WiFiMetrics: Add LastResortWatchdog success metric

Added a metric that tracks how often WifiLastResortWatchdog triggers
successfully fix wifi, allowing wifi to connect to a network after
triggering. It does not count a success, if the connection occurs
after a new network becomes available.

BUG=30407550
TEST=Unit Tests

Change-Id: I68d1f003fee9eb8074c04db141bd7b5c3089d57b

5 files changed, 81 insertions, 2 deletions

diff --git a/service/java/com/android/server/wifi/WifiLastResortWatchdog.java b/service/java/com/android/server/wifi/WifiLastResortWatchdog.java
index 558b50ef1..0885e46fd 100644
--- a/service/java/com/android/server/wifi/WifiLastResortWatchdog.java
+++ b/service/java/com/android/server/wifi/WifiLastResortWatchdog.java
@@ -209,6 +209,12 @@ public class WifiLastResortWatchdog {
     public void connectedStateTransition(boolean isEntering) {
         if (VDBG) Log.v(TAG, "connectedStateTransition: isEntering = " + isEntering);
         mWifiIsConnected = isEntering;
+
+        if (!mWatchdogAllowedToTrigger) {
+            // WiFi has connected after a Watchdog trigger, without any new networks becoming
+            // available, log a Watchdog success in wifi metrics
+            mWifiMetrics.incrementNumLastResortWatchdogSuccesses();
+        }
         if (isEntering) {
             // We connected to something! Reset failure counts for everything
             clearAllFailureCounts();
diff --git a/service/java/com/android/server/wifi/WifiMetrics.java b/service/java/com/android/server/wifi/WifiMetrics.java
index 4547466c3..a6f6ab069 100644
--- a/service/java/com/android/server/wifi/WifiMetrics.java
+++ b/service/java/com/android/server/wifi/WifiMetrics.java
@@ -810,6 +810,15 @@ public class WifiMetrics {
     }
 
     /**
+     * Increment count of Watchdog successes.
+     */
+    public void incrementNumLastResortWatchdogSuccesses() {
+        synchronized (mLock) {
+            mWifiLogProto.numLastResortWatchdogSuccesses++;
+        }
+    }
+
+    /**
      * Increments the count of alerts by alert reason.
      *
      * @param reason The cause of the alert. The reason values are driver-specific.
@@ -940,6 +949,8 @@ public class WifiMetrics {
                         + mWifiLogProto.numLastResortWatchdogTriggersWithBadDhcp);
                 pw.println("mWifiLogProto.numLastResortWatchdogTriggersWithBadOther="
                         + mWifiLogProto.numLastResortWatchdogTriggersWithBadOther);
+                pw.println("mWifiLogProto.numLastResortWatchdogSuccesses="
+                        + mWifiLogProto.numLastResortWatchdogSuccesses);
                 pw.println("mWifiLogProto.recordDurationSec="
                         + ((mClock.elapsedRealtime() / 1000) - mRecordStartTimeSec));
                 pw.println("mWifiLogProto.rssiPollRssiCount: Printing counts for [" + MIN_RSSI_POLL
diff --git a/service/proto/wifi.proto b/service/proto/wifi.proto
index 05ca06de8..862c8667d 100644
--- a/service/proto/wifi.proto
+++ b/service/proto/wifi.proto
@@ -190,6 +190,10 @@ message WifiLog {
   // Counts the occurrences of each individual RSSI poll level
   repeated RssiPollCount rssi_poll_rssi_count = 35;
 
+  // Total number of times WiFi connected immediately after a Last Resort Watchdog trigger,
+  // without new networks becoming available.
+  optional int32 num_last_resort_watchdog_successes = 36;
+
   // Counts the occurrences of each alert reason.
   repeated AlertReasonCount alert_reason_count = 47;
 }
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiLastResortWatchdogTest.java b/tests/wifitests/src/com/android/server/wifi/WifiLastResortWatchdogTest.java
index 237fc666d..08163e7f2 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiLastResortWatchdogTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiLastResortWatchdogTest.java
@@ -1440,7 +1440,7 @@ public class WifiLastResortWatchdogTest {
         int[] levels = {-60, -86, -50, -62, -60};
         boolean[] isEphemeral = {false, false, false, false, false};
         boolean[] hasEverConnected = {true, false, false, false, false};
-        // Buffer potential candidates 1,2,3 & 4
+        // Buffer potential candidates 1,2,3,4 & 5
         List<Pair<ScanDetail, WifiConfiguration>> candidates = createFilteredQnsCandidates(ssids,
                 bssids, frequencies, caps, levels, isEphemeral, hasEverConnected);
         mLastResortWatchdog.updateAvailableNetworks(candidates);
@@ -1450,7 +1450,7 @@ public class WifiLastResortWatchdogTest {
             assertFailureCountEquals(bssids[i], 0, 0, 0);
         }
 
