使Guid属性成为线程安全的 [英] Making Guid properties threadsafe

问题描述

我的一个班级有一个Guid类型的属性.多个线程可以同时读取和写入此属性.我的印象是对Guid的读写不是原子的，因此我应该锁定它们.

One of my classes has a property of type Guid. This property can read and written simultaneously by more than one thread. I'm under the impression that reads and writes to a Guid are NOT atomic, therefore I should lock them.

我选择这样做:

public Guid TestKey
{
    get
    {
        lock (_testKeyLock)
        {
            return _testKey;
        }
    }

    set
    {
        lock (_testKeyLock)
        {
            _testKey = value;
        }
    }
}

(在我的课程中，对Guid的所有访问也都通过该属性完成，而不是直接访问_testKey.)

(Inside my class, all access to the Guid is also done through that property rather than accessing _testKey directly.)

我有两个问题:

(1)真的有必要像这样锁定Guid以防止读取被撕裂吗? (我很确定是这样.)

(1) Is it really necessary to lock the Guid like that to prevent torn reads? (I'm pretty sure it is.)

(2)这是进行锁定的合理方法吗?还是我需要像下面这样:

(2) Is that a reasonable way to do the locking? Or do I need to do it like the following:

get
{
    Guid result;

    lock (_testKeyLock)
    {
        result = _testKey;
    }

    return result;
}

本文确实确认了Guids会遭受读取撕裂的影响: http ://msdn.microsoft.com/zh-CN/magazine/jj863136.aspx

This article does confirm that Guids will suffer from torn reads: http://msdn.microsoft.com/en-us/magazine/jj863136.aspx

推荐答案

1)真的有必要像这样锁定Guid以防止读取中断吗? (我很确定是这样.)

1) Is it really necessary to lock the Guid like that to prevent torn reads? (I'm pretty sure it is.)

是的.

2)这是进行锁定的合理方法吗?

2) Is that a reasonable way to do the locking?

再次:是.

如果存在Guid的Interlocked方法，那会更好(更快).

If there had existed an Interlocked method for Guid then that would have been better (faster).

对于double(另一个非原子结构)，Interlocked提供了支持，而对于引用则不需要.

For double (another non-atomic struct) there is support from Interlocked and for references it is not needed.

因此，作为一种模式，仅当Interlocked不支持的较大结构时才需要.

So as a pattern this is only required for larger structs that are not supported by Interlocked.

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