Fix access point list jumping around in WifiSettings
This happens because the scan times are very aggressive
(to save power); and we don't find all APs on each scan.
So on each scan, some APs are considered lost and some
other are considered found; resulting in reordering the
list.
This change fixes that by requiring 3 scans to confirm
absence of an AP.
Bug: 7263326
Change-Id: I04f61ec5e5aa1589f457645acbf538c7e275a4bf
diff --git a/packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java b/packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java
index 4cef286..0180a30 100644
--- a/packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java
+++ b/packages/SettingsLib/src/com/android/settingslib/wifi/AccessPoint.java
@@ -46,6 +46,7 @@
import com.android.settingslib.R;
+import java.util.ArrayList;
import java.util.Map;
@@ -79,10 +80,15 @@
* For now this data is used only with Verbose Logging so as to show the band and number
* of BSSIDs on which that network is seen.
*/
- public LruCache<String, ScanResult> mScanResultCache;
+ public LruCache<String, ScanResult> mScanResultCache = new LruCache<String, ScanResult>(32);
+
private static final String KEY_NETWORKINFO = "key_networkinfo";
private static final String KEY_WIFIINFO = "key_wifiinfo";
private static final String KEY_SCANRESULT = "key_scanresult";
+ private static final String KEY_SSID = "key_ssid";
+ private static final String KEY_SECURITY = "key_security";
+ private static final String KEY_PSKTYPE = "key_psktype";
+ private static final String KEY_SCANRESULTCACHE = "key_scanresultcache";
private static final String KEY_CONFIG = "key_config";
/**
@@ -108,7 +114,6 @@
private int pskType = PSK_UNKNOWN;
private WifiConfiguration mConfig;
- private ScanResult mScanResult;
private int mRssi = Integer.MAX_VALUE;
private long mSeen = 0;
@@ -125,20 +130,35 @@
if (mConfig != null) {
loadConfig(mConfig);
}
- mScanResult = (ScanResult) savedState.getParcelable(KEY_SCANRESULT);
- if (mScanResult != null) {
- loadResult(mScanResult);
+ if (savedState.containsKey(KEY_SSID)) {
+ ssid = savedState.getString(KEY_SSID);
+ }
+ if (savedState.containsKey(KEY_SECURITY)) {
+ security = savedState.getInt(KEY_SECURITY);
+ }
+ if (savedState.containsKey(KEY_PSKTYPE)) {
+ pskType = savedState.getInt(KEY_PSKTYPE);
}
mInfo = (WifiInfo) savedState.getParcelable(KEY_WIFIINFO);
if (savedState.containsKey(KEY_NETWORKINFO)) {
mNetworkInfo = savedState.getParcelable(KEY_NETWORKINFO);
}
+ if (savedState.containsKey(KEY_SCANRESULTCACHE)) {
+ ArrayList<ScanResult> scanResultArrayList =
+ savedState.getParcelableArrayList(KEY_SCANRESULTCACHE);
+ mScanResultCache.evictAll();
+ for (ScanResult result : scanResultArrayList) {
+ mScanResultCache.put(result.BSSID, result);
+ }
+ }
update(mInfo, mNetworkInfo);
+ mRssi = getRssi();
+ mSeen = getSeen();
}
AccessPoint(Context context, ScanResult result) {
mContext = context;
- loadResult(result);
+ initWithScanResult(result);
}
AccessPoint(Context context, WifiConfiguration config) {
@@ -240,6 +260,28 @@
return WifiManager.calculateSignalLevel(mRssi, 4);
}
+ public int getRssi() {
+ int rssi = Integer.MIN_VALUE;
+ for (ScanResult result : mScanResultCache.snapshot().values()) {
+ if (result.level > rssi) {
+ rssi = result.level;
+ }
+ }
+
+ return rssi;
+ }
+
+ public long getSeen() {
+ long seen = 0;
+ for (ScanResult result : mScanResultCache.snapshot().values()) {
