Disallow UI/IO thread blocking on any other thread.

base/threading/thread.cc

 // 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.
 
 #include "base/threading/thread.h"
 
 #include "base/bind.h"
 #include "base/lazy_instance.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/threading/thread_local.h"
+#include "base/threading/thread_restrictions.h"
 #include "base/synchronization/waitable_event.h"
 
 namespace base {
 
 namespace {
 
 // We use this thread-local variable to record whether or not a thread exited
 // because its Stop method was called.  This allows us to catch cases where
 // MessageLoop::Quit() is called directly, which is unexpected when using a
 // Thread to setup and run a MessageLoop.
@@ skipping 48 matching lines @@
   StartupData startup_data(options);
   startup_data_ = &startup_data;
 
   if (!PlatformThread::Create(options.stack_size, this, &thread_)) {
     DLOG(ERROR) << "failed to create thread";
     startup_data_ = NULL;
     return false;
   }
 
   // Wait for the thread to start and initialize message_loop_
+  base::ThreadRestrictions::ScopedAllowWait allow_wait;
   startup_data.event.Wait();
 
   // set it to NULL so we don't keep a pointer to some object on the stack.
   startup_data_ = NULL;
   started_ = true;
 
   DCHECK(message_loop_);
   return true;
 }
 
@@ skipping 77 matching lines @@
     // Assert that MessageLoop::Quit was called by ThreadQuitHelper.
     DCHECK(GetThreadWasQuitProperly());
 
     // We can't receive messages anymore.
     message_loop_ = NULL;
   }
   thread_id_ = kInvalidThreadId;
 }
 
 }  // namespace base