[SOLVED] CS /* The main thread acquires a lock. Then it creates a

/* The main thread acquires a lock.Then it creates a
higher-priority thread that blocks acquiring the lock, causing
it to donate their priorities to the main thread.The main
thread attempts to lower its priority, which should not take
effect until the donation is released. */

#include
#include tests/threads/tests.h
#include threads/init.h
#include threads/lock.h
#include threads/thread.h

static thread_func acquire_thread_func;

void
test_priority_donate_lower (void)
{
struct lock lock;

/* This test does not work with the MLFQS. */
ASSERT (!thread_mlfqs);

/* Make sure our priority is the default. */
ASSERT (thread_get_priority () == PRI_DEFAULT);

lock_init (&lock);
lock_acquire (&lock);
thread_create (acquire, PRI_DEFAULT + 10, acquire_thread_func, &lock);
msg (Main thread should have priority %d.Actual priority: %d.,
PRI_DEFAULT + 10, thread_get_priority ());

msg (Lowering base priority);
thread_set_priority (PRI_DEFAULT 10);
msg (Main thread should have priority %d.Actual priority: %d.,
PRI_DEFAULT + 10, thread_get_priority ());
lock_release (&lock);
msg (acquire must already have finished.);
msg (Main thread should have priority %d.Actual priority: %d.,
PRI_DEFAULT 10, thread_get_priority ());
}

static void
acquire_thread_func (void *lock_)
{
struct lock *lock = lock_;

lock_acquire (lock);
msg (acquire: got the lock);
lock_release (lock);
msg (acquire: done);
}