private async Task <InvokeRoutineResult> RunRoutineAsync(
ITransitionCarrier transitionCarrier,
TransitionDescriptor transitionDescriptor,
CancellationToken ct)
{
var invocationResult = new InvokeRoutineResult();
using (_transitionScope.Enter(transitionDescriptor))
{
var transitionMonitor = _transitionScope.CurrentMonitor;
var serviceId = await transitionCarrier.GetServiceIdAsync(ct);
var methodId = await transitionCarrier.GetRoutineDescriptorAsync(ct);
var serviceReference = _serviceResolver.Resolve(serviceId);
var methodReference = _methodResolver.Resolve(serviceReference.Definition, methodId);
object serviceInstance = serviceReference.GetInstance();
//var serviceStateContainer = _serviceStateValueContainerProvider.CreateContainer(serviceInstance);
//var isStatefullService = serviceStateContainer.GetCount() > 0;
//if (isStatefullService)
// await transitionCarrier.ReadServiceStateAsync(serviceStateContainer, ct);
Type taskResultType =
methodReference.Definition.MethodInfo.ReturnType == typeof(void)
? TaskAccessor.VoidTaskResultType
: TaskAccessor.GetTaskResultType(methodReference.Definition.MethodInfo.ReturnType);
Task completionTask;
IValueContainer asmValueContainer = null;
if (TryCreateAsyncStateMachine(methodReference.Definition.MethodInfo, methodId.IntentId, out var asmInstance, out var asmMetadata))
{
var isContinuation = transitionDescriptor.Type == TransitionType.ContinueRoutine;
asmValueContainer = await LoadRoutineStateAsync(transitionCarrier, asmInstance, asmMetadata, isContinuation, ct);
asmMetadata.Owner.FieldInfo?.SetValue(asmInstance, serviceInstance);
transitionMonitor.OnRoutineStart(
serviceReference,
methodReference,
methodId,
serviceInstance,
asmInstance,
(transitionCarrier as TransitionCarrier)?.Caller);
try
{
asmInstance.MoveNext();
completionTask = GetCompletionTask(asmInstance, asmMetadata);
}
catch (Exception ex)
{
// The MoveNext() must not throw, but instead complete the task with an error.
// try-catch is added just in case for a non-compiler-generated state machine.
completionTask = TaskAccessor.FromException(taskResultType, ex);
}
}
public async Task CommitAsync(ScheduledActions actions, ITransitionCarrier transitionCarrier, TransitionCommitOptions options, CancellationToken ct)
{
if (actions.ExecuteRoutineIntents?.Count > 0)
{
foreach (var intent in actions.ExecuteRoutineIntents)
{
var serviceDefinition = GetServiceDefinition(intent.ServiceId);
if (serviceDefinition.Type == ServiceType.Local)
{
#pragma warning disable CS4014
Task.Run(() => RunRoutineInBackground(serviceDefinition, intent));
#pragma warning restore CS4014
}
else
{
var platformHttpClient = _platformHttpClientProvider.GetClient(serviceDefinition);
var routineInfo = await platformHttpClient.ScheduleRoutineAsync(intent, _transitionUserContext.Current, ct);
if (routineInfo.Result != null)
{
_routineCompletionSink.OnRoutineCompleted(intent.Id, routineInfo.Result);
}
}
}
}
if (actions.RaiseEventIntents?.Count > 0)
{
foreach (var intent in actions.RaiseEventIntents)
{
await _eventDispatcher.PublishEvent(intent);
}
}
}
public async Task RunAsync(
ITransitionCarrier transitionCarrier,
CancellationToken ct)
{
var transitionDescriptor = await transitionCarrier.GetTransitionDescriptorAsync(ct);
if (transitionDescriptor.Type == TransitionType.InvokeRoutine ||
transitionDescriptor.Type == TransitionType.ContinueRoutine)
{
await RunRoutineAsync(transitionCarrier, transitionDescriptor, ct);
}
else
{
throw new InvalidOperationException($"Unknown transition type '{transitionDescriptor.Type}'.");
}
}
public async Task CommitAsync(
ITransitionCarrier transitionCarrier,
ScheduledActions actions,
CancellationToken ct)
{
#warning This need deep thinking on how to achieve transictionality
if (actions.SaveStateIntent != null)
{
#warning Make sure that saving service and routine state is transactional - you don't want to re-run routine on failure after service state was saved only.
var intent = actions.SaveStateIntent;
await transitionCarrier.SaveStateAsync(intent, ct);
}
if (actions.ExecuteRoutineIntents?.Count > 0)
{
foreach (var intent in actions.ExecuteRoutineIntents)
{
var connector = _fabricConnectorSelector.Select(intent.ServiceId);
#warning TODO: try to pre-generate routine ID - needed for transactionality.
