for循环生成的工作线程列表超出了循环迭代次数(List of worker threads spawned by for loop is exceeding for-loop iterations)

 我对于正确的线程我是相对绿色的，我有这个，它是为了简单而修改但它基本上是相同的东西： 
 
//Global:
N=2
bool[] mySwitches;

//In my main:

mySwitches = new bool[N];
for (int i = 0; i < N; i++)
{
    ThreadList.Add(new Thread(() => Worker(i)));
    ThreadList[i].Start();
}

//Outside of main:

Private Void Worker(int num)
{
  while(true)
  {
    if (mySwitches[num]) //error happes here because num is equal to N, how?
    {
        //do something
    }
  }
}
 
 如上所示，工作线程以某种方式得到num = N的值，我希望它只能达到N-1。 我知道在创建Worker之后我会增加，是不是以某种方式通过引用而不是值传递？ 
 
 我尝试通过在我的while循环之前进行测试来修复问题，如果num = N则返回，但即使使用此规定，我也会得到相同的错误。 这让我相信在线程启动后，num会以某种方式递增。 
 
 我通过在ThreadList [i] .Start（）之后直接放置Sleep（20）来解决这个问题，但我真的不喜欢使用Sleep，很明显我不知道这个线程场景是如何工作的。 
 
 任何人都可以对此有所了解吗？ 

I am relatively green to proper threading, I have this, it's modified for simplicity but it is essentially the same thing:
 
//Global:
N=2
bool[] mySwitches;

//In my main:

mySwitches = new bool[N];
for (int i = 0; i < N; i++)
{
    ThreadList.Add(new Thread(() => Worker(i)));
    ThreadList[i].Start();
}

//Outside of main:

Private Void Worker(int num)
{
  while(true)
  {
    if (mySwitches[num]) //error happes here because num is equal to N, how?
    {
        //do something
    }
  }
}
 
As shown above, somehow a worker thread gets a value of num=N, I expect it to only reach N-1. I know that i will get incremented after the Worker is created, is i somehow getting passed by reference instead of value?
 
I tried to fix the issue by putting a test before my while loop to return if num=N, but even with this provision I get the same error. This leads me to believe that num is incremented somehow after the thread starts.
 
I fixed this issue by putting a Sleep(20) directly after ThreadList[i].Start(), but I don't really like using Sleep, and it's clear I don't know how this threading scenario actually works.
 
Can anyone shed any light on this?

原文：https://stackoverflow.com/questions/32073961