Rewrite lingering.
The two major changes here are:
- Move lingering out of NetworkMonitor. The fact that lingering
is currently its own state in NetworkMonitor complicates the
logic there: while a network is lingering it cannot be in any
other state, we have to take care not to leave LingeringState
for the wrong reason, etc.
- Instead of keeping a single per-network boolean to indicate
whether a network is lingered or not, keep a linger timer for
every request. This allows us to fix various corner-case bugs
in lingering.
The changes in behaviour compared to the current code can be seen
in the unit test changes. Specifically:
1. Bug fix: when a network is lingered, and a request is added
and removed to it, the existing code tears the network down
immediately. The new code just sends another CALLBACK_LOSING
and resumes lingering with the original timeout.
2. Bug fix: if cell is unvalidated and wifi comes up and
validates before cell does (as might happen on boot), the
existing code immediately tears down cell. The new code
lingers cell, which is correct because unvalidated cell was
the default network, so an app might have been using it.
3. Correctness improvement: always send CALLBACK_AVAILABLE for
the new network before sending CALLBACK_LOSING. This was not
really an issue in practice, because the usual flow is:
- Network A is the default.
- Network B connects, CALLBACK_AVAILABLE.
- Network B validates, CALLBACK_LOSING.
Bug: 23113288
Change-Id: I2f1e779ff6eb869e62921a95aa9d356f380cf30a
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 995a910..b12a961 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -94,6 +94,7 @@
import android.os.Process;
import android.os.RemoteException;
import android.os.ResultReceiver;
+import android.os.SystemClock;
import android.os.SystemProperties;
import android.os.UserHandle;
import android.os.UserManager;
@@ -125,6 +126,7 @@
import com.android.internal.util.AsyncChannel;
import com.android.internal.util.IndentingPrintWriter;
import com.android.internal.util.MessageUtils;
+import com.android.internal.util.WakeupMessage;
import com.android.internal.util.XmlUtils;
import com.android.server.am.BatteryStatsService;
import com.android.server.connectivity.DataConnectionStats;
@@ -171,7 +173,7 @@
*/
public class ConnectivityService extends IConnectivityManager.Stub
implements PendingIntent.OnFinished {
- private static final String TAG = "ConnectivityService";
+ private static final String TAG = ConnectivityService.class.getSimpleName();
private static final boolean DBG = true;
private static final boolean VDBG = false;
@@ -191,6 +193,12 @@
// connect anyway?" dialog after the user selects a network that doesn't validate.
private static final int PROMPT_UNVALIDATED_DELAY_MS = 8 * 1000;
+ // Default to 30s linger time-out. Modifiable only for testing.
+ private static final String LINGER_DELAY_PROPERTY = "persist.netmon.linger";
+ private static final int DEFAULT_LINGER_DELAY_MS = 30_000;
+ @VisibleForTesting
+ protected int mLingerDelayMs; // Can't be final, or test subclass constructors can't change it.
+
// How long to delay to removal of a pending intent based request.
