From 0ed524dee8a22c18f9617a314ac6e65ac1e94380 Mon Sep 17 00:00:00 2001
From: Mitchell Wills <mwills@google.com>
Date: Thu, 14 Apr 2016 13:39:44 -0700
Subject: [PATCH] Connect WifiScanner synchronously without sync barrier

This allows the WifiScanner constructor to be called from the Looper
that is associated with the provided handler instead of relying on the
provided looper to execute initialization async.

Bug: 27695292
Change-Id: Id30dbb8d181971035a0b3f76dd485875e9d03ca3
---
 wifi/java/android/net/wifi/WifiScanner.java | 44 ++-------------------
 1 file changed, 4 insertions(+), 40 deletions(-)

diff --git a/wifi/java/android/net/wifi/WifiScanner.java b/wifi/java/android/net/wifi/WifiScanner.java
index 1a8197c85dbd9..2ee1aefc559e2 100644
--- a/wifi/java/android/net/wifi/WifiScanner.java
+++ b/wifi/java/android/net/wifi/WifiScanner.java
@@ -20,7 +20,6 @@ import android.annotation.SystemApi;
 import android.content.Context;
 import android.os.Bundle;
 import android.os.Handler;
-import android.os.HandlerThread;
 import android.os.Looper;
 import android.os.Message;
 import android.os.Messenger;
@@ -31,13 +30,11 @@ import android.os.WorkSource;
 import android.util.Log;
 import android.util.SparseArray;
 
-import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.AsyncChannel;
 import com.android.internal.util.Preconditions;
 import com.android.internal.util.Protocol;
 
 import java.util.List;
-import java.util.concurrent.CountDownLatch;
 
 
 /**
@@ -1143,7 +1140,6 @@ public class WifiScanner {
     private final Object mListenerMapLock = new Object();
 
     private AsyncChannel mAsyncChannel;
-    private final CountDownLatch mConnected;
     private final Handler mInternalHandler;
 
     /**
@@ -1157,22 +1153,6 @@ public class WifiScanner {
      * @hide
      */
     public WifiScanner(Context context, IWifiScanner service, Looper looper) {
-        this(context, service, looper, true);
-    }
-
-    /**
-     * Create a new WifiScanner instance.
-     *
-     * @param context The application context.
-     * @param service The IWifiScanner Binder interface
-     * @param looper the Looper used to deliver callbacks
-     * @param waitForConnection If true, this will not return until a connection to Wifi Scanner
-     *          service is established.
-     * @hide
-     */
-    @VisibleForTesting
-    public WifiScanner(Context context, IWifiScanner service, Looper looper,
-            boolean waitForConnection) {
         mContext = context;
         mService = service;
 
@@ -1188,17 +1168,12 @@ public class WifiScanner {
         }
 
         mAsyncChannel = new AsyncChannel();
-        mConnected = new CountDownLatch(1);
 
         mInternalHandler = new ServiceHandler(looper);
-        mAsyncChannel.connect(mContext, mInternalHandler, messenger);
-        if (waitForConnection) {
-            try {
-                mConnected.await();
-            } catch (InterruptedException e) {
-                Log.e(TAG, "interrupted wait at init");
-            }
-        }
+        mAsyncChannel.connectSync(mContext, mInternalHandler, messenger);
+        // We cannot use fullyConnectSync because it sends the FULL_CONNECTION message
+        // synchronously, which causes WifiScanningService to receive the wrong replyTo value.
+        mAsyncChannel.sendMessage(AsyncChannel.CMD_CHANNEL_FULL_CONNECTION);
     }
 
     private void validateChannel() {
@@ -1326,17 +1301,6 @@ public class WifiScanner {
         @Override
         public void handleMessage(Message msg) {
             switch (msg.what) {
-                case AsyncChannel.CMD_CHANNEL_HALF_CONNECTED:
-                    if (msg.arg1 == AsyncChannel.STATUS_SUCCESSFUL) {
-                        mAsyncChannel.sendMessage(AsyncChannel.CMD_CHANNEL_FULL_CONNECTION);
-                    } else {
-                        Log.e(TAG, "Failed to set up channel connection");
-                        // This will cause all further async API calls on the WifiManager
-                        // to fail and throw an exception
-                        mAsyncChannel = null;
-                    }
-                    mConnected.countDown();
-                    return;
                 case AsyncChannel.CMD_CHANNEL_FULLY_CONNECTED:
                     return;
                 case AsyncChannel.CMD_CHANNEL_DISCONNECTED: