Add getExtension to android.os.IBinder interface
Provide a mechanism to extend and customize a binder interface without
having to modify the original (base) interface.
See the full motivation here: aosp/1099664
Bug: 147834064
Test: atest FrameworksCoreTests:BinderTest FrameworksCoreTests:BinderProxyTest
Change-Id: Idd3595b1302cf7ac0590d064e795ba0b75811af6
diff --git a/core/java/android/os/Binder.java b/core/java/android/os/Binder.java
index 9c4a36f..2fa75f1 100644
--- a/core/java/android/os/Binder.java
+++ b/core/java/android/os/Binder.java
@@ -913,6 +913,18 @@
resultReceiver.send(0, null);
}
+ /** @hide */
+ @Override
+ public final native @Nullable IBinder getExtension();
+
+ /**
+ * Set the binder extension.
+ * This should be called immediately when the object is created.
+ *
+ * @hide
+ */
+ public final native void setExtension(@Nullable IBinder extension);
+
/**
* Default implementation rewinds the parcels and calls onTransact. On
* the remote side, transact calls into the binder to do the IPC.
diff --git a/core/java/android/os/BinderProxy.java b/core/java/android/os/BinderProxy.java
index c35b05f..a26bd39 100644
--- a/core/java/android/os/BinderProxy.java
+++ b/core/java/android/os/BinderProxy.java
@@ -454,6 +454,10 @@
return null;
}
+ /** @hide */
+ @Override
+ public native @Nullable IBinder getExtension() throws RemoteException;
+
/**
* Perform a binder transaction on a proxy.
*
diff --git a/core/java/android/os/IBinder.java b/core/java/android/os/IBinder.java
index d9ed327..c43644d 100644
--- a/core/java/android/os/IBinder.java
+++ b/core/java/android/os/IBinder.java
@@ -244,6 +244,18 @@
@NonNull ResultReceiver resultReceiver) throws RemoteException;
/**
+ * Get the binder extension of this binder interface.
+ * This allows one to customize an interface without having to modify the original interface.
+ *
+ * @return null if don't have binder extension
+ * @throws RemoteException
+ * @hide
+ */
+ public default @Nullable IBinder getExtension() throws RemoteException {
+ throw new IllegalStateException("Method is not implemented");
+ }
+
+ /**
* Perform a generic operation with the object.
*
* @param code The action to perform. This should
diff --git a/core/jni/android_util_Binder.cpp b/core/jni/android_util_Binder.cpp
index a236f31..079c265 100644
--- a/core/jni/android_util_Binder.cpp
+++ b/core/jni/android_util_Binder.cpp
@@ -463,6 +463,9 @@
if (mVintf) {
::android::internal::Stability::markVintf(b.get());
}
+ if (mExtension != nullptr) {
+ b.get()->setExtension(mExtension);
+ }
mBinder = b;
ALOGV("Creating JavaBinder %p (refs %p) for Object %p, weakCount=%" PRId32 "\n",
b.get(), b->getWeakRefs(), obj, b->getWeakRefs()->getWeakCount());
@@ -481,6 +484,24 @@
mVintf = true;
}
+ sp<IBinder> getExtension() {
+ AutoMutex _l(mLock);
+ sp<JavaBBinder> b = mBinder.promote();
+ if (b != nullptr) {
+ return b.get()->getExtension();
+ }
+ return mExtension;
+ }
+
+ void setExtension(const sp<IBinder>& extension) {
+ AutoMutex _l(mLock);
+ mExtension = extension;
+ sp<JavaBBinder> b = mBinder.promote();
+ if (b != nullptr) {
+ b.get()->setExtension(mExtension);
+ }
+ }
+
private:
Mutex mLock;
wp<JavaBBinder> mBinder;
@@ -489,6 +510,8 @@
// is too much binder state here, we can think about making JavaBBinder an
// sp here (avoid recreating it)
bool mVintf = false;
+
+ sp<IBinder> mExtension;
};
// ----------------------------------------------------------------------------
@@ -1033,6 +1056,17 @@
return javaObjectForIBinder(env, service);
}
+static jobject android_os_Binder_getExtension(JNIEnv* env, jobject obj) {
+ JavaBBinderHolder* jbh = (JavaBBinderHolder*) env->GetLongField(obj, gBinderOffsets.mObject);
+ return javaObjectForIBinder(env, jbh->getExtension());
+}
+
+static void android_os_Binder_setExtension(JNIEnv* env, jobject obj, jobject extensionObject) {
+ JavaBBinderHolder* jbh = (JavaBBinderHolder*) env->GetLongField(obj, gBinderOffsets.mObject);
+ sp<IBinder> extension = ibinderForJavaObject(env, extensionObject);
+ jbh->setExtension(extension);
+}
+
// ----------------------------------------------------------------------------
static const JNINativeMethod gBinderMethods[] = {
@@ -1062,7 +1096,9 @@
{ "getNativeBBinderHolder", "()J", (void*)android_os_Binder_getNativeBBinderHolder },
{ "getNativeFinalizer", "()J", (void*)android_os_Binder_getNativeFinalizer },
{ "blockUntilThreadAvailable", "()V", (void*)android_os_Binder_blockUntilThreadAvailable },
- { "waitForService", "(Ljava/lang/String;)Landroid/os/IBinder;", (void*)android_os_Binder_waitForService }
+ { "waitForService", "(Ljava/lang/String;)Landroid/os/IBinder;", (void*)android_os_Binder_waitForService },
+ { "getExtension", "()Landroid/os/IBinder;", (void*)android_os_Binder_getExtension },
+ { "setExtension", "(Landroid/os/IBinder;)V", (void*)android_os_Binder_setExtension },
};
const char* const kBinderPathName = "android/os/Binder";
@@ -1502,6 +1538,21 @@
return (jlong) BinderProxy_destroy;
}