#warning TODO: check if target fabric can route back the continuation. If not, come up with another strategy, e.g. polling, or gateway?
var info = await connector.ScheduleRoutineAsync(intent, ct);
#warning TODO: check if routine is already done - it's possible on retry to run the transition, or under some special circumstances.
#warning TODO: save scheduled routine info into current routine's state - needed for dynamic subscription.
}
}
if (actions.ResumeRoutineIntent != null)
{
#warning need ability to overwrite existing message instead of creating a new one (if supported)
var intent = actions.ResumeRoutineIntent;
var connector = _fabricConnectorSelector.Select(intent.Continuation.ServiceId);
var info = await connector.ScheduleContinuationAsync(intent, ct);
}
if (actions.ContinuationIntents?.Count > 0)
{
foreach (var intent in actions.ContinuationIntents)
{
var connector = _fabricConnectorSelector.Select(intent.Continuation.ServiceId);
var info = await connector.ScheduleContinuationAsync(intent, ct);
}
}
}
public async Task CommitAsync(
ScheduledActions actions,
// Carrier is NULL when call is made outside of a transition scope, e.g. from entry point of a console app.
ITransitionCarrier transitionCarrier,
TransitionCommitOptions options,
CancellationToken ct)
{
#warning This need deep thinking on how to achieve consistency
if (actions.SaveStateIntent != null)
{
#warning Make sure that saving service and routine state is transactional - you don't want to re-run routine on failure after service state was saved only.
var intent = actions.SaveStateIntent;
await((ITransitionStateSaver)transitionCarrier).SaveStateAsync(intent, ct);
}
if (actions.ExecuteRoutineIntents?.Count > 0)
{
foreach (var intent in actions.ExecuteRoutineIntents)
{
var connector = _fabricConnectorSelector.Select(intent.ServiceId);
#warning TODO: try to pre-generate routine ID - needed for transactionality.
#warning TODO: check if target fabric can route back the continuation. If not, come up with another strategy, e.g. polling, or gateway?
var info = await connector.ScheduleRoutineAsync(intent, ct);
#warning TODO: check if routine is already done - it's possible on retry to run the transition, or under some special circumstances.
#warning TODO: save scheduled routine info into current routine's state - needed for dynamic subscription.
if (options.NotifyOnRoutineCompletion)
{
((IInternalRoutineCompletionNotifier)_routineCompletionNotifier).RegisterComittedRoutine(intent.Id, connector, info);
}
}
}
if (actions.ResumeRoutineIntent != null)
{
#warning need ability to overwrite existing message instead of creating a new one (if supported)
var intent = actions.ResumeRoutineIntent;
var connector = _fabricConnectorSelector.Select(intent.Continuation.ServiceId);
var info = await connector.ScheduleContinuationAsync(intent, ct);
}
if (actions.ContinuationIntents?.Count > 0)
{
foreach (var intent in actions.ContinuationIntents)
{
var connector = _fabricConnectorSelector.Select(intent.Continuation.ServiceId);
var info = await connector.ScheduleContinuationAsync(intent, ct);
}
}
if (actions.RaiseEventIntents?.Count > 0)
{
foreach (var intent in actions.RaiseEventIntents)
{
if (intent.ServiceId == null)
{
throw new NotSupportedException();
}
var connector = _fabricConnectorSelector.Select(intent.ServiceId);
await connector.PublishEventAsync(intent, ct);
}
}
if (actions.RegisterTriggerIntents?.Count > 0)
{
var connector = ((ICurrentConnectorProvider)transitionCarrier).Connector;
foreach (var intent in actions.RegisterTriggerIntents)
{
await connector.RegisterTriggerAsync(intent, ct);
}
}
if (actions.ActivateTriggerIntents?.Count > 0)
{
var connector = ((ICurrentConnectorProvider)transitionCarrier).Connector;
foreach (var intent in actions.ActivateTriggerIntents)
{
await connector.ActivateTriggerAsync(intent, ct);
}
}
if (actions.SubscribeToTriggerIntents?.Count > 0)
{
var connector = ((ICurrentConnectorProvider)transitionCarrier).Connector;
foreach (var intent in actions.SubscribeToTriggerIntents)
{
await connector.SubscribeToTriggerAsync(intent, ct);
}
}
}
private async Task RunRoutineAsync(
ITransitionCarrier transitionCarrier,
TransitionDescriptor transitionDescriptor,
CancellationToken ct)
{
using (_transitionScope.Enter(transitionDescriptor))
{
var transitionMonitor = _transitionScope.CurrentMonitor;
var serviceId = await transitionCarrier.GetServiceIdAsync(ct);
var routineDescriptor = await transitionCarrier.GetRoutineDescriptorAsync(ct);
object serviceInstance;
IServiceDefinition serviceDefinition;
#warning IntrinsicRoutines must be registered in the service registry, but it needs the engine IoC to resolve.
