Fix bg starter bug, fix process output reading bug

Author: brugeman

README.md

@@ -4,7 +4,7 @@ This app includes bitcoind and bitcoin-cli compiled for Android. All command lin
 
 Run it for fun, or to help me experiment with NAT traversal and other new capabilities. Please do not rely on this app to serve your wallet or you might lose all your funds.
 
-Download on PlayStore, or build yourself. 
+Download on [PlayStore](https://play.google.com/store/apps/details?id=org.lndroid.bitcoincore), or build yourself. 
 
 To download the debug.log file from the app, use:
 

app/src/main/AndroidManifest.xml

@@ -5,6 +5,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
 
     <application
         android:allowBackup="true"

app/src/main/java/org/lndroid/bitcoincore/AutoStartWorker.java

@@ -6,6 +6,7 @@
 import android.content.Intent;
 import android.content.ServiceConnection;
 import android.content.SharedPreferences;
+import android.os.Handler;
 import android.os.IBinder;
 import android.os.Message;
 import android.os.Messenger;
@@ -31,12 +32,14 @@ public class AutoStartWorker extends androidx.work.ListenableWorker {
 
     private static final long WORK_INTERVAL = 15 * 60 * 1000; // 15 min
 
+    private Handler handler_;
     private CallbackToFutureAdapter.Completer<Result> completer_;
 
     private ServiceConnection connection_ = new ServiceConnection() {
         public void onServiceConnected(ComponentName className,
                                        IBinder service) {
 
+            Log.i(TAG, "sending start command");
             Messenger daemon = new Messenger(service);
             try {
                 Message msg = Message.obtain(null, DaemonService.MSG_START);
@@ -45,11 +48,21 @@ public void onServiceConnected(ComponentName className,
                 Log.e(TAG, "Failed to send to daemon: "+e.getLocalizedMessage());
             }
 
-            // we're done
-            AutoStartWorker.this.getApplicationContext().unbindService(connection_);
-
-            // ok
-            completer_.set(Result.success());
+            // pause to let daemon turn into foreground service so that
+            // OS wouldn't kill our process. we can't block the current thread
+            // bcs service will be started on the same thread
+            Log.i(TAG, "waiting for service to start");
+            handler_.postDelayed(new Runnable() {
+                @Override
+                public void run() {
+                    // we're done
+                    Log.i(TAG, "done");
+                    AutoStartWorker.this.getApplicationContext().unbindService(connection_);
+
+                    // ok
+                    completer_.set(Result.success());
+                }
+            }, 5000);
         }
 
         public void onServiceDisconnected(ComponentName className) {
@@ -63,6 +76,7 @@ public void onServiceDisconnected(ComponentName className) {
 
     public AutoStartWorker(@NonNull Context context, @NonNull WorkerParameters params) {
         super(context, params);
+        handler_ = new Handler(getApplicationContext().getMainLooper());
     }
 
     @NonNull

app/src/main/java/org/lndroid/bitcoincore/DaemonService.java

@@ -29,6 +29,12 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import java.io.BufferedInputStream;
+import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.lang.ref.WeakReference;
 import java.util.LinkedList;
 import java.util.ListIterator;
@@ -310,6 +316,28 @@ private void onDone(String result) {
 
         Log.i(TAG,"stopped");
 
+        // check if parent as killed and we have a detached child daemon now,
+        // this is bad and we should terminate the child ASAP
+/*        if (result.contains("Cannot obtain a lock on data directory")) {
+            // get pid of orphaned bitcoid
+            try {
+                java.lang.Process p = new ProcessBuilder("ps").start();
+                BufferedReader r = new BufferedReader(
+                        new InputStreamReader(p.getInputStream(), "UTF-8"));
+                String line;
+                while ((line = r.readLine()) != null) {
+                    if (line.contains("libbitcoind.so")) {
+
+                    }
+                }
+
+
+            } catch (IOException e) {
+                // do not loop/retry. just let
+                // bg worker retry starting the daemon
+            }
+        }
+*/
         // notify clients about status change
         notifyClients(MSG_STATUS, "Stopped");
 

app/src/main/java/org/lndroid/bitcoincore/ProcessWorker.java

@@ -5,11 +5,13 @@
 import android.widget.Toast;
 
 import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.lang.reflect.Field;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.Callable;
@@ -109,8 +111,8 @@ public void run() {
                     InputStream stdout = p.getInputStream();
                     InputStream stderr = p.getErrorStream();
 
-                    StringBuilder out = new StringBuilder();
-                    StringBuilder err = new StringBuilder();
+                    ByteArrayOutputStream out = new ByteArrayOutputStream();
+                    ByteArrayOutputStream err = new ByteArrayOutputStream();
 
                     byte[] buf = new byte[256];
                     boolean alive = true;
@@ -119,12 +121,12 @@ public void run() {
                             final int max = Math.min(stdout.available(), buf.length);
                             final int r = stdout.read(buf, 0, max);
                             if (!stdoutDevnull_)
-                                out.append(new String(buf, 0, r, "UTF-8"));
+                                out.write(buf, 0, r);
                         }
                         if (stderr.available() > 0) {
                             final int max = Math.min(stderr.available(), buf.length);
                             final int r = stderr.read(buf, 0, max);
-                            err.append(new String(buf, 0, r, "UTF-8"));
+                            err.write(buf, 0, r);
                         }
 
                         if (alive) {
@@ -140,10 +142,12 @@ public void run() {
                         }
                     }
 
+                    byte[] data;
                     if (p.exitValue() != 0)
-                        result_.set(err.toString());
+                        data = err.toByteArray();
                     else
-                        result_.set(out.toString());
+                        data = out.toByteArray();
+                    result_.set(new String(data, 0, data.length, StandardCharsets.UTF_8));
 
                     Log.i(TAG, "process "+command_.get(0)+" done "+p.exitValue());
                     Log.i(TAG, "result "+result_.get());