Parallel For Bug in static constructor

最近老是遇到bug,神烦。

第一步,构造这样的一个类:

    public class ParallelForBug
    {
        public static string StaticProperty = "StaticProperty";

        static void method(int i)
        {
            Console.WriteLine("null method: " + i);
        }

        static ParallelForBug()
        {
            Parallel.For(0, 10, i => {
                Console.WriteLine(i);
                method(i);
            });

        }
    }

第二步,调用

            string staticProperty = ParallelForBug.StaticProperty;
            Console.WriteLine(staticProperty);

但不幸的是,你将永远不会看到

Console.WriteLine(staticProperty)

的结果。Why???

在MSDN上问了这个问题,得到了一个回复,看起来这不是bug,是by design

详细文档如下:

devblogs.microsoft.com/pfxteam/static-constructor-deadlocks/ 

   This CLR behavior is defined in section 10.5.3.3 of the ECMA CLI specification:

   “Type initialization alone shall not create a deadlock unless some code called from a type initializer (directly or indirectly) explicitly invokes blocking operations.”

   So, any operation that blocks the current thread in a static constructor potentially risks a deadlock. For example, just as waiting on threads can deadlock a static constructor, waiting on a task can have the same effect. And the same goes for Parallel.For, Parallel.ForEach, Parallel.Invoke, PLINQ queries, etc.

还是理解不深啊。

原文地址:https://www.cnblogs.com/crazyghostvon/p/ParallelForBug.html