ruanjiangongcheng/process（800-1200）.cpp

```c
// 去掉初始化标签
kerInitProcess->processStatus &= ~OS_PROCESS_STATUS_INIT;
g_processGroup = kerInitProcess->group;
LOS_ListInit(&g_processGroup->groupList);
OsCurrProcessSet(kerInitProcess);

// 创建内核态0号进程
LosProcessCB *idleProcess = OS_PCB_FROM_PID(g_kernelIdleProcess);
ret = OsInitPCB(idleProcess, OS_KERNEL_MODE, OS_TASK_PRIORITY_LOWEST, "KIdle");
if (ret != LOS_OK) {
    return ret;
}
idleProcess->parentProcessID = kerInitProcess->processID;
LOS_ListTailInsert(&kerInitProcess->childrenList, &idleProcess->siblingList);
idleProcess->group = kerInitProcess->group;
LOS_ListTailInsert(&kerInitProcess->group->processList, &idleProcess->subordinateGroupList);

#ifdef LOSCFG_SECURITY_CAPABILITY
idleProcess->user = kerInitProcess->user;
#endif

#ifdef LOSCFG_FS_VFS
idleProcess->files = kerInitProcess->files;
#endif

// 创建空闲任务并将其指定给内核态0号进程
ret = OsIdleTaskCreate();
if (ret != LOS_OK) {
    return ret;
}
idleProcess->threadGroupID = OsPercpuGet()->idleTaskID;

return LOS_OK;
```

```c
// 进程调度参数检查
STATIC INLINE INT32 OsProcessSchedlerParamCheck(INT32 which, INT32 pid, UINT16 prio, UINT16 policy)
{
    if (OS_PID_CHECK_INVALID(pid)) {
        return LOS_EINVAL;
    }

    if (which != LOS_PRIO_PROCESS) {
        return LOS_EINVAL;
    }

    if (prio > OS_PROCESS_PRIORITY_LOWEST) {
        return LOS_EINVAL;
    }

    if (policy != LOS_SCHED_RR) {
        return LOS_EINVAL;
    }

    return LOS_OK;
}

#ifdef LOSCFG_SECURITY_CAPABILITY
STATIC BOOL OsProcessCapPermitCheck(const LosProcessCB *processCB, UINT16 prio)
{
    LosProcessCB *runProcess = OsCurrProcessGet();

    // 对于内核态进程直接通过检查
    if (!OsProcessIsUserMode(runProcess)) {
        return TRUE;
    }

    // 用户态进程可以降低自己的优先级
    if ((runProcess->processID == processCB->processID) && (prio > processCB->priority)) {
        return TRUE;
    }

    // 如果具有 CAP_SCHED_SETPRIORITY 权限，可以修改进程的优先级
    if (IsCapPermit(CAP_SCHED_SETPRIORITY)) {
        return TRUE;
    }
    return FALSE;
}
#endif

LITE_OS_SEC_TEXT INT32 OsSetProcessScheduler(INT32 which, INT32 pid, UINT16 prio, UINT16 policy)
{
    LosProcessCB *processCB = NULL;
    BOOL needSched = FALSE;
    UINT32 intSave;
    INT32 ret;

    ret = OsProcessSchedlerParamCheck(which, pid, prio, policy);
    if (ret != LOS_OK) {
        return -ret;
    }

    SCHEDULER_LOCK(intSave);
    processCB = OS_PCB_FROM_PID(pid);

    // 如果进程未激活，则返回错误
    if (OsProcessIsInactive(processCB)) {
        ret = LOS_ESRCH;
        goto EXIT;
    }

#ifdef LOSCFG_SECURITY_CAPABILITY
    // 如果权限不足，则返回错误
    if (!OsProcessCapPermitCheck(processCB, prio)) {
        ret = LOS_EPERM;
        goto EXIT;
    }
#endif

    // 修改进程调度参数，判断是否需要进行调度
    needSched = OsSchedModifyProcessSchedParam(processCB, policy, prio);
