Sometimes you want to enforce that some but not all of your methods are called on the same thread as the constructor. ThreadChecker allows you to do this.

BUG=38475
TEST=base_unittests --gtest_filter=NonThreadSafeTest.* and base_unittests --gtest_filter=ThreadChecker.*

Review URL: http://codereview.chromium.org/3148032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57140 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 53 insertions, 0 deletions

diff --git a/base/thread_checker.h b/base/thread_checker.h
new file mode 100644
index 0000000..4e1d792
--- /dev/null
+++ b/base/thread_checker.h
@@ -0,0 +1,53 @@
+// Copyright (c) 2010 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.
+
+#ifndef BASE_THREAD_CHECKER_H_
+#define BASE_THREAD_CHECKER_H_
+#pragma once
+
+#include "base/platform_thread.h"
+
+// Before using this class, please consider using NonThreadSafe as it
+// makes it much easier to determine the nature of your class.
+//
+// A helper class used to help verify that some methods of a class are
+// called from the same thread.  One can inherit from this class and use
+// CalledOnValidThread() to verify.
+//
+// Inheriting from class indicates that one must be careful when using the class
+// with multiple threads. However, it is up to the class document to indicate
+// how it can be used with threads.
+//
+// Example:
+// class MyClass : public ThreadChecker {
+//  public:
+//   void Foo() {
+//     DCHECK(CalledOnValidThread());
+//     ... (do stuff) ...
+//   }
+// }
+//
+// In Release mode, CalledOnValidThread will always return true.
+//
+#ifndef NDEBUG
+class ThreadChecker {
+ public:
+  ThreadChecker();
+
+  bool CalledOnValidThread() const;
+
+ private:
+  const PlatformThreadId valid_thread_id_;
+};
+#else
+// Do nothing in release mode.
+class ThreadChecker {
+ public:
+  bool CalledOnValidThread() const {
+    return true;
+  }
+};
+#endif  // NDEBUG
+
+#endif  // BASE_THREAD_CHECKER_H_