+ if (result.timestamp > seen) {
+ seen = result.timestamp;
+ }
+ }
+
+ return seen;
+ }
+
public NetworkInfo getNetworkInfo() {
return mNetworkInfo;
}
@@ -455,120 +497,109 @@
visibility.append(String.format("rx=%.1f", mInfo.rxSuccessRate));
}
- if (mScanResultCache != null) {
- int rssi5 = WifiConfiguration.INVALID_RSSI;
- int rssi24 = WifiConfiguration.INVALID_RSSI;
- int num5 = 0;
- int num24 = 0;
- int numBlackListed = 0;
- int n24 = 0; // Number scan results we included in the string
- int n5 = 0; // Number scan results we included in the string
- Map<String, ScanResult> list = mScanResultCache.snapshot();
- // TODO: sort list by RSSI or age
- for (ScanResult result : list.values()) {
- if (result.seen == 0)
- continue;
+ int rssi5 = WifiConfiguration.INVALID_RSSI;
+ int rssi24 = WifiConfiguration.INVALID_RSSI;
+ int num5 = 0;
+ int num24 = 0;
+ int numBlackListed = 0;
+ int n24 = 0; // Number scan results we included in the string
+ int n5 = 0; // Number scan results we included in the string
+ Map<String, ScanResult> list = mScanResultCache.snapshot();
+ // TODO: sort list by RSSI or age
+ for (ScanResult result : list.values()) {
+ if (result.seen == 0)
+ continue;
- if (result.autoJoinStatus != ScanResult.ENABLED) numBlackListed++;
+ if (result.autoJoinStatus != ScanResult.ENABLED) numBlackListed++;
- if (result.frequency >= LOWER_FREQ_5GHZ
- && result.frequency <= HIGHER_FREQ_5GHZ) {
- // Strictly speaking: [4915, 5825]
- // number of known BSSID on 5GHz band
- num5 = num5 + 1;
- } else if (result.frequency >= LOWER_FREQ_24GHZ
- && result.frequency <= HIGHER_FREQ_24GHZ) {
- // Strictly speaking: [2412, 2482]
- // number of known BSSID on 2.4Ghz band
- num24 = num24 + 1;
- }
-
- // Ignore results seen, older than 20 seconds
- if (now - result.seen > VISIBILITY_OUTDATED_AGE_IN_MILLI) continue;
-
- if (result.frequency >= LOWER_FREQ_5GHZ
- && result.frequency <= HIGHER_FREQ_5GHZ) {
- if (result.level > rssi5) {
- rssi5 = result.level;
- }
- if (n5 < 4) {
- if (scans5GHz == null) scans5GHz = new StringBuilder();
- scans5GHz.append(" \n{").append(result.BSSID);
- if (bssid != null && result.BSSID.equals(bssid)) scans5GHz.append("*");
- scans5GHz.append("=").append(result.frequency);
- scans5GHz.append(",").append(result.level);
- if (result.autoJoinStatus != 0) {
- scans5GHz.append(",st=").append(result.autoJoinStatus);
- }
- if (result.numIpConfigFailures != 0) {
- scans5GHz.append(",ipf=").append(result.numIpConfigFailures);
- }
- scans5GHz.append("}");
- n5++;
- }
- } else if (result.frequency >= LOWER_FREQ_24GHZ
- && result.frequency <= HIGHER_FREQ_24GHZ) {
- if (result.level > rssi24) {
- rssi24 = result.level;
- }
- if (n24 < 4) {
- if (scans24GHz == null) scans24GHz = new StringBuilder();
- scans24GHz.append(" \n{").append(result.BSSID);
- if (bssid != null && result.BSSID.equals(bssid)) scans24GHz.append("*");
- scans24GHz.append("=").append(result.frequency);
- scans24GHz.append(",").append(result.level);
- if (result.autoJoinStatus != 0) {
- scans24GHz.append(",st=").append(result.autoJoinStatus);
- }
- if (result.numIpConfigFailures != 0) {
- scans24GHz.append(",ipf=").append(result.numIpConfigFailures);
- }
- scans24GHz.append("}");
- n24++;
- }
- }
+ if (result.frequency >= LOWER_FREQ_5GHZ
+ && result.frequency <= HIGHER_FREQ_5GHZ) {
+ // Strictly speaking: [4915, 5825]
