i thought it'd be better to rephrase. my earlier formulation of my question could have been better focused. the trouble with presence notifications, while real and still recurring, is kind of minor. the things i haven't figured out yet i can fake or work around. much less of a concern than getting basic text chat messages moving between users.
again, still fairly new with this combo of tech flavors - using libjingle as the heart (and liver and kidneys...) of an iphone xmpp/jabber app. got the sign on part, the presence notification/roster updating business actually seems to be working more or less as it should. but xmpp text chat message stanzas seem to vanish before making it out on the wire. capturing other network traffic, and perusing the pretty packets, i yeah, i can see the exchanges for sign on, etc. that got us going, but then nothing for chat.
i've checked and double checked how i'm putting together the stanzas, attributes, namespaces, etc. everything looks jim-dandy to me. i can see that a message is getting queued in the libjingle internal infrastructure. but no results on the ethernet.
hoping somebody who has played around with this stuff before might remember a similar stumbling block and can offer up a hint, suggestion, or pointer in the right direction.
thanks for any help.
mike
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This might be the wrong StackExchange board to ask this on but, why does the history of an email thread get copied into my reply to that same thread? Is this some historical thing? It seems to be the case that if I delete the history in my reply it has no affect on whether or not it renders properly in the client and no affect on whether or not it gets attached to the right thread. So why does every email client do that?
I believe it is historical, before the days of 'conversation view' which would make the need for the history of the message redundant because it threads all the past related messages together. (It does this via the email subject line.)
However, there are still many people who (a) don't have 'conversation view', or, (b) don't want conversation view. So that is why email clients probably still do this - to compensate for those people who would otherwise have to do a separate search to find the prior messages (really, really annoying). But keeping it there for those who have conversation view is only very mildly annoying - if noticed at all (typically this can be mostly hidden unless you expand it).
Therefore, it still makes good sense from a UX point of view to do this (yes, is this a https://ux.stackexchange.com/ candidate?)
I'm making a simple mmorpg server with IOCP.
I implemented a simple movement function so I tested with dummy clients(also IOCP).
Everything works fine only when few clients are connected. After around 500~1000 clients are connected, some dummy clients occasionally read weird data. I checked that server sends data as I expected but when it comes to dummy clients reading them, they read random data.
My guess is that it could be related to operation system's recv buffer being overflowed but I'm only guessing right now... I have no idea how to check them.
Any suggestion would be very thankful!
The problem with too many WSASends doesn't usually manifest as corrupted data; that's more likely to be a bug in your code. Perhaps your problem is caused by you failing to manage the lifetime of the buffer that is being used to send data correctly? It needs to stay stable until you get the completion for the WSASend call. If you were reusing it sooner than that then you would corrupt the data being sent.
The reason this may show up when you have lots of WSASends outstanding to lots of clients is that the send operations may be taking longer to complete and so make it more likely that your bug will be hit...
It doesn't matter how many WSASends you issue as long as your clients are able to receive the data as fast as you can send it. As soon as you are sending faster than they can receive then there will be problems. I address these problems in this answer.
I'm trying to develop a TCG(trading card game) in Unity(I'm Unity newbie) and currently stuck on the architecture of the project and the card effects in particular. Coming from web development background for me all the logic and card effects should be on the server but going through some tutorials for Unity I think the logic should be on the client and I should use a simple room-based server to notify for player actions. Is that correct?
To summarize - where the game logic should be(e.g. card effects, rounds etc)? On the client or on the server?
I actually worked on one of the major TCG's out now for iOS/droid, so this is coming from experience. You definitely want all game logic and rules to be on the server. Do not trust your client to be the source of truth for any game outcomes etc. People will be able to hack that by tampering with the data sent back to the server. They don't have to decompile the game to do that, it can be done merely by sniffing the net traffic.
That said, you may end up with some duplicated logic on both client and server, only so that you can enforce game rules and display the outcomes without always hitting the server. However, your server is always the source of truth and the client is just there to accept input and display outcomes.
The general flow was the client would send a message requesting a new game to the server. The server would respond with the cards for each side and the opening move for the first player. Then the client would simply parse each move and display the outcome. On the cards objects we had methods for many of the actions, such as DrainHealth() and BuffAttack(). When called, these methods would trigger things like particle effects and sound fx attached to the card script.
Yeah the effects should be on the client, I assume your game will be turn based right? You might want to take a look at photon then:
https://doc.photonengine.com/en-us/realtime/current/getting-started/realtime-intro
They have a loot of good tutorials about their API and it's well documented :)
Hope that helps you,
good luck
For a toy project I want to find out if a mobile phone is connected to gsm or not. So I thought "Okay, let's use my local sip provider and see".
