Fix default network transition event recording
When disconnecting from a default network X and falling back on another
connected network Y as the new default, ConnectivityService was
attempting to record this event as a X -> Y "atomic" transition.
In practice the default network connectivity is actually lost and
recovering default network takes some non-zero time.
This patch changes the event recording to always record disconnection as
X -> 0 events. At the same time, if there is a fallback network that is
elected as the new default ConnectivityService will also record a 0 -> Y
event.
This patch also improves pretty-printing of DefaultNetworkEvent.
Extract from $ adb shell dumpsys connectivity_metrics_logger --events
17:51:00.086: DefaultNetworkEvent(0 -> 100:CELLULAR)
17:51:25.232: DefaultNetworkEvent(100:IPv4 -> 101:WIFI) # wifi goes on
17:51:44.064: DefaultNetworkEvent(101:DUAL -> 0) # wifi goes off
17:51:44.187: DefaultNetworkEvent(0 -> 100:CELLULAR)
Bug: 28204408
Change-Id: I63252633235bf6ba833b9ac431a80dda75a93e67
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index c096fa5f..c30e540 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -2245,6 +2245,11 @@
final boolean wasDefault = isDefaultNetwork(nai);
if (wasDefault) {
mDefaultInetConditionPublished = 0;
+ // Log default network disconnection before required book-keeping.
+ // Let rematchAllNetworksAndRequests() below record a new default network event
+ // if there is a fallback. Taken together, the two form a X -> 0, 0 -> Y sequence
+ // whose timestamps tell how long it takes to recover a default network.
+ logDefaultNetworkEvent(null, nai);
}
notifyIfacesChangedForNetworkStats();
// TODO - we shouldn't send CALLBACK_LOST to requests that can be satisfied
@@ -2278,10 +2283,6 @@
}
mLegacyTypeTracker.remove(nai, wasDefault);
rematchAllNetworksAndRequests(null, 0);
- if (wasDefault && getDefaultNetwork() == null) {
- // Log that we lost the default network and there is no replacement.
- logDefaultNetworkEvent(null, nai);
- }
if (nai.created) {
// Tell netd to clean up the configuration for this network
// (routing rules, DNS, etc).
@@ -4583,7 +4584,7 @@
teardownUnneededNetwork(oldNetwork);
}
- private void makeDefault(NetworkAgentInfo newNetwork, NetworkAgentInfo prevNetwork) {
+ private void makeDefault(NetworkAgentInfo newNetwork) {
if (DBG) log("Switching to new default network: " + newNetwork);
setupDataActivityTracking(newNetwork);
try {
@@ -4595,7 +4596,6 @@
handleApplyDefaultProxy(newNetwork.linkProperties.getHttpProxy());
updateTcpBufferSizes(newNetwork);
setDefaultDnsSystemProperties(newNetwork.linkProperties.getDnsServers());
- logDefaultNetworkEvent(newNetwork, prevNetwork);
}
// Handles a network appearing or improving its score.
@@ -4746,7 +4746,9 @@
}
if (isNewDefault) {
// Notify system services that this network is up.
- makeDefault(newNetwork, oldDefaultNetwork);
+ makeDefault(newNetwork);
+ // Log 0 -> X and Y -> X default network transitions, where X is the new default.
+ logDefaultNetworkEvent(newNetwork, oldDefaultNetwork);
synchronized (ConnectivityService.this) {
// have a new default network, release the transition wakelock in
// a second if it's held. The second pause is to allow apps