I developed a game for android with the google play services realtime multiplayer feature. I currently have a problem when matching the players. I dont use any invite feature, so all players just use the automatch functionality.
My game can be played with 4 players, but games with just 3 or 2 players are also possible. For my testing with 2 devices i use:
RoomConfig.createAutoMatchCriteria(minNumberOfOpponents, maxNumberOfOpponents, 0);
If i keep starting, ending and restarting games for a number of times, it often happens that the clients are not connected correctly. In the working cases the games onRoomConnected is called correctly and the game starts. In some cases tho, this is not happening. In theses cases, one device finds the other device and its onPeerJoined() and onRoomConnecting() callback is called. onRoomConnected() is never called tho. Thats because the other device gets no information whatsoever, just the roomCreated callback is called, and thats it.
So one device finds the other, and gets the information that another device joined the room. It also gets informed when this device leaves the room again. But the other device doesnt recognize any of this.
If this helps. i had some issues with losing connection before, and fixed it by restarting the apiClient everytime a room left on any clint. I dont think this is related tho.
I thought that might be a problem with leaving the current room correctly, and somehow joining the old room again, but it also happens ehen starting the app for the first time. Also the apiClient reconnect should avoid this problem
Thx in advance
Edit: It seems like its just my nexus 5 which produces the error. Every other device i tested works fine. The Nexus 5 does too in most cases. If the clients get connected and the game starts, there has never been any problem. The errrr just happens on this one device, and only in maybe 5 out of 6 cases, when searching an online game.
It just stops getting any callbacks called, sometimes right after the onRoomCreated(), sometime after he found another peer and onRoomConnecting(), and sometimes after onRoomConnected() has been called.
The other device gets its appropiate callbacks called tho in these cases.
So if the error device stops at onRoomCreated() the other device finds the client.
If the error device finds the other device and gets onRoomConnecting() called and stops after, the other device gets its onRoomConnected().
And if the error device gets its onRoomConnected() called, it sometimes even stops getting any messages from there on, while the other device is already in the game.
Maybe this helps someone. i'm not 100 % sure i fixed my problem. Haven't tested it in depth, but it seems everything is working fine now.
My problem was, that i have 2 different threads in my application, where the standard activity GUI thread starts the apiClient and handles the callbacks, while the gameengine thread initiates the room creation and sends the reliable messages via the apiClient.
It seems, sometimes things mess up while the peers connect and trade their first data. Currently i avoided directly calling any apiClient actions from the gameengine thread, but use runOnGuiThread to handle these actions on the Activity Gui Thread.
Related
I was able to make a working HID USB stack on my "StartUSB for PIC" board for the 18F2550 microcontroller. I based it on one of the MLA libraries, which was made for the 18F45K50 (MLA 2018_11_26, hid_custom, picdem_fs_usb_k50.x), but I converted it to work with the 18F2550 (there might have been easier ways, but only learned to work with PIC about 1 month ago). On the host side, I'm using LibUsbDotNet (also here, there might be easier ways - the documentation on this library really sucks) on a Windows 10 machine.
I'm using the HID class, full speed, and all seems to work. Although, I get some random errors on the host PC (see below), but doing one close/re-open cycle on the host side when getting the error is kind of solving it. Dirty, but it works. So I kind of ignore this now.
Win32Error:Win32Error:GetOverlappedResult Ep 0x01
995:The I/O operation has been aborted because of either a thread exit or an application request.
I'm not an expert on USB (yet). But all examples I'm seeing are based on 1) you send first a command to the device and 2) then you retrieve the answer from the device. I did some performance tests, and see that this indeed shows that I can do about 500 cycles/second. I think that is correct, because each cycle, sending command and retrieving answer, each takes 1 msec.
But do I really need to send a command? Can't I just keep reading endlessly, and when the device has somthing to say, it does send the data in an IN transaction, and when not it ignores which creates a timeout on the host side. That would mean that I can poll at 1000 cycles/second? Unfortunately, I have tried it by changing my implementation on the PIC, but I get very weird results. I think I have issues with suspend mode. That brings me to another question - how can I make the device get out of suspend mode (means that not the host, but the device should be triggering this event). I have searched the MLA library for command such as "wakeup", "resume", ... but couldn't find anything.
So, to summarize, 2 questions:
Conceptual: Can I send data from device to host without being requested for it by a command from the host?
For PIC experts: How can I have a device trigger for a wakeup from suspend mode?
And indeed, the answer is Yes on the first question.
In the meantime, I found another link on the web that contains a Visual Studio C# implementation of a USB library including all the source files.
If you're interested, this is the link
This C# host implementation works as a charm. Without sending a command to the device, I get notified immediately if a button is pressed. Great!
It also proofs that my earlier device implementation based on the original MicroChip MLA, is 100% correct. I stress tested the implementation by sending a "toggle LED command" as fast as I could, and I reach 1000 commands/second. Again great!
I think that LibUsbDotNet isn't that perfect after all. As I wrote above, I get rather unstable communication (Win32Error). But with this implementation, I don't get a single error, even after running for half an hour # 1000 commands/second.
So for me, case closed.
I'm using code from Google's sample game "ButtonClicker2000" found here: https://github.com/playgameservices/android-basic-samples
I have 3 androids running this game in genymotion plus one on my own phone, debugging them all from android studio. I've gotten to a point where I'm trying to gracefully handle disconnect in the event of network issues. The way I'm simulating network issues is toggling the wifi on my phone. (on or off, same behavior) After that, real time messages from my phone are no longer being received by the virtual devices, and my phone is no longer receiving real time messages from the other devices. However, my phone never enters onDisconnect() and the other devices never enter onPeersDisconnected. If I exit the app on my phone after communication ceases, onPeerLeft fires on the other devices.