+ // number of known BSSID on 5GHz band
+ num5 = num5 + 1;
+ } else if (result.frequency >= LOWER_FREQ_24GHZ
+ && result.frequency <= HIGHER_FREQ_24GHZ) {
+ // Strictly speaking: [2412, 2482]
+ // number of known BSSID on 2.4Ghz band
+ num24 = num24 + 1;
}
- visibility.append(" [");
- if (num24 > 0) {
- visibility.append("(").append(num24).append(")");
- if (n24 <= 4) {
- if (scans24GHz != null) {
- visibility.append(scans24GHz.toString());
- }
- } else {
- visibility.append("max=").append(rssi24);
- if (scans24GHz != null) {
- visibility.append(",").append(scans24GHz.toString());
- }
+
+ // Ignore results seen, older than 20 seconds
+ if (now - result.seen > VISIBILITY_OUTDATED_AGE_IN_MILLI) continue;
+
+ if (result.frequency >= LOWER_FREQ_5GHZ
+ && result.frequency <= HIGHER_FREQ_5GHZ) {
+ if (result.level > rssi5) {
+ rssi5 = result.level;
}
- }
- visibility.append(";");
- if (num5 > 0) {
- visibility.append("(").append(num5).append(")");
- if (n5 <= 4) {
- if (scans5GHz != null) {
- visibility.append(scans5GHz.toString());
+ if (n5 < 4) {
+ if (scans5GHz == null) scans5GHz = new StringBuilder();
+ scans5GHz.append(" \n{").append(result.BSSID);
+ if (bssid != null && result.BSSID.equals(bssid)) scans5GHz.append("*");
+ scans5GHz.append("=").append(result.frequency);
+ scans5GHz.append(",").append(result.level);
+ if (result.autoJoinStatus != 0) {
+ scans5GHz.append(",st=").append(result.autoJoinStatus);
}
- } else {
- visibility.append("max=").append(rssi5);
- if (scans5GHz != null) {
- visibility.append(",").append(scans5GHz.toString());
+ if (result.numIpConfigFailures != 0) {
+ scans5GHz.append(",ipf=").append(result.numIpConfigFailures);
}
+ scans5GHz.append("}");
+ n5++;
}
- }
- if (numBlackListed > 0)
- visibility.append("!").append(numBlackListed);
- visibility.append("]");
- } else {
- if (mRssi != Integer.MAX_VALUE) {
- visibility.append(" rssi=");
- visibility.append(mRssi);
- if (mScanResult != null) {
- visibility.append(", f=");
- visibility.append(mScanResult.frequency);
+ } else if (result.frequency >= LOWER_FREQ_24GHZ
+ && result.frequency <= HIGHER_FREQ_24GHZ) {
+ if (result.level > rssi24) {
+ rssi24 = result.level;
+ }
+ if (n24 < 4) {
+ if (scans24GHz == null) scans24GHz = new StringBuilder();
+ scans24GHz.append(" \n{").append(result.BSSID);
+ if (bssid != null && result.BSSID.equals(bssid)) scans24GHz.append("*");
+ scans24GHz.append("=").append(result.frequency);
+ scans24GHz.append(",").append(result.level);
+ if (result.autoJoinStatus != 0) {
+ scans24GHz.append(",st=").append(result.autoJoinStatus);
+ }
+ if (result.numIpConfigFailures != 0) {
+ scans24GHz.append(",ipf=").append(result.numIpConfigFailures);
+ }
+ scans24GHz.append("}");
+ n24++;
}
}
}
+ visibility.append(" [");
+ if (num24 > 0) {
+ visibility.append("(").append(num24).append(")");
+ if (n24 <= 4) {
+ if (scans24GHz != null) {
+ visibility.append(scans24GHz.toString());
+ }
+ } else {
+ visibility.append("max=").append(rssi24);
+ if (scans24GHz != null) {
+ visibility.append(",").append(scans24GHz.toString());
+ }
+ }
+ }
+ visibility.append(";");
+ if (num5 > 0) {
+ visibility.append("(").append(num5).append(")");
+ if (n5 <= 4) {
+ if (scans5GHz != null) {
+ visibility.append(scans5GHz.toString());
+ }
+ } else {
+ visibility.append("max=").append(rssi5);
+ if (scans5GHz != null) {