    SCHEDULER_UNLOCK(intSave);

    // 调度其他核上的进程
    LOS_MpSchedule(OS_MP_CPU_ALL);

    // 如果需要调度且调度器已经激活，则进行调度
    if (needSched && OS_SCHEDULER_ACTIVE) {
        LOS_Schedule();
    }
    return LOS_OK;

EXIT:
    SCHEDULER_UNLOCK(intSave);
    return -ret;
}

LITE_OS_SEC_TEXT INT32 LOS_SetProcessScheduler(INT32 pid, UINT16 policy, UINT16 prio)
{
    return OsSetProcessScheduler(LOS_PRIO_PROCESS, pid, prio, policy);
}

LITE_OS_SEC_TEXT INT32 LOS_GetProcessScheduler(INT32 pid)
{
    UINT32 intSave;

    if (OS_PID_CHECK_INVALID(pid)) {
        return -LOS_EINVAL;
    }

    SCHEDULER_LOCK(intSave);
    LosProcessCB *processCB = OS_PCB_FROM_PID(pid);

    // 如果进程未使用，则返回错误
    if (OsProcessIsUnused(processCB)) {
        SCHEDULER_UNLOCK(intSave);
        return -LOS_ESRCH;
    }

    SCHEDULER_UNLOCK(intSave);

    return LOS_SCHED_RR;
}

LITE_OS_SEC_TEXT INT32 LOS_SetProcessPriority(INT32 pid, UINT16 prio)
{
    return OsSetProcessScheduler(LOS_PRIO_PROCESS, pid, prio, LOS_GetProcessScheduler(pid));
}

LITE_OS_SEC_TEXT INT32 OsGetProcessPriority(INT32 which, INT32 pid)
{
    LosProcessCB *processCB = NULL;
    INT32 prio;
    UINT32 intSave;
    (VOID)which;

    if (OS_PID_CHECK_INVALID(pid)) {
        return -LOS_EINVAL;
    }

    if (which != LOS_PRIO_PROCESS) {
        return -LOS_EINVAL;
    }

    SCHEDULER_LOCK(intSave);
    processCB = OS_PCB_FROM_PID(pid);

    // 如果进程未使用，则返回错误
    if (OsProcessIsUnused(processCB)) {
        prio = -LOS_ESRCH;
        goto OUT;
    }

    prio = (INT32)processCB->priority;

OUT:
    SCHEDULER_UNLOCK(intSave);
    return prio;
}

LITE_OS_SEC_TEXT INT32 LOS_GetProcessPriority(INT32 pid)
{
    return OsGetProcessPriority(LOS_PRIO_PROCESS, pid);
}

// 将运行任务插入等待列表
STATIC VOID OsWaitInsertWaitListInOrder(LosTaskCB *runTask, LosProcessCB *processCB)
{
    LOS_DL_LIST *head = &processCB->waitList;
    LOS_DL_LIST *list = head;
    LosTaskCB *taskCB = NULL;

    if (runTask->waitFlag == OS_PROCESS_WAIT_GID) {
        while (list->pstNext != head) {
            taskCB = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(list));

            // 如果等待标记为 OS_PROCESS_WAIT_PRO，则继续查找下一个等待队列
            if (taskCB->waitFlag == OS_PROCESS_WAIT_PRO) {
                list = list->pstNext;
                continue;
            }
            break;
        }
    } else if (runTask->waitFlag == OS_PROCESS_WAIT_ANY) {
        while (list->pstNext != head) {
            taskCB = OS_TCB_FROM_PENDLIST(LOS_DL_LIST_FIRST(list));

            // 如果等待标记不为 OS_PROCESS_WAIT_ANY，则继续查找下一个等待队列
            if (taskCB->waitFlag != OS_PROCESS_WAIT_ANY) {
                list = list->pstNext;
                continue;
            }
            break;
        }
    }
}

