public static void DowngradeQuirks_ChangedInDotNetCore()
{
var trwl = new TestReaderWriterLock();
TestLockCookie tlc;
// Downgrade quirk when downgrading from a state where multiple recursive write locks are held, when the lock cookie
// was obtained from a state where:
// - No lock was held
// - When any number of recursive write locks are held
// The expectation in both cases is that a downgrade respects the lock cookie and restores the write lock recursion
// level to the point indicated by the lock cookie.
{
// Lock cookie obtained when no lock is held
tlc = trwl.UpgradeToWriterLock();
trwl.AcquireWriterLock();
trwl.DowngradeFromWriterLock(tlc);
trwl.VerifyIsReaderLockHeld(false);
trwl.VerifyIsWriterLockHeld(false);
// Lock cookie obtained when write locks are held
trwl.AcquireWriterLock();
tlc = trwl.UpgradeToWriterLock();
trwl.AcquireWriterLock();
trwl.DowngradeFromWriterLock(tlc);
trwl.VerifyIsReaderLockHeld(false);
trwl.VerifyIsWriterLockHeld(true);
trwl.ReleaseWriterLock();
trwl.VerifyIsWriterLockHeld(false);
}
// Cannot downgrade to a recursive write lock level greater than or equal to the current
trwl.AcquireWriterLock();
trwl.AcquireWriterLock();
tlc = trwl.UpgradeToWriterLock();
trwl.ReleaseWriterLock();
trwl.DowngradeFromWriterLock(tlc, InvalidLockCookieExceptionHResult);
trwl.ReleaseWriterLock();
trwl.DowngradeFromWriterLock(tlc, InvalidLockCookieExceptionHResult);
trwl.ReleaseWriterLock();
trwl.VerifyIsReaderLockHeld(false);
trwl.VerifyIsWriterLockHeld(false);
trwl.Dispose();
}
public static void ReadersWaitingOnWaitingUpgraderTest()
{
var trwl = new TestReaderWriterLock();
trwl.AcquireReaderLock();
var waitingUpgraderReady = new AutoResetEvent(false);
var continueWaitingUpgrader = new AutoResetEvent(false);
Action waitForWaitingUpgrader;
Thread waitingUpgrader =
ThreadTestHelpers.CreateGuardedThread(out waitForWaitingUpgrader, () =>
{
trwl.AcquireReaderLock();
trwl.UpgradeToWriterLock();
waitingUpgraderReady.Set();
continueWaitingUpgrader.CheckedWait();
trwl.ReleaseWriterLock();
trwl.VerifyIsReaderLockHeld(false);
trwl.VerifyIsWriterLockHeld(false);
});
waitingUpgrader.IsBackground = true;
waitingUpgrader.Start();
ThreadTestHelpers.WaitForCondition(() => (waitingUpgrader.ThreadState & ThreadState.WaitSleepJoin) != 0);
Action acquireReleaseReaderLock =
() =>
{
trwl.AcquireReaderLock();
trwl.ReleaseReaderLock();
};
Action waitForWaitingReader1, waitForWaitingReader2;
Thread waitingReader1 = ThreadTestHelpers.CreateGuardedThread(out waitForWaitingReader1, acquireReleaseReaderLock);
Thread waitingReader2 = ThreadTestHelpers.CreateGuardedThread(out waitForWaitingReader2, acquireReleaseReaderLock);
waitingReader1.IsBackground = true;
waitingReader2.IsBackground = true;
waitingReader1.Start();
waitingReader2.Start();
ThreadTestHelpers.WaitForCondition(() => (waitingReader1.ThreadState & ThreadState.WaitSleepJoin) != 0);
ThreadTestHelpers.WaitForCondition(() => (waitingReader2.ThreadState & ThreadState.WaitSleepJoin) != 0);
// Releasing the read lock releases the waiting upgrader
trwl.ReleaseReaderLock();
waitingUpgraderReady.CheckedWait();
// Releasing the now-writer's write lock releases all waiting readers
continueWaitingUpgrader.Set();
waitForWaitingUpgrader();
waitForWaitingReader1();
waitForWaitingReader2();
trwl.Dispose();
}
