Update scan band channels when needed

The involves adding an ability to channel helper to trigger a channel
list update.

Bug: 27381346
Change-Id: I7908018ff8136b9ce7880d5090bbe9e6fb63405d

11 files changed, 109 insertions, 42 deletions

diff --git a/service/java/com/android/server/wifi/HalWifiScannerImpl.java b/service/java/com/android/server/wifi/HalWifiScannerImpl.java
index b892f2d54..90a54f09f 100644
--- a/service/java/com/android/server/wifi/HalWifiScannerImpl.java
+++ b/service/java/com/android/server/wifi/HalWifiScannerImpl.java
@@ -25,8 +25,7 @@ import android.util.Log;
 
 import com.android.server.wifi.scanner.ChannelHelper;
 import com.android.server.wifi.scanner.ChannelHelper.ChannelCollection;
-import com.android.server.wifi.scanner.KnownBandsChannelHelper;
-import com.android.server.wifi.scanner.NoBandChannelHelper;
+import com.android.server.wifi.scanner.HalChannelHelper;
 
 import java.util.Arrays;
 import java.util.List;
@@ -53,32 +52,7 @@ public class HalWifiScannerImpl extends WifiScannerImpl implements Handler.Callb
         mWifiNative = wifiNative;
         mEventHandler = new Handler(looper, this);
 
-        // TODO(b/27324226) Remove this retry loop
-        // Sometimes angler returns an empty channel list the first time the channel list is queried
-        int[] channels24G = new int[0];
-        int[] channels5G = new int[0];
-        int[] channelsDfs = new int[0];
-        ChannelHelper channelHelper = null;
-        for (int i = 0; i < 4; ++i) {
-            channels24G = mWifiNative.getChannelsForBand(WifiScanner.WIFI_BAND_24_GHZ);
-            if (channels24G == null) Log.e(TAG, "Failed to get channels for 2.4GHz band");
-            channels5G = mWifiNative.getChannelsForBand(WifiScanner.WIFI_BAND_5_GHZ);
-            if (channels5G == null) Log.e(TAG, "Failed to get channels for 5GHz band");
-            channelsDfs = mWifiNative.getChannelsForBand(WifiScanner.WIFI_BAND_5_GHZ_DFS_ONLY);
-            if (channelsDfs == null) Log.e(TAG, "Failed to get channels for 5GHz DFS only band");
-            if (channels24G == null || channels5G == null || channelsDfs == null) {
-                Log.e(TAG, "Falling back to NoBandChannelHelper");
-                channelHelper = new NoBandChannelHelper();
-                break;
-            } else if (channels24G.length > 0 || channels5G.length > 0 || channelsDfs.length > 0) {
-                channelHelper = new KnownBandsChannelHelper(channels24G, channels5G, channelsDfs);
-            }
-            try { Thread.sleep(50); } catch (Exception e) {}
-        }
-        if (channelHelper == null) {
-            channelHelper = new KnownBandsChannelHelper(channels24G, channels5G, channelsDfs);
-        }
-        mChannelHelper = channelHelper;
+        mChannelHelper = new HalChannelHelper(wifiNative);
 
         // We can't enable these until WifiStateMachine switches to using WifiScanner because
         //   WifiMonitor only supports sending results to one listener
diff --git a/service/java/com/android/server/wifi/WifiScanningServiceImpl.java b/service/java/com/android/server/wifi/WifiScanningServiceImpl.java
index efc64e86c..75f2cc229 100644
--- a/service/java/com/android/server/wifi/WifiScanningServiceImpl.java
+++ b/service/java/com/android/server/wifi/WifiScanningServiceImpl.java
@@ -99,6 +99,7 @@ public class WifiScanningServiceImpl extends IWifiScanner.Stub {
 
