implemented startForeground(), with some reservation

NOTES

@@ -245,8 +245,69 @@ all of the off_t to off64_t and hope for the best.
 sftp and rsync work!  Not gonna bother testing scp on big files...
 
 
-XXX - Jared Stafford says startForeground() improves responsiveness
-substantially on Nkey Lime Pie
+October 1, 2016.
 
-XXX - if you remove it from the recent apps list, does it stop the service??
-XXX - support password-based logins?
+Jared Stafford told me startForeground() improves responsiveness on
+Nougat.  There had been a comment suggesting startForeground(), but I
+never got around to trying it because it has worked "well enough".  With
+Nougat, though, there is a definite tendency for SimpleSSHD to be
+non-responsive.  I'm not sure exactly what its cause is, but the symptom
+I notice most frequently is that the first ssh connection after a while
+will be delayed "a long time" - on the order of 10-30 seconds, or maybe
+indefinitely sometimes.  Oddly, a second connection can sometimes get
+through undelayed, even before the first connection does.  It is as if
+the fork() of process for the new connection is where the delay is, not
+in the listen() call.
+
+That's not overall too surprising, Nougat is a lot harsher about
+background processes as part of a Google push to reduce power consumption
+on idle devices.
+
+Another concern is related to a change back in July - sometimes the
+system will kill the sshd process for no good reason (maybe because they
+removed it from the recent apps list).  The remedy I settled on was to
+monitor for the sshd process dying from within the regular
+Android-managed process, and restart it.  I guess I didn't write down
+where in the documentation I found it, but Android seems expressly
+antagonistic to non-system-managed processes.  If they ever get more
+hard-assed about that, this whole idea goes out the window.
+
+Anyways, I implemented startForeground(), and I am unhappy that it
+requires a Notification. At API 7 (Android 2.1) those are really
+primitive.  For example, the PRIORITY_MIN behavior which will sometimes
+hide the notification is added in API 16 (Android 4.1).  So, I've got it
+with this stupid old-style notification, and it really doesn't look good,
+and it is always present.  That is not awesome.
+
+On the other hand, it's easy to block the notifications, and a few people
+have expressed an interest in a notification.
+
+It doesn't seem worth it to me to upgrade to a newer API just for the
+better notifications...  On the other hand, Google Play shows that I have
+862 users:
+    Android 7+  :  3.13%
+    Android 6+  : 37.47%
+    Android 5+  : 67.86%
+    Android 4.1+: 96.62%
+    Android 4.0+: 98.01%
+
+The oldest reported version is Android 2.3.
+
+So, there are a few people on very old versions, but actually SimpleSSHD
+is used on newer devices than the average app, which is the reverse of my
+typical trend.  So a few people would be negatively impacted, but not a
+very large number.  I could switch to multi-APK mode so that legacy users
+are just stuck with an unsupported back-version, which is probably what
+they truly want anyways..
+
+Anyways, I'm gonna use it with startForeground() and the notifications
+disabled for a while, and if I find it to be an improvement then I'll
+just make it so clicking on the notification goes to the app, update the
+doc, and then publish it.
+
+
+
+XXX - make clicking on the notification go to the app?
+
+
+XXX - support password-based logins for boot-strapping?

src/org/galexander/sshd/SimpleSSHDService.java

@@ -1,5 +1,6 @@
 package org.galexander.sshd;
 
+import android.app.Notification;
 import android.app.Service;
 import android.content.Intent;
 import android.content.Context;
@@ -31,15 +32,12 @@ public class SimpleSSHDService extends Service {
 		if ((intent == null) ||
 		    (!intent.getBooleanExtra("stop", false))) {
 			do_start();
-/* XXX - maybe we should call startForeground(), but then we'd have to make a
- * bogus notification... and START_STICKY seems to actually do a good job of
- * restarting us if we're killed...  */
+			do_foreground();
 			return START_STICKY;
 		} else {
 			stop_sshd();
+			stop_service();
 			SimpleSSHD.update_startstop();
-			stopSelf();
-/* XXX - need stopForeground() too ? */
 			return START_NOT_STICKY;
 		}
 	}
@@ -52,10 +50,17 @@ public class SimpleSSHDService extends Service {
 		 * the package is upgraded... so it's really pretty useless */
 	public void onDestroy() {
 		stop_sshd();
-		stopSelf();
+		stop_service();
 		super.onDestroy();
 	}
 
+	private void do_foreground() {
+		Notification n = new Notification(R.drawable.notification_icon,
+					"SimpleSSHD", 0);
+		n.tickerText = "SimpleSSHD";
+		startForeground(1, n);
+	}
+
 	public static boolean is_started() {
 		return (sshd_pid != 0);
 	}
@@ -71,6 +76,11 @@ public class SimpleSSHDService extends Service {
 		}
 	}
 
+	private void stop_service() {
+		stopSelf();
+		stopForeground(true);
+	}
+
 	private static void maybe_restart(int pid) {
 		boolean do_restart = false;
 		long now = System.currentTimeMillis();