[Cronet] Do not call into BidirectionalStream::SendData if stream failed

components/cronet/android/test/src/org/chromium/net/QuicTestServer.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;
 
 import android.content.Context;
 import android.os.ConditionVariable;
 
 import org.chromium.base.Log;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 
 /**
  * Wrapper class to start a Quic test server.
  */
 @JNINamespace("cronet")
 public final class QuicTestServer {
     private static final ConditionVariable sBlock = new ConditionVariable();
     private static final String TAG = "cr.QuicTestServer";
 
     private static final String CERT_USED = "quic_test.example.com.crt";
     private static final String KEY_USED = "quic_test.example.com.key";
     private static final String[] CERTS_USED = {CERT_USED};
 
+    private static boolean sServerRunning = false;
+
+    /*
+     * Starts the server.
+     */
     public static void startQuicTestServer(Context context) {
+        if (sServerRunning) {
+            throw new IllegalStateException("Quic server is already running");
+        }
         TestFilesInstaller.installIfNeeded(context);
         nativeStartQuicTestServer(TestFilesInstaller.getInstalledPath(context));
         sBlock.block();
+        sBlock.close();
+        sServerRunning = true;
     }
 
+    /**
+     * Shuts down the server. No-op if the server is already shut down.
+     */
     public static void shutdownQuicTestServer() {
+        if (!sServerRunning) {
+            return;
+        }
         nativeShutdownQuicTestServer();
-        sBlock.close();
+        sServerRunning = false;
     }
 
     public static String getServerURL() {
         return "https://" + getServerHost() + ":" + getServerPort();
     }
 
     public static String getServerHost() {
         return nativeGetServerHost();
     }
 
@@ skipping 17 matching lines @@
     private static void onServerStarted() {
         Log.i(TAG, "Quic server started.");
         sBlock.open();
     }
 
     private static native void nativeStartQuicTestServer(String filePath);
     private static native void nativeShutdownQuicTestServer();
     private static native String nativeGetServerHost();
     private static native int nativeGetServerPort();
 }