Are public static members (properties) of static class thread safe

Question

I have a sample static class

public static class SampleClass { private static readonly string _personName; private static readonly string _country; static SampleClass() { _personName = "JourneyMan"; _country = "Zee"; System.Threading.Thread.Sleep(5000); } public static string PersonName { get { return _personName; } } public static string Country { get { return _country; } } }

I have deliberately introduced a Thread.Sleep in the static constructor.

I wrote a sample application in which two threads wait on a ManualResetEvent. I tried to simulate the scenario where one thread tries to query a property and is executing the static constructor and is put to sleep, can the other thread access the second property and return null value?

But according to what I observed, the second thread cannot fetch the property value unless the construction is complete.

Is this handled for us? or am I doing something wrong?

So can I assume, in the above case, there is no lock needed to ensure construction of static class is complete?

Thanks

Anything is only as thread safe as you make it; the standard, AFAIK, is that your static methods *should* be thread safe. — Grant Thomas
– Grant Thomas, Commented Jun 28, 2013 at 13:12
@GrantThomas so I can assume, no thread is allowed to query a property of a class unless construction is complete? — Sandepku
– Sandepku, Commented Jun 28, 2013 at 13:14
Eric Lippert did a series on static constructors. Part 1 is at ericlippert.com/2013/02/06/static-constructors-part-one. Well worth reading. And, yes, there is no lock needed in this case. — Jim Mischel
– Jim Mischel, Commented Jun 28, 2013 at 13:35

Ahmed KRAIEM · Accepted Answer · 2013-06-28 13:14:25Z

3

The static constructor is thread safe, static properties no.

Static constructors are guaranteed to be run only once per application domain, before any instances of a class are created or any static members are accessed. http://msdn.microsoft.com/en-us/library/aa645612.aspx

answered Jun 28, 2013 at 13:14

Ahmed KRAIEM

10.4k4 gold badges32 silver badges33 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Sandepku Over a year ago

so I can assume, no thread is allowed to query a property of a class unless construction is complete (may be by another thread)??

Sandepku Over a year ago

i had a doubt whether the second thread waits for the construction to complete before the first thread comes out of Thread.Sleep , cheers

user2478493 · Accepted Answer · 2013-06-28 13:15:16Z

You should be thread safe in this example. Based on the Static Constructors documentation a static constructor 'is called automatically before the first instance is created or any static members are referenced', so it should be impossible to reference the members before the constructor has completed.

Collectives™ on Stack Overflow

Are public static members (properties) of static class thread safe

2 Answers 2

2 Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Related