SubSpace Java Client

[»jabjabjab]

I have 3 nights off tomorrow to be able to do more work.

 

 

Edit:shifted by one day. Something went wrong in my work scheduling >.>

Edited September 27, 2011 by jabjabjab

[»jabjabjab]

I just made most of a ToDo list. So many X's in things.. heh. Anyways working on special weapons

[»Lynx]

How's networking coming along?

[»jabjabjab]

I honestly hate the noise the decoy noise makes, so i went out to find a replacement. this is the result:

http://www.sounddogs.com/previews/2109/mp3/147873_SOUNDDOGS__do.mp3

[»jabjabjab]

With the help of spidernl, the jvm crash is history.

 

A tip for those who wish to use CopyOnWriteArrayList objects, please do not do this when running multiple threads:

 

Subtracting at an thread not synced with another listening to it.

 

Edit: oh and multiple for loops reading the info across threads.

Edited October 1, 2011 by jabjabjab

[Drake7707]

Use synchronized() { } ?

[spidernl]

Making the add/remove/loop "methods" synchronized doesn't help much. Far as I know that'd just prevent multiple threads from both adding at the same time, or both removing at the same time, etc. A thread-safe list would have to make all functions that can modify the list's contents block when one of them is 'in use'. Not that that's impossible, just sayin'.

[Drake7707]

I usually do a

List<meh> list;
lock(somequeue)
    list = somequeue.ToList();

foreach l in list
{ 
  ...
}

 

in c#. Without the handy linq functions such as ToList twould be slightly more of a hassle, but it could still be done if there aren't a lot of methods that access the list, and by keeping those methods in the same class (otherwise it gets confusing very fast). Isn't there a thread safe list in java, similar to the recently added ConcurrentBag in c# (although locking yourself woulds probably still be faster)?

[»jabjabjab]

I honestly dont know,. Im not out of the woods with the error yet. Only the update thread works, but the collision thread is identical, and is accessing the same info to push a method, (and i cant seem to merge both because of delay on updates) so i dunno atm wut to do about that.

[spidernl]

class YourList extends ArrayList
{
   FancyLockingSystem mySystem;
   
   @override
   public void add()
   {
       //Do cool stuff with locks
   }
   
   @override
   public void remove()
   {
       //Do cool stuff with locks
   }
}

 

edit: You could also have a global lock and not do the locking inside the list, but instead lock the list whenever you want to access it, and unlock it whenever you're done. Then you just go like..

 

lock();

for (element : elements)

//loop

unlock();

Edited October 2, 2011 by spidernl

[Drake7707]

Holding the locks for the entire action on the array is usually a bad idea when there are a lot of concurrent threads that access the same list. If it's only occasionally this wouldn't pose a problem, but if it's accessed per frame by multiple threads I'd go for a copy of the list and do the actions on the copy (well unless the action itself also has to be blocked, then this would be fine).

 

 

The lock(); and unlock(); mentioned would have to be implemented with a mutex, semaphore or monitor, depending on what kind of locking you'd need

[JoWie]

Or just use 1 of the 100 java thread safe collections? Edited October 2, 2011 by JoWie

[Cheese]

from the moment you touch threads, its only a matter of time until youre forced to learn about mutexes

[»jabjabjab]

3 more days off now. Will work on stuff later tonight.

[»jabjabjab]

http://i559.photobucket.com/albums/ss31/XDreamersMS/Continuum/Aphelion/AphelionLogo2.png?t=1317992328

 

 

How is this for a logo?

[Dr Brain]

Fine, but you spelled Javaspace wrong.

[Resol]

Did it it take you all 3 days to make that?

[»jabjabjab]

Look whose getting impatient

[Cheese]

who's*

[»jabjabjab]

http://i559.photobucket.com/albums/ss31/XDreamersMS/Continuum/Aphelion/AphelionLogo4.png

http://i559.photobucket.com/albums/ss31/XDreamersMS/Continuum/Aphelion/AphelionLogo3.png

[»jabjabjab]

When SSDR comes out of Beta (which is probably due in a few days) I will resume work on this client.

[»jabjabjab]

It's pretty obvious that I know next to nothing on networking, so this is going to be a big horrid thing for me to do :/... (tries to find way to set this up)

[Drake7707]

Best way is much like an IRC chat system, where all messages from a client are applied on the server and are forwarded to the others. It's not really that hard in java.

 

I wouldn't focus much on optimization or lag issues at first though, even if it takes 20kb/s per client at first, getting it to work is more important. Otherwise it might end up as a case of premature optimization.

[Cheese]

basically, you need a socket on the server for each connected client

client sends data to the server, whether a weapon packet or a chat message

server checks to see if its legit and other stuff, then sends it to all connected clients

 

piece of cake

[»Lynx]

Don't bother with the checks until you've got the basics down, or you'll be adding more work prematurely. Have a look at getting a basic chat client working first (using the method Cheese highlighted).