/// <summary>
/// Performs a dynamic transition; i.e., the transition path is determined on the fly and not recorded.
/// </summary>
/// <param name="targetState">The <see cref="QState"/> to transition to.</param>
protected void TransitionTo(QState targetState)
{
Debug.Assert(targetState != s_TopState); // can't target 'top' state
OnEvent(targetState.GetMethodInfo());
ExitUpToSourceState();
// This is a dynamic transition. We pass in null instead of a recorder
TransitionFromSourceToTarget(targetState.GetMethodInfo(), null);
OnEvent(null);
}
private void TransitionToSynchronized(QState targetState, ref TransitionChain transitionChain)
{
//The entire method had been embedded within [MethodImpl(MethodImplOptions.Synchronized)],
//which is not available in .NET Core, and so a lock is used instead...
lock (this)
{
if (transitionChain != null)
{
// We encountered a race condition. The first (non-synchronized) check indicated that the transition chain
// is null. However, a second threat beat us in getting into this synchronized method and populated
// the transition chain in the meantime. We can execute the regular method again now.
TransitionTo(targetState, ref transitionChain);
}
else
{
// The transition chain is not initialized yet, we need to dynamically retrieve
// the required transition steps and record them so that we can subsequently simply
// play them back.
TransitionChainRecorder recorder = new TransitionChainRecorder();
TransitionFromSourceToTarget(targetState.GetMethodInfo(), recorder);
// We pass the recorded transition steps back to the caller:
transitionChain = recorder.GetRecordedTransitionChain();
}
}
}
///<summary>
/// Retrieves the super state (parent state) of the specified
/// state by sending it the empty signal.
///</summary>
private MethodInfo GetSuperStateMethod(MethodInfo stateMethod)
{
QState superState = (QState)stateMethod.Invoke(this, new object[] { new QEvent((int)QSignals.Empty) });
if (superState != null)
{
return(superState.GetMethodInfo());
}
else
{
return(null);
}
}
/// <summary>
/// Determines whether the state machine is in the state specified by <see paramref="inquiredState"/>.
/// </summary>
/// <param name="inquiredState">The state to check for.</param>
/// <returns>
/// <see langword="true"/> if the state machine is in the specified state;
/// <see langword="false"/> otherwise.
/// </returns>
/// <remarks>
/// If the currently active state of a hierarchical state machine is s then it is in the
/// state s AND all its parent states.
/// </remarks>
public bool IsInState(QState inquiredState)
{
MethodInfo stateMethod;
for (stateMethod = m_MyStateMethod;
stateMethod != null;
stateMethod = GetSuperStateMethod(stateMethod))
{
if (stateMethod == inquiredState.GetMethodInfo()) // do the states match?
{
return(true);
}
}
return(false); // no match found
}
private MethodInfo Trigger(MethodInfo stateMethod, QSignals qSignal)
{
var evt = new QEvent((int)qSignal);
OnEvent(stateMethod, evt);
QState state = (QState)stateMethod.Invoke(this, new object[] { evt });
if (state == null)
{
return(null);
}
else
{
return(state.GetMethodInfo());
}
}
/// <summary>
/// Dispatches the specified event to this state machine
/// </summary>
/// <param name="qEvent">The <see cref="IQEvent"/> to dispatch.</param>
protected void CoreDispatch(IQEvent qEvent)
{
// We let the event bubble up the chain until it is handled by a state handler
m_MySourceStateMethod = m_MyStateMethod;
do
{
OnEvent(m_MySourceStateMethod, qEvent);
QState state = (QState)m_MySourceStateMethod.Invoke(this, new object[] { qEvent });
if (state != null)
{
m_MySourceStateMethod = state.GetMethodInfo();
}
else
{
m_MySourceStateMethod = null;
}
} while (m_MySourceStateMethod != null);
}
/// <summary>
/// Represents the macro Q_INIT in Miro Samek's implementation
/// </summary>
protected void InitializeState(QState state)
{
m_MyStateMethod = state.GetMethodInfo();
}