// See Settings.Secure.CONNECTIVITY_RELEASE_PENDING_INTENT_DELAY_MS
private final int mReleasePendingIntentDelayMs;
@@ -239,7 +247,8 @@
private static final int DISABLED = 0;
private static final SparseArray<String> sMagicDecoderRing = MessageUtils.findMessageNames(
- new Class[] { AsyncChannel.class, ConnectivityService.class, NetworkAgent.class });
+ new Class[] { AsyncChannel.class, ConnectivityService.class, NetworkAgent.class,
+ NetworkAgentInfo.class });
private enum ReapUnvalidatedNetworks {
// Tear down networks that have no chance (e.g. even if validated) of becoming
@@ -681,6 +690,8 @@
mReleasePendingIntentDelayMs = Settings.Secure.getInt(context.getContentResolver(),
Settings.Secure.CONNECTIVITY_RELEASE_PENDING_INTENT_DELAY_MS, 5_000);
+ mLingerDelayMs = SystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS);
+
mContext = checkNotNull(context, "missing Context");
mNetd = checkNotNull(netManager, "missing INetworkManagementService");
mStatsService = checkNotNull(statsService, "missing INetworkStatsService");
@@ -1905,7 +1916,8 @@
for (NetworkAgentInfo nai : mNetworkAgentInfos.values()) {
pw.println(nai.toString());
pw.increaseIndent();
- pw.println("Requests:");
+ pw.println(String.format("Requests: %d request/%d total",
+ nai.numRequestNetworkRequests(), nai.numNetworkRequests()));
pw.increaseIndent();
for (int i = 0; i < nai.numNetworkRequests(); i++) {
pw.println(nai.requestAt(i).toString());
@@ -1913,7 +1925,7 @@
pw.decreaseIndent();
pw.println("Lingered:");
pw.increaseIndent();
- for (NetworkRequest nr : nai.networkLingered) pw.println(nr.toString());
+ nai.dumpLingerTimers(pw);
pw.decreaseIndent();
pw.decreaseIndent();
}
@@ -2158,13 +2170,6 @@
}
break;
}
- case NetworkMonitor.EVENT_NETWORK_LINGER_COMPLETE: {
- NetworkAgentInfo nai = (NetworkAgentInfo)msg.obj;
- if (isLiveNetworkAgent(nai, msg.what)) {
- handleLingerComplete(nai);
- }
- break;
- }
case NetworkMonitor.EVENT_PROVISIONING_NOTIFICATION: {
final int netId = msg.arg2;
final boolean visible = (msg.arg1 != 0);
@@ -2197,33 +2202,50 @@
return true;
}
+ private boolean maybeHandleNetworkAgentInfoMessage(Message msg) {
+ switch (msg.what) {
+ default:
+ return false;
+ case NetworkAgentInfo.EVENT_NETWORK_LINGER_COMPLETE: {
+ NetworkAgentInfo nai = (NetworkAgentInfo) msg.obj;
+ if (nai != null && isLiveNetworkAgent(nai, msg.what)) {
+ handleLingerComplete(nai);
+ }
+ break;
+ }
+ }
+ return true;
+ }
+
@Override
public void handleMessage(Message msg) {
- if (!maybeHandleAsyncChannelMessage(msg) && !maybeHandleNetworkMonitorMessage(msg)) {
+ if (!maybeHandleAsyncChannelMessage(msg) &&
+ !maybeHandleNetworkMonitorMessage(msg) &&
+ !maybeHandleNetworkAgentInfoMessage(msg)) {
maybeHandleNetworkAgentMessage(msg);
}
}
}
- private void linger(NetworkAgentInfo nai) {
- nai.lingering = true;
- logNetworkEvent(nai, NetworkEvent.NETWORK_LINGER);
- nai.networkMonitor.sendMessage(NetworkMonitor.CMD_NETWORK_LINGER);
- notifyNetworkCallbacks(nai, ConnectivityManager.CALLBACK_LOSING);
- }
-
- // Cancel any lingering so the linger timeout doesn't teardown a network.
- // This should be called when a network begins satisfying a NetworkRequest.
- // Note: depending on what state the NetworkMonitor is in (e.g.,
- // if it's awaiting captive portal login, or if validation failed), this
- // may trigger a re-evaluation of the network.
- private void unlinger(NetworkAgentInfo nai) {
- nai.networkLingered.clear();
- if (!nai.lingering) return;
- nai.lingering = false;
- logNetworkEvent(nai, NetworkEvent.NETWORK_UNLINGER);
- if (VDBG) log("Canceling linger of " + nai.name());
- nai.networkMonitor.sendMessage(NetworkMonitor.CMD_NETWORK_CONNECTED);
+ private void updateLingerState(NetworkAgentInfo nai, long now) {
+ // 1. Update the linger timer. If it's changed, reschedule or cancel the alarm.
+ // 2. If the network was lingering and there are now requests, unlinger it.
+ // 3. If this network is unneeded (which implies it is not lingering), and there is at least
+ // one lingered request, start lingering.
