System.Threading.Tests.ReaderWriterLockTests.TestReaderWriterLock.DowngradeFromWriterLock C# (CSharp) Method

            public void DowngradeFromWriterLock(TestLockCookie tlc, int expectedFailureHResult = 0)
            {
                Assert.NotNull(tlc);

                PerformLockAction(
                    expectedFailureHResult,
                    false /* isBlockingOperation */,
                    () => _rwl.DowngradeFromWriterLock(ref tlc._lockCookie),
                    () =>
                    {
                        Assert.Equal(Environment.CurrentManagedThreadId, _writerThreadID);
                        Assert.NotEqual(0, _writerLevel);
                        if (tlc._readerLevel == 0)
                        {
                            Assert.True(_writerLevel > tlc._writerLevel);
                            _writerLevel = tlc._writerLevel;
                            if (_writerLevel == 0)
                            {
                                _writerThreadID = InvalidThreadID;
                            }
                        }
                        else
                        {
                            _writerLevel = 0;
                            _writerThreadID = InvalidThreadID;
                            Assert.True(ThreadReaderLevel == 0);
                            ThreadReaderLevel = tlc._readerLevel;
                        }
                    });
            }