class HijackTest()
{
    public volatile bool flag;
    public volatile int num;

    // Set breakpoint at ThreadSuspend::SuspendEE then step out and look at the main thread stack
    // (bu coreclr!ThreadSuspend::SuspendEE)
    // Note: HijackFrames are not used on Windows if CET is enabled. Either test on non-Windows
    // or disable CET by modifying Thread::AreShadowStacksEnabled to return false.
    [MethodImpl(MethodImplOptions.AggressiveOptimization)]
    public void Test()
    {
        // start other thread that will force a GC collection.
        Task.Run(Work);

        // run loop checking volatile variable to generate non-interruptible code.
        while (!flag)
        {
            TestLoop();
        }
    }
    public void Work()
    {
        Thread.Sleep(500);
        GC.Collect();
    }

    [MethodImpl(MethodImplOptions.NoInlining | MethodImplOptions.AggressiveOptimization)]
    public void TestLoop()
    {
        num++; num++; num++; num++; num++;
        num++; num++; num++; num++; num++;
        num++; num++; num++; num++; num++;
        num++; num++; num++; num++; num++;
        num++; num++; num++; num++; num++;
        num++; num++; num++; num++; num++;
    }
}