+ nai.updateLingerTimer();
+ if (nai.isLingering() && nai.numRequestNetworkRequests() > 0) {
+ if (DBG) log("Unlingering " + nai.name());
+ nai.unlinger();
+ logNetworkEvent(nai, NetworkEvent.NETWORK_UNLINGER);
+ } else if (unneeded(nai) && nai.getLingerExpiry() > 0) { // unneeded() calls isLingering()
+ int lingerTime = (int) (nai.getLingerExpiry() - now);
+ if (DBG) {
+ Log.d(TAG, "Lingering " + nai.name() + " for " + lingerTime + "ms");
+ }
+ nai.linger();
+ logNetworkEvent(nai, NetworkEvent.NETWORK_LINGER);
+ notifyNetworkCallbacks(nai, ConnectivityManager.CALLBACK_LOSING, lingerTime);
+ }
}
private void handleAsyncChannelHalfConnect(Message msg) {
@@ -2313,6 +2335,7 @@
sendUpdatedScoreToFactories(request, 0);
}
}
+ nai.clearLingerState();
if (nai.isSatisfyingRequest(mDefaultRequest.requestId)) {
removeDataActivityTracking(nai);
notifyLockdownVpn(nai);
@@ -2400,7 +2423,10 @@
// This is whether it is satisfying any NetworkRequests or were it to become validated,
// would it have a chance of satisfying any NetworkRequests.
private boolean unneeded(NetworkAgentInfo nai) {
- if (!nai.everConnected || nai.isVPN() || nai.lingering) return false;
+ if (!nai.everConnected || nai.isVPN() ||
+ nai.isLingering() || nai.numRequestNetworkRequests() > 0) {
+ return false;
+ }
for (NetworkRequestInfo nri : mNetworkRequests.values()) {
// If this Network is already the highest scoring Network for a request, or if
// there is hope for it to become one if it validated, then it is needed.
@@ -2453,6 +2479,9 @@
log(" Removing from current network " + nai.name() +
", leaving " + nai.numNetworkRequests() + " requests.");
}
+ // If there are still lingered requests on this network, don't tear it down,
+ // but resume lingering instead.
+ updateLingerState(nai, SystemClock.elapsedRealtime());
if (unneeded(nai)) {
if (DBG) log("no live requests for " + nai.name() + "; disconnecting");
teardownUnneededNetwork(nai);
@@ -2516,7 +2545,7 @@
}
}
}
- callCallbackForRequest(nri, null, ConnectivityManager.CALLBACK_RELEASED);
+ callCallbackForRequest(nri, null, ConnectivityManager.CALLBACK_RELEASED, 0);
}
}
@@ -4503,7 +4532,7 @@
}
private void callCallbackForRequest(NetworkRequestInfo nri,
- NetworkAgentInfo networkAgent, int notificationType) {
+ NetworkAgentInfo networkAgent, int notificationType, int arg1) {
if (nri.messenger == null) return; // Default request has no msgr
Bundle bundle = new Bundle();
bundle.putParcelable(NetworkRequest.class.getSimpleName(),
@@ -4515,7 +4544,7 @@
}
switch (notificationType) {
case ConnectivityManager.CALLBACK_LOSING: {
- msg.arg1 = 30 * 1000; // TODO - read this from NetworkMonitor
+ msg.arg1 = arg1;
break;
}
case ConnectivityManager.CALLBACK_CAP_CHANGED: {
@@ -4562,7 +4591,14 @@
return;
}
if (DBG) log("handleLingerComplete for " + oldNetwork.name());
- teardownUnneededNetwork(oldNetwork);
+
+ // If we get here it means that the last linger timeout for this network expired. So there
+ // must be no other active linger timers, and we must stop lingering.
