Added Network Quality Estimator Real-time interface to Cronet

components/cronet/android/java/src/org/chromium/net/CronetUrlRequestContext.java

Index: components/cronet/android/java/src/org/chromium/net/CronetUrlRequestContext.java
diff --git a/components/cronet/android/java/src/org/chromium/net/CronetUrlRequestContext.java b/components/cronet/android/java/src/org/chromium/net/CronetUrlRequestContext.java
index 7bae2883221d5340a4ddbb23c19c9bf4865d978a..22c7045957ded0bf8015e81daa22e1a74c5cf790 100644
--- a/components/cronet/android/java/src/org/chromium/net/CronetUrlRequestContext.java
+++ b/components/cronet/android/java/src/org/chromium/net/CronetUrlRequestContext.java
@@ -12,6 +12,7 @@ import android.os.Looper;
 import android.os.Process;
 import android.util.Log;
 
+import org.chromium.base.ObserverList;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
@@ -19,6 +20,7 @@ import org.chromium.base.annotations.NativeClassQualifiedName;
 import org.chromium.base.annotations.UsedByReflection;
 
 import java.util.concurrent.Executor;
+import java.util.concurrent.RejectedExecutionException;
 import java.util.concurrent.atomic.AtomicInteger;
 
 /**
@@ -42,6 +44,14 @@ class CronetUrlRequestContext extends UrlRequestContext {
     private long mUrlRequestContextAdapter = 0;
     private Thread mNetworkThread;
 
+    private Executor mNetworkQualityExecutor;
+    private final Object mNetworkQualityLock = new Object();

[pauljensen, 2015/09/02 16:54:48]

Please add a comment about what this is locking.

[bengr, 2015/09/14 21:04:35]

Done.

+
+    private final ObserverList<NetworkQualityRTTObserver> mRTTObserverList =

[pauljensen, 2015/09/02 16:54:48]

Can we use @GuardedBy?

[bengr, 2015/09/14 21:04:35]

Done.

+            new ObserverList<NetworkQualityRTTObserver>();
+    private final ObserverList<NetworkQualityThroughputObserver> mThroughputObserverList =
+            new ObserverList<NetworkQualityThroughputObserver>();
+
     @UsedByReflection("UrlRequestContext.java")
     public CronetUrlRequestContext(Context context,
                                    UrlRequestContextConfig config) {
@@ -148,6 +158,74 @@ class CronetUrlRequestContext extends UrlRequestContext {
         }
     }
 
+    @Override
+    public void enableNetworkQualityEstimator(Executor executor) {
+        enableNetworkQualityEstimator(false, false, executor);
+    }
+
+    @Override
+    void enableNetworkQualityEstimator(
+            boolean useLocalHostRequests, boolean useSmallerResponses, Executor executor) {
+        mNetworkQualityExecutor = executor;
+        synchronized (mLock) {
+            checkHaveAdapter();
+            nativeEnableNetworkQualityEstimator(
+                    mUrlRequestContextAdapter, useLocalHostRequests, useSmallerResponses);
+        }
+    }
+
+    @Override
+    public void addRTTObserver(NetworkQualityRTTObserver observer) {
+        if (mRTTObserverList.isEmpty()) {

[pauljensen, 2015/09/02 16:54:48]

You lock mRTTObserverList on line 186 but not here?  Ditto for other functions
and mThroughputObserverList.

[bengr, 2015/09/14 21:04:35]

Good catch. Thanks.

+            synchronized (mLock) {
+                checkHaveAdapter();
+                nativeProvideRTTObservations(mUrlRequestContextAdapter, true);
+            }
+        }
+        synchronized (mNetworkQualityLock) {
+            mRTTObserverList.addObserver(observer);
+        }
+    }
+
+    @Override
+    public void removeRTTObserver(NetworkQualityRTTObserver observer) {
+        synchronized (mNetworkQualityLock) {
+            mRTTObserverList.removeObserver(observer);
+        }
+        if (mRTTObserverList.isEmpty()) {
+            synchronized (mLock) {
+                checkHaveAdapter();
+                nativeProvideRTTObservations(mUrlRequestContextAdapter, false);
+            }
+        }
+    }
+
+    @Override
+    public void addThroughputObserver(NetworkQualityThroughputObserver observer) {
+        if (mThroughputObserverList.isEmpty()) {
+            synchronized (mLock) {
+                checkHaveAdapter();
+                nativeProvideThroughputObservations(mUrlRequestContextAdapter, true);
+            }
+        }
+        synchronized (mNetworkQualityLock) {
+            mThroughputObserverList.addObserver(observer);
+        }
+    }
+
+    @Override
+    public void removeThroughputObserver(NetworkQualityThroughputObserver observer) {
+        synchronized (mNetworkQualityLock) {
+            mThroughputObserverList.removeObserver(observer);
+        }
+        if (mThroughputObserverList.isEmpty()) {
+            synchronized (mLock) {
+                checkHaveAdapter();
+                nativeProvideThroughputObservations(mUrlRequestContextAdapter, false);
+            }
+        }
+    }
+
     /**
      * Mark request as started to prevent shutdown when there are active
      * requests.
@@ -209,6 +287,45 @@ class CronetUrlRequestContext extends UrlRequestContext {
         Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
     }
 
+    @SuppressWarnings("unused")
+    @CalledByNative
+    private void onRTTObservation(final int value, final long when, final int source) {
+        Runnable task = new Runnable() {
+            @Override
+            public void run() {
+                for (NetworkQualityRTTObserver observer : mRTTObserverList) {
+                    observer.onRTTObservation(value, when, source);
+                }
+            }
+        };
+        postObservationTaskToExecutor(task);
+    }
+
+    @SuppressWarnings("unused")
+    @CalledByNative
+    private void onThroughputObservation(final int value, final long when, final int source) {
+        Runnable task = new Runnable() {
+            @Override
+            public void run() {
+                for (NetworkQualityThroughputObserver observer : mThroughputObserverList) {
+                    observer.onThroughputObservation(value, when, source);
+                }
+            }
+        };
+        postObservationTaskToExecutor(task);
+    }
+
+    void postObservationTaskToExecutor(Runnable task) {
+        try {
+            synchronized (mNetworkQualityLock) {
+                mNetworkQualityExecutor.execute(task);
+            }
+        } catch (RejectedExecutionException failException) {
+            Log.e(CronetUrlRequestContext.LOG_TAG, "Exception posting task to executor",
+                    failException);
+        }
+    }
+
     // Native methods are implemented in cronet_url_request_context.cc.
     private static native long nativeCreateRequestContextAdapter(String config);
 
@@ -226,4 +343,14 @@ class CronetUrlRequestContext extends UrlRequestContext {
 
     @NativeClassQualifiedName("CronetURLRequestContextAdapter")
     private native void nativeInitRequestContextOnMainThread(long nativePtr);
+
+    @NativeClassQualifiedName("CronetURLRequestContextAdapter")
+    private native void nativeEnableNetworkQualityEstimator(
+            long nativePtr, boolean useLocalHostRequests, boolean useSmallerResponses);
+
+    @NativeClassQualifiedName("CronetURLRequestContextAdapter")
+    private native void nativeProvideRTTObservations(long nativePtr, boolean should);
+
+    @NativeClassQualifiedName("CronetURLRequestContextAdapter")
+    private native void nativeProvideThroughputObservations(long nativePtr, boolean should);
 }