIFEXITED(status)
&& WEXITSTATUS(status) == 0)
{
printf("Test Pass\n");
retval = PTS_PASS;
goto clean_up;
}
printf("Test Fail: Expect child_1: %d, got %d\n",
c_1, ret_pid);
retval = PTS_FAIL;
goto clean_up;
}
else
{
printf("Test Fail: Expect child_3: %d, got %d\n",
c_3, ret_pid);
retval = PTS_FAIL;
sem_post(sem);
while((wait(NULL) > 0));
goto clean_up;
}
}
else
{
printf("Test Fail: Expect child_2: %d, got %d\n",
c_2, ret_pid);
retval = PTS_FAIL;
sem_post(sem);
sem_post(sem);
while((wait(NULL) > 0));
goto clean_up;
}
clean_up:
sem_close(sem);
sem_close(sem_1);
sem_unlink(semname);
sem_unlink(semname_1);
return retval;
}
int main(void)
{
#ifndef _POSIX_PRIORITY_SCHEDULING
printf("_POSIX_PRIORITY_SCHEDULING not defined\n");
return PTS_UNTESTED;
#endif
sem_t *sem, *sem_1;
int val;
int priority;
pid_t c_1, c_2, c_3, ret_pid;
int retval = PTS_UNRESOLVED;
int status;
snprintf(semname, sizeof(semname), "/" TEST "_%d", getpid());
sem = sem_open(semname, O_CREAT | O_EXCL, 0777, 1);
if (sem == SEM_FAILED) {
perror("sem_open(semname)");
return PTS_UNRESOLVED;
}
snprintf(semname_1, sizeof(semname_1), "/" TEST "_%d_1", getpid());
sem_1 = sem_open(semname_1, O_CREAT | O_EXCL, 0777, 3);
if (sem_1 == SEM_FAILED) {
perror("sem_open(semname_1)");
sem_unlink(semname);
return PTS_UNRESOLVED;
}
/* The parent has highest priority */
priority = sched_get_priority_min(SCHED_FIFO) + 3;
if (set_my_prio(priority) == -1) {
retval = PTS_UNRESOLVED;
goto clean_up;
}
/* Lock Semaphore */
if (sem_wait(sem) == -1) {
perror("sem_wait()");
retval = PTS_UNRESOLVED;
goto clean_up;
}
c_1 = fork();
switch (c_1) {
case 0:
child_fn(priority - 2, 1);
break;
case -1:
perror("fork()");
retval = PTS_UNRESOLVED;
goto clean_up;
break;
}
fprintf(stderr, "P: child_1: %d forked\n", c_1);
c_2 = fork();
switch (c_2) {
case 0:
child_fn(priority - 1, 2);
break;
case -1:
perror("fork()");
retval = PTS_UNRESOLVED;
goto clean_up;
break;
}
fprintf(stderr, "P: child_2: %d forked\n", c_2);
/* Make sure the two children has been waiting */
do {
usleep(100);
sem_getvalue(sem_1, &val);
} while (val != 1);
usleep(100);
c_3 = fork();
switch (c_3) {
case 0:
child_fn(priority - 1, 3);
break;
case -1:
perror("fork()");
retval = PTS_UNRESOLVED;
goto clean_up;
break;
}
fprintf(stderr, "P: child_3: %d forked\n", c_3);
/* Make sure child 3 has been waiting for the lock */
do {
usleep(100);
sem_getvalue(sem_1, &val);
} while (val != 0);
usleep(100);
/* Ok, let's release the lock */
fprintf(stderr, "P: release lock\n");
sem_post(sem);
ret_pid = wait(&status);
if (ret_pid == c_2 && WIFEXITED(status)
&& WEXITSTATUS(status) == 0) {
fprintf(stderr, "P: release lock\n");
sem_post(sem);
ret_pid = wait(&status);
if (ret_pid == c_3 && WIFEXITED(status)
&& WEXITSTATUS(status) == 0){
fprintf(stderr, "P: release lock\n");
sem_post(sem);
ret_pid = wait(&status);
if (ret_pid == c_1 && WIFEXITED(status)
&& WEXITSTATUS(status) == 0) {
printf("Test PASSED\n");
retval = PTS_PASS;
goto clean_up;
}
printf("Test Fail: Expect child_1: %d, got %d\n",
c_1, ret_pid);
retval = PTS_FAIL;
goto clean_up;
} else {
printf("Test Fail: Expect child_3: %d, got %d\n",
c_3, ret_pid);
retval = PTS_FAIL;
sem_post(sem);
while ((wait(NULL) > 0));
goto clean_up;
}
} else {
printf("Test Fail: Expect child_2: %d, got %d\n",
c_2, ret_pid);
retval = PTS_FAIL;
sem_post(sem);
sem_post(sem);
while ((wait(NULL) > 0));
goto clean_up;
}
clean_up:
sem_close(sem);
sem_close(sem_1);
sem_unlink(semname);
sem_unlink(semname_1);
return retval;
}