-        //Increment failure count for the first test network ssid & bssid
+        //Increment failure counts
         for (int i = 0; i < WifiLastResortWatchdog.FAILURE_THRESHOLD; i++) {
             mLastResortWatchdog.noteConnectionFailureAndTriggerIfNeeded(
                     ssids[1], bssids[1], WifiLastResortWatchdog.FAILURE_CODE_AUTHENTICATION);
@@ -1478,6 +1478,58 @@ public class WifiLastResortWatchdogTest {
         verify(mWifiMetrics, times(1)).incrementNumLastResortWatchdogTriggersWithBadAssociation();
         verify(mWifiMetrics, times(1)).addCountToNumLastResortWatchdogBadDhcpNetworksTotal(3);
         verify(mWifiMetrics, times(1)).incrementNumLastResortWatchdogTriggersWithBadDhcp();
+
+        // Simulate wifi connecting after triggering
+        mLastResortWatchdog.connectedStateTransition(true);
+
+        // Verify that WifiMetrics counted this as a Watchdog success
+        verify(mWifiMetrics, times(1)).incrementNumLastResortWatchdogSuccesses();
+
+        // Simulate wifi disconnecting
+        mLastResortWatchdog.connectedStateTransition(false);
+
+        // Verify that WifiMetrics has still only counted one success
+        verify(mWifiMetrics, times(1)).incrementNumLastResortWatchdogSuccesses();
+
+        // Remove the fifth network from candidates
+        candidates = createFilteredQnsCandidates(Arrays.copyOfRange(mSsids, 0, 4),
+            Arrays.copyOfRange(mBssids, 0, 4),
+            Arrays.copyOfRange(mFrequencies, 0, 4),
+            Arrays.copyOfRange(mCaps, 0, 4),
+            Arrays.copyOfRange(mLevels, 0, 4),
+            Arrays.copyOfRange(mIsEphemeral, 0, 4));
+
+        // Age out the fifth network
+        for (int i = 0; i < WifiLastResortWatchdog.MAX_BSSID_AGE; i++) {
+            mLastResortWatchdog.updateAvailableNetworks(candidates);
+        }
+
+        //Increment failure counts
+        for (int i = 0; i < WifiLastResortWatchdog.FAILURE_THRESHOLD; i++) {
+            mLastResortWatchdog.noteConnectionFailureAndTriggerIfNeeded(
+                    ssids[1], bssids[1], WifiLastResortWatchdog.FAILURE_CODE_AUTHENTICATION);
+            mLastResortWatchdog.noteConnectionFailureAndTriggerIfNeeded(
+                    ssids[2], bssids[2], WifiLastResortWatchdog.FAILURE_CODE_DHCP);
+            mLastResortWatchdog.noteConnectionFailureAndTriggerIfNeeded(
+                    ssids[3], bssids[3], WifiLastResortWatchdog.FAILURE_CODE_DHCP);
+            mLastResortWatchdog.noteConnectionFailureAndTriggerIfNeeded(
+                    ssids[0], bssids[0], WifiLastResortWatchdog.FAILURE_CODE_ASSOCIATION);
+        }
+
+        // Add network #5 back into the candidates
+        candidates = createFilteredQnsCandidates(ssids,
+                bssids, frequencies, caps, levels, isEphemeral, hasEverConnected);
+
+        // LastResortWatchdog should reactivate because there is a new network (#5) available,
+        // Not because it was successful
+        mLastResortWatchdog.updateAvailableNetworks(candidates);
+
+        // Simulate wifi connecting
+        mLastResortWatchdog.connectedStateTransition(true);
+
+        // Verify that WifiMetrics did not count another success, as the connection could be due
+        // to the newly available network #5
+        verify(mWifiMetrics, times(1)).incrementNumLastResortWatchdogSuccesses();
     }
 
     /**
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiMetricsTest.java b/tests/wifitests/src/com/android/server/wifi/WifiMetricsTest.java
index b10f5734a..0b4e49846 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiMetricsTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiMetricsTest.java
@@ -171,6 +171,7 @@ public class WifiMetricsTest {
     private static final int NUM_LAST_RESORT_WATCHDOG_TRIGGERS_WITH_BAD_AUTHENTICATION = 8;
     private static final int NUM_LAST_RESORT_WATCHDOG_TRIGGERS_WITH_BAD_DHCP = 9;
     private static final int NUM_LAST_RESORT_WATCHDOG_TRIGGERS_WITH_BAD_OTHER = 10;
+    private static final int NUM_LAST_RESORT_WATCHDOG_SUCCESSES = 5;
     private static final int NUM_RSSI_LEVELS_TO_INCREMENT = 20;
     private static final int FIRST_RSSI_LEVEL = -80;
     /**
@@ -255,6 +256,9 @@ public class WifiMetricsTest {
         for (int i = 0; i < NUM_LAST_RESORT_WATCHDOG_TRIGGERS_WITH_BAD_OTHER; i++) {
             mWifiMetrics.incrementNumLastResortWatchdogTriggersWithBadOther();
         }
+        for (int i = 0; i < NUM_LAST_RESORT_WATCHDOG_SUCCESSES; i++) {
+            mWifiMetrics.incrementNumLastResortWatchdogSuccesses();
+        }
         for (int i = 0; i < NUM_RSSI_LEVELS_TO_INCREMENT; i++) {
             for (int j = 0; j <= i; j++) {
                 mWifiMetrics.incrementRssiPollRssiCount(FIRST_RSSI_LEVEL + i);
@@ -343,6 +347,8 @@ public class WifiMetricsTest {
                 mDeserializedWifiMetrics.numLastResortWatchdogTriggersWithBadDhcp);
         assertEquals(NUM_LAST_RESORT_WATCHDOG_TRIGGERS_WITH_BAD_OTHER,
                 mDeserializedWifiMetrics.numLastResortWatchdogTriggersWithBadOther);
+        assertEquals(NUM_LAST_RESORT_WATCHDOG_SUCCESSES,
+                mDeserializedWifiMetrics.numLastResortWatchdogSuccesses);
         assertEquals(TEST_RECORD_DURATION_SEC,
                 mDeserializedWifiMetrics.recordDurationSec);
         for (int i = 0; i < NUM_RSSI_LEVELS_TO_INCREMENT; i++) {