```
// 等待指定的子进程退出
STATIC UINT32 OsWaitSetFlag(const LosProcessCB *processCB, INT32 pid, LosProcessCB **child)
{
    LosProcessCB *childCB = NULL;
    ProcessGroup *group = NULL;
    LosTaskCB *runTask = OsCurrTaskGet();  // 获取当前运行的任务控制块
    UINT32 ret;

    if (pid > 0) {
        // 等待具有指定进程号的子进程退出
        childCB = OsFindExitChildProcess(processCB, pid);  // 查找具有指定进程号的已退出的子进程
        if (childCB != NULL) {
            goto WAIT_BACK;  // 子进程已退出，则跳转到WAIT_BACK标签处
        }

        ret = OsFindChildProcess(processCB, pid);  // 查找具有指定进程号的子进程是否存在
        if (ret != LOS_OK) {
            return LOS_ECHILD;  // 没有找到指定进程号的子进程，返回错误码LOS_ECHILD
        }
        runTask->waitFlag = OS_PROCESS_WAIT_PRO;  // 设置当前任务的等待标志为进程号
        runTask->waitID = pid;  // 设置当前任务等待的进程号为指定进程号
    } else if (pid == 0) {
        // 等待同一进程组中的任何子进程退出
        childCB = OsFindGroupExitProcess(processCB->group, OS_INVALID_VALUE);  // 查找同一进程组中的已退出的子进程
        if (childCB != NULL) {
            goto WAIT_BACK;  // 子进程已退出，则跳转到WAIT_BACK标签处
        }
        runTask->waitID = processCB->group->groupID;  // 设置当前任务等待的进程号为进程组号
        runTask->waitFlag = OS_PROCESS_WAIT_GID;  // 设置当前任务的等待标志为进程组号
    } else if (pid == -1) {
        // 等待任何子进程退出
        childCB = OsFindExitChildProcess(processCB, OS_INVALID_VALUE);  // 查找任何已退出的子进程
        if (childCB != NULL) {
            goto WAIT_BACK;  // 子进程已退出，则跳转到WAIT_BACK标签处
        }
        runTask->waitID = pid;  // 设置当前任务等待的进程号为-1
        runTask->waitFlag = OS_PROCESS_WAIT_ANY;  // 设置当前任务的等待标志为任何子进程
    } else {  // pid < -1
        // 等待进程组号为pid绝对值的任何子进程退出
        group = OsFindProcessGroup(-pid);  // 查找具有指定进程组号的进程组
        if (group == NULL) {
            return LOS_ECHILD;  // 没有找到指定进程组号的进程组，返回错误码LOS_ECHILD
        }

        childCB = OsFindGroupExitProcess(group, OS_INVALID_VALUE);  // 查找指定进程组中已退出的子进程
        if (childCB != NULL) {
            goto WAIT_BACK;  // 子进程已退出，则跳转到WAIT_BACK标签处
        }

        runTask->waitID = -pid;  // 设置当前任务等待的进程号为进程组号的绝对值
        runTask->waitFlag = OS_PROCESS_WAIT_GID;  // 设置当前任务的等待标志为进程组号
    }

WAIT_BACK:
    *child = childCB;  // 返回已退出的子进程
    return LOS_OK;
}

// 回收已退出的子进程资源，并返回进程号
STATIC UINT32 OsWaitRecycleChildProcess(const LosProcessCB *childCB, UINT32 intSave, INT32 *status, siginfo_t *info)
{
    ProcessGroup *group = NULL;
    UINT32 pid = childCB->processID;  // 子进程的进程号
    UINT16 mode = childCB->processMode;  // 子进程的运行模式
    INT32 exitCode = childCB->exitCode;  // 子进程的退出码
    UINT32 uid = 0;

#ifdef LOSCFG_SECURITY_CAPABILITY
    if (childCB->user != NULL) {
        uid = childCB->user->userID;  // 子进程的用户ID
    }
#endif

    OsRecycleZombiesProcess((LosProcessCB *)childCB, &group);  // 回收已退出的子进程资源，并获取进程组

    SCHEDULER_UNLOCK(intSave);  // 解锁调度器

    if (status != NULL) {
        if (mode == OS_USER_MODE) {
            (VOID)LOS_ArchCopyToUser((VOID *)status, (const VOID *)(&(exitCode)), sizeof(INT32));  // 拷贝退出码到用户空间
        } else {
            *status = exitCode;  // 将退出码保存到status中
        }
    }
    /* get signal info */
    if (info != NULL) {
        siginfo_t tempinfo = { 0 };

        tempinfo.si_signo = SIGCHLD;
        tempinfo.si_errno = 0;
        tempinfo.si_pid = pid;
        tempinfo.si_uid = uid;
        /*
         * Process exit code
         * 31      15         8       7      0
         * |      | exit code | core dump | signal |
         */
        if ((exitCode & 0x7f) == 0) {
            tempinfo.si_code = CLD_EXITED;
            tempinfo.si_status = (exitCode >> 8U);
        } else {
            tempinfo.si_code = (exitCode & 0x80) ? CLD_DUMPED : CLD_KILLED;
            tempinfo.si_status = (exitCode & 0x7f);
        }

