Merge "Make NetworkMonitor do exponential backoff between reevaluation attempts." into mnc-dev (0c506582) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/connectivity/NetworkMonitor.java

+40 −74

Original line number	Diff line number	Diff line
		@@ -149,7 +149,6 @@ public class NetworkMonitor extends StateMachine {
		/**
		* Force evaluation even if it has succeeded in the past.
		* arg1 = UID responsible for requesting this reeval. Will be billed for data.
		* arg2 = Number of evaluation attempts to make. (If 0, make INITIAL_ATTEMPTS attempts.)
		*/
		public static final int CMD_FORCE_REEVALUATION = BASE + 8;

		@@ -183,20 +182,18 @@ public class NetworkMonitor extends StateMachine {
		private final int mLingerDelayMs;
		private int mLingerToken = 0;

		// Negative values disable reevaluation.
		private static final String REEVALUATE_DELAY_PROPERTY = "persist.netmon.reeval_delay";
		// When connecting, attempt to validate 3 times, pausing 5s between them.
		private static final int DEFAULT_REEVALUATE_DELAY_MS = 5000;
		private static final int INITIAL_ATTEMPTS = 3;
		// If a network is not validated, make one attempt every 10 mins to see if it starts working.
		private static final int REEVALUATE_PAUSE_MS = 10601000;
		private static final int PERIODIC_ATTEMPTS = 1;
		// When an application calls reportNetworkConnectivity, only make one attempt.
		private static final int REEVALUATE_ATTEMPTS = 1;
		private final int mReevaluateDelayMs;
		// Start mReevaluateDelayMs at this value and double.
		private static final int INITIAL_REEVALUATE_DELAY_MS = 1000;
		private static final int MAX_REEVALUATE_DELAY_MS = 10601000;
		// Before network has been evaluated this many times, ignore repeated reevaluate requests.
		private static final int IGNORE_REEVALUATE_ATTEMPTS = 5;
		private int mReevaluateToken = 0;
		private static final int INVALID_UID = -1;
		private int mUidResponsibleForReeval = INVALID_UID;
		// When network has been evaluated this many times:
		// 1. report NETWORK_TEST_RESULT_INVALID
		// 2. stop blaming UID that requested re-evaluation for further attempts
		private static final int INITIAL_EVALUATION_ATTEMPTS = 3;

		private final Context mContext;
		private final Handler mConnectivityServiceHandler;
		@@ -212,18 +209,9 @@ public class NetworkMonitor extends StateMachine {
		// Set if the user explicitly selected "Do not use this network" in captive portal sign-in app.
		private boolean mUserDoesNotWant = false;

		// How many times we should attempt validation. Only checked in EvaluatingState; must be set
		// before entering EvaluatingState. Note that whatever code causes us to transition to
		// EvaluatingState last decides how many attempts will be made, so if one codepath were to
		// enter EvaluatingState with a specific number of attempts, and then another were to enter it
		// with a different number of attempts, the second number would be used. This is not currently
		// a problem because EvaluatingState is not reentrant.
		private int mMaxAttempts;

		public boolean systemReady = false;

		private final State mDefaultState = new DefaultState();
		private final State mOfflineState = new OfflineState();
		private final State mValidatedState = new ValidatedState();
		private final State mMaybeNotifyState = new MaybeNotifyState();
		private final State mEvaluatingState = new EvaluatingState();
		@@ -247,7 +235,6 @@ public class NetworkMonitor extends StateMachine {
		mDefaultRequest = defaultRequest;

		addState(mDefaultState);
		addState(mOfflineState, mDefaultState);
		addState(mValidatedState, mDefaultState);
		addState(mMaybeNotifyState, mDefaultState);
		addState(mEvaluatingState, mMaybeNotifyState);
		@@ -260,8 +247,6 @@ public class NetworkMonitor extends StateMachine {
		if (mServer == null) mServer = DEFAULT_SERVER;

