int
ipc_sem_get_value(sem_t sem_id, int *value_store) {
assert(current->sem_queue != NULL);
if (value_store == NULL) {
return -E_INVAL;
}
struct mm_struct *mm = current->mm;
if (!user_mem_check(mm, (uintptr_t)value_store, sizeof(int), 1)) {
return -E_INVAL;
}
sem_undo_t *semu;
sem_queue_t *sem_queue = current->sem_queue;
down(&(sem_queue->sem));
semu = semu_list_search(&(sem_queue->semu_list), sem_id);
up(&(sem_queue->sem));
int ret = -E_INVAL;
if (semu != NULL) {
int value = semu->sem->value;
lock_mm(mm);
{
if (copy_to_user(mm, value_store, &value, sizeof(int))) {
ret = 0;
}
}
unlock_mm(mm);
}
return ret;
}
int
ipc_sem_post(sem_t sem_id) {
assert(current->sem_queue != NULL);
sem_undo_t *semu;
sem_queue_t *sem_queue = current->sem_queue;
down(&(sem_queue->sem));
semu = semu_list_search(&(sem_queue->semu_list), sem_id);
up(&(sem_queue->sem));
if (semu != NULL) {
return usem_up(semu->sem);
}
return -E_INVAL;
}
int
ipc_sem_wait(sem_t sem_id, unsigned int timeout) {
assert(current->sem_queue != NULL);
sem_undo_t *semu;
sem_queue_t *sem_queue = current->sem_queue;
down(&(sem_queue->sem));
semu = semu_list_search(&(sem_queue->semu_list), sem_id);
up(&(sem_queue->sem));
if (semu != NULL) {
return usem_down(semu->sem, timeout);
}
return -E_INVAL;
}
int ipc_sem_post_max(sem_t sem_id, int max) {
assert(pls_read(current)->sem_queue != NULL);
sem_undo_t *semu;
sem_queue_t *sem_queue = pls_read(current)->sem_queue;
down(&(sem_queue->sem));
semu = semu_list_search(&(sem_queue->semu_list), sem_id);
up(&(sem_queue->sem));
if(semu != NULL) {
int i;
int ret = 0;
for(i = 0; i < max; ++i) {
if(wait_queue_empty(&(semu->sem->wait_queue)))
break;
usem_up(semu->sem);
++ret;
}
return ret;
}
return -E_INVAL;
}
int
ipc_sem_free(sem_t sem_id) {
assert(current->sem_queue != NULL);
sem_undo_t *semu;
sem_queue_t *sem_queue = current->sem_queue;
down(&(sem_queue->sem));
semu = semu_list_search(&(sem_queue->semu_list), sem_id);
up(&(sem_queue->sem));
int ret = -E_INVAL;
if (semu != NULL) {
bool intr_flag;
local_intr_save(intr_flag);
{
semaphore_t *sem = semu->sem;
sem->valid = 0, ret = 0;
wakeup_queue(&(sem->wait_queue), WT_INTERRUPTED, 1);
}
local_intr_restore(intr_flag);
}
return ret;
}