Improve external process handling

app/src/main/java/org/purplei2p/i2pd/AbstractProcess.java

@@ -1,5 +1,7 @@
 package org.purplei2p.i2pd;
 
 public interface AbstractProcess {
-    void kill();
+    /** @param tr can be null
+     */
+    void kill(Throwable tr);
 }

app/src/main/java/org/purplei2p/i2pd/DaemonWrapper.java

@@ -153,13 +153,18 @@ public class DaemonWrapper {
         return getState().isStartedOkay();
     }
 
-    public synchronized void stopDaemon() {
+    public void stopDaemon() {
+        stopDaemon(null);
+    }
+
+    public synchronized void stopDaemon(final Throwable throwable) {
         if (isStartedOkay()) {
             try {
-                I2pdApi.stopDaemon();
+                I2pdApi.stopDaemon(throwable);
             } catch (Throwable tr) {
                 Log.e(TAG, "", tr);
             }
+            if (throwable != null) lastThrowable = throwable;
             setState(State.stopped);
         }
     }
@@ -179,7 +184,7 @@ public class DaemonWrapper {
                     String locale = getAppLocale();
                     Log.i(TAG, "setting webconsole language to " + locale);
 
-                    daemonStartResult = I2pdApi.startDaemon(ctx, i2pdpath, locale);
+                    daemonStartResult = I2pdApi.startDaemon(ctx, i2pdpath, locale, DaemonWrapper.this);
                     if ("ok".equals(daemonStartResult)) {
                         setState(State.startedOkay);
                     } else

app/src/main/java/org/purplei2p/i2pd/ExternalProcessImpl.java

@@ -3,17 +3,20 @@ package org.purplei2p.i2pd;
 import android.util.Log;
 
 public class ExternalProcessImpl implements AbstractProcess {
+    public static final String TAG = "ExtProcKill";
     private final int pid;
     public ExternalProcessImpl(int pid) {
         this.pid = pid;
     }
-    public void kill() {
+    public void kill(Throwable reasonThrowable) {
+        if(reasonThrowable!=null) Log.e(TAG,"reasonThrowable", reasonThrowable);
+        else Log.e(TAG,"reasonThrowable==null");
         try {
             Runtime.getRuntime().exec(new String[]{
                     "/system/bin/sh", "-c", "kill " + pid
             });
         }catch(Throwable tr){
-            Log.e("ExtProcKill","",tr);
+            Log.e(TAG,"",tr);
         }
     }
 }

app/src/main/java/org/purplei2p/i2pd/I2PDActivity.java

@@ -83,9 +83,12 @@ public class I2PDActivity extends Activity {
 //                    I2CPState.setChecked(I2pdApi.getI2CPState());
 //                }
 
+                final Throwable lastThrowable = daemon.getLastThrowable();
                 String startResultStr = DaemonWrapper.State.startFailed.equals(state) ? String.format(": %s", daemon.getDaemonStartResult()) : "";
+                String stopReasonStr = DaemonWrapper.State.stopped.equals(state) && lastThrowable != null ?
+                        String.format(": %s", lastThrowable) : "";
                 String graceStr = DaemonWrapper.State.gracefulShutdownInProgress.equals(state) ? String.format(": %s %s", formatGraceTimeRemaining(), getText(R.string.remaining)) : "";
-                textView.setText(String.format("%s%s%s", getText(state.getStatusStringResourceId()), startResultStr, graceStr));
+                textView.setText(String.format("%s%s%s%s", getText(state.getStatusStringResourceId()), startResultStr, graceStr, stopReasonStr));
             } catch (Throwable tr) {
                 Log.e(TAG,"error ignored",tr);
             }