if (serviceId.ProxyName == nameof(IntrinsicRoutines))
{
serviceInstance = _intrinsicRoutines;
serviceDefinition = IntrinsicCommunicationModel.IntrinsicRoutinesServiceDefinition;
}
else
{
serviceInstance = _serviceProxyBuilder.Build(serviceId);
serviceDefinition = ((ServiceProxyContext)((IProxy)serviceInstance).Context).Definition;
}
var routineMethod = _routineMethodResolver.Resolve(serviceDefinition, routineDescriptor.MethodId);
//var serviceStateContainer = _serviceStateValueContainerProvider.CreateContainer(serviceInstance);
//var isStatefullService = serviceStateContainer.GetCount() > 0;
//if (isStatefullService)
// await transitionCarrier.ReadServiceStateAsync(serviceStateContainer, ct);
Task completionTask;
IValueContainer asmValueContainer = null;
if (TryCreateAsyncStateMachine(routineMethod, out var asmInstance, out var asmMetadata))
{
var isContinuation = transitionDescriptor.Type == TransitionType.ContinueRoutine;
asmValueContainer = await LoadRoutineStateAsync(transitionCarrier, asmInstance, asmMetadata, isContinuation, ct);
asmMetadata.Owner.FieldInfo?.SetValue(asmInstance, serviceInstance);
transitionMonitor.OnRoutineStart(
serviceId,
routineDescriptor,
serviceInstance,
routineMethod,
asmInstance);
try
{
#warning possibly need to create a proxy? on a sealed ASM class? How to capture Task.Delay if it's not immediate after first MoveNext?
asmInstance.MoveNext();
completionTask = GetCompletionTask(asmInstance, asmMetadata);
}
catch (Exception ex)
{
// The MoveNext() must not throw, but instead complete the task with an error.
// try-catch is added just in case for a non-compiler-generated state machine.
var taskResultType = TaskAccessor.GetTaskResultType(routineMethod.ReturnType);
completionTask = TaskAccessor.FromException(taskResultType, ex);
}
}
private async Task RunRoutineAsync(
ITransitionCarrier transitionCarrier,
ITransitionData transitionData,
TransitionDescriptor transitionDescriptor,
CancellationToken ct)
{
using (_transitionScope.Enter(transitionDescriptor))
{
var transitionMonitor = _transitionScope.CurrentMonitor;
var serviceId = await transitionData.GetServiceIdAsync(ct);
var routineDescriptor = await transitionData.GetRoutineDescriptorAsync(ct);
var serviceInstance =
#warning IntrinsicRoutines must be registered in the service registry, but it needs the engine IoC to resolve.
serviceId.ProxyName == nameof(IntrinsicRoutines)
? _intrinsicRoutines
: _serviceProxyBuilder.Build(serviceId);
#warning check if the serviceInstance proxy is an actual non-abstract class with implementation
// Need exact underlying type of the service implementation type to call
// the routine method directly without using the virtual method table.
