What is the SQL Server CLR Integration Life Cycle?

Question

How are CLR (.NET) objects managed in SQL Server?

The entry point to any CLR code from SQL Server is a static method. Typically you\'ll only create objects that exi

Answer 1

SQL Server allows static readonly members if assembly is deployed with Unsafe permission level.

Practically objects are retained in memory until SQL service is stopped/restarted.

Regarding concurrency, your object and methods should be thread-safe as everywhere else.

For example:

public static class MyCLRClass
{
    private static readonly ReaderWriterLock rwlock = new ReaderWriterLock();
    private static readonly ArrayList list = new ArrayList();

    private static void AddToList(object obj)
    {
        rwlock.AcquireWriterLock(1000);
        try
        {
            list.Add(obj);
        }
        finally
        {
            rwlock.ReleaseLock();
        }
    }

    [SqlProcedure(Name="MyCLRProc")]
    public static void MyCLRProc()
    {
        rwlock.AcquireReaderLock(1000);
        try
        {
            SqlContext.Pipe.Send(string.Format("items in list: {0}", list.Count));
        }
        finally
        {
            rwlock.ReleaseLock();
        }
    }
}

I use such things in SQL CLR and it works.