Propagate exception stacktrace via AndroidFuture IPC (49b8cdf5) · Commits · e / os / android_frameworks_base

core/java/android/os/Parcel.java

+59 −47

Original line number	Diff line number	Diff line
		@@ -1886,6 +1886,43 @@ public final class Parcel {
		public final void writeException(@NonNull Exception e) {
		AppOpsManager.prefixParcelWithAppOpsIfNeeded(this);

		int code = getExceptionCode(e);
		writeInt(code);
		StrictMode.clearGatheredViolations();
		if (code == 0) {
		if (e instanceof RuntimeException) {
		throw (RuntimeException) e;
		}
		throw new RuntimeException(e);
		}
		writeString(e.getMessage());
		final long timeNow = sParcelExceptionStackTrace ? SystemClock.elapsedRealtime() : 0;
		if (sParcelExceptionStackTrace && (timeNow - sLastWriteExceptionStackTrace
		> WRITE_EXCEPTION_STACK_TRACE_THRESHOLD_MS)) {
		sLastWriteExceptionStackTrace = timeNow;
		writeStackTrace(e);
		} else {
		writeInt(0);
		}
		switch (code) {
		case EX_SERVICE_SPECIFIC:
		writeInt(((ServiceSpecificException) e).errorCode);
		break;
		case EX_PARCELABLE:
		// Write parceled exception prefixed by length
		final int sizePosition = dataPosition();
		writeInt(0);
		writeParcelable((Parcelable) e, Parcelable.PARCELABLE_WRITE_RETURN_VALUE);
		final int payloadPosition = dataPosition();
		setDataPosition(sizePosition);
		writeInt(payloadPosition - sizePosition);
		setDataPosition(payloadPosition);
		break;
		}
		}

		/** @hide */
		public static int getExceptionCode(@NonNull Throwable e) {
		int code = 0;
		if (e instanceof Parcelable
		&& (e.getClass().getClassLoader() == Parcelable.class.getClassLoader())) {
		@@ -1909,19 +1946,11 @@ public final class Parcel {
		} else if (e instanceof ServiceSpecificException) {
		code = EX_SERVICE_SPECIFIC;
		}
		writeInt(code);
		StrictMode.clearGatheredViolations();
		if (code == 0) {
		if (e instanceof RuntimeException) {
		throw (RuntimeException) e;
		}
		throw new RuntimeException(e);
		return code;
		}
		writeString(e.getMessage());
		final long timeNow = sParcelExceptionStackTrace ? SystemClock.elapsedRealtime() : 0;
		if (sParcelExceptionStackTrace && (timeNow - sLastWriteExceptionStackTrace
		> WRITE_EXCEPTION_STACK_TRACE_THRESHOLD_MS)) {
		sLastWriteExceptionStackTrace = timeNow;

		/** @hide */
		public void writeStackTrace(@NonNull Throwable e) {
		final int sizePosition = dataPosition();
		writeInt(0); // Header size will be filled in later
		StackTraceElement[] stackTrace = e.getStackTrace();
		@@ -1936,24 +1965,6 @@ public final class Parcel {
		// Write stack trace header size. Used in native side to skip the header
		writeInt(payloadPosition - sizePosition);
		setDataPosition(payloadPosition);
		} else {
		writeInt(0);
		}
		switch (code) {
		case EX_SERVICE_SPECIFIC:
		writeInt(((ServiceSpecificException) e).errorCode);
		break;
		case EX_PARCELABLE:
		// Write parceled exception prefixed by length
		final int sizePosition = dataPosition();
		writeInt(0);
		writeParcelable((Parcelable) e, Parcelable.PARCELABLE_WRITE_RETURN_VALUE);
		final int payloadPosition = dataPosition();
		setDataPosition(sizePosition);
		writeInt(payloadPosition - sizePosition);
		setDataPosition(payloadPosition);
		break;
		}
		}

		/**
		@@ -2069,14 +2080,7 @@ public final class Parcel {
		if (remoteStackTrace != null) {
		RemoteException cause = new RemoteException(
		"Remote stack trace:\n" + remoteStackTrace, null, false, false);
		try {
		Throwable rootCause = ExceptionUtils.getRootCause(e);
		if (rootCause != null) {
		rootCause.initCause(cause);
		}
		} catch (RuntimeException ex) {
		Log.e(TAG, "Cannot set cause " + cause + " for " + e, ex);
		}
		ExceptionUtils.appendCause(e, cause);
		}
		SneakyThrow.sneakyThrow(e);
		}
		@@ -2088,6 +2092,14 @@ public final class Parcel {
		* @param msg The exception message.
		*/
		private Exception createException(int code, String msg) {
		Exception exception = createExceptionOrNull(code, msg);
		return exception != null
		? exception
		: new RuntimeException("Unknown exception code: " + code + " msg " + msg);
		}

		/** @hide */
		public Exception createExceptionOrNull(int code, String msg) {
		switch (code) {
		case EX_PARCELABLE:
		if (readInt() > 0) {
		@@ -2111,9 +2123,9 @@ public final class Parcel {
		return new UnsupportedOperationException(msg);
		case EX_SERVICE_SPECIFIC:
		return new ServiceSpecificException(readInt(), msg);
		default:
		return null;
		}
		return new RuntimeException("Unknown exception code: " + code
		+ " msg " + msg);
		}

