ScheduleActivity Method Returns Immediately?

Question

Hello All,

I've got a ScheduleActivity call within one of my CodeActivities which is returning immediately. The Activity it's scheduling is a Delay, with a Duration of 30 seconds, yet it returns immediately.

Here's some code:

        protected override void CacheMetadata(NativeActivityMetadata metadata)
        {
            mDelay.Duration = TimeSpan.FromSeconds(30);
            metadata.AddImplementationChild(mDelay);
            base.CacheMetadata(metadata);
        }

        private bool DoRetryable(Func<bool> function, TimeSpan timeout, NativeActivityContext context)
        {
            bool result = false;
            DateTime start = DateTime.Now;

            while ((DateTime.Now - start) < timeout)
            {
                result = function();
                if (result)
                {
                    break;
                }

                context.ScheduleActivity(mDelay);
            }

            return result;
        }


        private readonly Delay mDelay = new Delay();

The ScheduleActivity(mDelay) call is returning right away. I figured it would execute the Activity, which has its Duration set to 30 seconds.

Any ideas?

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Answer 1

Hi,

The workflow engine schedule activities in unspecified execution order, this should be the reason you got unexpected behavior.

Basic Activity Scheduling in Workflow 4.0

http://blogs.msdn.com/b/tilovell/archive/2010/01/27/basic-activity-scheduling-in-workflow-4.0.aspx