Provide NetworkChangeNotifierAndroid with the actual initial connection type.

net/android/network_change_notifier_delegate_android.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/android/network_change_notifier_delegate_android.h"
 
+#include "base/bind.h"
+#include "base/compiler_specific.h"
 #include "base/logging.h"
+#include "base/message_loop_proxy.h"
+#include "base/single_thread_task_runner.h"
 #include "jni/NetworkChangeNotifier_jni.h"
 
 namespace net {
 
 namespace {
 
 // Returns whether the provided connection type is known.
 bool CheckConnectionType(int connection_type) {
   switch (connection_type) {
     case NetworkChangeNotifier::CONNECTION_UNKNOWN:
     case NetworkChangeNotifier::CONNECTION_ETHERNET:
     case NetworkChangeNotifier::CONNECTION_WIFI:
     case NetworkChangeNotifier::CONNECTION_2G:
     case NetworkChangeNotifier::CONNECTION_3G:
     case NetworkChangeNotifier::CONNECTION_4G:
     case NetworkChangeNotifier::CONNECTION_NONE:
       return true;
     default:
       NOTREACHED() << "Unknown connection type received: " << connection_type;
       return false;
   }
 }
 
 }  // namespace
 
 NetworkChangeNotifierDelegateAndroid::NetworkChangeNotifierDelegateAndroid()
-    : observers_(new ObserverListThreadSafe<Observer>()) {
+    : jni_task_runner_(base::MessageLoopProxy::current()),
+      ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)),
+      weak_ptr_(weak_ptr_factory_.GetWeakPtr()),
+      observers_(new ObserverListThreadSafe<Observer>()),
+      connection_type_(NetworkChangeNotifier::CONNECTION_UNKNOWN) {
+  JNIEnv* env = base::android::AttachCurrentThread();
   java_network_change_notifier_.Reset(
-      Java_NetworkChangeNotifier_createInstance(
-          base::android::AttachCurrentThread(),
-          base::android::GetApplicationContext(),
-          reinterpret_cast<jint>(this)));
+      Java_NetworkChangeNotifier_init(
+          env, base::android::GetApplicationContext()));
+  Java_NetworkChangeNotifier_addNativeObserver(
+      env, java_network_change_notifier_.obj(), reinterpret_cast<jint>(this));
 }
 
 NetworkChangeNotifierDelegateAndroid::~NetworkChangeNotifierDelegateAndroid() {
   DCHECK(thread_checker_.CalledOnValidThread());
   observers_->AssertEmpty();
   JNIEnv* env = base::android::AttachCurrentThread();
-  Java_NetworkChangeNotifier_destroyInstance(env);
+  Java_NetworkChangeNotifier_removeNativeObserver(
+      env, java_network_change_notifier_.obj(), reinterpret_cast<jint>(this));
 }
 
 void NetworkChangeNotifierDelegateAndroid::NotifyConnectionTypeChanged(
     JNIEnv* env,
     jobject obj,
     jint new_connection_type) {
   DCHECK(thread_checker_.CalledOnValidThread());
   connection_type_ = CheckConnectionType(new_connection_type) ?
       static_cast<ConnectionType>(new_connection_type) :
       NetworkChangeNotifier::CONNECTION_UNKNOWN;
   observers_->Notify(&Observer::OnConnectionTypeChanged, connection_type_);
 }
 
 jint NetworkChangeNotifierDelegateAndroid::GetConnectionType(JNIEnv*,
                                                              jobject) const {
   DCHECK(thread_checker_.CalledOnValidThread());
   return connection_type_;
 }
 
 void NetworkChangeNotifierDelegateAndroid::AddObserver(
     Observer* observer) {
   observers_->AddObserver(observer);
+  SendInitialNotification();
 }
 
 void NetworkChangeNotifierDelegateAndroid::RemoveObserver(
     Observer* observer) {
   observers_->RemoveObserver(observer);
 }
 
 void NetworkChangeNotifierDelegateAndroid::ForceConnectivityState(
     ConnectivityState state) {
   DCHECK(thread_checker_.CalledOnValidThread());
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_NetworkChangeNotifier_forceConnectivityState(env, state == ONLINE);
 }
 
 // static
 bool NetworkChangeNotifierDelegateAndroid::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
+void NetworkChangeNotifierDelegateAndroid::SendInitialNotification() {
+  // This function must be executed on the JNI thread since it reads
+  // |connection_type_| which is written on the JNI thread (with no lock).
+  if (!jni_task_runner_->BelongsToCurrentThread()) {
+    // Note that copying a weak pointer (which is constructed on the JNI thread
+    // in this case) is thread-safe.
+    jni_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(
+            &NetworkChangeNotifierDelegateAndroid::SendInitialNotification,
+            weak_ptr_));
+    return;
+  }
+  // Ideally only the newly added observer should be notified to receive the
+  // current connection type. ObserverListThreadSafe doesn't support this
+  // functionality unfortunately. Note that the observers (a small number of
+  // NetworkChangeNotifierAndroid instances) will forward the notification only
+  // if the provided connection type is different from the previous one. This
+  // means that notifying all observers has no impact from the client
+  // perspective.
+  observers_->Notify(&Observer::OnConnectionTypeChanged, connection_type_);
+}
+
 }  // namespace net