Monitor.TryEnter always returns true even just after Monitor.Enter

问题

I think I am missing something about correct behaviour of Monitor.Enter and Monitor.TryEnter. Here is a piece of code I wrote to separate the issue from the rest of the code:

object lockObj = new object();
bool result = Monitor.TryEnter(lockObj);
Console.Write(result);

Result is always true. No surprises here.

object lockObj = new object();
Monitor.Enter(lockObj);
bool result = Monitor.TryEnter(lockObj);
Console.Write(result);

But this time it is also true. So is lockObj locked after Monitor.Enter or not? Please give me some fresh look at this.

回答1:

This is because you are doing this in the same thread.

Also keep in mind that (MSDN):

It is legal for the same thread to invoke Enter more than once without it blocking; however, an equal number of Exit calls must be invoked before other threads waiting on the object will unblock

回答2:

The same thread that has already acquired a monitor is always allow to reaquire it (to allow for re-enterant code).

来源：https://stackoverflow.com/questions/11154401/monitor-tryenter-always-returns-true-even-just-after-monitor-enter