WifiStateMachine: Dont repeatedly call sendExplicitlySelected

Use the last selected network timestamp
(WifiConfigManager.getLastSelectedTimestamp) to limit the invocation of
NetworkAgent.sendExplicitlySelected. The current expiration is set at 30
seconds to prevent the user from receiving notifications about lack of
internet connectivity repeatedly on the same network.

Bug: 62503737
Test: Added a unit test for the helper function. Ideally would have
wanted to use a mock WifiNetworkAgent and capture the interaction on it,
but because of the way WSM is designed currently, it's impossible to use
a WifiInjector to mock it out.

Change-Id: I342b617769141c3e8071e5aba89efebe42c97390
(cherry-picked from 674c12b8a66d2961cf9a5930b1e0fab4dda86152)

2 files changed, 95 insertions, 4 deletions

diff --git a/service/java/com/android/server/wifi/WifiStateMachine.java b/service/java/com/android/server/wifi/WifiStateMachine.java
index b247083fb..eec0996c1 100644
--- a/service/java/com/android/server/wifi/WifiStateMachine.java
+++ b/service/java/com/android/server/wifi/WifiStateMachine.java
@@ -769,6 +769,14 @@ public class WifiStateMachine extends StateMachine implements WifiNative.WifiRss
     private static final int SUSPEND_DUE_TO_HIGH_PERF = 1 << 1;
     private static final int SUSPEND_DUE_TO_SCREEN = 1 << 2;
 
+    /**
+     * Time window in milliseconds for which we send
+     * {@link NetworkAgent#explicitlySelected(boolean)}
+     * after connecting to the network which the user last selected.
+     */
+    @VisibleForTesting
+    public static final int LAST_SELECTED_NETWORK_EXPIRATION_AGE_MILLIS = 30 * 1000;
+
     /* Tracks if user has enabled suspend optimizations through settings */
     private AtomicBoolean mUserWantsSuspendOpt = new AtomicBoolean(true);
 
@@ -6077,13 +6085,29 @@ public class WifiStateMachine extends StateMachine implements WifiNative.WifiRss
         }
     }
 
+    /**
+     * Helper function to check if we need to invoke
+     * {@link NetworkAgent#explicitlySelected(boolean)} to indicate that we connected to a network
+     * which the user just chose
+     * (i.e less than {@link #LAST_SELECTED_NETWORK_EXPIRATION_AGE_MILLIS) before).
+     */
+    @VisibleForTesting
+    public boolean shouldEvaluateWhetherToSendExplicitlySelected(WifiConfiguration currentConfig) {
+        if (currentConfig == null) {
+            Log.wtf(TAG, "Current WifiConfiguration is null, but IP provisioning just succeeded");
+            return false;
+        }
+        long currentTimeMillis = mClock.getElapsedSinceBootMillis();
+        return (mWifiConfigManager.getLastSelectedNetwork() == currentConfig.networkId
+                && currentTimeMillis - mWifiConfigManager.getLastSelectedTimeStamp()
+                < LAST_SELECTED_NETWORK_EXPIRATION_AGE_MILLIS);
+    }
+
     private void sendConnectedState() {
         // If this network was explicitly selected by the user, evaluate whether to call
         // explicitlySelected() so the system can treat it appropriately.
         WifiConfiguration config = getCurrentWifiConfiguration();
-        if (config == null) {
-            Log.wtf(TAG, "Current WifiConfiguration is null, but IP provisioning just succeeded");
-        } else if (mWifiConfigManager.getLastSelectedNetwork() == config.networkId) {
+        if (shouldEvaluateWhetherToSendExplicitlySelected(config)) {
             boolean prompt =
                     mWifiPermissionsUtil.checkConfigOverridePermission(config.lastConnectUid);
             if (mVerboseLoggingEnabled) {
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiStateMachineTest.java b/tests/wifitests/src/com/android/server/wifi/WifiStateMachineTest.java
index eb1bae018..8d578b3d9 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiStateMachineTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiStateMachineTest.java
@@ -346,6 +346,7 @@ public class WifiStateMachineTest {
     @Mock IpManager mIpManager;
     @Mock TelephonyManager mTelephonyManager;
     @Mock WrongPasswordNotifier mWrongPasswordNotifier;
+    @Mock Clock mClock;
 
     public WifiStateMachineTest() throws Exception {
     }
@@ -387,6 +388,7 @@ public class WifiStateMachineTest {
         when(mWifiInjector.getWifiNative()).thenReturn(mWifiNative);
         when(mWifiInjector.getSelfRecovery()).thenReturn(mSelfRecovery);
         when(mWifiInjector.makeTelephonyManager()).thenReturn(mTelephonyManager);
+        when(mWifiInjector.getClock()).thenReturn(mClock);
 
         when(mWifiNative.setupForClientMode())
                 .thenReturn(Pair.create(WifiNative.SETUP_SUCCESS, mClientInterface));
@@ -2028,7 +2030,7 @@ public class WifiStateMachineTest {
         verify(mWifiNative, never()).resetTxPowerLimit();
     }
 