+ visibility.append(",").append(scans5GHz.toString());
+ }
+ }
+ }
+ if (numBlackListed > 0)
+ visibility.append("!").append(numBlackListed);
+ visibility.append("]");
return visibility.toString();
}
@@ -635,28 +666,29 @@
ssid = config.providerFriendlyName;
else
ssid = (config.SSID == null ? "" : removeDoubleQuotes(config.SSID));
-
+
security = getSecurity(config);
networkId = config.networkId;
mConfig = config;
}
- private void loadResult(ScanResult result) {
+ private void initWithScanResult(ScanResult result) {
ssid = result.SSID;
security = getSecurity(result);
if (security == SECURITY_PSK)
pskType = getPskType(result);
mRssi = result.level;
- mScanResult = result;
- if (result.seen > mSeen) {
- mSeen = result.seen;
- }
+ mSeen = result.timestamp;
}
public void saveWifiState(Bundle savedState) {
- savedState.putParcelable(KEY_CONFIG, mConfig);
- savedState.putParcelable(KEY_SCANRESULT, mScanResult);
+ if (ssid != null) savedState.putString(KEY_SSID, getSsidStr());
+ savedState.putInt(KEY_SECURITY, security);
+ savedState.putInt(KEY_PSKTYPE, pskType);
+ if (mConfig != null) savedState.putParcelable(KEY_CONFIG, mConfig);
savedState.putParcelable(KEY_WIFIINFO, mInfo);
+ savedState.putParcelableArrayList(KEY_SCANRESULTCACHE,
+ new ArrayList<ScanResult>(mScanResultCache.snapshot().values()));
if (mNetworkInfo != null) {
savedState.putParcelable(KEY_NETWORKINFO, mNetworkInfo);
}
@@ -667,32 +699,31 @@
}
boolean update(ScanResult result) {
- if (result.seen > mSeen) {
- mSeen = result.seen;
- }
- if (WifiTracker.sVerboseLogging > 0) {
- if (mScanResultCache == null) {
- mScanResultCache = new LruCache<String, ScanResult>(32);
- }
- mScanResultCache.put(result.BSSID, result);
- }
-
if (ssid.equals(result.SSID) && security == getSecurity(result)) {
- if (WifiManager.compareSignalLevel(result.level, mRssi) > 0) {
- int oldLevel = getLevel();
- mRssi = result.level;
- if (getLevel() != oldLevel && mAccessPointListener != null) {
- mAccessPointListener.onLevelChanged(this);
- }
+ /* Update the LRU timestamp, if BSSID exists */
+ mScanResultCache.get(result.BSSID);
+
+ /* Add or update the scan result for the BSSID */
+ mScanResultCache.put(result.BSSID, result);
+
+ int oldLevel = getLevel();
+ int oldRssi = getRssi();
+ mSeen = getSeen();
+ mRssi = (getRssi() + oldRssi)/2;
+ int newLevel = getLevel();
+
+ if (newLevel > 0 && newLevel != oldLevel && mAccessPointListener != null) {
+ mAccessPointListener.onLevelChanged(this);
}
// This flag only comes from scans, is not easily saved in config
if (security == SECURITY_PSK) {
pskType = getPskType(result);
}
- mScanResult = result;
+
if (mAccessPointListener != null) {
mAccessPointListener.onAccessPointChanged(this);
}
+
return true;
}
return false;
diff --git a/packages/SettingsLib/src/com/android/settingslib/wifi/WifiTracker.java b/packages/SettingsLib/src/com/android/settingslib/wifi/WifiTracker.java
index 19be4a5..f4e4ea1 100644
--- a/packages/SettingsLib/src/com/android/settingslib/wifi/WifiTracker.java
+++ b/packages/SettingsLib/src/com/android/settingslib/wifi/WifiTracker.java
@@ -28,6 +28,7 @@
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
+import android.util.Log;
import android.widget.Toast;
import com.android.internal.annotations.VisibleForTesting;
@@ -35,9 +36,12 @@
import java.io.PrintWriter;
import java.util.ArrayList;
+import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
