“printf”似乎在Qt中是不确定的？

Question

我知道“printf”是标准的，应该是确定性的。但是当在Qt中运行时，我会看到更多的非确定性响应（时钟周期）。这可能是因为Qt在其回应中添加了一些“猪肉”吗？

我有多个线程调用使用互斥锁的函数。当一个线程进入它时，设置一个开关，以便其他线程完成。事情似乎适用于acouple秒，然后线程似乎从10到1线程被杀死。所以我尝试添加延迟：（k = k + 1：没有帮助），然后（循环k = k + 1：没有帮助），（usleep工作），（printf）工作创建随机延迟并允许所有线程继续运行。

void CCB::Write(int iThread)
{
    static bool bUse = false;
    bool bDone = false;
    char cStr[20];
    int posWrite;// = *m_posWrite;  // issue of posWrite be altered with next extrance
    long k = 0;
    long m = 0;
    m_threadCount++;

    while(bDone == false){

        if(bUse == false){
            bUse = true;
            posWrite = *m_posWrite;

            memcpy(m_cmMessageCB + posWrite, &m_cmMessageWrite, sizeof(typeCanMessage));

            memset(cStr, '\0', 20);
            memcpy(cStr, (m_cmMessageCB + posWrite)->cMessage, 11); //fails: every 20

            *m_posWrite = *m_posWrite + 1;
            if(*m_posWrite == m_iNBufferLength)
                *m_posWrite = 0;

            bDone = true;
            bUse = false;

        }else if(bUse == true){
            //why are threads being killed ?
    //            printf("T%d_%d ", iThread, m_threadCount);//non-deterministic value ?
            usleep(1);//non-deterministic value
            //k++;//delay of a couple clock cycles was not enough

            /*
            for(k = 0; k < iThread * 100; k++){//deterministic and fails to resolve thread problem
                m++;
            }
            */
        }
    }
}