        if (mode == OS_USER_MODE) {
            (VOID)LOS_ArchCopyToUser((VOID *)(info), (const VOID *)(&(tempinfo)), sizeof(siginfo_t));  // 拷贝信号信息到用户空间
        } else {
            (VOID)memcpy_s((VOID *)(info), sizeof(siginfo_t), (const VOID *)(&(tempinfo)), sizeof(siginfo_t));
        }
    }
    (VOID)LOS_MemFree(m_aucSysMem1, group);  // 释放进程组资源
    return pid;  // 返回子进程的进程号
}

// 检查等待子进程的具体信息
STATIC UINT32 OsWaitChildProcessCheck(LosProcessCB *processCB, INT32 pid, LosProcessCB **childCB)
{
    if (LOS_ListEmpty(&(processCB->childrenList)) && LOS_ListEmpty(&(processCB->exitChildList))) {
        return LOS_ECHILD;  // 没有子进程，则返回错误码LOS_ECHILD
    }

    return OsWaitSetFlag(processCB, pid, childCB);  // 设置等待标志等信息
}

// 检查等待选项是否正确
STATIC UINT32 OsWaitOptionsCheck(UINT32 options)
{
    UINT32 flag = LOS_WAIT_WNOHANG | LOS_WAIT_WUNTRACED | LOS_WAIT_WCONTINUED;

    flag = ~flag & options;
    if (flag != 0) {
        return LOS_EINVAL;  // 选项不正确，返回错误码LOS_EINVAL
    }

    if ((options & (LOS_WAIT_WCONTINUED | LOS_WAIT_WUNTRACED)) != 0) {
        return LOS_EOPNOTSUPP;  // 不支持的选项，返回错误码LOS_EOPNOTSUPP
    }

    if (OS_INT_ACTIVE) {
        return LOS_EINTR;  // 当前处于中断上下文中，返回错误码LOS_EINTR
    }

    return LOS_OK;  // 选项正确，返回LOS_OK
}

// 等待子进程退出
STATIC INT32 OsWait(INT32 pid, USER INT32 *status, USER siginfo_t *info, UINT32 options, VOID *rusage)
{
    (VOID)rusage;
    UINT32 ret;
    UINT32 intSave;
    LosProcessCB *childCB = NULL;
    LosProcessCB *processCB = NULL;
    LosTaskCB *runTask = NULL;

    SCHEDULER_LOCK(intSave);  // 加锁调度器
    processCB = OsCurrProcessGet();  // 获取当前进程控制块
    runTask = OsCurrTaskGet();  // 获取当前任务控制块

    ret = OsWaitChildProcessCheck(processCB, pid, &childCB);  // 检查等待子进程的具体信息
    if (ret != LOS_OK) {
        pid = -ret;  // 若等待子进程的标志不正确，将错误码赋值给pid
        goto ERROR;
    }

    if (childCB != NULL) {
        return (INT32)OsWaitRecycleChildProcess(childCB, intSave, status, info);  // 回收已退出的子进程资源并返回进程号
    }

    if ((options & LOS_WAIT_WNOHANG) != 0) {
        runTask->waitFlag = 0;  // 不阻塞任务
        pid = 0;
        goto ERROR;
    }

    OsWaitInsertWaitListInOrder(runTask, processCB);  // 将当前任务插入等待列表中

    runTask->waitFlag = 0;
    if (runTask->waitID == OS_INVALID_VALUE) {
        pid = -LOS_ECHILD;  // 没有子进程需要等待，返回错误码LOS_ECHILD
        goto ERROR;
    }

    childCB = OS_PCB_FROM_PID(runTask->waitID);  // 根据等待的进程号获取子进程控制块
    if (!(childCB->processStatus & OS_PROCESS_STATUS_ZOMBIES)) {
        pid = -LOS_ESRCH;  // 子进程没有退出，返回错误码LOS_ESRCH
        goto ERROR;
    }

    return (INT32)OsWaitRecycleChildProcess(childCB, intSave, status, info);  // 回收已退出的子进程资源并返回进程号

ERROR:
    SCHEDULER_UNLOCK(intSave);  // 解锁调度器
    return pid;
}