[Distributed_systems] week 7

[Lukács Dániel]

Hi Márk,


I've seen the change, this is what I referred to as "new counter". Even 
there, I can only reproduce race conditions (since counter += 1 is not 
atomic), but what I hoped too see is that a thread consistently works 
with an old (cached) value of the non-volatile variable. But my solution 
doesn't work for me either. Maybe my OpenJDK doesn't do caching. Not 
sure if it's required by the JVM specs.


Video: See MS Stream in my other mail. You can use your INF account to 
upload there. Did you mean something like that?


I introduced some system in the repo, please see the timeline and update 
your local copy. The handout (neither mine or yours) doesn't have any 
info about wait/notify. Do you have some time to upgrade the Hungarian one?


Dániel


On 3/31/20 11:33 AM, Török Márk wrote:
>   
> Hi Dani,
>
> Yesterday I changed the exercise regarding volatile.
>
> Is it possible to arrange a storage place for videos where we can see video streaming?
> It would be a nice approach if we can use the videos in the next semesters as well.
>
> If we use teams for this, we should add students to the same course in every semester to use the same video.
> Do we have a video portal where we can upload videos and videos are available like in youtube or any other kind of video sharing portal?
>
> Mark
>   
> 2020 Március 31, Kedd 00:15 CEST dátummal, Lukács Dániel <dlukacs at caesar.elte.hu> ezt írta:
>   
>> Done, but I still cannot seem to reproduce memory inconsistency neither
>> with mine or your new counter. For me, reads and writes in your counter
>> code are always in proper "happens-before" order even without volatile :/
>>
>> Maybe it's platform specific (is it?). If it works for you it's fine.
>>
>>
>> On 3/30/20 8:47 PM, Török Márk wrote:
>>
>>> Hi Dani,
>>>
>>> Can you please add some solutions for the last exercise of week7?
>>>
>>> Thank you,
>>> Mark
>>>    
>>>    
>>> 2020 Március 30, Hétfő 20:30 CEST dátummal, Török Márk <tmark at caesar.elte.hu> ezt írta:
>>>    
>>>> Hi All,
>>>>
>>>> Do we have a streaming server? Where can we store these videos and how can we make them available for students?
>>>>
>>>> Thank you,
>>>> Mark
>>>>    
>>>>    
>>>> 2020 Március 30, Hétfő 14:25 CEST dátummal, Lukács Dániel <dlukacs at caesar.elte.hu> ezt írta:
>>>>    
>>>>> Hi!
>>>>>
>>>>> That's awesome! :) I think most of us are new to this, so it's still all
>>>>> experimental.
>>>>>
>>>>> The length should be around 20 minutes. Maybe less, but definitely not
>>>>> more.
>>>>>
>>>>> I guess the topic is mostly up to you (until it's multithreaded servers
>>>>> :)), but if you need a plan:
>>>>>
>>>>>     * The *video* could be some theory intro and a demo about moving from
>>>>>       iterative server to multithreaded server. (With iterative server,
>>>>>       one client has to wait until the other client finished
>>>>>       communication. Threads can solve this problem.) If you don't want to
>>>>>       code everything from scratch, it may be a good idea to create a
>>>>>       supplementary handout and refer to that in the video.
>>>>>     * During class they could implement Robi's chat server and chat client
>>>>>       during *class*. They will need a detailed assignment text for this.
>>>>>       As Robi said, a demo (or written instruction) could be necessary
>>>>>       here if there are difficult or unexpected or tricky operations.
>>>>>     * Finally, they could solve Robi's HTTP server for *homework*. They
>>>>>       will need a detailed assignment text for this.
>>>>>
>>>>> If they have this down, then week 9 could be about implementing
>>>>> ping-pong and avoiding deadlocks.
>>>>>
>>>>> Is it realistic for you to finish the video until Thursday night? We
>>>>> could then review it on Friday and publish it, so students would have
>>>>> time to watch it during the weekend.
>>>>>
>>>>> Bests,
>>>>>
>>>>> Dániel
>>>>>
>>>>>
>>>>> On 3/30/20 10:17 AM, Grünwald Péter wrote:
>>>>>> Sziasztok!
>>>>>>
>>>>>> Hát ilyen videót még nem csináltam, de megpróbálom.
>>>>>> Milyen hosszú legyen?
>>>>>> Milyen témákat tárgyaljon pontosan?
>>>>>>
>>>>>> Üdv,
>>>>>> Péter
>>>>>>
>>>>>> On Sun, Mar 29, 2020 at 1:16 PM Lukács Dániel <dlukacs at caesar.elte.hu
>>>>>> <mailto:dlukacs at caesar.elte.hu>> wrote:
>>>>>>
>>>>>>       Dear All,
>>>>>>
>>>>>>       No one signed up yet for preparing teaching materials for week 8 (the
>>>>>>       one starting on April 6). The topic is Multithreaded client-server 1.
>>>>>>
>>>>>>       I would do it because new topics are usually easier, but I'm already
>>>>>>       working on the large assignment :(
>>>>>>
>>>>>>       Péter, is it possible for you to prepare the materials for week 8?
>>>>>>
>>>>>>       Dániel
>>>>>>
>>>>    
>>>>    
>>>>
>>>>
>>>> _______________________________________________
>>>> Distributed_systems mailing list
>>>> Distributed_systems at plc.inf.elte.hu
>>>> https://plc.inf.elte.hu/mailman/listinfo/distributed_systems
>>>    
>>>    
>>>
>>>
>   
>   
>
>