How can I either ensure communication between devices in a game isn't lost in the likely event that a user at some point comes in or out of range of their wifi? If that's not possible, how can I at least ensure the onDisconnect event is firing from the offending device and onPeersDisconnected event is firing on the others?
If we're going with what the documentation states, onDisconnect usually happens when there's a problem with the remote services (crash or resource problem). having the WiFi turned off doesn't look like it fits with those criteria. [onPeersDisconnected](https://developers.google.com/android/reference/com/google/android/gms/games/multiplayer/realtime/RoomStatusUpdateListener#onPeersDisconnected(com.google.android.gms.games.multiplayer.realtime.Room, java.util.List)) is called when the participants are disconnected from the room.
Determine if the onP2PConnected is called when its connected and onP2PDisconnected when disconnected (hopefully this can catch WiFi toggling cases) since I think its more appropriate when you're using real-time multiplayer.
You can also read more about it in the Real-time Multiplayer section of the documentaiton.
Hope this helps!
I have been working on Reachability class for a while and have tried both the one from Apple sample and the one from ddg. I wonder whether the Reachability class keep sending / receiving data after starting the notifier.
As I'm developing an app which connect to different hosts quite often, I decided to write a singleton and attach the reachability classes I need on it. The reacability classes would be initiated and start their notifiers once the app start. I use the singleton approach as I want this singleton class to be portable and can be applied to other apps without much rewriting. I am not sure if it is good idea to implement like this but it worked quite well.
However, someone reported that the battery of his device drain significantly faster after using the app and someone reported more data usage. My app does not send / receive data on background so I start wondering if it is related to the reachability.
I tried profiling the energy usage with Instrument and I notice that there are continuous small data (few hundred bytes in average) coming in via the network interfaces even I put my app in idle. However, there are almost no data sending out.
I know that Reachability requires data usage when initiate (resolving DNS etc) but I am not sure that whether it still keep using data after starting notifier. Does anyone can tell?
I am not familiar with the low-level programming, it would be nice if someone could explain how does the Reachability work.
I use Reachability, and while I haven't monitored the connections, I have browsed the code, and I can't see any reason why it would keep sending ( or receiving).
If you have a ethernet connection to your Mac, it is quite easy to check. Enable sharing over wifi of your ethernet connection. Install little snitch, it will run in demo mode for three hours after every boot. Turn off the data connection on the test device and connect it to your mac over wifi.
This will allow you to see any network access your test device is making.
If this isn't possible, you can also run your app in the simulator as the network side should be the same, so you should be able to check.
There are also a ton of other tools to track network activity, but I think little snitch is the easiest to use.
I'm new to driver programming in general and also to USB. However, I managed to write a driver for Windows CE (6.0) and I also had access to an USB-Sniffer to read all traffic between the host and the device.
The problem now occurs on some boards (2 out of the 3 I have):
When the device has no data to send and I issue an Interrupt-In-Transfer the device sends an ACK.
So far this is expected. However, something (I guess either the USB-Controller or WinCE) seems to automatically issue more IN-Transfers (3 on one board, 4 on another) and I get subsequent ACK. This isn't a problem so far either.
But the next IN-Transfer will also result in an ACK, no matter if there is data to send or not, I receive zero bytes in the driver.
Yet, when I look at the USB-Sniffer the proper telegram was send, however 2 more IN-Transfers are automatically issued and are responded with an ACK. So it seems like the data is overwritten by the ACK.
I tried everything that came to my mind so far: Reset the pipe, close and reopen the connection, but nothing seems to work out properly. Resetting the Pipe solves the problem in about half of the cases though. I really ran out of ideas for solving the problem.
Is there a way to tell the USB-Controller (or WinCE or whatever causes this behaviour) to always only issue one single transfer?
EDIT
Turns out it was a threading issue. Unfortunately I wasn't the one who fixed it and I have no access to the working solution, thus I cannot give further details.
I have created a web-service app and i want to populate my view controllers according to the response i fetch(via GET) in main thread. But i want to create a scheduled timer which will go and control my server, if there becomes any difference(let's say if the count of an array has changed) i will create a local notification. As far as i read from here and some google results, i cant run my app in background more then ten minutes expect from some special situations(Audio, Vo-IP, GPS).. But i need to control the server at least one per minute.. Can anyone offer some idea-or link please?
EDIT
I will not sell the app in store, just for a local area network. Let's say, from the server i will send some text messages to the users and if a new message comes, the count of messages array will increment, in this situation i will create a notification. I need to keep this 'controlling' routing alive forever, whether in foreground or background. Does GCD give such a solution do anyone have any idea?
Just simply play a mute audio file in loop in the background, OR, ping the user's location in the background. Yes, that will drain the battery a bit, but it's a simple hack for in-home applications. Just remember to enable the background types in your Info.plist!
Note: "[...] I fetch (via GET) in main thread." This is not a good approach. You should never fetch any network resources on the main thread. Why? Because your GUI, which is maintained by the main thread, will become unresponsive whenever a fetch isn't instantaneous. Any lag spike on the network results in a less than desirable user experience.
Answer: Aside from the listed special situations, you can't run background apps. The way I see it:
Don't put the app in the background. (crappy solution)
Try putting another "entity" between the app and the "server". I don't know why you "need to control the server at least one per minute" but perhaps you can delegate this "control" to another process outside the device?
.
iOS app -> some form of proxy server -> server which requires
"babysitting" every minute.