+static jobject android_os_BinderProxy_getExtension(JNIEnv* env, jobject obj) {
+ IBinder* binder = getBPNativeData(env, obj)->mObject.get();
+ if (binder == nullptr) {
+ jniThrowException(env, "java/lang/IllegalStateException", "Native IBinder is null");
+ return nullptr;
+ }
+ sp<IBinder> extension;
+ status_t err = binder->getExtension(&extension);
+ if (err != OK) {
+ signalExceptionForError(env, obj, err, true /* canThrowRemoteException */);
+ return nullptr;
+ }
+ return javaObjectForIBinder(env, extension);
+}
+
// ----------------------------------------------------------------------------
static const JNINativeMethod gBinderProxyMethods[] = {
@@ -1513,6 +1564,7 @@
{"linkToDeath", "(Landroid/os/IBinder$DeathRecipient;I)V", (void*)android_os_BinderProxy_linkToDeath},
{"unlinkToDeath", "(Landroid/os/IBinder$DeathRecipient;I)Z", (void*)android_os_BinderProxy_unlinkToDeath},
{"getNativeFinalizer", "()J", (void*)android_os_BinderProxy_getNativeFinalizer},
+ {"getExtension", "()Landroid/os/IBinder;", (void*)android_os_BinderProxy_getExtension},
};
const char* const kBinderProxyPathName = "android/os/BinderProxy";
diff --git a/core/tests/coretests/AndroidManifest.xml b/core/tests/coretests/AndroidManifest.xml
index 9955c51..a9e0a77 100644
--- a/core/tests/coretests/AndroidManifest.xml
+++ b/core/tests/coretests/AndroidManifest.xml
@@ -1340,6 +1340,10 @@
<service android:name="android.os.BinderWorkSourceNestedService"
android:process=":BinderWorkSourceNestedService" />
+ <!-- Used by BinderProxyTest -->
+ <service android:name="android.os.BinderProxyService"
+ android:process=":BinderProxyService" />
+
<!-- Application components used for search manager tests -->
<activity android:name="android.app.activity.SearchableActivity"
diff --git a/core/tests/coretests/src/android/os/BinderProxyService.java b/core/tests/coretests/src/android/os/BinderProxyService.java
new file mode 100644
index 0000000..bf1fbc5
--- /dev/null
+++ b/core/tests/coretests/src/android/os/BinderProxyService.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.os;
+
+import android.app.Service;
+import android.content.Intent;
+
+public class BinderProxyService extends Service {
+ private final Binder mBinder = new Binder();
+
+ @Override
+ public void onCreate() {
+ super.onCreate();
+ mBinder.setExtension(new Binder());
+ }
+
+ @Override
+ public IBinder onBind(Intent intent) {
+ return mBinder;
+ }
+}
diff --git a/core/tests/coretests/src/android/os/BinderProxyTest.java b/core/tests/coretests/src/android/os/BinderProxyTest.java
index aceda2d..3567d17 100644
--- a/core/tests/coretests/src/android/os/BinderProxyTest.java
+++ b/core/tests/coretests/src/android/os/BinderProxyTest.java
@@ -17,11 +17,17 @@
package android.os;
import android.annotation.Nullable;
+import android.content.ComponentName;
import android.content.Context;
+import android.content.Intent;
+import android.content.ServiceConnection;
import android.test.AndroidTestCase;
import androidx.test.filters.MediumTest;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
public class BinderProxyTest extends AndroidTestCase {
private static class CountingListener implements Binder.ProxyTransactListener {
int mStartedCount;
@@ -86,4 +92,41 @@
// Check it does not throw..
mPowerManager.isInteractive();
}
+
+ private IBinder mRemoteBinder = null;
+
+ @MediumTest
+ public void testGetExtension() throws Exception {
+ final CountDownLatch bindLatch = new CountDownLatch(1);
+ ServiceConnection connection =
+ new ServiceConnection() {
+ @Override
+ public void onServiceConnected(ComponentName name, IBinder service) {
+ mRemoteBinder = service;
+ bindLatch.countDown();
+ }
+
+ @Override
+ public void onServiceDisconnected(ComponentName name) {}
+ };
+ try {
+ mContext.bindService(
+ new Intent(mContext, BinderProxyService.class),
+ connection,
+ Context.BIND_AUTO_CREATE);
+ if (!bindLatch.await(500, TimeUnit.MILLISECONDS)) {
+ fail(
+ "Timed out while binding service: "
+ + BinderProxyService.class.getSimpleName());
+ }
+ assertTrue(mRemoteBinder instanceof BinderProxy);
+ assertNotNull(mRemoteBinder);
+
+ IBinder extension = mRemoteBinder.getExtension();
+ assertNotNull(extension);
+ assertTrue(extension.pingBinder());
+ } finally {
+ mContext.unbindService(connection);
+ }
+ }
}
diff --git a/core/tests/coretests/src/android/os/BinderTest.java b/core/tests/coretests/src/android/os/BinderTest.java
index a354195..99dbe64 100644
--- a/core/tests/coretests/src/android/os/BinderTest.java
+++ b/core/tests/coretests/src/android/os/BinderTest.java
@@ -52,4 +52,18 @@
} catch (IllegalStateException expected) {
}
}
+
+ @SmallTest
+ public void testGetExtension() throws Exception {
+ Binder binder = new Binder();
+ assertNull(binder.getExtension());
+
+ IBinder extension = new Binder();
+ binder.setExtension(extension);
+ assertNotNull(binder.getExtension());
+ assertSame(binder.getExtension(), extension);
+
+ binder.setExtension(null);
+ assertNull(binder.getExtension());
+ }
}