+ oldNetwork.clearLingerState();
+
+ if (unneeded(oldNetwork)) {
+ teardownUnneededNetwork(oldNetwork);
+ }
}
private void makeDefault(NetworkAgentInfo newNetwork) {
@@ -4607,7 +4643,7 @@
// performed to tear down unvalidated networks that have no chance (i.e. even if
// validated) of becoming the highest scoring network.
private void rematchNetworkAndRequests(NetworkAgentInfo newNetwork,
- ReapUnvalidatedNetworks reapUnvalidatedNetworks) {
+ ReapUnvalidatedNetworks reapUnvalidatedNetworks, long now) {
if (!newNetwork.everConnected) return;
boolean keep = newNetwork.isVPN();
boolean isNewDefault = false;
@@ -4653,12 +4689,12 @@
if (currentNetwork != null) {
if (VDBG) log(" accepting network in place of " + currentNetwork.name());
currentNetwork.removeRequest(nri.request.requestId);
- currentNetwork.networkLingered.add(nri.request);
+ currentNetwork.lingerRequest(nri.request, now, mLingerDelayMs);
affectedNetworks.add(currentNetwork);
} else {
if (VDBG) log(" accepting network in place of null");
}
- unlinger(newNetwork);
+ newNetwork.unlingerRequest(nri.request);
mNetworkForRequestId.put(nri.request.requestId, newNetwork);
if (!newNetwork.addRequest(nri.request)) {
Slog.wtf(TAG, "BUG: " + newNetwork.name() + " already has " + nri.request);
@@ -4706,23 +4742,7 @@
// a) be requested and b) change is NET_CAPABILITY_TRUSTED,
// so this code is only incorrect for a network that loses
// the TRUSTED capability, which is a rare case.
- callCallbackForRequest(nri, newNetwork, ConnectivityManager.CALLBACK_LOST);
- }
- }
- // Linger any networks that are no longer needed.
- for (NetworkAgentInfo nai : affectedNetworks) {
- if (nai.lingering) {
- // Already lingered. Nothing to do. This can only happen if "nai" is in
- // "affectedNetworks" twice. The reasoning being that to get added to
- // "affectedNetworks", "nai" must have been satisfying a NetworkRequest
- // (i.e. not lingered) so it could have only been lingered by this loop.
- // unneeded(nai) will be false and we'll call unlinger() below which would
- // be bad, so handle it here.
- } else if (unneeded(nai)) {
- linger(nai);
- } else {
- // Clear nai.networkLingered we might have added above.
- unlinger(nai);
+ callCallbackForRequest(nri, newNetwork, ConnectivityManager.CALLBACK_LOST, 0);
}
}
if (isNewDefault) {
@@ -4747,6 +4767,15 @@
// before LegacyTypeTracker sends legacy broadcasts
for (NetworkRequestInfo nri : addedRequests) notifyNetworkCallback(newNetwork, nri);
+ // Linger any networks that are no longer needed. This should be done after sending the
+ // available callback for newNetwork.
+ for (NetworkAgentInfo nai : affectedNetworks) {
+ updateLingerState(nai, now);
+ }
+ // Possibly unlinger newNetwork. Unlingering a network does not send any callbacks so it
+ // does not need to be done in any particular order.
+ updateLingerState(newNetwork, now);
+
if (isNewDefault) {
// Maintain the illusion: since the legacy API only
// understands one network at a time, we must pretend
@@ -4812,8 +4841,19 @@
if (reapUnvalidatedNetworks == ReapUnvalidatedNetworks.REAP) {
for (NetworkAgentInfo nai : mNetworkAgentInfos.values()) {
if (unneeded(nai)) {
- if (DBG) log("Reaping " + nai.name());
- teardownUnneededNetwork(nai);
+ if (nai.getLingerExpiry() > 0) {
+ // This network has active linger timers and no requests, but is not
+ // lingering. Linger it.
+ //
+ // One way (the only way?) this can happen if this network is unvalidated
+ // and became unneeded due to another network improving its score to the
+ // point where this network will no longer be able to satisfy any requests
+ // even if it validates.
+ updateLingerState(nai, now);
+ } else {
+ if (DBG) log("Reaping " + nai.name());
+ teardownUnneededNetwork(nai);
+ }
}
}
}
@@ -4840,8 +4880,9 @@
// Optimization: Only reprocess "changed" if its score improved. This is safe because it
// can only add more NetworkRequests satisfied by "changed", and this is exactly what
// rematchNetworkAndRequests() handles.
