//
// Constructor: registers a take with a blocking queue.
//
internal StRegisteredTake(StBlockingQueue <T> queue, StTakeCallback <T> callback,
object cbState, int timeout, bool executeOnce)
{
//
// Validate the arguments.
//
if (timeout == 0)
{
throw new ArgumentOutOfRangeException("\"timeout\" can not be zero");
}
if (callback == null)
{
throw new ArgumentOutOfRangeException("\"callback\" must be specified");
}
//
// Initialize the registered take fields.
//
this.queue = queue;
cbparker = new CbParker(UnparkCallback);
if ((this.timeout = timeout) != Timeout.Infinite)
{
toTimer = new RawTimer(cbparker);
}
this.executeOnce = executeOnce;
this.callback = callback;
this.cbState = cbState;
//
// Execute the TryTakePrologue prologue on the queue.
//
waitNode = queue.TryTakePrologue(cbparker, StParkStatus.Success, out dataItem,
ref hint);
//
// Set the state to active and enable the unpark callback.
//
state = ACTIVE;
int ws;
if ((ws = cbparker.EnableCallback(timeout, toTimer)) != StParkStatus.Pending)
{
//
// The take operation was already accomplished. To prevent
// uncontrolled reentrancy, the unpark callback is executed inline.
//
UnparkCallback(ws);
}
}
//
// Exchanges a data item asynchronously. The specified callback gets called
// when the exchange completes and is passed the received data item.
//
// TODO: Prevent unbounded reentrancy (hacked by queueing to the pool).
//
public ExchangeRegistration RegisterExchange(T myData, ExchangeCallback <T> callback,
object state, int timeout)
{
if (timeout == 0)
{
throw new ArgumentOutOfRangeException("timeout", "The timeout can't be zero");
}
if (callback == null)
{
throw new ArgumentNullException("callback");
}
T yourData;
if (TryExchange(myData, out yourData))
{
ThreadPool.QueueUserWorkItem(_ => callback(state, yourData, false));
return(new ExchangeRegistration());
}
state = state ?? this;
WaitNode wn = null;
var cbparker = new CbParker(ws => {
if (ws != StParkStatus.Success && xchgPoint == wn)
{
Interlocked.CompareExchange(ref xchgPoint, null, wn);
}
if (ws != StParkStatus.WaitCancelled)
{
callback(state, wn.Channel, ws == StParkStatus.Timeout);
}
});
wn = new WaitNode(cbparker, myData);
if (TryExchange(wn, myData, out yourData))
{
ThreadPool.QueueUserWorkItem(_ => callback(state, yourData, false));
return(new ExchangeRegistration());
}
var timer = timeout != Timeout.Infinite ? new RawTimer(cbparker) : null;
int waitStatus = cbparker.EnableCallback(timeout, timer);
if (waitStatus != StParkStatus.Pending)
{
ThreadPool.QueueUserWorkItem(_ => callback(state, wn.Channel, waitStatus == StParkStatus.Timeout));
return(new ExchangeRegistration());
}
return(new ExchangeRegistration(cbparker));
}
//
// Executes the unpark callback.
//
private void UnparkCallback(int ws)
{
Debug.Assert(ws == StParkStatus.Success || ws == StParkStatus.Timeout ||
ws == StParkStatus.TakeCancelled);
//
// If the registered take was cancelled, cancel the take attempt
// and return immediately.
//
if (ws == StParkStatus.TakeCancelled)
{
queue.CancelTakeAttempt(waitNode, hint);
return;
}
//
// Set state to *our busy*, grabing the current state.
//
StParker myBusy = new SentinelParker();
StParker oldState = Interlocked.Exchange <StParker>(ref state, myBusy);
do
{
//
// If the take operation succeeded, execute the take epilogue;
// otherwise, cancel the take attempt.
//
if (ws == StParkStatus.Success)
{
queue.TakeEpilogue();
}
else
{
queue.CancelTakeAttempt(waitNode, hint);
}
//
// Execute the user callback routine.
//
cbtid = Thread.CurrentThread.ManagedThreadId;
callback(cbState, waitNode == null ? dataItem : waitNode.channel,
ws == StParkStatus.Timeout);
cbtid = 0;
//
// If the registered take was configured to execute once or
// there is an unregister in progress, set the state to INACTIVE.
// If a thread is waiting to unregister, unpark it.
//
if (executeOnce || !(oldState is SentinelParker))
{
if (!(oldState is SentinelParker))
{
oldState.Unpark(StParkStatus.Success);
}
else
{
state = INACTIVE;
}
return;
}
//
// We must re-register with the queue.
// So, initialize the parker and execute the TakeAny prologue.
//
cbparker.Reset();
waitNode = queue.TryTakePrologue(cbparker, StParkStatus.Success, out dataItem,
ref hint);
//
// Enable the unpark callback.
//
if ((ws = cbparker.EnableCallback(timeout, toTimer)) == StParkStatus.Pending)
{
//
// If the *state* field is still *my busy* set it to ACTIVE;
// anyway, return.
//
if (state == myBusy)
{
Interlocked.CompareExchange <StParker>(ref state, ACTIVE, myBusy);
}
return;
}
//
// The take was already accomplished; so, to prevent uncontrolled
// reentrancy execute the unpark callback inline.
//
} while (true);
}
//
// Executes the unpark callback.