		mLingerDelayMs = SystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS);
		mReevaluateDelayMs = SystemProperties.getInt(REEVALUATE_DELAY_PROPERTY,
		DEFAULT_REEVALUATE_DELAY_MS);

		mIsCaptivePortalCheckEnabled = Settings.Global.getInt(mContext.getContentResolver(),
		Settings.Global.CAPTIVE_PORTAL_DETECTION_ENABLED, 1) == 1;
		@@ -289,7 +274,6 @@ public class NetworkMonitor extends StateMachine {
		return HANDLED;
		case CMD_NETWORK_CONNECTED:
		if (DBG) log("Connected");
		mMaxAttempts = INITIAL_ATTEMPTS;
		transitionTo(mEvaluatingState);
		return HANDLED;
		case CMD_NETWORK_DISCONNECTED:
		@@ -303,7 +287,6 @@ public class NetworkMonitor extends StateMachine {
		case CMD_FORCE_REEVALUATION:
		if (DBG) log("Forcing reevaluation");
		mUidResponsibleForReeval = message.arg1;
		mMaxAttempts = message.arg2 != 0 ? message.arg2 : REEVALUATE_ATTEMPTS;
		transitionTo(mEvaluatingState);
		return HANDLED;
		case CMD_CAPTIVE_PORTAL_APP_FINISHED:
		@@ -313,8 +296,7 @@ public class NetworkMonitor extends StateMachine {
		mCaptivePortalLoggedInResponseToken = String.valueOf(new Random().nextLong());
		switch (message.arg1) {
		case ConnectivityManager.CAPTIVE_PORTAL_APP_RETURN_DISMISSED:
		sendMessage(CMD_FORCE_REEVALUATION, 0 /* no UID */,
		0 /* INITIAL_ATTEMPTS */);
		sendMessage(CMD_FORCE_REEVALUATION, 0 /* no UID */, 0);
		break;
		case ConnectivityManager.CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS:
		// TODO: Distinguish this from a network that actually validates.
		@@ -323,8 +305,12 @@ public class NetworkMonitor extends StateMachine {
		break;
		case ConnectivityManager.CAPTIVE_PORTAL_APP_RETURN_UNWANTED:
		mUserDoesNotWant = true;
		mConnectivityServiceHandler.sendMessage(obtainMessage(
		EVENT_NETWORK_TESTED, NETWORK_TEST_RESULT_INVALID, 0,
		mNetworkAgentInfo));
		// TODO: Should teardown network.
		transitionTo(mOfflineState);
		mUidResponsibleForReeval = 0;
		transitionTo(mEvaluatingState);
		break;
		}
		return HANDLED;
		@@ -334,42 +320,6 @@ public class NetworkMonitor extends StateMachine {
		}
		}

		// Being in the OfflineState State indicates a Network is unwanted or failed validation.
		private class OfflineState extends State {
		@Override
		public void enter() {
		mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED,
		NETWORK_TEST_RESULT_INVALID, 0, mNetworkAgentInfo));
		if (!mUserDoesNotWant) {
		sendMessageDelayed(CMD_FORCE_REEVALUATION, 0 /* no UID */,
		PERIODIC_ATTEMPTS, REEVALUATE_PAUSE_MS);
		}
		}

		@Override
		public boolean processMessage(Message message) {
		if (DBG) log(getName() + message.toString());
		switch (message.what) {
		case CMD_FORCE_REEVALUATION:
		// If the user has indicated they explicitly do not want to use this network,
		// don't allow a reevaluation as this will be pointless and could result in
		// the user being annoyed with repeated unwanted notifications.
		return mUserDoesNotWant ? HANDLED : NOT_HANDLED;
		default:
		return NOT_HANDLED;
		}
		}

		@Override
		public void exit() {
		// NOTE: This removes the delayed message posted by enter() but will inadvertently
		// remove any other CMD_FORCE_REEVALUATION in the message queue. At the moment this
		// is harmless. If in the future this becomes problematic a different message could
		// be used.
		removeMessages(CMD_FORCE_REEVALUATION);
		}
		}

