Share static data between C# and Burst

Burst has basic support for accessing static readonly data. However, if you want to share static mutable data between C# and HPC#, use the SharedStatic<T> struct.

The following example shows accessing an int static field that both C# and HPC# can change:

    public abstract class MutableStaticTest
    {
        public static readonly SharedStatic<int> IntField = SharedStatic<int>.GetOrCreate<MutableStaticTest, IntFieldKey>();

        // Define a Key type to identify IntField
        private class IntFieldKey {}
    }

C# and HPC# can then access this:

    // Write to a shared static 
    MutableStaticTest.IntField.Data = 5;
    // Read from a shared static
    var value = 1 + MutableStaticTest.IntField.Data;

When you use SharedStatic<T>, be aware of the following:

• The T in SharedStatic<T> defines the data type.
• To identify a static field, provide a context for it. To do this, create a key for both the containing type (for example, MutableStaticTest in the example above), identify the field (for example, IntFieldKey class in the example above) and pass these classes as generic arguments of SharedStatic<int>.GetOrCreate<MutableStaticTest, IntFieldKey>().
• Always initialize the shared static field in C# from a static constructor before accessing it from HPC#. If you don’t initialize the data before accessing it, it might lead to an undefined initialization state.

Additional resources

• Calling Burst-compiled code