Merge "Do not block for connector in TetheringManager" am: 283abc0ad4 am: bd9b1908fb am: e094cf9519
Change-Id: If1187beb53716d2c8f9855634a9b913ffceee604
diff --git a/Tethering/common/TetheringLib/jarjar-rules.txt b/Tethering/common/TetheringLib/jarjar-rules.txt
index 35e0f88..1403bba 100644
--- a/Tethering/common/TetheringLib/jarjar-rules.txt
+++ b/Tethering/common/TetheringLib/jarjar-rules.txt
@@ -1 +1,2 @@
rule android.annotation.** com.android.networkstack.tethering.annotation.@1
+rule com.android.internal.annotations.** com.android.networkstack.tethering.annotation.@1
\ No newline at end of file
diff --git a/Tethering/common/TetheringLib/src/android/net/TetheringManager.java b/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
index 37ce1d5..53a358f 100644
--- a/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
+++ b/Tethering/common/TetheringLib/src/android/net/TetheringManager.java
@@ -30,6 +30,9 @@
import android.util.ArrayMap;
import android.util.Log;
+import com.android.internal.annotations.GuardedBy;
+
+import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
@@ -37,6 +40,7 @@
import java.util.List;
import java.util.Objects;
import java.util.concurrent.Executor;
+import java.util.function.Supplier;
/**
* This class provides the APIs to control the tethering service.
@@ -50,17 +54,23 @@
public class TetheringManager {
private static final String TAG = TetheringManager.class.getSimpleName();
private static final int DEFAULT_TIMEOUT_MS = 60_000;
+ private static final long CONNECTOR_POLL_INTERVAL_MILLIS = 200L;
- private static TetheringManager sInstance;
+ @GuardedBy("mConnectorWaitQueue")
+ @Nullable
+ private ITetheringConnector mConnector;
+ @GuardedBy("mConnectorWaitQueue")
+ @NonNull
+ private final List<ConnectorConsumer> mConnectorWaitQueue = new ArrayList<>();
+ private final Supplier<IBinder> mConnectorSupplier;
- private final ITetheringConnector mConnector;
private final TetheringCallbackInternal mCallback;
private final Context mContext;
private final ArrayMap<TetheringEventCallback, ITetheringEventCallback>
mTetheringEventCallbacks = new ArrayMap<>();
- private TetheringConfigurationParcel mTetheringConfiguration;
- private TetherStatesParcel mTetherStatesParcel;
+ private volatile TetheringConfigurationParcel mTetheringConfiguration;
+ private volatile TetherStatesParcel mTetherStatesParcel;
/**
* Broadcast Action: A tetherable connection has come or gone.
@@ -162,29 +172,139 @@
/**
* Create a TetheringManager object for interacting with the tethering service.
*
+ * @param context Context for the manager.
+ * @param connectorSupplier Supplier for the manager connector; may return null while the
+ * service is not connected.
* {@hide}
*/
- public TetheringManager(@NonNull final Context context, @NonNull final IBinder service) {
+ public TetheringManager(@NonNull final Context context,
+ @NonNull Supplier<IBinder> connectorSupplier) {
mContext = context;
- mConnector = ITetheringConnector.Stub.asInterface(service);
mCallback = new TetheringCallbackInternal();
+ mConnectorSupplier = connectorSupplier;
final String pkgName = mContext.getOpPackageName();
+
+ final IBinder connector = mConnectorSupplier.get();
+ // If the connector is available on start, do not start a polling thread. This introduces
+ // differences in the thread that sends the oneway binder calls to the service between the
+ // first few seconds after boot and later, but it avoids always having differences between
+ // the first usage of TetheringManager from a process and subsequent usages (so the
+ // difference is only on boot). On boot binder calls may be queued until the service comes
+ // up and be sent from a worker thread; later, they are always sent from the caller thread.
+ // Considering that it's just oneway binder calls, and ordering is preserved, this seems
+ // better than inconsistent behavior persisting after boot.
+ if (connector != null) {
+ mConnector = ITetheringConnector.Stub.asInterface(connector);
+ } else {
+ startPollingForConnector();
+ }
+
Log.i(TAG, "registerTetheringEventCallback:" + pkgName);
+ getConnector(c -> c.registerTetheringEventCallback(mCallback, pkgName));
+ }
+
+ private void startPollingForConnector() {
+ new Thread(() -> {
+ while (true) {
+ try {
+ Thread.sleep(200);
+ } catch (InterruptedException e) {
+ // Not much to do here, the system needs to wait for the connector
+ }
+
+ final IBinder connector = mConnectorSupplier.get();
+ if (connector != null) {
+ onTetheringConnected(ITetheringConnector.Stub.asInterface(connector));
+ return;
+ }
+ }
+ }).start();
+ }
+
+ private interface ConnectorConsumer {
+ void onConnectorAvailable(ITetheringConnector connector) throws RemoteException;
+ }
+
+ private void onTetheringConnected(ITetheringConnector connector) {
+ // Process the connector wait queue in order, including any items that are added
+ // while processing.
