c# - 您可以在调用 GC.Collect 和 GC.WaitForPendingFinalizers 时出现死锁吗？

Question

鉴于以下情况:

GC.Collect(GC.MaxGeneration);
GC.WaitForPendingFinalizers();
GC.Collect(GC.MaxGeneration);

考虑到多线程和垃圾收集模式，在什么情况下您会在 WaitForPendingFinalizers 上发生死锁？

注意:我不是在寻找您不应该调用 GC.Collect 的原因的答案。

Answer 1

// causes a deadlock when built with release config and no debugger attached
// building in debug mode and/or attaching the debugger might keep
// badIdea alive for longer, in which case you won't see the deadlock
// unless you explicitly set badIdea to null after calling Monitor.Enter

var badIdea = new BadIdea();
Monitor.Enter(badIdea);

GC.Collect(GC.MaxGeneration);
GC.WaitForPendingFinalizers();
GC.Collect(GC.MaxGeneration);

// ...

public class BadIdea
{
    ~BadIdea()
    {
        lock (this)
        {
            // ...
        }
    }
}