System.Threading.Tests.ReaderWriterLockTests.SingleThreadLockOwnerMiscellaneousTest C# (CSharp) Method

        public static void SingleThreadLockOwnerMiscellaneousTest()
        {
            var trwl = new TestReaderWriterLock();
            TestLockCookie tlc, tlc2;

            // Read lock owner can upgrade to a write lock
            trwl.AcquireReaderLock();
            tlc = trwl.UpgradeToWriterLock();
            trwl.DowngradeFromWriterLock(tlc);
            trwl.ReleaseReaderLock();

            // Can acquire and release a recursive write lock in multiple ways
            trwl.AcquireWriterLock();
            trwl.AcquireWriterLock();
            trwl.ReleaseWriterLock();
            trwl.AcquireReaderLock();
            trwl.ReleaseReaderLock();
            trwl.UpgradeToWriterLock();
            trwl.ReleaseWriterLock();
            trwl.ReleaseWriterLock();

            // Typical upgrade with single read lock
            trwl.AcquireReaderLock();
            tlc = trwl.UpgradeToWriterLock();
            trwl.DowngradeFromWriterLock(tlc);
            trwl.ReleaseReaderLock();

            // Write lock can be taken with UpgradeToWriterLock when no read lock is held, and with that lock cookie,
            // DowngradeFromWriterLock does not acquire a read lock
            tlc = trwl.UpgradeToWriterLock();
            tlc2 = trwl.UpgradeToWriterLock();
            trwl.DowngradeFromWriterLock(tlc2);
            trwl.DowngradeFromWriterLock(tlc);

            // Upgrading from recursive read lock downgrades back to recursive read lock
            trwl.AcquireReaderLock();
            trwl.AcquireReaderLock();
            tlc = trwl.UpgradeToWriterLock();
            trwl.DowngradeFromWriterLock(tlc);
            trwl.ReleaseReaderLock();
            trwl.ReleaseReaderLock();

            // Can downgrade from any write lock level, and to any read lock level with lock cookie from ReleaseLock
            trwl.AcquireReaderLock();
            trwl.AcquireReaderLock();
            tlc = trwl.ReleaseLock();
            trwl.AcquireWriterLock();
            trwl.AcquireWriterLock();
            trwl.DowngradeFromWriterLock(tlc);
            trwl.ReleaseReaderLock();
            trwl.ReleaseReaderLock();

            // Typical release/restore
            {
                trwl.AcquireReaderLock();
                trwl.AcquireReaderLock();
                tlc = trwl.ReleaseLock();
                trwl.RestoreLock(tlc);
                trwl.ReleaseReaderLock();
                trwl.ReleaseReaderLock();

                trwl.AcquireWriterLock();
                trwl.AcquireWriterLock();
                tlc = trwl.ReleaseLock();
                trwl.RestoreLock(tlc);
                trwl.ReleaseWriterLock();
                trwl.ReleaseWriterLock();
            }

            // Can restore to any read lock level with lock cookie from UpgradeToWriterLock
            trwl.AcquireReaderLock();
            trwl.AcquireReaderLock();
            tlc = trwl.UpgradeToWriterLock();
            trwl.ReleaseWriterLock();
            trwl.RestoreLock(tlc);
            trwl.ReleaseReaderLock();
            trwl.ReleaseReaderLock();

            trwl.Dispose();
        }