c# - Monitor.Enter(object, ref bool) 比 Monitor.Enter(object) 有什么优势？

Question

根据语言规范，lock(obj) statement; 会被编译为:

object lockObj = obj; // (the langspec doesn't mention this var, but it wouldn't be safe without it)
Monitor.Enter(lockObj);
try
{
    statement;
}
finally
{
    Monitor.Exit(lockObj);
}

然而，它被编译为:

try
{
    object lockObj = obj;
    bool lockTaken = false;
    Monitor.Enter(lockObj, ref lockTaken);
    statement;
}
finally
{
    if (lockTaken) Monitor.Exit(lockObj);
}

这似乎比必要的要复杂得多。那么问题是，该实现的优势是什么？

Answer 1

一如既往，Eric Lippert 已经回答了这个问题:

Fabulous Adventures In Coding: Locks and exceptions do not mix