-    /*
+    /**
      * Verifies that a network disconnection event will result in WifiStateMachine invoking
      * {@link WifiConfigManager#removeAllEphemeralOrPasspointConfiguredNetworks()} to remove
      * any ephemeral or passpoint networks from it's internal database.
@@ -2075,4 +2077,69 @@ public class WifiStateMachineTest {
         verify(mWifiConfigManager).clearRecentFailureReason(eq(0));
         verify(mWifiConfigManager, never()).setRecentFailureAssociationStatus(anyInt(), anyInt());
     }
+
+    /**
+     * Test that the helper method
+     * {@link WifiStateMachine#shouldEvaluateWhetherToSendExplicitlySelected(WifiConfiguration)}
+     * returns true when we connect to the last selected network before expiration of
+     * {@link WifiStateMachine#LAST_SELECTED_NETWORK_EXPIRATION_AGE_MILLIS}.
+     */
+    @Test
+    public void testShouldEvaluateWhetherToSendExplicitlySelected_SameNetworkNotExpired() {
+        long lastSelectedTimestamp = 45666743454L;
+        int lastSelectedNetworkId = 5;
+
+        when(mClock.getElapsedSinceBootMillis()).thenReturn(
+                lastSelectedTimestamp
+                        + WifiStateMachine.LAST_SELECTED_NETWORK_EXPIRATION_AGE_MILLIS - 1);
+        when(mWifiConfigManager.getLastSelectedTimeStamp()).thenReturn(lastSelectedTimestamp);
+        when(mWifiConfigManager.getLastSelectedNetwork()).thenReturn(lastSelectedNetworkId);
+
+        WifiConfiguration currentConfig = new WifiConfiguration();
+        currentConfig.networkId = lastSelectedNetworkId;
+        assertTrue(mWsm.shouldEvaluateWhetherToSendExplicitlySelected(currentConfig));
+    }
+
+    /**
+     * Test that the helper method
+     * {@link WifiStateMachine#shouldEvaluateWhetherToSendExplicitlySelected(WifiConfiguration)}
+     * returns false when we connect to the last selected network after expiration of
+     * {@link WifiStateMachine#LAST_SELECTED_NETWORK_EXPIRATION_AGE_MILLIS}.
+     */
+    @Test
+    public void testShouldEvaluateWhetherToSendExplicitlySelected_SameNetworkExpired() {
+        long lastSelectedTimestamp = 45666743454L;
+        int lastSelectedNetworkId = 5;
+
+        when(mClock.getElapsedSinceBootMillis()).thenReturn(
+                lastSelectedTimestamp
+                        + WifiStateMachine.LAST_SELECTED_NETWORK_EXPIRATION_AGE_MILLIS + 1);
+        when(mWifiConfigManager.getLastSelectedTimeStamp()).thenReturn(lastSelectedTimestamp);
+        when(mWifiConfigManager.getLastSelectedNetwork()).thenReturn(lastSelectedNetworkId);
+
+        WifiConfiguration currentConfig = new WifiConfiguration();
+        currentConfig.networkId = lastSelectedNetworkId;
+        assertFalse(mWsm.shouldEvaluateWhetherToSendExplicitlySelected(currentConfig));
+    }
+
+    /**
+     * Test that the helper method
+     * {@link WifiStateMachine#shouldEvaluateWhetherToSendExplicitlySelected(WifiConfiguration)}
+     * returns false when we connect to a different network to the last selected network.
+     */
+    @Test
+    public void testShouldEvaluateWhetherToSendExplicitlySelected_DifferentNetwork() {
+        long lastSelectedTimestamp = 45666743454L;
+        int lastSelectedNetworkId = 5;
+
+        when(mClock.getElapsedSinceBootMillis()).thenReturn(
+                lastSelectedTimestamp
+                        + WifiStateMachine.LAST_SELECTED_NETWORK_EXPIRATION_AGE_MILLIS - 1);
+        when(mWifiConfigManager.getLastSelectedTimeStamp()).thenReturn(lastSelectedTimestamp);
+        when(mWifiConfigManager.getLastSelectedNetwork()).thenReturn(lastSelectedNetworkId);
+
+        WifiConfiguration currentConfig = new WifiConfiguration();
+        currentConfig.networkId = lastSelectedNetworkId - 1;
+        assertFalse(mWsm.shouldEvaluateWhetherToSendExplicitlySelected(currentConfig));
+    }
 }