		/**

core/java/com/android/internal/infra/AndroidFuture.java

+66 −24

Original line number	Diff line number	Diff line
		@@ -75,6 +75,7 @@ public class AndroidFuture<T> extends CompletableFuture<T> implements Parcelable

		private static final boolean DEBUG = false;
		private static final String LOG_TAG = AndroidFuture.class.getSimpleName();
		private static final StackTraceElement[] EMPTY_STACK_TRACE = new StackTraceElement[0];

		private final @NonNull Object mLock = new Object();
		@GuardedBy("mLock")
		@@ -95,15 +96,7 @@ public class AndroidFuture<T> extends CompletableFuture<T> implements Parcelable
		// Done
		if (in.readBoolean()) {
		// Failed
		try {
		in.readException();
		} catch (Throwable e) {
		completeExceptionally(e);
		}
		if (!isCompletedExceptionally()) {
		throw new IllegalStateException(
		"Error unparceling AndroidFuture: exception expected");
		}
		completeExceptionally(unparcelException(in));
		} else {
		// Success
		complete((T) in.readValue(null));
		@@ -512,14 +505,9 @@ public class AndroidFuture<T> extends CompletableFuture<T> implements Parcelable
		T result;
		try {
		result = get();
		} catch (Exception t) {
		// Exceptions coming out of get() are wrapped in ExecutionException, which is not
		// handled by Parcel.
		if (t instanceof ExecutionException && t.getCause() instanceof Exception) {
		t = (Exception) t.getCause();
		}
		} catch (Throwable t) {
		dest.writeBoolean(true);
		dest.writeException(t);
		parcelException(dest, unwrapExecutionException(t));
		return;
		}
		dest.writeBoolean(false);
		@@ -528,22 +516,76 @@ public class AndroidFuture<T> extends CompletableFuture<T> implements Parcelable
		dest.writeStrongBinder(new IAndroidFuture.Stub() {
		@Override
		public void complete(AndroidFuture resultContainer) {
		boolean changed;
		try {
		AndroidFuture.this.complete((T) resultContainer.get());
		changed = AndroidFuture.this.complete((T) resultContainer.get());
		} catch (Throwable t) {
		// If resultContainer was completed exceptionally, get() wraps the
		// underlying exception in an ExecutionException. Unwrap it now to avoid
		// double-layering ExecutionExceptions.
		if (t instanceof ExecutionException && t.getCause() != null) {
		t = t.getCause();
		changed = completeExceptionally(unwrapExecutionException(t));
		}
		completeExceptionally(t);
		if (!changed) {
		Log.w(LOG_TAG, "Remote result " + resultContainer
		+ " ignored, as local future is already completed: "
		+ AndroidFuture.this);
		}
		}
		}.asBinder());
		}
		}

		/**
		* Exceptions coming out of {@link #get} are wrapped in {@link ExecutionException}
		*/
		Throwable unwrapExecutionException(Throwable t) {
		return t instanceof ExecutionException
		? t.getCause()
		: t;
		}

		/**
		* Alternative to {@link Parcel#writeException} that stores the stack trace, in a
		* way consistent with the binder IPC exception propagation behavior.
		*/
		private static void parcelException(Parcel p, @Nullable Throwable t) {
		p.writeBoolean(t == null);
		if (t == null) {
		return;
		}

		p.writeInt(Parcel.getExceptionCode(t));
		p.writeString(t.getClass().getName());
		p.writeString(t.getMessage());
		p.writeStackTrace(t);
		parcelException(p, t.getCause());
		}

		/**
		* @see #parcelException
		*/
		private static @Nullable Throwable unparcelException(Parcel p) {
		if (p.readBoolean()) {
		return null;
		}

		int exCode = p.readInt();
		String cls = p.readString();
		String msg = p.readString();
		String stackTrace = p.readInt() > 0 ? p.readString() : "\t<stack trace unavailable>";
		msg += "\n" + stackTrace;

		Exception ex = p.createExceptionOrNull(exCode, msg);
		if (ex == null) {
		ex = new RuntimeException(cls + ": " + msg);
		}
		ex.setStackTrace(EMPTY_STACK_TRACE);

		Throwable cause = unparcelException(p);
		if (cause != null) {
		ex.initCause(ex);
		}

		return ex;
		}

		@Override
		public int describeContents() {
		return 0;

core/tests/coretests/src/com/android/internal/infra/AndroidFutureTest.java

+6 −1

Original line number	Diff line number	Diff line
		@@ -121,7 +121,12 @@ public class AndroidFutureTest {
		AndroidFuture future2 = AndroidFuture.CREATOR.createFromParcel(parcel);
		ExecutionException executionException =
		expectThrows(ExecutionException.class, future2::get);
		assertThat(executionException.getCause()).isInstanceOf(UnsupportedOperationException.class);

		Throwable cause = executionException.getCause();
		String msg = cause.getMessage();
		assertThat(cause).isInstanceOf(UnsupportedOperationException.class);
		assertThat(msg).contains(getClass().getName());
		assertThat(msg).contains("testWriteToParcel_Exception");
		}

		@Test