Support setReadTimeout in CronetHttpURLConnection

components/cronet/android/java/src/org/chromium/net/urlconnection/CronetHttpURLConnection.java

 // Copyright 2014 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.
 
 package org.chromium.net.urlconnection;
 
 import android.util.Pair;
 
 import org.chromium.base.Log;
 import org.chromium.net.CronetEngine;
@@ skipping 387 matching lines @@
 
     /**
      * Used by {@link CronetInputStream} to get more data from the network
      * stack. This should only be called after the request has started. Note
      * that this call might block if there isn't any more data to be read.
      * Since byteBuffer is passed to the UrlRequest, it must be a direct
      * ByteBuffer.
      */
     void getMoreData(ByteBuffer byteBuffer) throws IOException {
         mRequest.read(byteBuffer);
-        mMessageLoop.loop();
+        mMessageLoop.loop(getReadTimeout());

[jdcormie, 2016/05/17 17:48:34]

MessageLoop.loop(int timeout) appears to pull and run tasks from the queue until
it is quit() or until a single poll() blocks for more than "timeout"
milliseconds. But that's pretty different than what we want here which is the
following: run as many tasks from the queue as you want and block as many times
as you want, but don't spend more than getReadTimeout() milliseconds in total.

This version would be correct if you knew that a single task would be enough and
that no other tasks can be in the queue. Even if that happens to be true today,
it seems pretty brittle.

Instead, consider having MessageLoop.loop() interpret "timeout" as the time
budget for the whole call. Each time around the loop, compute how much time
remains before that deadline and pass that number as the timeout to poll().

[xunjieli, 2016/05/17 19:43:07]

Talked to Andrei. MessageLoop is our internal implementation detail. There is
only one MessageLoop per HttpURLConnection. When user calls InputStream.read(),
we will time out exactly after getReadTimeout(), so we think this what you want.

     }
 
     /**
      * Returns the index of request header in {@link #mRequestHeaders} or
      * -1 if not found.
      */
     private int findRequestProperty(String key) {
         for (int i = 0; i < mRequestHeaders.size(); i++) {
             Pair<String, String> entry = mRequestHeaders.get(i);
             if (entry.first.equalsIgnoreCase(key)) {
@@ skipping 90 matching lines @@
         if (mOutputStream != null) {
             mOutputStream.checkReceivedEnoughContent();
             if (isChunkedUpload()) {
                 // Write last chunk.
                 mOutputStream.close();
             }
         }
         if (!mHasResponse) {
             startRequest();
             // Blocks until onResponseStarted or onFailed is called.
-            mMessageLoop.loop();
+            mMessageLoop.loop(getConnectTimeout());
             mHasResponse = true;
         }
         checkHasResponse();
     }
 
     /**
      * Checks whether response headers are received, and throws an exception if
      * an exception occurred before headers received. This method should only be
      * called after onResponseStarted or onFailed.
      */
@@ skipping 58 matching lines @@
             // Strips Content-Encoding response header. See crbug.com/592700.
             if (!entry.getKey().equalsIgnoreCase("Content-Encoding")) {
                 mResponseHeadersList.add(
                         new AbstractMap.SimpleImmutableEntry<String, String>(entry));
             }
         }
         mResponseHeadersList = Collections.unmodifiableList(mResponseHeadersList);
         return mResponseHeadersList;
     }
 }