var serviceType = (serviceInstance as IProxy)?.ObjectType ?? serviceInstance.GetType();
var routineMethod = _routineMethodResolver.Resolve(serviceType, routineDescriptor.MethodId);
var serviceStateContainer = _serviceStateValueContainerProvider.CreateContainer(serviceInstance);
var isStatefullService = serviceStateContainer.GetCount() > 0;
if (isStatefullService)
{
await transitionData.ReadServiceStateAsync(serviceStateContainer, ct);
}
Task completionTask;
IValueContainer asmValueContainer = null;
if (TryCreateAsyncStateMachine(routineMethod, out var asmInstance, out var asmMetadata, out completionTask))
{
var isContinuation = transitionDescriptor.Type == TransitionType.ContinueRoutine;
asmValueContainer = await LoadRoutineStateAsync(transitionData, asmInstance, asmMetadata, isContinuation, ct);
asmMetadata.Owner.FieldInfo?.SetValue(asmInstance, serviceInstance);
transitionMonitor.OnRoutineStart(
serviceId,
routineDescriptor,
serviceInstance,
routineMethod,
asmInstance);
try
{
#warning possibly need to create a proxy? on a sealed ASM class? How to capture Task.Delay if it's not immediate after first MoveNext?
asmInstance.MoveNext();
}
catch (Exception ex)
{
// The MoveNext() must not throw, but instead complete the task with an error.
// try-catch is added just in case for a non-compiler-generated state machine.
var taskResultType = TaskAccessor.GetTaskResultType(routineMethod.ReturnType);
completionTask = TaskAccessor.FromException(taskResultType, ex);
}
}
public async Task CommitAsync(
ScheduledActions actions,
ITransitionCarrier transitionCarrier,
TransitionCommitOptions options,
CancellationToken ct)
{
ITransitionContext context = _transitionScope.CurrentMonitor.Context;
SerializedMethodContinuationState continuationState = null;
if (actions.SaveStateIntent != null)
{
var intent = actions.SaveStateIntent;
var serviceRef = _serviceResolver.Resolve(context.Service);
var methodRef = _methodResolver.Resolve(serviceRef.Definition, context.Method);
var behaviorSettings = _communicationSettingsProvider.GetMethodSettings(methodRef.Definition);
IMethodStateStorage stateStorage = null;
if (intent.RoutineState != null && intent.RoutineResult == null)
{
var roamState = behaviorSettings.RoamingState;
if (!roamState)
{
stateStorage = _methodStateStorageProvider.GetStorage(context.Service, context.Method, returnNullIfNotFound: true);
if (stateStorage == null)
{
// Fallback: try to roam the state if possible
roamState = true;
}
}
if (roamState)
{
// Aggregate methods (WhenAll, WhenAny) must have a concurrency control
// using a persistence mechanism to aggregate multiple results.
roamState = methodRef.Definition.FindProperty("aggregate")?.Value != (object)true;
}
if (!roamState && stateStorage == null)
{
throw new InvalidOperationException($"Invoking method '{methodRef.Id}' on '{serviceRef.Id}' requires persistence for aggregating result.");
}
if (roamState)
{
continuationState = EncodeContinuationState(intent, transitionCarrier, context);
}
else
{
try
{
var executionState = GetMethodExecutionState(
actions.SaveStateIntent, transitionCarrier, context);
var etag = await stateStorage.WriteStateAsync(
actions.SaveStateIntent.Service,
actions.SaveStateIntent.Method,
executionState);
// NOTE: assume that ContinuationDescriptor instances refer to this instance of
// PersistedMethodId and the ETag gets automatically propagated to the invoke intents.
actions.SaveStateIntent.Method.ETag = etag;
}
catch (ETagMismatchException ex)
{
// The record in the storage has changed since the beginning of the transition.
// There must have been a concurrent transition.
// Discard current results and try again.
throw new ConcurrentTransitionException(ex);
}
}
}
else if (intent.RoutineResult != null)
{
var expectsSyncReply = (transitionCarrier as TransitionCarrier)?.Message.CommunicatorTraits.HasFlag(CommunicationTraits.SyncReplies) == true;
// TODO: make this behavior optional if a continuation is present (no polling expected).
// TODO: for the event sourcing style, the result must be written by the receiver of the response.
var writeResult = !expectsSyncReply;
if (writeResult && context.Caller?.Event != null)
{
writeResult = false;
}
if (writeResult && stateStorage == null)
{
stateStorage = _methodStateStorageProvider.GetStorage(context.Service, context.Method, returnNullIfNotFound: true);
}
if (stateStorage == null)
{
// Fallback (A): if the method has a continuation, assume that no polling is expected,
// so there is no need to write the result into a persisted storage.
// This does not cover 'fire and forget' scenarios.
// Fallback (B): This method must be an event handler - no need
// to write result because nothing should poll for the result.
if (expectsSyncReply ||
transitionCarrier.GetContinuationsAsync(default).Result?.Count > 0 ||