Bind to androidx.test.services.SpeakEasyService to mitigate LMK kills.

services/CHANGELOG.md

@@ -6,6 +6,9 @@
 
 **Bug Fixes**
 
+* Make ShellExecutor more resilient to low memory conditions by binding to
+  androidx.test.services.SpeakEasyService
+
 **New Features**
 
 **Breaking Changes**

services/shellexecutor/java/androidx/test/services/shellexecutor/ShellCommandClient.java

@@ -30,6 +30,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * Client for the ShellCommandExecutor service, to allow an instrumentation to executes a shell
@@ -44,6 +45,7 @@
 final class ShellCommandClient {
 
   private static final String TAG = "ShellCommandClient";
+  private static final ConcurrentHashMap<String, Command> stubCache = new ConcurrentHashMap<>();
 
   private ShellCommandClient() {
     // Should not be initialized
@@ -88,25 +90,28 @@ public static synchronized InputStream execOnServer(
       shellEnv = new HashMap<>();
     }
 
-    FindResult result;
-
-    try {
-      result = BlockingFind.getResult(Looper.getMainLooper(), context, secret);
-      if (!result.found) {
-        Log.e(TAG, "Couldn't find a published binder");
+    Command commandStub = stubCache.get(secret);
+    if (commandStub == null || !commandStub.asBinder().isBinderAlive()) {
+      FindResult result;
+      try {
+        result = BlockingFind.getResult(Looper.getMainLooper(), context, secret);
+        if (!result.found) {
+          Log.e(TAG, "Couldn't find a published binder");
+          throw new ClientNotConnected(
+              "Couldn't find a binder published by androidx.test.services. It is very likely that"
+                  + " androidx.test.services was killed, which is usually due to low memory"
+                  + " conditions. Consider switching to a device with more memory.");
+        }
+      } catch (InterruptedException e) {
         throw new ClientNotConnected(
-            "Couldn't find a binder published by androidx.test.services. It is very likely that"
-                + " androidx.test.services was killed, which is usually due to low memory"
-                + " conditions. Consider switching to a device with more memory.");
+            "Search for an androidx.test.services binder was interrupted", e);
       }
-    } catch (InterruptedException e) {
-      throw new ClientNotConnected(
-          "Search for an androidx.test.services binder was interrupted", e);
+      commandStub = Command.Stub.asInterface(result.binder);
+      stubCache.put(secret, commandStub);
     }
 
     ParcelFileDescriptor[] pipe = ParcelFileDescriptor.createPipe();
 
-    Command commandStub = Command.Stub.asInterface(result.binder);
     // Only use timeout version if timeout is greater than 0
     if (timeoutMs > 0L) {
       // NOTICE: this is not be supported on older versions of the Command server.

services/speakeasy/java/androidx/test/services/speakeasy/client/AppConnection.java

@@ -16,16 +16,20 @@
 
 package androidx.test.services.speakeasy.client;
 
+import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
+import android.content.ServiceConnection;
 import android.os.Build;
 import android.os.IBinder;
+import android.util.Log;
 import androidx.test.services.speakeasy.SpeakEasyProtocol;
 import java.security.SecureRandom;
 import java.util.Random;
 
 /** Allows callers to access the speakeasy binder registry when they have a Context. */
 public final class AppConnection implements Connection {
+  private static final String TAG = "AppConnection";
   private static final String PACKAGE_NAME = "androidx.test.services";
   static final String SERVICE =
       "androidx.test.services.speakeasy.server.SpeakEasyService";
@@ -45,11 +49,36 @@ public AppConnection(Context context) {
     this.random = checkNotNull(random);
   }
 
+  private static final ServiceConnection serviceConnection =
+      new ServiceConnection() {
+        @Override
+        public void onServiceConnected(ComponentName name, IBinder service) {}
+
+        @Override
+        public void onServiceDisconnected(ComponentName name) {}
+      };
+  private static boolean isBound = false;
+
+  private synchronized void ensureBound() {
+    if (!isBound) {
+      try {
+        isBound =
+            context.bindService(
+                makeIntent(),
+                serviceConnection,
+                Context.BIND_AUTO_CREATE | Context.BIND_IMPORTANT | Context.BIND_ABOVE_CLIENT);
+      } catch (SecurityException | IllegalArgumentException e) {
+        Log.w(TAG, "Failed to bind to SpeakEasyService", e);
+      }
+    }
+  }
+
   @Override
   public void publish(IBinder binder, PublishResultReceiver rr) {
     checkNotNull(binder);
     checkNotNull(rr);
 
+    ensureBound();
     String key = Long.toHexString(random.nextLong());
     Intent intent = makeIntent();
     intent.putExtras(SpeakEasyProtocol.Publish.asBundle(key, binder, rr));
@@ -60,6 +89,8 @@ public void publish(IBinder binder, PublishResultReceiver rr) {
   public void find(String key, FindResultReceiver rr) {
     checkNotNull(key);
     checkNotNull(rr);
+
+    ensureBound();
     Intent intent = makeIntent();
     intent.putExtras(SpeakEasyProtocol.Find.asBundle(key, rr));
     startForegroundService(context, intent);

services/speakeasy/java/androidx/test/services/speakeasy/server/SpeakEasyService.java

@@ -25,6 +25,7 @@
 import android.app.Service;
 import android.content.Context;
 import android.content.Intent;
+import android.os.Binder;
 import android.os.Build;
 import android.os.Handler;
 import android.os.HandlerThread;
@@ -72,7 +73,7 @@ public void onStart(Intent intent, int id) {
   @Override
   public int onStartCommand(Intent intent, int flags, int startId) {
     onStart(intent, startId);
-    return START_NOT_STICKY;
+    return START_STICKY;
   }
 
   @Override
@@ -108,6 +109,9 @@ public void run() {
   }
 
   private void serveIntent(Intent in, int startId) {
+    if (in == null || in.getExtras() == null) {
+      return;
+    }
     SpeakEasyProtocol sep = SpeakEasyProtocol.fromBundle(in.getExtras());
     if (null == sep) {
       return;
@@ -148,9 +152,14 @@ private void serveIntent(Intent in, int startId) {
     }
   }
 
+  private final IBinder binder = new Binder();
+
   @Override
   public IBinder onBind(Intent i) {
-    return null;
+    if (i != null && i.getExtras() != null) {
+      serveIntent(i, -1);
+    }
+    return binder;
   }
 
   private static class DeathCallback implements SpeakEasy.BinderDeathCallback {