//
private void UnparkCallback(int ws)
{
Debug.Assert(ws == StParkStatus.Success || ws == StParkStatus.Timeout ||
ws == StParkStatus.WaitCancelled);
//
// If the registered wait was cancelled, cancel the acquire
// attempt and return immediately.
//
if (ws == StParkStatus.WaitCancelled)
{
waitable._CancelAcquire(waitBlock, hint);
return;
}
//
// Set state to *our busy* grabing the current state, and execute
// the unpark callback processing.
//
StParker myBusy = new SentinelParker();
StParker oldState = Interlocked.Exchange <StParker>(ref state, myBusy);
do
{
//
// If the acquire operation was cancelled, cancel the acquire
// attempt on the waitable.
//
if (ws != StParkStatus.Success)
{
waitable._CancelAcquire(waitBlock, hint);
}
//
// Execute the user callback routine.
//
cbtid = Thread.CurrentThread.ManagedThreadId;
callback(cbState, ws == StParkStatus.Timeout);
cbtid = 0;
//
// If the registered wait was configured to execute once or
// there is an unregister in progress, set the state to INACTIVE.
// If a thread is waiting to unregister, unpark it.
//
if (executeOnce || !(oldState is SentinelParker))
{
if (!(oldState is SentinelParker))
{
oldState.Unpark(StParkStatus.Success);
}
else
{
state = INACTIVE;
}
return;
}
//
// We must re-register with the Waitable.
// So, initialize the parker and execute the WaitAny prologue.
//
cbparker.Reset(1);
int ignored = 0;
waitBlock = waitable._WaitAnyPrologue(cbparker, StParkStatus.Success, ref hint,
ref ignored);
//
// Enable the unpark callback.
//
ws = cbparker.EnableCallback(timeout, toTimer);
if (ws == StParkStatus.Pending)
{
//
// If the *state* field constains still *my busy* set it to ACTIVE.
//
if (state == myBusy)
{
Interlocked.CompareExchange <StParker>(ref state, ACTIVE, myBusy);
}
return;
}
//
// The waitable was already signalled. So, execute the unpark
// callback inline.
//
} while (true);
}
//
// Constructor: registers a wait with a Waitable synchronizer.
//
internal StRegisteredWait(StWaitable waitObject, WaitOrTimerCallback callback,
object cbState, int timeout, bool executeOnce)
{
//
// Validate the arguments.
//
if (timeout == 0)
{
throw new ArgumentOutOfRangeException("\"timeout\" can't be zero");
}
if (callback == null)
{
throw new ArgumentOutOfRangeException("\"callback\" can't be null");
}
if ((waitObject is StReentrantFairLock) || (waitObject is StReentrantReadWriteLock))
{
throw new InvalidOperationException("can't register waits on reentrant locks");
}
if ((waitObject is StNotificationEvent) && !executeOnce)
{
throw new InvalidOperationException("Notification event can't register waits"
+ " to execute more than once");
}
//
// Initialize the register wait fields
//
waitable = waitObject;
cbparker = new CbParker(UnparkCallback);
toTimer = new RawTimer(cbparker);
this.timeout = timeout;
this.executeOnce = executeOnce;
this.callback = callback;
this.cbState = (cbState != null) ? cbState : this;
//
// Execute the WaitAny prologue on the waitable.
//
int ignored = 0;
waitBlock = waitObject._WaitAnyPrologue(cbparker, StParkStatus.Success, ref hint,
ref ignored);
//
// Set the registered wait state to active and enable the
// unpark callback.
//
state = ACTIVE;
int ws = cbparker.EnableCallback(timeout, toTimer);
if (ws != StParkStatus.Pending)
{
//
// The acquire operation was already accomplished. To prevent
// uncontrolled reentrancy, the unpark callback is executed inline.
//
UnparkCallback(ws);
}
}
//
// Executes the timer callback
//
internal void TimerCallback(int ws)
{
Debug.Assert(ws == StParkStatus.Timeout || ws == StParkStatus.TimerCancelled);
//
// If the timer was cancelled, return immediately.
//
if (ws == StParkStatus.TimerCancelled)
{
return;
}
//
// Set timer state to *our busy* state, grabing the current state and
// execute the timer callback processing.
//
SentinelParker myBusy = new SentinelParker();
StParker oldState = Interlocked.Exchange <StParker>(ref state, myBusy);
do
{
//
// Signals the timer's event.
//
tmrEvent.Signal();
//
// Call the user-defined callback, if specified.
//
if (callback != null)
{
cbtid = Thread.CurrentThread.ManagedThreadId;
callback(cbState, true);
cbtid = 0;
}
//
// If the timer isn't periodic or if someone is trying to
// cancel it, process cancellation.
//
if (period == 0 || !(oldState is SentinelParker))
{
if (!(oldState is SentinelParker))
{
oldState.Unpark(StParkStatus.Success);
}
else
{
state = INACTIVE;
}
return;
}
//
// Initialize the timer's parker.
//
cbparker.Reset();
//
// Compute the timer delay and enable the unpark callback.
//
int timeout;
if (useDueTime)
{
timeout = dueTime;
useDueTime = false;
}
else
{
timeout = period | (1 << 31);
}
if ((ws = cbparker.EnableCallback(timeout, timer)) == StParkStatus.Pending)
{
if (state == myBusy)
{
Interlocked.CompareExchange <StParker>(ref state, ACTIVE, myBusy);
}
return;
}
//
// The timer already expired. So, execute the timer
// callback inline.
//
} while (true);
}