struct lock *
lock_create(const char *name)
{
struct lock* new_lock;
new_lock = kmalloc(sizeof(struct lock));
if (new_lock == NULL) {
return NULL;
}
new_lock->lk_name = kstrdup(name);
if (new_lock->lk_name == NULL) {
kfree(new_lock);
return NULL;
}
new_lock->lk_wchan = wchan_create(new_lock->lk_name);
if (new_lock->lk_wchan == NULL) {
kfree(new_lock->lk_name);
kfree(new_lock);
return NULL;
}
spinlock_init(&new_lock->spin_lock);
spinlock_data_set(&new_lock->lk_busy, 0);
new_lock->lk_cpu = NULL;
new_lock->lk_thread = NULL;
return new_lock;
}
void
lock_release(struct lock *lock)
{
if(lock_do_i_hold(lock)) {
spinlock_acquire(&lock->spin_lock);
spinlock_data_set(&lock->lk_busy,0);
lock->lk_cpu = NULL;
lock->lk_thread = NULL;
wchan_wakeone(lock->lk_wchan, &lock->spin_lock);
spinlock_release(&lock->spin_lock);
}
}
/*
* Release the lock.
*/
void
spinlock_release(struct spinlock *lk)
{
/* this must work before curcpu initialization */
if (CURCPU_EXISTS()) {
KASSERT(lk->lk_holder == curcpu->c_self);
}
lk->lk_holder = NULL;
spinlock_data_set(&lk->lk_lock, 0);
spllower(IPL_HIGH, IPL_NONE);
}
/*
* Initialize spinlock.
*/
void
spinlock_init(struct spinlock *lk)
{
spinlock_data_set(&lk->lk_lock, 0);
lk->lk_holder = NULL;
}