C++ (Cpp) sem2semid示例

示例#1

文件： sem.c 项目： TySag/project

static int semu_search_with_addr(list_entry_t * list, uintptr_t addr)
{
	list_entry_t *le = list;
	while ((le = list_next(le)) != list) {
		sem_undo_t *semu = le2semu(le, semu_link);
		if (semu->sem->addr == addr)
			return sem2semid(semu->sem);
	}
	return -1;
}

示例#2

文件： sem.c 项目： spinlock/ucore

int
ipc_sem_init(int value) {
    assert(current->sem_queue != NULL);

    sem_undo_t *semu;
    if ((semu = semu_create(NULL, value)) == NULL) {
        return -E_NO_MEM;
    }

    sem_queue_t *sem_queue = current->sem_queue;
    down(&(sem_queue->sem));
    list_add_after(&(sem_queue->semu_list), &(semu->semu_link));
    up(&(sem_queue->sem));
    return sem2semid(semu->sem);
}

示例#3

文件： sem.c 项目： haozhun/ucore_plus

static int
ipc_sem_find_or_init_with_address(uintptr_t addr, int value, int create) {
	assert(pls_read(current)->sem_queue != NULL);

	sem_queue_t *sem_queue = pls_read(current)->sem_queue;
	down(&(sem_queue->sem));
	sem_t sem_id = semu_search_with_addr(&(sem_queue->semu_list), addr);
	up(&(sem_queue->sem));
	if(sem_id != -1)
		return sem_id;

	if(!create)
		return -E_NO_MEM;
	sem_undo_t *semu;
	if((semu = semu_create_with_address(NULL, addr, value)) == NULL) {
		return -E_NO_MEM;
	}

	down(&(sem_queue->sem));
	list_add_after(&(sem_queue->semu_list), &(semu->semu_link));
	up(&(sem_queue->sem));
	return sem2semid(semu->sem);
}