public static void SimpleSync()
{
var control = new int[3];
var thread = new Thread
(
() =>
{
var spinWait = new SpinWait();
Volatile.Write(ref control[0], 1);
while (Volatile.Read(ref control[1]) == 0)
{
spinWait.SpinOnce();
}
Volatile.Write(ref control[2], 1);
}
);
thread.Start();
ThreadingHelper.SpinWaitUntil(ref control[0], 1);
Volatile.Write(ref control[1], 1);
thread.Join();
Assert.AreEqual(1, Volatile.Read(ref control[2]));
}
private ManualResetEvent RetriveWaitHandle()
{
// At the end of this method: _requested will be 2 or ObjectDisposedException is thrown
var found = Interlocked.CompareExchange(ref _requested, 1, 0);
switch (found)
{
case -1:
throw new ObjectDisposedException(GetType().FullName);
case 0:
// Found 0, was set to 1, create the wait handle
var isSet = Thread.VolatileRead(ref _state) != 0;
// State may have been set here
var created = new ManualResetEvent(isSet);
if (Interlocked.CompareExchange(ref _handle, created, null) != null)
{
created.Close();
}
Thread.VolatileWrite(ref _requested, 2);
goto default;
case 1:
// Found 1, another thread is creating the wait handle
ThreadingHelper.SpinWaitUntil(ref _requested, 2);
goto default;
default:
// Found 2, the wait handle is already created
// Check if dispose has been called
return(TryGetWaitHandleExtracted());
}
}
private void CaptureAndWait(LockableSlot slot)
{
Capture(slot);
var thread = Thread.CurrentThread;
// The reason while I cannot make an smarter wait function:
// If another thread changed _needleLock.Value after the check but before the starting to wait, the wait will not finish.
ThreadingHelper.SpinWaitUntil(() => _needleLock.Value == thread);
}
internal LockableSlot(LockableContext context)
{
_context = context;
_parent = _context.Slot;
_context.Slot = this;
// --
LockSlot <Thread> lockSlot = null;
ThreadingHelper.SpinWaitUntil(() => _context.Context.ClaimSlot(out lockSlot));
lockSlot.Value = Thread.CurrentThread;
_lockSlot = lockSlot;
_needleLocks = new List <NeedleLock <Thread> >();
}
public ReadOnlyPromise(IPromise promised, bool allowWait)
{
_promised = promised;
if (allowWait)
{
if (_promised is IWaitablePromise promise)
{
_wait = promise.Wait;
}
else
{
_wait = () => ThreadingHelper.SpinWaitUntil(() => _promised.IsCompleted);
}
}
else
{
_wait =
() => throw new InvalidOperationException();
}
}
private ManualResetEvent GetWaitHandle()
{
var found = Thread.VolatileRead(ref _requested);
switch (found)
{
case -1:
throw new ObjectDisposedException(GetType().FullName);
case 0:
return(null);
case 1:
// Found 1, another thread is creating the wait handle
ThreadingHelper.SpinWaitUntil(ref _requested, 2);
goto default;
default:
// Found 2, the wait handle is already created
// Check if dispose has been called
return(TryGetWaitHandleExtracted());
}
}
public ReadOnlyPromise(IPromise promised, bool allowWait)
{
_promised = promised;
if (allowWait)
{
var promise = _promised as IWaitablePromise;
if (promise != null)
{
_wait = () => promise.Wait();
}
else
{
_wait = () => ThreadingHelper.SpinWaitUntil(() => _promised.IsCompleted);
}
}
else
{
_wait = () =>
{
throw new InvalidOperationException();
};
}
}
public bool Commit()
{
if (_currentTransaction != this)
{
throw new InvalidOperationException("Cannot commit a non-current transaction.");
}
ThreadingHelper.MemoryBarrier();
try
{
if (!CheckValue())
{
//the resources has been modified by another thread
return(false);
}
try
{
ThreadingHelper.SpinWaitUntil(() => Context.ClaimSlot(out LockSlot));
LockSlot.Value = Thread.CurrentThread;
if (!Capture())
{
//Nothing to commit
return(true);
}
ThreadingHelper.MemoryBarrier();
if (!CheckCapture() || !CheckValue())
{
//the resources has been claimed by another thread
return(false);
}
var written = false;
foreach (var resource in WriteLog)
{
if (resource.Key.Commit())
{
written = true;
}
else
{
//unexpected
if (written)
{
// TODO - the transaction was partially written, this should not be possible.
