Video: Windows Workflow Foundation: Synchronising Activities

Presenter:Mike Taulty

Within a Workflow, it is sometimes important to ensure that a group of activities are scheduled for execution as a single block. This session looks at the Synchronization Activity that enables this.

The following text is a software generated transcript of the video. Click on a minute link to jump to a location within the video


Minute 0

Well and will consist on a nugget session it s one in a series of short lessons were still looking at it isn t as visual studio net framework minus m Tolkien I work in the developer and platform group in Microsoft in the UK and this is one of a series of sessions around the rivers works of foundation as part of an effect suite of technologies which will ship a time when this is done like 20 006 Digital Windows XP service back to Winston is through in a ridiculous that I suspect very brief look at the synchronisation activity at all that useful resin worth of foundation in this nationality with visual studio 2005 with XP to two and working on Windows XP service pack two or Kate and visual studio with an existing solution artificial illustrates the point so solution here we discover a workflow console application with Walworth Lauren and we only construct one instance at workflow

Minute 1

We have a parallel activity inside that parallel activity we have two wire loops each of these wireless lives forever and within the wireless reality sequence of three activities a for XYZ s code activities on the right hand side we have a B C s code activities now as it in previous sessions while this is a parallel activity what that does not mean is that these two sequences and ultimately everything within it doesn t mean that they run on separate threads we said before that within a work so they will only ever be one thread executing at the same time and so what happens with workflow is that these activities will be queued up execution in some currency could

Minute 2

Rather imagine that that figure in this consequence you must do right now if is code behind these different activities is little behind the ex activity even do this right excellent console similarly why right one to the console and then we get a right line is there to the console over here we got a right range that console would not be written to the console and only had a right life see red consoles are exposed at London s what s going on everyone is very policy is that it is somewhat of S in that we get say why DZ see a much repeatedly as we run now that is very artificial because it it was important to us that X why NZ always executed as a lump of activity together if there was

Minute 3

Cross dependency here that meant that we really needed to run the strange things in sequence in 60 if I will ever do anything else like running history activities now this is where the synchronisation activity comes into play out their activity on the Toolbox called synchronisation scope and is important to realise that whilst synchronisation is an overloaded term this is not to do necessarily with leading this is not to do with locks and those kinds of things this is deteriorating shoulder activities execute together so if you take a synchronisation so from here and drop life sequence and will take three activities here Dragon and that synchronisation scope after the sale on the right hand side of the so what do is grab ourselves synchronisation scope again and will take a three activities agency Allah Dragon and that s an

Minute 4

Is aged appear so hasn t changed in any way we re just easy synchronisation is coach to make sure that if X X or Tuesday will be followed by why NZ is similarly a will be followed by being sea and effectively Robert is taking this whole synchronisation area and turning into and atomic set of activities at last be executed together now that the last thing needed before a gun actually the programme is a need to ensure that the synchronisation scope is tied in with this one of the is all we do is going at the properties for synchronisation scope and into the synchronisation handles property we get is a name that all at my handle or look at my scope similarly we go over to a second synchronisation scope here and make sure that it is to using my scope and it looks like I got the first one runs at London again to have my scope here

Minute 5

Analysts only also have my scope if he said anyway long run they will finally get a little behaviour in a very perfect interleaving survey then be then see excellent while NZ will only break from that such a simple thing to understand if we want these things rescue together because they do something let s say should be atomic in some fashion and we can put them into a synchronisation scope and we can tie together with synchronisation service need to be synchronised with each other as a consultant at property in the synchronisation handles just that arrival is in its very short video which showed that they will have a synchronisation scope activity within workflow foundation and idea that is not

Minute 6

Brings light locking with respect to threat what this is about is making sure that we have a way of telling the workflow runtime that certain activities need to be executed together and must not be interleaved with certain other activities but I have a fact that activity onto the land surface and configure it up and we had that synchronisation handles property and if we set out to her a unique name than any synchronisation is failed to share that same handles 40 will be synchronised with respect to each other and it is ideally used when you ve got things that need to occur together and into leavings of your activities were costing to break in Ashington Tyler sings together okay so where can you go to want more information on the windows were of the foundation of a Christian developer Centre embassy in the Microsoft com when effects are not legally to information on all the perfect presentation communication and workflow authors and you dedicated site

Minute 7

At www Windowsworkflow net which is purely about the windows with the foundation is lots of examples and examples of their final if you ve got specific questions on this session if it only might notice it on the screen and their provide feedback and so on other than a thank you listening wrote

Click here to go to original video page