Disallow UI/IO thread blocking on any other thread.

base/threading/simple_thread.h

 // Copyright (c) 2011 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.
 
 // WARNING: You should probably be using Thread (thread.h) instead.  Thread is
 //          Chrome's message-loop based Thread abstraction, and if you are a
 //          thread running in the browser, there will likely be assumptions
 //          that your thread will have an associated message loop.
 //
 // This is a simple thread interface that backs to a native operating system
@@ skipping 79 matching lines @@
   // Return the thread name prefix, or "unnamed" if none was supplied.
   std::string name_prefix() { return name_prefix_; }
 
   // Return the completed name including TID, only valid after Start().
   std::string name() { return name_; }
 
   // Return the thread id, only valid after Start().
   PlatformThreadId tid() { return tid_; }
 
   // Return True if Start() has ever been called.
-  bool HasBeenStarted() { return event_.IsSignaled(); }
+  bool HasBeenStarted();
 
   // Return True if Join() has evern been called.
   bool HasBeenJoined() { return joined_; }
 
   // Overridden from PlatformThread::Delegate:
   virtual void ThreadMain() OVERRIDE;
 
   // Only set priorities with a careful understanding of the consequences.
   // This is meant for very limited use cases.
   void SetThreadPriority(ThreadPriority priority) {
@@ skipping 71 matching lines @@
   int num_threads_;
   std::vector<DelegateSimpleThread*> threads_;
   std::queue<Delegate*> delegates_;
   base::Lock lock_;            // Locks delegates_
   WaitableEvent dry_;    // Not signaled when there is no work to do.
 };
 
 }  // namespace base
 
 #endif  // BASE_THREADING_SIMPLE_THREAD_H_