		// Being in the ValidatedState State indicates a Network is:
		// - Successfully validated, or
		// - Wanted "as is" by the user, or
		@@ -426,18 +376,20 @@ public class NetworkMonitor extends StateMachine {
		}

		// Being in the EvaluatingState State indicates the Network is being evaluated for internet
		// connectivity.
		// connectivity, or that the user has indicated that this network is unwanted.
		private class EvaluatingState extends State {
		private int mAttempt;
		private int mReevaluateDelayMs;
		private int mAttempts;

		@Override
		public void enter() {
		mAttempt = 1;
		sendMessage(CMD_REEVALUATE, ++mReevaluateToken, 0);
		if (mUidResponsibleForReeval != INVALID_UID) {
		TrafficStats.setThreadStatsUid(mUidResponsibleForReeval);
		mUidResponsibleForReeval = INVALID_UID;
		}
		mReevaluateDelayMs = INITIAL_REEVALUATE_DELAY_MS;
		mAttempts = 0;
		}

		@Override
		@@ -445,7 +397,7 @@ public class NetworkMonitor extends StateMachine {
		if (DBG) log(getName() + message.toString());
		switch (message.what) {
		case CMD_REEVALUATE:
		if (message.arg1 != mReevaluateToken)
		if (message.arg1 != mReevaluateToken \|\| mUserDoesNotWant)
		return HANDLED;
		// Don't bother validating networks that don't satisify the default request.
		// This includes:
		@@ -469,6 +421,7 @@ public class NetworkMonitor extends StateMachine {
		transitionTo(mValidatedState);
		return HANDLED;
		}
		mAttempts++;
		// Note: This call to isCaptivePortal() could take up to a minute. Resolving the
		// server's IP addresses could hit the DNS timeout, and attempting connections
		// to each of the server's several IP addresses (currently one IPv4 and one
		@@ -480,16 +433,27 @@ public class NetworkMonitor extends StateMachine {
		transitionTo(mValidatedState);
		} else if (httpResponseCode >= 200 && httpResponseCode <= 399) {
		transitionTo(mCaptivePortalState);
		} else if (++mAttempt > mMaxAttempts) {
		transitionTo(mOfflineState);
		} else if (mReevaluateDelayMs >= 0) {
		} else {
		Message msg = obtainMessage(CMD_REEVALUATE, ++mReevaluateToken, 0);
		sendMessageDelayed(msg, mReevaluateDelayMs);
		if (mAttempts >= INITIAL_EVALUATION_ATTEMPTS) {
		mConnectivityServiceHandler.sendMessage(obtainMessage(
		EVENT_NETWORK_TESTED, NETWORK_TEST_RESULT_INVALID, 0,
		mNetworkAgentInfo));
		// Don't continue to blame UID forever.
		TrafficStats.clearThreadStatsUid();
		}
		mReevaluateDelayMs *= 2;
		if (mReevaluateDelayMs > MAX_REEVALUATE_DELAY_MS) {
		mReevaluateDelayMs = MAX_REEVALUATE_DELAY_MS;
		}
		}
		return HANDLED;
		case CMD_FORCE_REEVALUATION:
		// Ignore duplicate requests.
		return HANDLED;
		// Before IGNORE_REEVALUATE_ATTEMPTS attempts are made,
		// ignore any re-evaluation requests. After, restart the
		// evaluation process via EvaluatingState#enter.
		return mAttempts < IGNORE_REEVALUATE_ATTEMPTS ? HANDLED : NOT_HANDLED;
		default:
		return NOT_HANDLED;
		}
		@@ -533,6 +497,8 @@ public class NetworkMonitor extends StateMachine {
		public void enter() {
		mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED,
		NETWORK_TEST_RESULT_INVALID, 0, mNetworkAgentInfo));
		// Don't annoy user with sign-in notifications.
		if (mUserDoesNotWant) return;
		// Create a CustomIntentReceiver that sends us a
		// CMD_LAUNCH_CAPTIVE_PORTAL_APP message when the user
		// touches the notification.