Add a DCHECK for PlatformThread instances that are too busy.

webrtc/base/platform_thread_unittest.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include "webrtc/base/platform_thread.h"
 
 #include "webrtc/system_wrappers/include/sleep.h"
 #include "webrtc/test/gtest.h"
 
 namespace rtc {
 namespace {
 // Function that does nothing, and reports success.
 bool NullRunFunctionDeprecated(void* obj) {
-  webrtc::SleepMs(0);  // Hand over timeslice, prevents busy looping.
+  webrtc::SleepMs(2);  // Hand over timeslice, prevents busy looping.
   return true;
 }
 
+bool TooBusyRunFunction(void* obj) {
+  // Indentionally busy looping.
+  return true;
+}
+
 void NullRunFunction(void* obj) {}
 
 // Function that sets a boolean.
 bool SetFlagRunFunctionDeprecated(void* obj) {
   bool* obj_as_bool = static_cast<bool*>(obj);
   *obj_as_bool = true;
   webrtc::SleepMs(0);  // Hand over timeslice, prevents busy looping.
   return true;
 }
 
@@ skipping 67 matching lines @@
   PlatformThread thread(&SetFlagRunFunction, &flag, "RunFunctionIsCalled");
   thread.Start();
 
   // At this point, the flag may be either true or false.
   thread.Stop();
 
   // We expect the thread to have run at least once.
   EXPECT_TRUE(flag);
 }
 
+// This test is disabled since it will cause a crash.
+// There might be a way to implement this as a death test, but it looks like
+// a death test requires an expression to be checked but does not allow a
+// flag to be raised that says "some thread will crash after this point".
+// TODO(tommi): Look into ways to enable the test by default.
+TEST(PlatformThreadTest, DISABLED_TooBusyDeprecated) {
+  PlatformThread thread(&TooBusyRunFunction, nullptr, "BusyThread");
+  thread.Start();
+  webrtc::SleepMs(1000);
+  thread.Stop();
+}
+
 }  // rtc