Method fork

lab8/src/7/src/kernel/program.cpp:354–386

}

int ProgramManager::fork()
{
    bool status = interruptManager.getInterruptStatus();
    interruptManager.disableInterrupt();

    // 禁止内核线程调用
    PCB *parent = this->running;
    if (!parent->pageDirectoryAddress)
    {
        interruptManager.setInterruptStatus(status);
        return -1;
    }

    int pid = executeProcess("", 0);
    if (pid == -1)
    {
        interruptManager.setInterruptStatus(status);
        return -1;
    }

    PCB *child = ListItem2PCB(this->allPrograms.back(), tagInAllList);
    bool flag = copyProcess(parent, child);

    if (!flag)
    {
        child->status = ProgramStatus::DEAD;
        interruptManager.setInterruptStatus(status);
        return -1;
    }

    interruptManager.setInterruptStatus(status);
    return pid;
}

bool ProgramManager::copyProcess(PCB *parent, PCB *child)
{