[Cronet] Check whether request is done before spinning up message loop

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

 // Copyright 2015 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 org.chromium.net.UploadDataProvider;
 
 import java.io.IOException;
 import java.io.OutputStream;
 
 /**
  * An abstract class of {@link OutputStream} that concrete implementations must
  * extend in order to be used in {@link CronetHttpURLConnection}.
  */
 abstract class CronetOutputStream extends OutputStream {
+    private IOException mException;
+    private boolean mClosed;
+    private boolean mRequestCompleted;
+
+    @Override
+    public void close() throws IOException {
+        mClosed = true;
+    }
+
     /**
      * Tells the underlying implementation that connection has been established.
      * Used in {@link CronetHttpURLConnection}.
      */
     abstract void setConnected() throws IOException;
 
     /**
      * Checks whether content received is less than Content-Length.
      * Used in {@link CronetHttpURLConnection}.
      */
     abstract void checkReceivedEnoughContent() throws IOException;
 
     /**
      * Returns {@link UploadDataProvider} implementation.
      */
     abstract UploadDataProvider getUploadDataProvider();
+
+    /**
+     * Signals that the request is done. If there is no error,
+     * {@code exception} is null. Used by {@link CronetHttpURLConnection}.
+     */
+    void setRequestCompleted(IOException exception) {
+        mException = exception;
+        mRequestCompleted = true;
+    }
+
+    /**
+     * Throws an IOException if the stream is closed or the request is done.
+     */
+    protected void checkNotClosed() throws IOException {
+        if (mRequestCompleted) {
+            if (mException != null) {
+                throw mException;
+            }
+            throw new IOException("Writing after request completed.");
+        }
+        if (mClosed) {
+            throw new IOException("Stream has been closed.");
+        }
+    }
 }