public static void ReadersWaitingOnWaitingUpgraderTest()
{
var trwl = new TestReaderWriterLock();
trwl.AcquireReaderLock();
var waitingUpgraderReady = new AutoResetEvent(false);
var continueWaitingUpgrader = new AutoResetEvent(false);
Action waitForWaitingUpgrader;
Thread waitingUpgrader =
ThreadTestHelpers.CreateGuardedThread(out waitForWaitingUpgrader, () =>
{
trwl.AcquireReaderLock();
trwl.UpgradeToWriterLock();
waitingUpgraderReady.Set();
continueWaitingUpgrader.CheckedWait();
trwl.ReleaseWriterLock();
trwl.VerifyIsReaderLockHeld(false);
trwl.VerifyIsWriterLockHeld(false);
});
waitingUpgrader.IsBackground = true;
waitingUpgrader.Start();
ThreadTestHelpers.WaitForCondition(() => (waitingUpgrader.ThreadState & ThreadState.WaitSleepJoin) != 0);
Action acquireReleaseReaderLock =
() =>
{
trwl.AcquireReaderLock();
trwl.ReleaseReaderLock();
};
Action waitForWaitingReader1, waitForWaitingReader2;
Thread waitingReader1 = ThreadTestHelpers.CreateGuardedThread(out waitForWaitingReader1, acquireReleaseReaderLock);
Thread waitingReader2 = ThreadTestHelpers.CreateGuardedThread(out waitForWaitingReader2, acquireReleaseReaderLock);
waitingReader1.IsBackground = true;
waitingReader2.IsBackground = true;
waitingReader1.Start();
waitingReader2.Start();
ThreadTestHelpers.WaitForCondition(() => (waitingReader1.ThreadState & ThreadState.WaitSleepJoin) != 0);
ThreadTestHelpers.WaitForCondition(() => (waitingReader2.ThreadState & ThreadState.WaitSleepJoin) != 0);
// Releasing the read lock releases the waiting upgrader
trwl.ReleaseReaderLock();
waitingUpgraderReady.CheckedWait();
// Releasing the now-writer's write lock releases all waiting readers
continueWaitingUpgrader.Set();
waitForWaitingUpgrader();
waitForWaitingReader1();
waitForWaitingReader2();
trwl.Dispose();
}
public static void DowngradeQuirks_ChangedInDotNetCore()
{
var trwl = new TestReaderWriterLock();
TestLockCookie tlc;
// Downgrade quirk when downgrading from a state where multiple recursive write locks are held, when the lock cookie
// was obtained from a state where:
// - No lock was held
// - When any number of recursive write locks are held
// The expectation in both cases is that a downgrade respects the lock cookie and restores the write lock recursion
// level to the point indicated by the lock cookie.
{
// Lock cookie obtained when no lock is held
tlc = trwl.UpgradeToWriterLock();
trwl.AcquireWriterLock();
trwl.DowngradeFromWriterLock(tlc);
trwl.VerifyIsReaderLockHeld(false);
trwl.VerifyIsWriterLockHeld(false);
// Lock cookie obtained when write locks are held
trwl.AcquireWriterLock();
tlc = trwl.UpgradeToWriterLock();
trwl.AcquireWriterLock();
trwl.DowngradeFromWriterLock(tlc);
trwl.VerifyIsReaderLockHeld(false);
trwl.VerifyIsWriterLockHeld(true);
trwl.ReleaseWriterLock();
trwl.VerifyIsWriterLockHeld(false);
}
// Cannot downgrade to a recursive write lock level greater than or equal to the current
trwl.AcquireWriterLock();
trwl.AcquireWriterLock();
tlc = trwl.UpgradeToWriterLock();
trwl.ReleaseWriterLock();
trwl.DowngradeFromWriterLock(tlc, InvalidLockCookieExceptionHResult);
trwl.ReleaseWriterLock();
trwl.DowngradeFromWriterLock(tlc, InvalidLockCookieExceptionHResult);
trwl.ReleaseWriterLock();
trwl.VerifyIsReaderLockHeld(false);
trwl.VerifyIsWriterLockHeld(false);
trwl.Dispose();
}