     @Override
     public Bundle getAvailableChannels(int band) {
+        mChannelHelper.updateChannels();
         ChannelSpec[] channelSpecs = mChannelHelper.getAvailableScanChannels(band);
         ArrayList<Integer> list = new ArrayList<Integer>(channelSpecs.length);
         for (ChannelSpec channelSpec : channelSpecs) {
@@ -843,6 +844,7 @@ public class WifiScanningServiceImpl extends IWifiScanner.Stub {
     }
 
     private boolean updateSchedule() {
+        mChannelHelper.updateChannels();
         ArrayList<ScanSettings> settings = new ArrayList<>();
         for (ClientInfo client : mClients.values()) {
             settings.addAll(client.getScanSettings());
diff --git a/service/java/com/android/server/wifi/scanner/ChannelHelper.java b/service/java/com/android/server/wifi/scanner/ChannelHelper.java
index 0de1ca5e0..e6042c4b1 100644
--- a/service/java/com/android/server/wifi/scanner/ChannelHelper.java
+++ b/service/java/com/android/server/wifi/scanner/ChannelHelper.java
@@ -36,6 +36,8 @@ public abstract class ChannelHelper {
      */
     public static final int SCAN_PERIOD_PER_CHANNEL_MS = 200;
 
+    protected static final WifiScanner.ChannelSpec[] NO_CHANNELS = new WifiScanner.ChannelSpec[0];
+
     /**
      * Create a new collection that can be used to store channels
      */
@@ -58,6 +60,17 @@ public abstract class ChannelHelper {
     public abstract int estimateScanDuration(WifiScanner.ScanSettings settings);
 
     /**
+     * Update the channel information that this object has. The source of the update is
+     * implementation dependent and may result in no change. Warning the behavior of a
+     * ChannelCollection created using {@link #createChannelCollection createChannelCollection} is
+     * undefined after calling this method until the {@link ChannelColleciton#clear() clear} method
+     * is called on it.
+     */
+    public void updateChannels() {
+        // default implementation does nothing
+    }
+
+    /**
      * Object that supports accumulation of channels and bands
      */
     public abstract class ChannelCollection {
diff --git a/service/java/com/android/server/wifi/scanner/HalChannelHelper.java b/service/java/com/android/server/wifi/scanner/HalChannelHelper.java
new file mode 100644
index 000000000..83f4195f9
--- /dev/null
+++ b/service/java/com/android/server/wifi/scanner/HalChannelHelper.java
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.wifi.scanner;
+
+import android.net.wifi.WifiScanner;
+import android.util.Log;
+
+import com.android.server.wifi.WifiNative;
+
+/**
+ * KnownBandsChannelHelper that uses band to channel mappings retrieved from the HAL.
+ * Also supporting updating the channel list from the HAL on demand.
+ */
+public class HalChannelHelper extends KnownBandsChannelHelper {
+    private static final String TAG = "HalChannelHelper";
+
+    private final WifiNative mWifiNative;
+
+    public HalChannelHelper(WifiNative wifiNative) {
+        mWifiNative = wifiNative;
+        final int[] emptyFreqList = new int[0];
+        setBandChannels(emptyFreqList, emptyFreqList, emptyFreqList);
+        updateChannels();
+    }
+
+    @Override
+    public void updateChannels() {
+        int[] channels24G = mWifiNative.getChannelsForBand(WifiScanner.WIFI_BAND_24_GHZ);
+        if (channels24G == null) Log.e(TAG, "Failed to get channels for 2.4GHz band");
+        int[] channels5G = mWifiNative.getChannelsForBand(WifiScanner.WIFI_BAND_5_GHZ);
+        if (channels5G == null) Log.e(TAG, "Failed to get channels for 5GHz band");
+        int[] channelsDfs = mWifiNative.getChannelsForBand(WifiScanner.WIFI_BAND_5_GHZ_DFS_ONLY);
+        if (channelsDfs == null) Log.e(TAG, "Failed to get channels for 5GHz DFS only band");
+        if (channels24G == null || channels5G == null || channelsDfs == null) {
+            Log.e(TAG, "Failed to get all channels for band, not updating band channel lists");
+        } else if (channels24G.length > 0 || channels5G.length > 0 || channelsDfs.length > 0) {
+            setBandChannels(channels24G, channels5G, channelsDfs);
+        }
+
+    }
+}
diff --git a/service/java/com/android/server/wifi/scanner/KnownBandsChannelHelper.java b/service/java/com/android/server/wifi/scanner/KnownBandsChannelHelper.java
index 96dbeeaa6..3214cf2d1 100644
--- a/service/java/com/android/server/wifi/scanner/KnownBandsChannelHelper.java
+++ b/service/java/com/android/server/wifi/scanner/KnownBandsChannelHelper.java
@@ -29,11 +29,9 @@ import java.util.Set;
  */
 public class KnownBandsChannelHelper extends ChannelHelper {
 
