[DevTools] Network.emulateNetworkConditions now affects NetworkStateNotifier.

third_party/WebKit/Source/core/page/NetworkStateNotifier.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 24 matching lines @@
 #include "wtf/Threading.h"
 
 namespace blink {
 
 NetworkStateNotifier& networkStateNotifier()
 {
     DEFINE_THREAD_SAFE_STATIC_LOCAL(NetworkStateNotifier, networkStateNotifier, new NetworkStateNotifier);
     return networkStateNotifier;
 }
 
-void NetworkStateNotifier::setOnLine(bool onLine)
+void NetworkStateNotifier::setOnLine(bool onLineValue)
 {
-    ASSERT(isMainThread());
+    DCHECK(isMainThread());
 
     {
         MutexLocker locker(m_mutex);
-        if (m_isOnLine == onLine)
+        m_onLineInitialized = true;
+
+        if (m_isOnLine == onLineValue)
             return;
+        m_isOnLine = onLineValue;
 
-        m_isOnLine = onLine;
+        if (m_hasOverride)
+            return;
     }
 
-    Page::networkStateChanged(onLine);
+    Page::networkStateChanged(onLine());
 }
 
 void NetworkStateNotifier::setWebConnection(WebConnectionType type, double maxBandwidthMbps)
 {
-    ASSERT(isMainThread());
-    if (m_testUpdatesOnly)
-        return;
+    DCHECK(isMainThread());
 
-    setWebConnectionImpl(type, maxBandwidthMbps);
+    {
+        MutexLocker locker(m_mutex);
+        m_connectionInitialized = true;
+
+        if (m_type == type && m_maxBandwidthMbps == maxBandwidthMbps)
+            return;
+        m_type = type;
+        m_maxBandwidthMbps = maxBandwidthMbps;
+
+        if (m_hasOverride)
+            return;
+    }
+
+    notifyObservers();
 }
 
 void NetworkStateNotifier::addObserver(NetworkStateObserver* observer, ExecutionContext* context)
 {
     ASSERT(context->isContextThread());
     ASSERT(observer);
 
     MutexLocker locker(m_mutex);
     ObserverListMap::AddResult result = m_observers.add(context, nullptr);
     if (result.isNewEntry)
@@ skipping 16 matching lines @@
     size_t index = observers.find(observer);
     if (index != kNotFound) {
         observers[index] = 0;
         observerList->zeroedObservers.append(index);
     }
 
     if (!observerList->iterating && !observerList->zeroedObservers.isEmpty())
         collectZeroedObservers(observerList, context);
 }
 
-void NetworkStateNotifier::setTestUpdatesOnly(bool updatesOnly)
+void NetworkStateNotifier::setOverride(bool onLineValue, WebConnectionType type, double maxBandwidthMbps)
+{
+    DCHECK(isMainThread());
+
+    {
+        MutexLocker locker(m_mutex);
+        m_hasOverride = true;
+        m_overrideOnLine = onLineValue;
+        m_overrideType = type;
+        m_overrideMaxBandwidthMbps = maxBandwidthMbps;
+    }
+
+    notifyObservers();
+    Page::networkStateChanged(onLine());

[jkarlin, 2016/06/24 14:47:50]

setOnline and setWebConnection check if anything has actually changed before
sending out notification. This should as well.

[dgozman, 2016/06/24 15:13:44]

I think this would be undesirable. Consider two cases it's used:
- Tests. Here we cannot rely on the previous values (they can be arbitrary). And
if the test expects an event to be fired, event should fire no matter what.
- DevTools emulation. Here user expects an event to fire after an explicit
action. If it fires at some times and not the others, it would be perceived as
unreliable.

[jkarlin, 2016/06/24 19:20:16]

The clients of NetworkStateNotifier (e.g., the online event) don't expect to get
repeat values. Firing onLine twice without first calling offLine isn't spec'd
behavior.

If tests need an event, they can set it to one value and then another, the
second will trigger an event. That's what the existing tests do.
Do they? If my device is onLine and I change to 2G, I wouldn't expect to receive
an onLine event.

[dgozman, 2016/06/27 23:03:49]

Alright, you convinced me. Can't go against the spec.

+}
+
+void NetworkStateNotifier::clearOverride()
+{
+    DCHECK(isMainThread());
+
+    {
+        MutexLocker locker(m_mutex);
+        m_hasOverride = false;
+    }
+
+    notifyObservers();
+    Page::networkStateChanged(onLine());

[jkarlin, 2016/06/24 14:47:50]

setOnline and setWebConnection check if anything has actually changed before
sending out notification. This should as well.

+}
+
+void NetworkStateNotifier::notifyObservers()
 {
     ASSERT(isMainThread());
-    MutexLocker locker(m_mutex);
-
-    // Reset state to default when entering or leaving test mode.
-    if (updatesOnly != m_testUpdatesOnly) {
-        m_isOnLine = true;
-        m_type = WebConnectionTypeOther;
-        m_maxBandwidthMbps = std::numeric_limits<double>::infinity();
-    }
-
-    m_testUpdatesOnly = updatesOnly;
-}
-
-void NetworkStateNotifier::setWebConnectionForTest(WebConnectionType type, double maxBandwidthMbps)
-{
-    ASSERT(isMainThread());
-    ASSERT(m_testUpdatesOnly);
-    setWebConnectionImpl(type, maxBandwidthMbps);
-}
-
-void NetworkStateNotifier::setWebConnectionImpl(WebConnectionType type, double maxBandwidthMbps)
-{
-    ASSERT(isMainThread());
+    WebConnectionType type = connectionType();
+    double maxBandwidthMbps = maxBandwidth();
 
     MutexLocker locker(m_mutex);
-    m_initialized = true;
-
-    if (m_type == type && m_maxBandwidthMbps == maxBandwidthMbps)
-        return;
-    m_type = type;
-    m_maxBandwidthMbps = maxBandwidthMbps;
-
     for (const auto& entry : m_observers) {
         ExecutionContext* context = entry.key;
         context->postTask(BLINK_FROM_HERE, createCrossThreadTask(&NetworkStateNotifier::notifyObserversOfConnectionChangeOnContext, crossThreadUnretained(this), type, maxBandwidthMbps));
     }
 }
 
 void NetworkStateNotifier::notifyObserversOfConnectionChangeOnContext(WebConnectionType type, double maxBandwidthMbps, ExecutionContext* context)
 {
     ObserverList* observerList = lockAndFindObserverList(context);
 
@@ skipping 36 matching lines @@
 
     list->zeroedObservers.clear();
 
     if (list->observers.isEmpty()) {
         MutexLocker locker(m_mutex);
         m_observers.remove(context); // deletes list
     }
 }
 
 } // namespace blink