c++ - 虽然循环比我指定的要循环更多次

Question

我正在制作一个时钟驱动的模拟程序，除此之外，还有我的主要 while 循环，while(jobsCompleted < jobsToComplete)比预期/想要的循环次数更多。例如，如果我要将 500 分配给 jobsToComplete ，程序结束时的输出会告诉我完成了 505 个作业。我已经尝试调试这个问题至少一个小时了，但无济于事。任何帮助表示赞赏。谢谢!

#include <iostream>
#include <string>
#include <stdlib.h>
#include <queue>
#include <fstream>
#include "job.cpp"

using namespace std;

int main()
{
  ofstream cpuSim;
  cpuSim.open("cpuSim.out.txt");

  int clock = 0, jobsCompleted = 0, jobsToComplete = 0, probUser = 0, probability, id = 0;
  jobType_t job_type;
  int inWQ, outWQ, inCPUQ, outCPUQ, required, given, jobTypeInt, timeSpentInCPUqueue = 0, timeSpentInWaitQueue = 0, CPUidle = 0;
  queue<job> CPUqueue, waitQueue;

  int numIO = 0, numCPU = 0;

  srand(time(NULL));

  cout << "Enter how many jobs need to be completed: ";
  cin >> jobsToComplete;
  cout << endl <<  "Enter the probability that a new job is created: ";
  cin >> probUser;
  cout << endl;

  while(jobsCompleted < jobsToComplete)
    {
      clock++;
      probability = rand() % 100 + 1;

      if(probability > probUser)
    {
      for(int i=0; i<jobsToComplete; i++)
        {
          id = rand() % 1000 + 1;
          jobTypeInt = rand() % 100 + 1;
          if(jobTypeInt >= 50)
        job_type = IO_bound;
          else
              job_type = CPU_bound;
      required = rand() % 10;
          job *newJob = new job(id, job_type, inWQ, outWQ, inCPUQ, outCPUQ, required, given);
          waitQueue.push(*newJob);
        }

      while((CPUqueue.size() <= 10) && waitQueue.empty() == false)
        {
          waitQueue.front();
          job temp = waitQueue.back();
          waitQueue.pop();
          temp.setTimeExitedWQueue(clock);
          temp.setTimeEnteredCPUQueue(clock);     
          CPUqueue.push(temp);
        }

      double oneSecond = 1.0, timeSpent = 0;

      while((oneSecond > 0.0) && (!CPUqueue.empty()))
        {
          job top = CPUqueue.front();
          CPUqueue.pop();
          if(top.getJobType() == IO_bound)
        {        
          top.setTimeGiven(top.getTimeGiven() + .1);
          timeSpent = .1;
          numIO++;
        }
          else
        {
          top.setTimeGiven(top.getTimeGiven() + .2);
          timeSpent = .2;
          numCPU++;
        }

          if(top.getTimeRequired() <= top.getTimeGiven())
        {
          top.setTimeExitedCPUQueue(clock);
          jobsCompleted++;

          timeSpentInWaitQueue += (top.getTimeExitedWQueue() - top.getTimeEnteredWQueue());
          timeSpentInCPUqueue += (top.getTimeExitedCPUQueue() - top.getTimeEnteredCPUQueue());
        }
          else
        CPUqueue.push(top);
          oneSecond -= timeSpent;

          if((clock%60 == 0) && (clock > 600)) //every 60 seconds after the first 10 minutes
        {
              cout << "After the first 10 minutes:" << endl;
      cout << "Time: " << clock << endl;
          cout << "Number of jobs in the wait queue: " << waitQueue.size() << endl;

          cout << "Number of jobs in the CPU queue: " << CPUqueue.size() << endl;
                  job temp1 = waitQueue.front();
          job temp2 = CPUqueue.front();
          cout << "Job number of front wait job: " << temp1.getID() << endl;
          cout << "Job number of front CPU job: " << temp2.getID() << endl;
        }
          else
        {
          cout << "Job Number: " << jobsCompleted << endl;
          cout << "Job ID: " << top.getID() << endl;
          cout << "Job Type: " << top.getJobType() << endl;
          cout << "Time in CPU Queue: " << timeSpentInCPUqueue << endl;
          cout << "Time Entered CPU Queue: " << top.getTimeEnteredCPUQueue() << endl << endl;
        }
        }

      if((oneSecond > 0) && (CPUqueue.empty()))
        CPUidle += oneSecond;
    }
    }
  cout << "I/O_bound jobs: " << numIO << endl;
  cout << "CPU_bound jobs: " << numCPU << endl;
  cout << "*****JOBS COMPLETED: " << jobsCompleted << " *****" << endl << endl;

  return 0;
}

作为一个不太相关的问题，我无法正确打印我的枚举数据类型，也无法在最开始将我的 ID 传递到 *newJob 中。正确...

Answer 1

假设它已经循环了一段时间，现在 jobsCompleted 是 499(而您的 jobsToComplete 是 500)。好的，所以这是最后一个循环，对吗？是的!但是 jobsCompleted 的递增发生在另一个嵌套的 while 循环中。因此，如果该嵌套循环发生 6 次，jobsCompleted 将为 505，然后外部 while 循环将结束，使您完成的作业总数为 505。

告诉您如何修复它需要理解您的代码的逻辑，但有太多的东西让我无法弄清楚。也许这会对您有所帮助。