bindService never calls onServiceConnected

Question

My company produces an SDK delivered as an Android Library aar file. As part of that SDK, we define a service:

    <service
        android:name=".session.internal.ChatSession"
        android:description="@string/description"
        android:enabled="true"
        android:exported="false"
        android:label="Network communication service"
    />

This service is then started and bound by more code in the SDK:

public boolean bindService(final Runnable whenBound) {
    if (connection == null) {
        // Make sure the service is running
        boolean success = startService();
        if(BuildConfig.DEBUG && !success) {
            throw new AssertionError("startService failed");
        }

        connection = new ServiceConnection() {
            @Override
            public void onServiceConnected(ComponentName name, IBinder service) {
                chatSession = (IChatSession) service;
                if(whenBound != null) {
                    whenBound.run();
                }
            }

            @Override
            public void onServiceDisconnected(ComponentName name) {
                chatSession = null;
                connection = null;
            }
        };

        success = context.bindService(new Intent(context, ChatSession.class), connection, Context.BIND_IMPORTANT);
        if(BuildConfig.DEBUG && !success) {
            throw new AssertionError("bindService failed");
        }

        return success;
    }

    if(whenBound != null) {
        whenBound.run();
    }

    return true;
}

boolean startService() {
    boolean success = true;

    if(!isServiceRunning()) {
        success = context.startService(new Intent(context, ChatSession.class)) != null;
    }
    return success;
}

This all works fine as long as there is only one application using the SDK installed on the mobile device.

Since the service is both explicitly not exported (android:exported="false") and implicitly not exported (there is no <intent-filter> defined) we expected this to work fine with multiple applications installed as well, with each application getting it's own, private, instance of the service when bindService is called.

What actually happens is that neither application works any more as neither ServiceConnection.onServiceConnected or ServiceConnected.onServiceDisconnected is ever called, although the calls to context.startService and context.bindService both return success.

Once both applications have been installed, the only way to get either of them to work is to uninstall both, and then reinstall only one. It's not sufficient to uninstall either independently.

That's bizarre. If you ever create a pair of projects that reproduces this problem and post the source for it, let me know, as I would be interested in trying it out. — CommonsWare, Jul 29 '15 at 16:52
That is really weird. You are not using aidl services so there is no way to bind to service in other application — jakubbialkowski, Jul 29 '15 at 17:21
@jakubbialkowski AIDL has little to do with binding to local / remote Service — pskink, Jul 29 '15 at 17:28
@pskink yes I know that. I pointed that because I don't think that many applications with same sdk may cause such problem without aidl service — jakubbialkowski, Jul 29 '15 at 17:31

score 0 · Accepted Answer · answered Jul 29 '15 at 19:07

0

It turns out, the problem was actually this bit of code that was preventing the service from being started in the first place:

if(!isServiceRunning()) {
    success = context.startService(new Intent(context, ChatSession.class)) != null;
}

I had cribbed code for isServiceRunning that was incorrectly determining that the service was running based only on the name:

public boolean isServiceRunning() {
    ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    List<ActivityManager.RunningServiceInfo> services = manager.getRunningServices(Integer.MAX_VALUE);
    if(services == null) {
        return false;
    }
    for (ActivityManager.RunningServiceInfo service : services) {
        if (ChatSession.class.getName().equals(service.service.getClassName())) {
            return true;
        }
    }
    return false;
}

Replacing the if with:

        if (Process.myPid() == service.pid && ChatSession.class.getName().equals(service.service.getClassName())) {

seems to resolve the issue.

I'm still not thrilled with this as it seems like there should be a better way of checking.

answered Jul 29 '15 at 19:07

David Berry

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actually you can delete `isServiceRunning`, you dont need it at all: just call `startService` unconditionally – pskink Jul 30 '15 at 05:18
Thanks @pskink. I wasn't sure about that. Was going to try it and see. – David Berry Jul 30 '15 at 06:22
`startService` docs say: "... If this service is not already running, it will be instantiated and started (creating a process for it if needed); if it is running then it remains running. ... Note that calls to startService() are not nesting: no matter how many times you call startService(), a single call to stopService(Intent) will stop it. ..." – pskink Jul 30 '15 at 06:25
also, you can use BIND_AUTO_CREATE flag when `bindService` (so `startService` is not needed) unless you really want the service to survive and still be running after the client unbinds from the service – pskink Jul 30 '15 at 06:32
In this case, I actually want the service to persist even after all clients are unbound, so it seems like I have to explicitly start (and stop) the service. – David Berry Jul 30 '15 at 15:11
You can use flag START_STICKY in service to have service runninig with no clients – jakubbialkowski Jul 30 '15 at 16:05
@jakubbialkowski i'm afraid it doesn't work that way – pskink Jul 30 '15 at 16:29

bindService never calls onServiceConnected

1 Answers1