//--- Methods ---
/// <summary>
/// Signal the RendezVousEvent. If a receiver continuation is present, trigger it.
/// Otherwise, store the signal until a continuation is registered.
/// </summary>
/// <exception cref="InvalidOperationException">The RendezVousEvent instance has already been signaled.</exception>
public void Signal()
{
if (HasCompleted)
{
throw new InvalidOperationException("event has already been used");
}
object value = Interlocked.Exchange(ref _placeholder, TOKEN);
if (value != null)
{
if (!(value is Action))
{
throw new InvalidOperationException("event has already been signaled");
}
Action handler = (Action)value;
Interlocked.Decrement(ref _pendingCounter);
if (_captured)
{
lock (Pending) {
Pending.Remove(this);
}
}
_placeholder = USED;
try {
handler();
} catch (Exception e) {
// log exception, but ignore it; outer task is immune to it
_log.WarnExceptionMethodCall(e, "Signal: unhandled exception in continuation");
}
}
}
/// <summary>
/// Invoke a zero arg action.
/// </summary>
/// <param name="handler">Action to invoke.</param>
public void Invoke(Action handler)
{
if (handler == null)
{
throw new ArgumentNullException("handler");
}
if (_referenceCount < 1)
{
throw new InvalidOperationException("Cannot call invoke an unaquired TaskEnv");
}
#pragma warning disable 219
System.Diagnostics.StackTrace stacktrace = DebugUtil.GetStackTrace();
#pragma warning restore 219
// check if handler can be invoked in-place or needs to queued up
if (_dispatchQueue != null)
{
_dispatchQueue.QueueWorkItem(() => {
// store current thread-specific settings
TaskEnv previousEnv = _currentEnv;
try {
// set thread-specific settings
_currentEnv = this;
// execute handler
handler();
} catch (Exception e) {
_log.ErrorExceptionMethodCall(e, "Invoke: unhandled exception in handler");
} finally {
Release();
// restore thread-specific settings
_currentEnv = previousEnv;
}
});
}
else
{
// store current thread-specific settings
TaskEnv previousEnv = _currentEnv;
try {
// set thread-specific settings
_currentEnv = this;
// execute handler
handler();
} catch (Exception e) {
_log.WarnExceptionMethodCall(e, "Invoke: unhandled exception in handler");
} finally {
Release();
// restore thread-specific settings
_currentEnv = previousEnv;
}
}
}
//--- Methods ---
/// <summary>
/// Adds a work-item to the thread pool. Depending on the implementation, this method may block the invoker
/// or throw an exception if the thread pool cannot accept more items.
/// </summary>
/// <param name="callback">Item to add to the thread pool.</param>
public void QueueWorkItem(Action callback)
{
try {
callback();
} catch (Exception e) {
// log exception, but ignore it; outer task is immune to it
_log.WarnExceptionMethodCall(e, "QueueWorkItem: unhandled exception in callback");
}
}
private void Dispose()
{
if (_iterator != null)
{
try {
_iterator.Dispose();
} catch (Exception e) {
_log.WarnExceptionMethodCall(e, "Dispose");
} finally {
_iterator = null;
}
}
}
//--- Methods ---
public void InstanceStarted(DateTime eventTime)
{
try {
XUri channel = _channel.At(SITE, STARTED);
XUri resource = _apiUri.AsServerUri();
Queue(eventTime, channel, resource, new[] { _apiUri.AsServerUri().ToString() }, new XDoc("deki-event")
.Elem("channel", channel)
.Elem("uri", _apiUri.AsServerUri().ToString()));
} catch (Exception e) {
_log.WarnExceptionMethodCall(e, "InstanceStarted", "event couldn't be created");
}
}