+ //
+ // 1. Copy the queue to a local variable under lock.
+ // 2. Drain the local queue with the lock released (otherwise, enqueuing future commands
+ // would block on the lock).
+ // 3. Acquire the lock again. If any new tasks were queued during step 2, goto 1.
+ // If not, set mConnector to non-null so future tasks are run immediately, not queued.
+ //
+ // For this to work, all calls to the tethering service must use getConnector(), which
+ // ensures that tasks are added to the queue with the lock held.
+ //
+ // Once mConnector is set to non-null, it will never be null again. If the network stack
+ // process crashes, no recovery is possible.
+ // TODO: evaluate whether it is possible to recover from network stack process crashes
+ // (though in most cases the system will have crashed when the network stack process
+ // crashes).
+ do {
+ final List<ConnectorConsumer> localWaitQueue;
+ synchronized (mConnectorWaitQueue) {
+ localWaitQueue = new ArrayList<>(mConnectorWaitQueue);
+ mConnectorWaitQueue.clear();
+ }
+
+ // Allow more tasks to be added at the end without blocking while draining the queue.
+ for (ConnectorConsumer task : localWaitQueue) {
+ try {
+ task.onConnectorAvailable(connector);
+ } catch (RemoteException e) {
+ // Most likely the network stack process crashed, which is likely to crash the
+ // system. Keep processing other requests but report the error loudly.
+ Log.wtf(TAG, "Error processing request for the tethering connector", e);
+ }
+ }
+
+ synchronized (mConnectorWaitQueue) {
+ if (mConnectorWaitQueue.size() == 0) {
+ mConnector = connector;
+ return;
+ }
+ }
+ } while (true);
+ }
+
+ /**
+ * Asynchronously get the ITetheringConnector to execute some operation.
+ *
+ * <p>If the connector is already available, the operation will be executed on the caller's
+ * thread. Otherwise it will be queued and executed on a worker thread. The operation should be
+ * limited to performing oneway binder calls to minimize differences due to threading.
+ */
+ private void getConnector(ConnectorConsumer consumer) {
+ final ITetheringConnector connector;
+ synchronized (mConnectorWaitQueue) {
+ connector = mConnector;
+ if (connector == null) {
+ mConnectorWaitQueue.add(consumer);
+ return;
+ }
+ }
+
try {
- mConnector.registerTetheringEventCallback(mCallback, pkgName);
+ consumer.onConnectorAvailable(connector);
} catch (RemoteException e) {
throw new IllegalStateException(e);
}
}
private interface RequestHelper {
- void runRequest(IIntResultListener listener);
+ void runRequest(ITetheringConnector connector, IIntResultListener listener);
}
+ // Used to dispatch legacy ConnectivityManager methods that expect tethering to be able to
+ // return results and perform operations synchronously.
+ // TODO: remove once there are no callers of these legacy methods.
private class RequestDispatcher {
private final ConditionVariable mWaiting;
- public int mRemoteResult;
+ public volatile int mRemoteResult;
private final IIntResultListener mListener = new IIntResultListener.Stub() {
@Override
@@ -199,7 +319,7 @@
}
int waitForResult(final RequestHelper request) {
- request.runRequest(mListener);
+ getConnector(c -> request.runRequest(c, mListener));
if (!mWaiting.block(DEFAULT_TIMEOUT_MS)) {
throw new IllegalStateException("Callback timeout");
}
@@ -222,7 +342,7 @@
}
private class TetheringCallbackInternal extends ITetheringEventCallback.Stub {
- private int mError = TETHER_ERROR_NO_ERROR;
+ private volatile int mError = TETHER_ERROR_NO_ERROR;
private final ConditionVariable mWaitForCallback = new ConditionVariable();
@Override
@@ -280,9 +400,9 @@
Log.i(TAG, "tether caller:" + callerPkg);
final RequestDispatcher dispatcher = new RequestDispatcher();
- return dispatcher.waitForResult(listener -> {
+ return dispatcher.waitForResult((connector, listener) -> {
try {
- mConnector.tether(iface, callerPkg, listener);
+ connector.tether(iface, callerPkg, listener);
} catch (RemoteException e) {
throw new IllegalStateException(e);
}
@@ -304,9 +424,9 @@
final RequestDispatcher dispatcher = new RequestDispatcher();