+ final long now = SystemClock.elapsedRealtime();
if (changed != null && oldScore < changed.getCurrentScore()) {
- rematchNetworkAndRequests(changed, ReapUnvalidatedNetworks.REAP);
+ rematchNetworkAndRequests(changed, ReapUnvalidatedNetworks.REAP, now);
} else {
final NetworkAgentInfo[] nais = mNetworkAgentInfos.values().toArray(
new NetworkAgentInfo[mNetworkAgentInfos.size()]);
@@ -4855,7 +4896,8 @@
// is complete could incorrectly teardown a network that hasn't yet been
// rematched.
(nai != nais[nais.length-1]) ? ReapUnvalidatedNetworks.DONT_REAP
- : ReapUnvalidatedNetworks.REAP);
+ : ReapUnvalidatedNetworks.REAP,
+ now);
}
}
}
@@ -4965,7 +5007,8 @@
updateSignalStrengthThresholds(networkAgent, "CONNECT", null);
// Consider network even though it is not yet validated.
- rematchNetworkAndRequests(networkAgent, ReapUnvalidatedNetworks.REAP);
+ final long now = SystemClock.elapsedRealtime();
+ rematchNetworkAndRequests(networkAgent, ReapUnvalidatedNetworks.REAP, now);
// This has to happen after matching the requests, because callbacks are just requests.
notifyNetworkCallbacks(networkAgent, ConnectivityManager.CALLBACK_PRECHECK);
@@ -5013,14 +5056,8 @@
// notify only this one new request of the current state
protected void notifyNetworkCallback(NetworkAgentInfo nai, NetworkRequestInfo nri) {
int notifyType = ConnectivityManager.CALLBACK_AVAILABLE;
- // TODO - read state from monitor to decide what to send.
-// if (nai.networkMonitor.isLingering()) {
-// notifyType = NetworkCallbacks.LOSING;
-// } else if (nai.networkMonitor.isEvaluating()) {
-// notifyType = NetworkCallbacks.callCallbackForRequest(request, nai, notifyType);
-// }
if (nri.mPendingIntent == null) {
- callCallbackForRequest(nri, nai, notifyType);
+ callCallbackForRequest(nri, nai, notifyType, 0);
} else {
sendPendingIntentForRequest(nri, nai, notifyType);
}
@@ -5072,20 +5109,24 @@
}
}
- protected void notifyNetworkCallbacks(NetworkAgentInfo networkAgent, int notifyType) {
+ protected void notifyNetworkCallbacks(NetworkAgentInfo networkAgent, int notifyType, int arg1) {
if (VDBG) log("notifyType " + notifyTypeToName(notifyType) + " for " + networkAgent.name());
for (int i = 0; i < networkAgent.numNetworkRequests(); i++) {
NetworkRequest nr = networkAgent.requestAt(i);
NetworkRequestInfo nri = mNetworkRequests.get(nr);
if (VDBG) log(" sending notification for " + nr);
if (nri.mPendingIntent == null) {
- callCallbackForRequest(nri, networkAgent, notifyType);
+ callCallbackForRequest(nri, networkAgent, notifyType, arg1);
} else {
sendPendingIntentForRequest(nri, networkAgent, notifyType);
}
}
}
+ protected void notifyNetworkCallbacks(NetworkAgentInfo networkAgent, int notifyType) {
+ notifyNetworkCallbacks(networkAgent, notifyType, 0);
+ }
+
private String notifyTypeToName(int notifyType) {
switch (notifyType) {
case ConnectivityManager.CALLBACK_PRECHECK: return "PRECHECK";
@@ -5216,6 +5257,11 @@
return new NetworkMonitor(context, handler, nai, defaultRequest);
}
+ @VisibleForTesting
+ public WakeupMessage makeWakeupMessage(Context c, Handler h, String s, int cmd, Object obj) {
+ return new WakeupMessage(c, h, s, cmd, 0, 0, obj);
+ }
+
private void logDefaultNetworkEvent(NetworkAgentInfo newNai, NetworkAgentInfo prevNai) {
int newNetid = NETID_UNSET;
int prevNetid = NETID_UNSET;