[Cronet] Fix race in UploadDataStream.attachToRequest.

components/cronet/android/java/src/org/chromium/net/CronetUrlRequest.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;
 
 import android.os.SystemClock;
 import android.support.annotation.Nullable;
 import android.util.Log;
 
@@ skipping 193 matching lines @@
                         throw new IllegalArgumentException(
                                 "Invalid header " + header.getKey() + "=" + header.getValue());
                     }
                 }
                 if (mUploadDataStream != null) {
                     if (!hasContentType) {
                         throw new IllegalArgumentException(
                                 "Requests with upload data must have a Content-Type.");
                     }
                     mStarted = true;
-                    mUploadDataStream.attachToRequest(this, mUrlRequestAdapter, new Runnable() {
+                    mUploadDataStream.postTaskToExecutor(new Runnable() {
                         @Override
                         public void run() {
+                            mUploadDataStream.initializeWithRequest(CronetUrlRequest.this);
                             synchronized (mUrlRequestAdapterLock) {
+                                if (isDoneLocked()) {
+                                    return;
+                                }
+                                mUploadDataStream.attachNativeAdapterToRequest(mUrlRequestAdapter);
                                 startInternalLocked();
                             }
                         }
                     });
                     return;
                 }
             } catch (RuntimeException e) {
                 // If there's an exception, cleanup and then throw the
                 // exception to the caller.
                 destroyRequestAdapter(false);
                 throw e;
             }
             mStarted = true;
             startInternalLocked();
         }
     }
 
     @GuardedBy("mUrlRequestAdapterLock")
     private void startInternalLocked() {
+        // Caller is expected to ensure that request isn't done and mUrlRequestAdapter is valid.

[xunjieli, 2016/03/10 22:40:54]

nit: maybe make this comment to the method level (java doc) where it is more
visible.

[mef, 2016/03/11 15:43:06]

Done. I wonder whether we should just put isDoneLocked check here for good
measure.

[xunjieli, 2016/03/11 15:44:32]

I am not sure. Your call :)

         if (mDisableCache) {
             nativeDisableCache(mUrlRequestAdapter);
         }
         if (mRequestMetricsAccumulator != null) {
             mRequestMetricsAccumulator.onRequestStarted();
         }
         nativeStart(mUrlRequestAdapter);
     }
 
     @Override
@@ skipping 489 matching lines @@
     @NativeClassQualifiedName("CronetURLRequestAdapter")
     private native boolean nativeReadData(long nativePtr, ByteBuffer byteBuffer,
             int position, int capacity);
 
     @NativeClassQualifiedName("CronetURLRequestAdapter")
     private native void nativeDestroy(long nativePtr, boolean sendOnCanceled);
 
     @NativeClassQualifiedName("CronetURLRequestAdapter")
     private native void nativeGetStatus(long nativePtr, UrlRequest.StatusListener listener);
 }