- return dispatcher.waitForResult(listener -> {
+ return dispatcher.waitForResult((connector, listener) -> {
try {
- mConnector.untether(iface, callerPkg, listener);
+ connector.untether(iface, callerPkg, listener);
} catch (RemoteException e) {
throw new IllegalStateException(e);
}
@@ -330,9 +450,9 @@
final RequestDispatcher dispatcher = new RequestDispatcher();
- return dispatcher.waitForResult(listener -> {
+ return dispatcher.waitForResult((connector, listener) -> {
try {
- mConnector.setUsbTethering(enable, callerPkg, listener);
+ connector.setUsbTethering(enable, callerPkg, listener);
} catch (RemoteException e) {
throw new IllegalStateException(e);
}
@@ -467,11 +587,7 @@
});
}
};
- try {
- mConnector.startTethering(request.getParcel(), callerPkg, listener);
- } catch (RemoteException e) {
- throw new IllegalStateException(e);
- }
+ getConnector(c -> c.startTethering(request.getParcel(), callerPkg, listener));
}
/**
@@ -509,15 +625,15 @@
final String callerPkg = mContext.getOpPackageName();
Log.i(TAG, "stopTethering caller:" + callerPkg);
- final RequestDispatcher dispatcher = new RequestDispatcher();
-
- dispatcher.waitForResult(listener -> {
- try {
- mConnector.stopTethering(type, callerPkg, listener);
- } catch (RemoteException e) {
- throw new IllegalStateException(e);
+ getConnector(c -> c.stopTethering(type, callerPkg, new IIntResultListener.Stub() {
+ @Override
+ public void onResult(int resultCode) {
+ // TODO: provide an API to obtain result
+ // This has never been possible as stopTethering has always been void and never
+ // taken a callback object. The only indication that callers have is if the call
+ // results in a TETHER_STATE_CHANGE broadcast.
}
- });
+ }));
}
/**
@@ -591,12 +707,8 @@
final String callerPkg = mContext.getOpPackageName();
Log.i(TAG, "getLatestTetheringEntitlementResult caller:" + callerPkg);
- try {
- mConnector.requestLatestTetheringEntitlementResult(type, receiver, showEntitlementUi,
- callerPkg);
- } catch (RemoteException e) {
- throw new IllegalStateException(e);
- }
+ getConnector(c -> c.requestLatestTetheringEntitlementResult(
+ type, receiver, showEntitlementUi, callerPkg));
}
/**
@@ -832,11 +944,7 @@
});
}
};
- try {
- mConnector.registerTetheringEventCallback(remoteCallback, callerPkg);
- } catch (RemoteException e) {
- throw new IllegalStateException(e);
- }
+ getConnector(c -> c.registerTetheringEventCallback(remoteCallback, callerPkg));
mTetheringEventCallbacks.put(callback, remoteCallback);
}
}
@@ -860,11 +968,8 @@
if (remoteCallback == null) {
throw new IllegalArgumentException("callback was not registered.");
}
- try {
- mConnector.unregisterTetheringEventCallback(remoteCallback, callerPkg);
- } catch (RemoteException e) {
- throw new IllegalStateException(e);
- }
+
+ getConnector(c -> c.unregisterTetheringEventCallback(remoteCallback, callerPkg));
}
}
@@ -1002,9 +1107,9 @@
final String callerPkg = mContext.getOpPackageName();
final RequestDispatcher dispatcher = new RequestDispatcher();
- final int ret = dispatcher.waitForResult(listener -> {
+ final int ret = dispatcher.waitForResult((connector, listener) -> {
try {
- mConnector.isTetheringSupported(callerPkg, listener);
+ connector.isTetheringSupported(callerPkg, listener);
} catch (RemoteException e) {
throw new IllegalStateException(e);
}
@@ -1027,13 +1132,14 @@
final String callerPkg = mContext.getOpPackageName();
Log.i(TAG, "stopAllTethering caller:" + callerPkg);
- final RequestDispatcher dispatcher = new RequestDispatcher();
- dispatcher.waitForResult(listener -> {
- try {
- mConnector.stopAllTethering(callerPkg, listener);
- } catch (RemoteException e) {
- throw new IllegalStateException(e);
+ getConnector(c -> c.stopAllTethering(callerPkg, new IIntResultListener.Stub() {
+ @Override
+ public void onResult(int resultCode) {
+ // TODO: add an API parameter to send result to caller.
+ // This has never been possible as stopAllTethering has always been void and never
+ // taken a callback object. The only indication that callers have is if the call
+ // results in a TETHER_STATE_CHANGE broadcast.
}
- });
+ }));
}
}