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1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. | 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 | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef BASE_SYNCHRONIZATION_CANCELLATION_FLAG_H_ | 5 #ifndef BASE_SYNCHRONIZATION_CANCELLATION_FLAG_H_ |
6 #define BASE_SYNCHRONIZATION_CANCELLATION_FLAG_H_ | 6 #define BASE_SYNCHRONIZATION_CANCELLATION_FLAG_H_ |
7 #pragma once | 7 #pragma once |
8 | 8 |
9 #include "base/base_api.h" | 9 #include "base/base_export.h" |
10 #include "base/atomicops.h" | 10 #include "base/atomicops.h" |
11 #include "base/threading/platform_thread.h" | 11 #include "base/threading/platform_thread.h" |
12 | 12 |
13 namespace base { | 13 namespace base { |
14 | 14 |
15 // CancellationFlag allows one thread to cancel jobs executed on some worker | 15 // CancellationFlag allows one thread to cancel jobs executed on some worker |
16 // thread. Calling Set() from one thread and IsSet() from a number of threads | 16 // thread. Calling Set() from one thread and IsSet() from a number of threads |
17 // is thread-safe. | 17 // is thread-safe. |
18 // | 18 // |
19 // This class IS NOT intended for synchronization between threads. | 19 // This class IS NOT intended for synchronization between threads. |
20 class BASE_API CancellationFlag { | 20 class BASE_EXPORT CancellationFlag { |
21 public: | 21 public: |
22 CancellationFlag() : flag_(false) { | 22 CancellationFlag() : flag_(false) { |
23 #if !defined(NDEBUG) | 23 #if !defined(NDEBUG) |
24 set_on_ = PlatformThread::CurrentId(); | 24 set_on_ = PlatformThread::CurrentId(); |
25 #endif | 25 #endif |
26 } | 26 } |
27 ~CancellationFlag() {} | 27 ~CancellationFlag() {} |
28 | 28 |
29 // Set the flag. May only be called on the thread which owns the object. | 29 // Set the flag. May only be called on the thread which owns the object. |
30 void Set(); | 30 void Set(); |
31 bool IsSet() const; // Returns true iff the flag was set. | 31 bool IsSet() const; // Returns true iff the flag was set. |
32 | 32 |
33 private: | 33 private: |
34 base::subtle::Atomic32 flag_; | 34 base::subtle::Atomic32 flag_; |
35 #if !defined(NDEBUG) | 35 #if !defined(NDEBUG) |
36 PlatformThreadId set_on_; | 36 PlatformThreadId set_on_; |
37 #endif | 37 #endif |
38 | 38 |
39 DISALLOW_COPY_AND_ASSIGN(CancellationFlag); | 39 DISALLOW_COPY_AND_ASSIGN(CancellationFlag); |
40 }; | 40 }; |
41 | 41 |
42 } // namespace base | 42 } // namespace base |
43 | 43 |
44 #endif // BASE_SYNCHRONIZATION_CANCELLATION_FLAG_H_ | 44 #endif // BASE_SYNCHRONIZATION_CANCELLATION_FLAG_H_ |
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