StackGuard.cs

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using System.Runtime.CompilerServices;
using System.Threading;
using System.Threading.Tasks;
 
namespace System.Linq.Expressions;
 
internal sealed class StackGuard
{
    private int _executionStackCount;
 
    public bool TryEnterOnCurrentStack()
    {
        if (RuntimeHelpers.TryEnsureSufficientExecutionStack())
        {
            return true;
        }
        if (_executionStackCount < 1024)
        {
            return false;
        }
        throw new InsufficientExecutionStackException();
    }
 
    public void RunOnEmptyStack<T1, T2>(Action<T1, T2> action, T1 arg1, T2 arg2)
    {
        RunOnEmptyStackCore(delegate(object s)
        {
            (Action<T1, T2>, T1, T2) tuple = ((Action<T1, T2>, T1, T2))s;
            tuple.Item1(tuple.Item2, tuple.Item3);
            return (object)null;
        }, (action, arg1, arg2));
    }
 
    public void RunOnEmptyStack<T1, T2, T3>(Action<T1, T2, T3> action, T1 arg1, T2 arg2, T3 arg3)
    {
        RunOnEmptyStackCore(delegate(object s)
        {
            (Action<T1, T2, T3>, T1, T2, T3) tuple = ((Action<T1, T2, T3>, T1, T2, T3))s;
            tuple.Item1(tuple.Item2, tuple.Item3, tuple.Item4);
            return (object)null;
        }, (action, arg1, arg2, arg3));
    }
 
    public R RunOnEmptyStack<T1, T2, R>(Func<T1, T2, R> action, T1 arg1, T2 arg2)
    {
        return RunOnEmptyStackCore(delegate(object s)
        {
            (Func<T1, T2, R>, T1, T2) tuple = ((Func<T1, T2, R>, T1, T2))s;
            return tuple.Item1(tuple.Item2, tuple.Item3);
        }, (action, arg1, arg2));
    }
 
    public R RunOnEmptyStack<T1, T2, T3, R>(Func<T1, T2, T3, R> action, T1 arg1, T2 arg2, T3 arg3)
    {
        return RunOnEmptyStackCore(delegate(object s)
        {
            (Func<T1, T2, T3, R>, T1, T2, T3) tuple = ((Func<T1, T2, T3, R>, T1, T2, T3))s;
            return tuple.Item1(tuple.Item2, tuple.Item3, tuple.Item4);
        }, (action, arg1, arg2, arg3));
    }
 
    private R RunOnEmptyStackCore<R>(Func<object, R> action, object state)
    {
        _executionStackCount++;
        try
        {
            Task<R> task = Task.Factory.StartNew(action, state, CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);
            if (!task.IsCompleted)
            {
                ((IAsyncResult)task).AsyncWaitHandle.WaitOne();
            }
            return task.GetAwaiter().GetResult();
        }
        finally
        {
            _executionStackCount--;
        }
    }
}