But in both cases, the thing goes like this:
I send an INVITE
0 s: I get a 100 Trying
5 s: I get a 183 Session description
I get an audio stream, in the one case with the ringing, in the other case with a "The person you are calling is…"
If I wait long enough (~ 40 s), I get a more appropiate status code like 180 Ringing.
Audio analysis is not an option, really.
Any hints on where to go now?
(I used twinkle for testing and a local german sip-provider.)
This issue is endemic in the way telephone networks work, and is not specific to SIP or IP. It's why, when you place a call to another country and the number is busy, you might sometimes hear your local country's busy tone, or you might hear a different busy tone that comes from the other country. In the latter case you cannot detect except by audio analysis, what the problem is. In SS7 and ISDN we speak of Q.931 cause codes instead of SIP error codes, but the principle is the same.
There's an argument to be made for configuring telephone systems to emit status codes instead of audio error messages. For callers using normal phones, the originating switch (the one closest to the caller) can then map that code to the appropriate spoken error message or audio tone. That way, when the call is being placed by software rather than by a person, the software can have access to the actual error code right away.
On the other hand you can also argue for having the remote switch (the one nearest the destination or the one that encounters the problem) speak its own error message. That switch knows best what the actual problem is. For example, a mobile operator can emit a spoken error message saying that the mobile phone you are trying to call is currently out of range. There is no Q.931 code (or SIP error code for that matter) with that meaning. It could return 27=Destination out of order?? Or 35=Destination unattainable?? Both of those codes are so esoteric, who knows what error message the local switch would translate them to (in practice: probably just a reorder tone, which is really user-unfriendly to a human caller). And when you try to map Q.931 cause codes to SIP error codes back and forth, even more information is lost because the codes really don't match up well at all. It's likely to be a much better user experience for the caller if the remote switch just plays back an informative, appropriate, recording which describes the problem.
Since there is this dilemma (arguments on both sides), we can conclude that this will not likely be resolved by completely standardizing on one way or ther other way anytime soon.
Anyway, sometimes this is configurable: your SIP provider may be able to configure your trunk for coded errors instead of recorded messages. If they offer this (some do), it's worth a try to set this option. But results will vary: this option only affects its local behaviour. In general if you want immediately call clearing with cause code and are instead getting a recorded error message from the other end, you will not be able to do anything about it, because the switch that makes the decision on which way it's going to respond is the remote one.
When using the audio message method, a proper Q.931 cause code or SIP error code usually comes eventually (after the recording is finished), but as you point out, it's probably too late by then.
I have a rather popular Bonjour-based application in App Store. It works perfectly, but around 0.2% of my users report a bizarre bug: "no arrows appear on the edges of the screen, so I can't share stuff with other people!". Needless to say, displaying these arrows is tied to the browsing of a particular Bonjour service on the local domain.
The problem is, the Apple review team seems to intermittently happen to be in this 0.2%. This isn't good for review results, as you might imagine. No matter how much I try, I cannot reproduce this bug.
From the few logs I have, it looks like my app is running correctly, just not receiving NSNetServiceBrowser delegate calls. What can cause this?
Things I've tried:
Having a shorter service name < 14 chars in length to be in spec.
Publishing on #"local." rather than #"" (aka Go Look For The Default Registration Domain). My app is rather useless on a wide-area network anyway.
Things I haven't tried: restarting the browsing machinery periodically. (I have two browsers, though, one looking for the legacy longer name, one for the new shorter one.)
What to do?
There are many areas where things can go wrong. Since the NSNetService instance provided to your delegate methods is autoreleased, you need to retain it if you plan on reusing it out of scope for that method. Most people will add it to an NSMutableArray or NSMutableDictionary so that it is automatically retained, and only autoreleased when removed from the collection. If that is the case for your code, make sure that you have properly initialized your collection before adding the object. Since messages to nil are perfectly ok, you may be sending the addObject:netService message to nil. You will not receive an obvious indication that you never initialized your array or dictionary, and it will appear as though everything is working just fine…except that delegate messages “mysteriously” don’t fire off when peers change status, when you try to connect to one, etc. This crops up often enough in Bonjour troubleshooting that I would recommend it as the first place to start your troubleshooting. It happens to the best of us.
One easily missed problem for apps running network code on a background thread: throwing an un-handled exception on that thread. This can occur without crashing your whole app due to Cocoa/Unix’s rules on threading. If your networking code “just stops working for no reason,” then you may want to check your iPhones Console and logs for error messages. Make sure you have set a breakpoint on the objc_exception_throw symbol.
For more, read the full article "Troubleshooting Bonjour Networking for the iPhone" at my dev blog.