包含具有infinte循环的线程的对象的垃圾收集

Question

可以说我有一个类正在做类似的事情:

 public class Foo
 {
     private bool _forceStop = false;
     private Queue<object> queue;
     private void ProcessInBackground()
     {
          while(!forceStop )
          {
              Moniter.Enter(queue);
              while(!_forceStop && queue.Count == 0)Moniter.Wait(queue);
              object data = null;                 
              if (!_forceStop)
                 data = queue.Dequeue(); 
              Moniter.Exit(queue);

              if (data != null)
                 processData(data);
           }
      }

      ...
  }

如果不再使用类Foo的对象,并且在该对象中_forceStop永远不会设置为true并且假设已调用ProcessInBackground,是否会收集它？

编辑:已解决,歧义增加了线程安全性.对不起,当我写这个例子时,我刚刚编写了一个场景.

Answer 1

(和Marc一样,我假设你指的是你所调用的对象ProcessInBackground.我也假设这queue是一个字段.)

不 - 你仍然指的是queue,这意味着将读取对象中的字段,这意味着包含的对象不能被垃圾收集.

请注意,仅仅因为对象中运行的方法不会阻止垃圾收集 - 垃圾收集器只关心是否有可能使用引用本身,或者是否正在读取对象中的字段.演示代码显示:

using System;
using System.Threading;

public class OddFinalizer   
{
    int field;

    public OddFinalizer(int field)
    {
        this.field = field;
    }

    ~OddFinalizer()
    {
        Console.WriteLine("OddFinalizer");
    }

    public void Work()
    {
        for (int i = 0; i < 5; i++)
        {
            Console.WriteLine("In loop before last access...");
            GC.Collect();
            GC.WaitForPendingFinalizers();            
            Thread.Sleep(1000);
        }
        Console.WriteLine("Field value: {0}", field);
        for (int i = 0; i < 5; i++)
        {
            Console.WriteLine("In loop after last access...");
            GC.Collect();
            GC.WaitForPendingFinalizers();
            Thread.Sleep(1000);
        }
    }

    static void Main(string[] args)
    {
        new OddFinalizer(10).Work();
    }
}

结果(使用/ o +编译,不在调试器中运行):

In loop before last access..
In loop before last access..
In loop before last access..
In loop before last access..
In loop before last access..
Field value: 10
In loop after last access...
OddFinalizer
In loop after last access...
In loop after last access...
In loop after last access...
In loop after last access...