问题描述
在 c# 线程应用程序中,如果我要锁定一个对象,假设是一个队列,如果发生异常,该对象会保持锁定状态吗?伪代码如下:
In a c# threading app, if I were to lock an object, let us say a queue, and if an exception occurs, will the object stay locked? Here is the pseudo-code:
int ii; lock(MyQueue) { MyClass LclClass = (MyClass)MyQueue.Dequeue(); try { ii = int.parse(LclClass.SomeString); } catch { MessageBox.Show("Error parsing string"); } }
据我了解,catch 之后的代码不会执行 - 但我一直想知道锁是否会被释放.
As I understand it, code after the catch doesn't execute - but I have been wondering if the lock will be freed.
推荐答案
First;你考虑过 TryParse 吗?
First; have you considered TryParse?
in li; if(int.TryParse(LclClass.SomeString, out li)) { // li is now assigned } else { // input string is dodgy }
锁会被释放有两个原因;首先,lock本质上是:
The lock will be released for 2 reasons; first, lock is essentially:
Monitor.Enter(lockObj); try { // ... } finally { Monitor.Exit(lockObj); }
第二;您捕获并且不重新抛出内部异常,因此 lock 实际上永远不会看到异常.当然,您在 MessageBox 的持续时间内持有锁,这可能是个问题.
Second; you catch and don't re-throw the inner exception, so the lock never actually sees an exception. Of course, you are holding the lock for the duration of a MessageBox, which might be a problem.
因此它将在除最致命的灾难性不可恢复异常之外的所有异常中释放.
So it will be released in all but the most fatal catastrophic unrecoverable exceptions.