/* Tests that the highest-priority thread waiting on a semaphore
is the first to wake up. */
#include
#include “tests/threads/tests.h”
#include “threads/init.h”
#include “threads/malloc.h”
#include “threads/semaphore.h”
#include “threads/thread.h”
#include “devices/timer.h”
static thread_func priority_sema_thread;
static struct semaphore sema;
void
test_priority_sema (void)
{
int i;
/* This test does not work with the MLFQS. */
ASSERT (!thread_mlfqs);
semaphore_init (&sema, 0);
thread_set_priority (PRI_MIN);
for (i = 0; i < 10; i++)
{
int priority = PRI_DEFAULT - (i + 3) % 10 - 1;
char name[16];
snprintf (name, sizeof name, "priority %d", priority);
thread_create (name, priority, priority_sema_thread, NULL);
}
for (i = 0; i < 10; i++)
{
semaphore_up (&sema);
msg ("Back in main thread.");
}
}
static void
priority_sema_thread (void *aux UNUSED)
{
semaphore_down (&sema);
msg ("Thread %s woke up.", thread_name ());
}