Merge "Fix cancellation race problem for aysnc DNS API" (1859ae7e) · Commits · e / os / android_frameworks_base

core/java/android/net/DnsResolver.java

+36 −26

Original line number	Diff line number	Diff line
		@@ -205,6 +205,7 @@ public final class DnsResolver {
		if (cancellationSignal != null && cancellationSignal.isCanceled()) {
		return;
		}
		final Object lock = new Object();
		final FileDescriptor queryfd;
		try {
		queryfd = resNetworkSend((network != null
		@@ -214,8 +215,8 @@ public final class DnsResolver {
		return;
		}

		maybeAddCancellationSignal(cancellationSignal, queryfd);
		registerFDListener(executor, queryfd, callback);
		maybeAddCancellationSignal(cancellationSignal, queryfd, lock);
		registerFDListener(executor, queryfd, callback, cancellationSignal, lock);
		}

		/**
		@@ -242,6 +243,7 @@ public final class DnsResolver {
		if (cancellationSignal != null && cancellationSignal.isCanceled()) {
		return;
		}
		final Object lock = new Object();
		final FileDescriptor queryfd;
		try {
		queryfd = resNetworkQuery((network != null
		@@ -251,17 +253,22 @@ public final class DnsResolver {
		return;
		}

		maybeAddCancellationSignal(cancellationSignal, queryfd);
		registerFDListener(executor, queryfd, callback);
		maybeAddCancellationSignal(cancellationSignal, queryfd, lock);
		registerFDListener(executor, queryfd, callback, cancellationSignal, lock);
		}

		private <T> void registerFDListener(@NonNull Executor executor,
		@NonNull FileDescriptor queryfd, @NonNull AnswerCallback<T> answerCallback) {
		@NonNull FileDescriptor queryfd, @NonNull AnswerCallback<T> answerCallback,
		@Nullable CancellationSignal cancellationSignal, @NonNull Object lock) {
		Looper.getMainLooper().getQueue().addOnFileDescriptorEventListener(
		queryfd,
		FD_EVENTS,
		(fd, events) -> {
		executor.execute(() -> {
		synchronized (lock) {
		if (cancellationSignal != null && cancellationSignal.isCanceled()) {
		return;
		}
		byte[] answerbuf = null;
		try {
		answerbuf = resNetworkResult(fd);
		@@ -277,6 +284,7 @@ public final class DnsResolver {
		} catch (ParseException e) {
		answerCallback.onParseException(e);
		}
		}
		});
		// Unregister this fd listener
		return 0;
		@@ -284,13 +292,15 @@ public final class DnsResolver {
		}

		private void maybeAddCancellationSignal(@Nullable CancellationSignal cancellationSignal,
		@NonNull FileDescriptor queryfd) {
		@NonNull FileDescriptor queryfd, @NonNull Object lock) {
		if (cancellationSignal == null) return;
		cancellationSignal.setOnCancelListener(
		() -> {
		cancellationSignal.setOnCancelListener(() -> {
		synchronized (lock) {
		if (!queryfd.valid()) return;
		Looper.getMainLooper().getQueue()
		.removeOnFileDescriptorEventListener(queryfd);
		resNetworkCancel(queryfd);
		}
		});
		}

core/jni/android_net_NetUtils.cpp

+2 −0

Original line number	Diff line number	Diff line
		@@ -470,6 +470,7 @@ static jbyteArray android_net_utils_resNetworkResult(JNIEnv *env, jobject thiz,
		std::vector<uint8_t> buf(MAXPACKETSIZE, 0);

		int res = resNetworkResult(fd, &rcode, buf.data(), MAXPACKETSIZE);
		jniSetFileDescriptorOfFD(env, javaFd, -1);
		if (res < 0) {
		throwErrnoException(env, "resNetworkResult", -res);
		return nullptr;
		@@ -490,6 +491,7 @@ static jbyteArray android_net_utils_resNetworkResult(JNIEnv *env, jobject thiz,
		static void android_net_utils_resNetworkCancel(JNIEnv *env, jobject thiz, jobject javaFd) {
		int fd = jniGetFDFromFileDescriptor(env, javaFd);
		resNetworkCancel(fd);
		jniSetFileDescriptorOfFD(env, javaFd, -1);
		}

		static jobject android_net_utils_getTcpRepairWindow(JNIEnv *env, jobject thiz, jobject javaFd) {