I am working on an (console) application, which should be executed on startup and keeps running all the time in the background (executing something every 30 minutes).
How can I, in another (device) application, check if my console application is running (and start it if its not)?I am using VB.NET CF 2.0 and everything is being deployed on a device running WM 6.5
All the code examples I found where only available on the "standard" .NET.
There are several ways your "monitoring" app could work (and certainly more than I list here).
Use a named mutex (you'll have to P/Invoke it). The monitored app would create and hold it, and the monitoring app would periodically check to make sure it's held. If it's not held, the monitored app is no longer running.
Use the Toolhelp APIs. Have the monitoring app use the Toolhelp APIs to periodically enumerate the running processes. If the monitored app is not in the process list, it is not running.
Use a named event. The monitored app would have a background thread that periodically sets a named (watchdog) event. The monitoring app would wait on that event and if it fails to get the event in a certain time bound, the other app is either not running or has locked up.
Use a socket. Have the monitored app open a socket and listen on it. The monitor app would send a "ping" periodically to the monitored app. The monitored app would respond to the ping with an ack. If the monitoring app doesn't get an ack, the monitored app is either not running or is locked up
Use a window handle. The monitor app periodically P/Invokes GetWindow of FindWindow to find an always-present window in the monitored app - often by Form text. If the monitoring app can't find the Window, the monitored app is not running.
Related
I have an application that runs in the background on Android device. The application performs certain tasks which are scheduled from a control panel. Normally the tasks are performed when requested. However many times the device goes into Doze mode and the tasks are never executed.
I have tried using the PowerManager feature called wake-locks but the system ignores the wake-locks.
Doze Restrictions
Is there a way to programmatically disable Doze Mode for processing background tasks of this app but keep the screen off?
I built a VoIP calling app which maintains a persistent connection with the server to listen to any incoming calls. I implemented a background service to do this.
But since Oreo, this running code is now broken because of the introduction of Background Execution Limits
After looking into forums, I found that some people are suggesting
Convert Service to JobService and let android schedule it
Doing so, my app won't be able to receive calls when it is stopped
Run your operations in foreground services
It is annoying for some users to see a constant notification in the notification bar. So these above-mentioned options aren't working for me to fix my code for Oreo.
How does WhatsApp get the incoming (VOIP) call in Android (Oreo onwards) working around the Background Execution Limits?
(Sticky) foreground services are not affected by the restrictions. So you could use one those as replacement for background services on Oreo.
But foreground services have two disadvantages: They are less likely killed by the system in order to reclaim resources compared to background services, and hence affects the Android system's self-healing capability. And they require you to display a permanent notification. But Users are able to suppress the notification, somewhat mitigating this disadvantage.
I am assuming that you are using SIP to establish the connection and initiate calls. Without a service constantly re-sending REGISTERs, the app doesn't receive INVITEs when the server sends them.
A workaround for this problem is what is called the "push notification strategy". It works as follows, when the server sends a INVITE, it also sends an FCM notification to your app, This wakes up your app which then sends a REGISTER to your server, which in return forks the call to your app. Here is a video that better explains this strategy
There are two options:
use platform push services (APNS or FCM)
maintain persistent socket connection and exclude application from battery optimisations.
I work on a mobile application and use MQTT (javascript paho client) for push notification. But after user or android close application ,MQTT socket has been disconnected and cannot receive notifications. So, I need to make a service to keep socket alive. How can I make a service by react-native?
I am using react-native-background-job for a similar use case. This library allows you to run a background job that will run periodically, but for this use case the important feature is that if you pass a alwaysRunning parameter when scheduling the job, the app will keep running in the background even if the user closes it.
I configured Windows 2012R2 with IIS 8.5 and turned on the new suspend option.
According to the documentation the state is written to disk and resources freed up.
I have a site that is strong on SignalR, when the site is started there is always a never-exiting thread that keeps track of parameters of a game, users come to the site, play the game and the state is saved in the database.
Before when the site terminated it would load everything from database to restore the game-state, which worked fine but it took a REAL long time before the site would start (sometimes up to 5 minutes).
Now I configured the suspend option and it looks to work fine, site starts up in matter of seconds, BUT the never-ending thread.. has ended.
What could be the culprit? Is there an event that is called when the site goes into suspend or comes out of suspend instead of a cold startup?
It's not a good idea to run background threads within IIS. See http://haacked.com/archive/2011/10/16/the-dangers-of-implementing-recurring-background-tasks-in-asp-net.aspx/
Possible solution is to have a Windows Service (I recommend TopShelf for easy bootstrap) that runs your background operations and communicates with your ASP.NET via API.
See this question: IIS Background thread and SignalR
I am writing a Windows device driver using WDF (KMDF) for a USB3 device that transfers data in large chunks at a time. I've written a user-level application that tests this functionality, and for the most part, things work.
The problem I encounter is this: I have found that when I force-close (CTRL+C from a cmd window) the application mid-transfer, the on-going data transfer at the time of cancel immediately stops and the host seems to simply stop communicating with that endpoint. I have observed this on a USB bus trace. The requests return in the function driver as "STATUS_CANCELLED"
I have looked at other similar third party devices and ran their test applications with their drivers on those devices and found that when I kill their test applications mid-data-transfer, the transfer completes before the application closes.
My question:
How/when does Windows decide to kill in-flight requests when applications are closed?
Is there any way to mark the request as "uncancelable"? I've scoured the documentation but found nothing that suggests I need to do something to keep requests from being cancelled behind the scenes mid-transfer.
Any insights appreciated, thanks.
It's not about the device driver; it's about the way the console application handles the Ctrl-C event. The console application must trap the Ctrl-C event, and wait for the transfer to finish before it exits.