/// <summary>
/// Message came in to create a new workflow.
/// </summary>
private void NewWorkflowInstance(object msg, CancellationToken ct, IMessageAcknowledge ack)
{
var wfc = (WorkflowCreate)msg;
Debug.Assert(!string.IsNullOrEmpty(wfc.TemplateName) || !string.IsNullOrEmpty(wfc.TemplateContent));
try
{
_log.InfoFormat("Hosting new workflow instance of type {0}", wfc.TemplateName);
string templateData = !string.IsNullOrEmpty(wfc.TemplateContent)
? wfc.TemplateContent
: LoadWorkflowTemplate(wfc.TemplateName);
var agent = new WorkflowAgent(this, wfc.Id, _ct, wfc.InitialData, templateData, _workflowDataRepositoryKey, _workflowMessagingKey, _workflowWorkspaceKey);
_agents.TryAdd(wfc.Id, agent);
agent.Start();
ack.MessageAcknowledged();
}
catch (Exception ex)
{
var es = string.Format("Problem while trying to host new workflow instance for type {0}: {1}",
wfc.TemplateName, ex);
_log.Error(es);
var on = Catalog.Factory.Resolve <IApplicationAlert>();
on.RaiseAlert(ApplicationAlertKind.Unknown, es);
if (_agents.ContainsKey(wfc.Id))
{
WorkflowAgent _;
_agents.TryRemove(wfc.Id, out _);
}
ack.MessageRejected();
}
}
/// <summary>
/// Try to lock and host a pre-existing workflow.
/// </summary>
/// <param name="workflowId"> </param>
/// <returns> </returns>
private WorkflowAgent TryAcquireWorkflow(string workflowId)
{
WorkflowAgent acquired = null;
var wfMutex = Catalog.Preconfigure()
.Add(DistributedMutexLocalConfig.Name, WorkflowShared.WorkflowInstanceLockName(workflowId))
.ConfiguredResolve <IDistributedMutex>();
if (wfMutex.Open())
{
try
{
var wftemp = GetWorkflowTemplate(workflowId);
if (!string.IsNullOrWhiteSpace(wftemp))
{
acquired = WorkflowAgent.AcquireSleepingOnLocked(wfMutex, this, workflowId, _ct, wftemp, _workflowDataRepositoryKey, _workflowMessagingKey, _workflowWorkspaceKey);
if (null != acquired)
{
if (_agents.TryAdd(workflowId, acquired))
{
acquired.Start();
}
else
{
_dblog.WarnFormat("Strange: locked workflow {0} but couldn't add it", workflowId);
}
}
}
}
catch (SynchronizationLockException)
{
_dblog.InfoFormat("Synchronization lock exception while trying to acquire {0}", workflowId);
wfMutex.Release();
}
catch (WorkflowTemplateException wfex)
{
var es = string.Format("Error loading template for workflow! {0}: {1}", workflowId, wfex);
_log.Error(es);
var on = Catalog.Factory.Resolve <IApplicationAlert>();
on.RaiseAlert(ApplicationAlertKind.Unknown, es);
wfMutex.Release();
}
catch (Exception ex)
{
var es = string.Format("Error while acquiring workflow, {0}", ex);
_log.Error(es);
var on = Catalog.Factory.Resolve <IApplicationAlert>();
on.RaiseAlert(ApplicationAlertKind.Unknown, es);
wfMutex.Release();
}
}
else
{
_dblog.InfoFormat("Could not lock {0}", workflowId);
}
return(acquired);
}