-    private static final WifiScanner.ChannelSpec[] NO_CHANNELS = new WifiScanner.ChannelSpec[0];
-
     private WifiScanner.ChannelSpec[][] mBandsToChannels;
 
-    public KnownBandsChannelHelper(int[] channels2G, int[] channels5G, int[] channelsDfs) {
+    protected void setBandChannels(int[] channels2G, int[] channels5G, int[] channelsDfs) {
         mBandsToChannels = new WifiScanner.ChannelSpec[8][];
 
         mBandsToChannels[0] = NO_CHANNELS;
diff --git a/service/java/com/android/server/wifi/scanner/NoBandChannelHelper.java b/service/java/com/android/server/wifi/scanner/NoBandChannelHelper.java
index ea1f999ce..4528a53a6 100644
--- a/service/java/com/android/server/wifi/scanner/NoBandChannelHelper.java
+++ b/service/java/com/android/server/wifi/scanner/NoBandChannelHelper.java
@@ -29,8 +29,6 @@ import java.util.Set;
  */
 public class NoBandChannelHelper extends ChannelHelper {
 
-    private static final WifiScanner.ChannelSpec[] NO_CHANNELS = new WifiScanner.ChannelSpec[0];
-
     /**
      * These parameters are used to estimate the scan duration.
      * This is a guess at the number of channels the device supports for use when a ScanSettings
diff --git a/service/java/com/android/server/wifi/scanner/PresetKnownBandsChannelHelper.java b/service/java/com/android/server/wifi/scanner/PresetKnownBandsChannelHelper.java
new file mode 100644
index 000000000..2bc8b19bd
--- /dev/null
+++ b/service/java/com/android/server/wifi/scanner/PresetKnownBandsChannelHelper.java
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.wifi.scanner;
+
+/**
+ * KnownBandsChannelHelper that uses a supplied list of band to channels mappings.
+ */
+public class PresetKnownBandsChannelHelper extends KnownBandsChannelHelper {
+    public PresetKnownBandsChannelHelper(int[] channels2G, int[] channels5G, int[] channelsDfs) {
+        setBandChannels(channels2G, channels5G, channelsDfs);
+    }
+}
diff --git a/tests/wifitests/src/com/android/server/wifi/MultiClientSchedulerFilterTest.java b/tests/wifitests/src/com/android/server/wifi/MultiClientSchedulerFilterTest.java
index 8f6e8fbba..3c539ed8f 100644
--- a/tests/wifitests/src/com/android/server/wifi/MultiClientSchedulerFilterTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/MultiClientSchedulerFilterTest.java
@@ -34,7 +34,7 @@ import android.net.wifi.WifiScanner.ScanSettings;
 import android.test.suitebuilder.annotation.SmallTest;
 
 import com.android.server.wifi.scanner.ChannelHelper;
-import com.android.server.wifi.scanner.KnownBandsChannelHelper;
+import com.android.server.wifi.scanner.PresetKnownBandsChannelHelper;
 
 import org.junit.After;
 import org.junit.Before;
@@ -58,7 +58,7 @@ public class MultiClientSchedulerFilterTest {
 