+import java.util.Iterator;
import java.util.List;
+import java.util.Map;
import java.util.concurrent.atomic.AtomicBoolean;
/**
@@ -45,6 +49,7 @@
*/
public class WifiTracker {
private static final String TAG = "WifiTracker";
+ private static final boolean DBG = false;
/** verbose logging flag. this flag is set thru developer debugging options
* and used so as to assist with in-the-field WiFi connectivity debugging */
@@ -70,6 +75,10 @@
private boolean mSavedNetworksExist;
private boolean mRegistered;
private ArrayList<AccessPoint> mAccessPoints = new ArrayList<>();
+ private HashMap<String, Integer> mSeenBssids = new HashMap<>();
+ private HashMap<String, ScanResult> mScanResultCache = new HashMap<>();
+ private Integer mScanId = 0;
+ private static final int NUM_SCANS_TO_CONFIRM_AP_LOSS = 3;
private NetworkInfo mLastNetworkInfo;
private WifiInfo mLastInfo;
@@ -166,6 +175,11 @@
if (mScanner == null) {
mScanner = new Scanner();
}
+
+ mScanResultCache.clear();
+ mSeenBssids.clear();
+ mScanId = 0;
+
if (mWifiManager.isWifiEnabled()) {
mScanner.resume();
}
@@ -237,6 +251,33 @@
}
}
+ private Collection<ScanResult> fetchScanResults() {
+ mScanId++;
+ final List<ScanResult> newResults = mWifiManager.getScanResults();
+ for (ScanResult newResult : newResults) {
+ mScanResultCache.put(newResult.BSSID, newResult);
+ mSeenBssids.put(newResult.BSSID, mScanId);
+ }
+
+ if (mScanId > NUM_SCANS_TO_CONFIRM_AP_LOSS) {
+ if (DBG) Log.d(TAG, "------ Dumping SSIDs that were expired on this scan ------");
+ Integer threshold = mScanId - NUM_SCANS_TO_CONFIRM_AP_LOSS;
+ for (Iterator<Map.Entry<String, Integer>> it = mSeenBssids.entrySet().iterator();
+ it.hasNext(); /* nothing */) {
+ Map.Entry<String, Integer> e = it.next();
+ if (e.getValue() < threshold) {
+ ScanResult result = mScanResultCache.get(e.getKey());
+ if (DBG) Log.d(TAG, "Removing " + e.getKey() + ":(" + result.SSID + ")");
+ mScanResultCache.remove(e.getKey());
+ it.remove();
+ }
+ }
+ if (DBG) Log.d(TAG, "---- Done Dumping SSIDs that were expired on this scan ----");
+ }
+
+ return mScanResultCache.values();
+ }
+
private void updateAccessPoints() {
// Swap the current access points into a cached list.
List<AccessPoint> cachedAccessPoints = getAccessPoints();
@@ -283,7 +324,7 @@
}
}
- final List<ScanResult> results = mWifiManager.getScanResults();
+ final Collection<ScanResult> results = fetchScanResults();
if (results != null) {
for (ScanResult result : results) {
// Ignore hidden and ad-hoc networks.
@@ -328,6 +369,24 @@
// Pre-sort accessPoints to speed preference insertion
Collections.sort(accessPoints);
+
+ // Log accesspoints that were deleted
+ if (DBG) Log.d(TAG, "------ Dumping SSIDs that were not seen on this scan ------");
+ for (AccessPoint prevAccessPoint : mAccessPoints) {
+ if (prevAccessPoint.getSsid() == null) continue;
+ String prevSsid = prevAccessPoint.getSsidStr();
+ boolean found = false;
+ for (AccessPoint newAccessPoint : accessPoints) {
+ if (newAccessPoint.getSsid() != null && newAccessPoint.getSsid().equals(prevSsid)) {
+ found = true;
+ break;
+ }
+ }
+ if (!found)
+ if (DBG) Log.d(TAG, "Did not find " + prevSsid + " in this scan");
+ }
+ if (DBG) Log.d(TAG, "---- Done dumping SSIDs that were not seen on this scan ----");
+
mAccessPoints = accessPoints;
mMainHandler.sendEmptyMessage(MainHandler.MSG_ACCESS_POINT_CHANGED);
}
