base/threading/thread_checker_impl.h

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_THREADING_THREAD_CHECKER_IMPL_H_
   6 #define BASE_THREADING_THREAD_CHECKER_IMPL_H_
   7
   8 #include "base/base_export.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/synchronization/lock.h"
  11 #include "base/threading/platform_thread.h"
  12
  13 namespace base {
  14
  15 // Real implementation of ThreadChecker, for use in debug mode, or
  16 // for temporary use in release mode (e.g. to CHECK on a threading issue
  17 // seen only in the wild).
  18 //
  19 // Note: You should almost always use the ThreadChecker class to get the
  20 // right version for your build configuration.
  21 class BASE_EXPORT ThreadCheckerImpl {
  22  public:
  23   ThreadCheckerImpl();
  24   ~ThreadCheckerImpl();
  25
  26   bool CalledOnValidThread() const WARN_UNUSED_RESULT;
  27
  28   // Changes the thread that is checked for in CalledOnValidThread.  This may
  29   // be useful when an object may be created on one thread and then used
  30   // exclusively on another thread.
  31   void DetachFromThread();
  32
  33  private:
  34   void EnsureThreadIdAssigned() const;
  35
  36   mutable base::Lock lock_;
  37   // This is mutable so that CalledOnValidThread can set it.
  38   // It's guarded by |lock_|.
  39   mutable PlatformThreadRef valid_thread_id_;
  40 };
  41
  42 }  // namespace base
  43
  44 #endif  // BASE_THREADING_THREAD_CHECKER_IMPL_H_