1 /*---------------------------------------------------------------------------*
2   Project:  Horizon
3   File:     fnd_Backoff.h
4 
5   Copyright (C)2009 Nintendo Co., Ltd.  All rights reserved.
6 
7   These coded instructions, statements, and computer programs contain
8   proprietary information of Nintendo of America Inc. and/or Nintendo
9   Company Ltd., and are protected by Federal copyright law.  They may
10   not be disclosed to third parties or copied or duplicated in any form,
11   in whole or in part, without the prior written consent of Nintendo.
12 
13   $Rev: 12449 $
14  *---------------------------------------------------------------------------*/
15 
16 #ifndef NN_FND_FND_BACKOFF_H_
17 #define NN_FND_FND_BACKOFF_H_
18 
19 #ifdef __cplusplus
20 
21 #include <nn/types.h>
22 
23 namespace nn { namespace fnd {
24 
25 class BackOffManager
26 {
27 private:
28     const u32 m_order;
29     u32 m_count;
30     void BackOffImpl();
31 
32 public:
BackOffManager(u32 order)33     BackOffManager(u32 order) : m_order(order), m_count(0) {}
34 
BackOff()35     void BackOff()
36     {
37         // 最初(m_count == 0)のときの競合は、
38         // コア同士の競合でなく、スレッド切り替えによるものの可能性が高いため、
39         // Back-off無しで通過する。
40         if (m_count++ > 0)
41         {
42             BackOffImpl();
43         }
44     }
45 };
46 
47 }}
48 
49 #endif // __cplusplus
50 
51 #endif  // NN_FND_FND_BACKOFF_H_
52