| OLD | NEW |
|---|
| (Empty) |
| 1 // Copyright (c) 2012 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_NON_THREAD_SAFE_H_ | |
| 6 #define BASE_THREADING_NON_THREAD_SAFE_H_ | |
| 7 | |
| 8 // Classes deriving from NonThreadSafe may need to suppress MSVC warning 4275: | |
| 9 // non dll-interface class 'Bar' used as base for dll-interface class 'Foo'. | |
| 10 // There is a specific macro to do it: NON_EXPORTED_BASE(), defined in | |
| 11 // compiler_specific.h | |
| 12 #include "base/compiler_specific.h" | |
| 13 | |
| 14 // See comment at top of thread_checker.h | |
| 15 #if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)) | |
| 16 #define ENABLE_NON_THREAD_SAFE 1 | |
| 17 #else | |
| 18 #define ENABLE_NON_THREAD_SAFE 0 | |
| 19 #endif | |
| 20 | |
| 21 #include "base/threading/non_thread_safe_impl.h" | |
| 22 | |
| 23 namespace base { | |
| 24 | |
| 25 // Do nothing implementation of NonThreadSafe, for release mode. | |
| 26 // | |
| 27 // Note: You should almost always use the NonThreadSafe class to get | |
| 28 // the right version of the class for your build configuration. | |
| 29 class NonThreadSafeDoNothing { | |
| 30 public: | |
| 31 bool CalledOnValidThread() const { | |
| 32 return true; | |
| 33 } | |
| 34 | |
| 35 protected: | |
| 36 ~NonThreadSafeDoNothing() {} | |
| 37 void DetachFromThread() {} | |
| 38 }; | |
| 39 | |
| 40 // NonThreadSafe is a helper class used to help verify that methods of a | |
| 41 // class are called from the same thread. One can inherit from this class | |
| 42 // and use CalledOnValidThread() to verify. | |
| 43 // | |
| 44 // This is intended to be used with classes that appear to be thread safe, but | |
| 45 // aren't. For example, a service or a singleton like the preferences system. | |
| 46 // | |
| 47 // Example: | |
| 48 // class MyClass : public base::NonThreadSafe { | |
| 49 // public: | |
| 50 // void Foo() { | |
| 51 // DCHECK(CalledOnValidThread()); | |
| 52 // ... (do stuff) ... | |
| 53 // } | |
| 54 // } | |
| 55 // | |
| 56 // Note that base::ThreadChecker offers identical functionality to | |
| 57 // NonThreadSafe, but does not require inheritance. In general, it is preferable | |
| 58 // to have a base::ThreadChecker as a member, rather than inherit from | |
| 59 // NonThreadSafe. For more details about when to choose one over the other, see | |
| 60 // the documentation for base::ThreadChecker. | |
| 61 #if ENABLE_NON_THREAD_SAFE | |
| 62 typedef NonThreadSafeImpl NonThreadSafe; | |
| 63 #else | |
| 64 typedef NonThreadSafeDoNothing NonThreadSafe; | |
| 65 #endif // ENABLE_NON_THREAD_SAFE | |
| 66 | |
| 67 #undef ENABLE_NON_THREAD_SAFE | |
| 68 | |
| 69 } // namespace base | |
| 70 | |
| 71 #endif // BASE_THREADING_NON_THREAD_SAFE_H_ | |
| OLD | NEW |
|---|
Chromium Code Reviews
