Merge "Keystore 2.0 SPI: Add back-off hint to BackendBusyException." am: 9aba68730c (b03763fb) · Commits · e / os / android_frameworks_base

core/api/current.txt

+4 −3

Original line number	Diff line number	Diff line
		@@ -36185,9 +36185,10 @@ package android.security.identity {
		package android.security.keystore {

		public class BackendBusyException extends java.security.ProviderException {
		ctor public BackendBusyException();
		ctor public BackendBusyException(@NonNull String);
		ctor public BackendBusyException(@NonNull String, @NonNull Throwable);
		ctor public BackendBusyException(long);
		ctor public BackendBusyException(long, @NonNull String);
		ctor public BackendBusyException(long, @NonNull String, @NonNull Throwable);
		method public long getBackOffHintMillis();
		}

		public class KeyExpiredException extends java.security.InvalidKeyException {

keystore/java/android/security/KeyStoreSecurityLevel.java

+4 −3

Original line number	Diff line number	Diff line
		@@ -96,20 +96,21 @@ public class KeyStoreSecurityLevel {
		} catch (ServiceSpecificException e) {
		switch (e.errorCode) {
		case ResponseCode.BACKEND_BUSY: {
		long backOffHint = (long) (Math.random() * 80 + 20);
		if (CompatChanges.isChangeEnabled(
		KeyStore2.KEYSTORE_OPERATION_CREATION_MAY_FAIL)) {
		// Starting with Android S we inform the caller about the
		// backend being busy.
		throw new BackendBusyException();
		throw new BackendBusyException(backOffHint);
		} else {
		// Before Android S operation creation must always succeed. So we
		// just have to retry. We do so with a randomized back-off between
		// 50 and 250ms.
		// 20 and 100ms.
		// It is a little awkward that we cannot break out of this loop
		// by interrupting this thread. But that is the expected behavior.
		// There is some comfort in the fact that interrupting a thread
		// also does not unblock a thread waiting for a binder transaction.
		interruptedPreservingSleep((long) (Math.random() * 200 + 50));
		interruptedPreservingSleep(backOffHint);
		}
		break;
		}

keystore/java/android/security/keystore/BackendBusyException.java

+33 −4

Original line number	Diff line number	Diff line
		@@ -16,37 +16,66 @@

		package android.security.keystore;

		import android.annotation.DurationMillisLong;
		import android.annotation.NonNull;

		import java.security.ProviderException;

		/**
		* Indicates a transient error that prevented a key operation from being created.
		* Callers should try again with a back-off period of 10-30 milliseconds.
		* Callers should try again with a back-off period of {@link #getBackOffHintMillis()}
		* milliseconds.
		*/
		public class BackendBusyException extends ProviderException {

		private final long mBackOffHintMillis;

		/**
		* Constructs a new {@code BackendBusyException} without detail message and cause.
		*
		*/
		public BackendBusyException() {
		public BackendBusyException(@DurationMillisLong long backOffHintMillis) {
		super("The keystore backend has no operation slots available. Retry later.");
		if (backOffHintMillis < 0) {
		throw new IllegalArgumentException("Back-off hint cannot be negative.");
		}
		mBackOffHintMillis = backOffHintMillis;
		}

		/**
		* Constructs a new {@code BackendBusyException} with the provided detail message and
		* no cause.
		*/
		public BackendBusyException(@NonNull String message) {
		public BackendBusyException(@DurationMillisLong long backOffHintMillis,
		@NonNull String message) {
		super(message);
		if (backOffHintMillis < 0) {
		throw new IllegalArgumentException("Back-off hint cannot be negative.");
		}
		mBackOffHintMillis = backOffHintMillis;
		}

		/**
		* Constructs a new {@code BackendBusyException} with the provided detail message and
		* cause.
		*/
		public BackendBusyException(@NonNull String message, @NonNull Throwable cause) {
		public BackendBusyException(@DurationMillisLong long backOffHintMillis,
		@NonNull String message, @NonNull Throwable cause) {
		super(message, cause);
		if (backOffHintMillis < 0) {
		throw new IllegalArgumentException("Back-off hint cannot be negative.");
		}
		mBackOffHintMillis = backOffHintMillis;
		}

		/**
		* When retrying to start a Keystore operation after receiving this exception, this can be
		* used to determine how long to wait before retrying. It is not guaranteed that the operation
		* will succeeds after this time. Multiple retries may be necessary if the system is congested.
		*
		* @return Number of milliseconds to back off before retrying.
		*/
		public @DurationMillisLong long getBackOffHintMillis() {
		return mBackOffHintMillis;
		}
		}