blob: 5f08742cae565c3dfc8403de0f0396a1439dfef9 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
|
/**
* @file lockstatic.h
* @author Nat Goodspeed
* @date 2019-12-03
* @brief LockStatic class provides mutex-guarded access to the specified
* static data.
*
* $LicenseInfo:firstyear=2019&license=viewerlgpl$
* Copyright (c) 2019, Linden Research, Inc.
* $/LicenseInfo$
*/
#if ! defined(LL_LOCKSTATIC_H)
#define LL_LOCKSTATIC_H
#include "mutex.h" // std::unique_lock
namespace llthread
{
// Instantiate this template to obtain a pointer to the canonical static
// instance of Static while holding a lock on that instance. Use of
// Static::mMutex presumes that Static declares some suitable mMutex.
template <typename Static>
class LockStatic
{
typedef std::unique_lock<decltype(Static::mMutex)> lock_t;
public:
LockStatic():
mData(getStatic()),
mLock(mData->mMutex)
{}
Static* get() const { return mData; }
operator Static*() const { return get(); }
Static* operator->() const { return get(); }
// sometimes we must explicitly unlock...
void unlock()
{
// but once we do, access is no longer permitted
mData = nullptr;
mLock.unlock();
}
protected:
Static* mData;
lock_t mLock;
private:
Static* getStatic()
{
static Static sData;
return &sData;
}
};
} // llthread namespace
#endif /* ! defined(LL_LOCKSTATIC_H) */
|