System.Diagnostics.Debug.Fail("unexpected - partially committed transaction");
}
return(false);
}
}
return(true);
}
finally
{
if (LockSlot != null)
{
LockSlot.Close();
LockSlot = null;
}
}
}
finally
{
Release(false);
}
}
public Progressor(IEnumerable <T> preface, Progressor <T> wrapped)
{
if (wrapped == null)
{
throw new ArgumentNullException("wrapped");
}
if (preface == null)
{
throw new ArgumentNullException("preface");
}
var enumerator = preface.GetEnumerator();
if (enumerator == null)
{
throw new ArgumentException("preface.GetEnumerator()");
}
var control = 0;
var guard = 0;
Predicate <T> newFilter = item => Thread.VolatileRead(ref control) == 0;
var buffer = new SafeQueue <T>();
wrapped.SubscribeAction
(
item =>
{
if (newFilter(item))
{
buffer.Add(item);
}
}
);
_proxy = new ProxyObservable <T>();
TryTake <T> tryTakeReplacement = (out T value) =>
{
Interlocked.Increment(ref control);
try
{
if (buffer.TryTake(out value) || wrapped.TryTake(out value))
{
_proxy.OnNext(value);
return(true);
}
else
{
_done = wrapped._done;
return(false);
}
}
finally
{
Interlocked.Decrement(ref control);
}
};
_tryTake = (out T value) =>
{
value = default(T);
if (Thread.VolatileRead(ref guard) == 0)
{
bool result;
// We need a lock, there is no way around it. IEnumerator is just awful. Use another overload if possible.
lock (enumerator)
{
result = enumerator.MoveNext();
if (result)
{
value = enumerator.Current;
}
}
if (result)
{
_proxy.OnNext(value);
return(true);
}
enumerator.Dispose();
Interlocked.CompareExchange(ref guard, 1, 0);
}
if (Interlocked.CompareExchange(ref guard, 2, 1) == 1)
{
_tryTake = tryTakeReplacement;
Thread.VolatileWrite(ref guard, 3);
}
else
{
ThreadingHelper.SpinWaitUntil(ref guard, 3);
}
var tryTake = _tryTake;
return(tryTake(out value));
};
}
public Progressor(T[] preface, Progressor <T> wrapped)
{
if (wrapped == null)
{
throw new ArgumentNullException("wrapped");
}
if (preface == null)
{
throw new ArgumentNullException("preface");
}
var control = 0;
var guard = 0;
var index = -1;
Predicate <T> newFilter = item => Thread.VolatileRead(ref control) == 0;
var buffer = new SafeQueue <T>();
wrapped.SubscribeAction
(
item =>
{
if (newFilter(item))
{
buffer.Add(item);
}
}
);
_proxy = new ProxyObservable <T>();
TryTake <T> tryTakeReplacement = (out T value) =>
{
Interlocked.Increment(ref control);
try
{
if (buffer.TryTake(out value) || wrapped.TryTake(out value))
{
_proxy.OnNext(value);
return(true);
}
else
{
_done = wrapped._done;
return(false);
}
}
finally
{
Interlocked.Decrement(ref control);
}
};
_tryTake = (out T value) =>
{
if (Thread.VolatileRead(ref guard) == 0)
{
var currentIndex = Interlocked.Increment(ref index);
if (currentIndex < preface.Length)
{
value = preface[currentIndex];
_proxy.OnNext(value);
return(true);
}
Interlocked.CompareExchange(ref guard, 1, 0);
}
if (Interlocked.CompareExchange(ref guard, 2, 1) == 1)
{
_tryTake = tryTakeReplacement;
Thread.VolatileWrite(ref guard, 3);
}
else
{
ThreadingHelper.SpinWaitUntil(ref guard, 3);
}
var tryTake = _tryTake;
return(tryTake(out value));
};
}
public static bool SpinUntil(Func <bool> condition, int millisecondsTimeout)
{
return(ThreadingHelper.SpinWaitUntil(condition, TimeSpan.FromMilliseconds(millisecondsTimeout)));
}
public static void SpinUntil(Func <bool> condition)
{
ThreadingHelper.SpinWaitUntil(condition);
}