app/src/main/java/org/purplei2p/i2pd/I2pdApi.java

@@ -29,19 +29,32 @@ public class I2pdApi {
      * returns error info if failed
      * returns "ok" if daemon initialized and started okay
      */
-    public static String startDaemon(Context ctx, String dataDir, String language){
+    public static String startDaemon(final Context ctx, final String dataDir, String language, final DaemonWrapper daemonWrapper){
         try {
             i2pdProcess = null;
             I2pdApi.dataDir = dataDir;
-            Process p = Runtime.getRuntime().exec(new String[]{
+            File pidFile = new File(dataDir, "i2pd.pid");
+            final Process p = Runtime.getRuntime().exec(new String[]{
                     ctx.getApplicationInfo().nativeLibraryDir + "/libi2pd.so",
-                    "--datadir=" + dataDir
+                    "--datadir=" + dataDir,
+                    "--pidfile=" + pidFile.getAbsolutePath()
             });
-            i2pdProcess = () -> {
+            i2pdProcess = (Throwable tr) -> {
                 try {
-                    p.destroy();
-                } catch (Throwable tr) {
-                    Log.e(TAG, "", tr);
+                    if (p.isAlive()) {
+                        if (tr != null)
+                            Log.e(TAG, "destroying the subprocess \"i2pd\", reason: " + tr, tr);
+                        else
+                            Log.e(TAG, "destroying the subprocess \"i2pd\", reason: null");
+                        p.destroy();
+                    }else{
+                        if (tr != null)
+                            Log.e(TAG, "skipping destroy of a dead subprocess \"i2pd\", reason: " + tr, tr);
+                        else
+                            Log.e(TAG, "skipping destroy of a dead subprocess \"i2pd\", reason: null");
+                    }
+                } catch (Throwable tr2) {
+                    Log.e(TAG, "", tr2);
                 }
             };
             new Thread(() -> {
@@ -60,7 +73,7 @@ public class I2pdApi {
                 } catch (Throwable tr) {
                     Log.e(TAG, "", tr);
                 }
-            }, "i2pd-stdout");
+            }, "i2pd-stdout").start();
             new Thread(() -> {
                 try {
                     try (BufferedInputStream bis = new BufferedInputStream(p.getErrorStream())) {
@@ -77,7 +90,29 @@ public class I2pdApi {
                 } catch (Throwable tr) {
                     Log.e(TAG, "", tr);
                 }
-            }, "i2pd-stderr");
+                try {
+                    p.waitFor();
+                } catch (Throwable tr) {
+                    Log.e(TAG, "", tr);
+                }
+                final int errorLevel = p.exitValue();
+                Log.i(TAG, "i2pd process exit code: " + errorLevel);
+                final Throwable trReason = new Throwable("subprocess \"i2pd\" exited with exit code " + errorLevel);
+                try {
+                    stopDaemon(trReason);
+                    Log.i(TAG, "stopDaemon completed");
+                } catch (Throwable tr) {
+                    Log.e(TAG, "Called stopDaemon, got exception", tr);
+                }
+                new Thread(() -> {
+                    try {
+                        daemonWrapper.stopDaemon(trReason);
+                        Log.i(TAG, "daemonWrapper.stopDaemon completed");
+                    } catch (Throwable tr) {
+                        Log.e(TAG, "Called daemonWrapper.stopDaemon, got exception", tr);
+                    }
+                }, "stop the daemonWrapper thread").start();
+            }, "i2pd-stderr").start();
             new Thread(() -> {
                 try {
                     try (BufferedOutputStream bos = new BufferedOutputStream(p.getOutputStream())) {
@@ -94,7 +129,7 @@ public class I2pdApi {
                 } catch (Throwable tr) {
                     Log.e(TAG, "", tr);
                 }
-            }, "i2pd-stdin");
+            }, "i2pd-stdin").start();
             return "ok";
         } catch (Throwable tr) {
             Log.e(TAG, "", tr);
@@ -102,10 +137,10 @@ public class I2pdApi {
         }
     }
 
-    public static void stopDaemon(){
+    public static void stopDaemon(Throwable tr){
         AbstractProcess p = i2pdProcess;
         if (p != null) {
-            p.kill();
+            p.kill(tr);
             i2pdProcess = null;
         }
     }