     @Before
     public void setUp() throws Exception {
-        ChannelHelper channelHelper = new KnownBandsChannelHelper(
+        ChannelHelper channelHelper = new PresetKnownBandsChannelHelper(
                 new int[]{2400, 2450},
                 new int[]{5150, 5175},
                 new int[]{5600, 5650});
diff --git a/tests/wifitests/src/com/android/server/wifi/MultiClientSchedulerTest.java b/tests/wifitests/src/com/android/server/wifi/MultiClientSchedulerTest.java
index 45de55960..f0e8e95b8 100644
--- a/tests/wifitests/src/com/android/server/wifi/MultiClientSchedulerTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/MultiClientSchedulerTest.java
@@ -31,6 +31,7 @@ import android.test.suitebuilder.annotation.SmallTest;
 import com.android.server.wifi.WifiNative.BucketSettings;
 import com.android.server.wifi.scanner.KnownBandsChannelHelper;
 import com.android.server.wifi.scanner.KnownBandsChannelHelper.KnownBandsChannelCollection;
+import com.android.server.wifi.scanner.PresetKnownBandsChannelHelper;
 
 import org.junit.After;
 import org.junit.Before;
@@ -58,7 +59,7 @@ public class MultiClientSchedulerTest {
 
     @Before
     public void setUp() throws Exception {
-        mChannelHelper = new KnownBandsChannelHelper(
+        mChannelHelper = new PresetKnownBandsChannelHelper(
                 new int[]{2400, 2450},
                 new int[]{5150, 5175},
                 new int[]{5600, 5650, 5660});
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiScanningServiceTest.java b/tests/wifitests/src/com/android/server/wifi/WifiScanningServiceTest.java
index 870455df9..853c895bd 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiScanningServiceTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiScanningServiceTest.java
@@ -45,7 +45,7 @@ import com.android.internal.app.IBatteryStats;
 import com.android.internal.util.Protocol;
 import com.android.server.wifi.MockAnswerUtil.AnswerWithArguments;
 import com.android.server.wifi.scanner.ChannelHelper;
-import com.android.server.wifi.scanner.KnownBandsChannelHelper;
+import com.android.server.wifi.scanner.PresetKnownBandsChannelHelper;
 
 import org.junit.After;
 import org.junit.Before;
@@ -73,7 +73,7 @@ public class WifiScanningServiceTest {
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
 
-        ChannelHelper channelHelper = new KnownBandsChannelHelper(
+        ChannelHelper channelHelper = new PresetKnownBandsChannelHelper(
                 new int[]{2400, 2450},
                 new int[]{5150, 5175},
                 new int[]{5600, 5650, 5660});
diff --git a/tests/wifitests/src/com/android/server/wifi/scanner/KnownBandsChannelHelperTest.java b/tests/wifitests/src/com/android/server/wifi/scanner/KnownBandsChannelHelperTest.java
index 550fe41f0..0fec0ff29 100644
--- a/tests/wifitests/src/com/android/server/wifi/scanner/KnownBandsChannelHelperTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/scanner/KnownBandsChannelHelperTest.java
@@ -65,7 +65,7 @@ public class KnownBandsChannelHelperTest {
          */
         @Before
         public void setUp() throws Exception {
-            mChannelHelper = new KnownBandsChannelHelper(
+            mChannelHelper = new PresetKnownBandsChannelHelper(
                     CHANNELS_24_GHZ,
                     CHANNELS_5_GHZ,
                     CHANNELS_DFS);
@@ -109,7 +109,7 @@ public class KnownBandsChannelHelperTest {
          */
         @Before
         public void setUp() throws Exception {
-            mChannelHelper = new KnownBandsChannelHelper(
+            mChannelHelper = new PresetKnownBandsChannelHelper(
                     CHANNELS_24_GHZ,
                     CHANNELS_5_GHZ,
                     CHANNELS_DFS);
@@ -191,7 +191,7 @@ public class KnownBandsChannelHelperTest {
          */
         @Before
         public void setUp() throws Exception {
-            mChannelHelper = new KnownBandsChannelHelper(
+            mChannelHelper = new PresetKnownBandsChannelHelper(
                     CHANNELS_24_GHZ,
                     CHANNELS_5_GHZ,
                     CHANNELS_DFS);
@@ -265,7 +265,7 @@ public class KnownBandsChannelHelperTest {
          */
         @Before
         public void setUp() throws Exception {
-            KnownBandsChannelHelper channelHelper = new KnownBandsChannelHelper(
+            KnownBandsChannelHelper channelHelper = new PresetKnownBandsChannelHelper(
                     CHANNELS_24_GHZ,
                     CHANNELS_5_GHZ,
                     CHANNELS_DFS);