blob: 4fc5ac796d98a45a0acf344ea11403418ce3a689 (
plain) (
blame)
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
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
|
// Copyright (c) 2020 Egor Tensin <Egor.Tensin@gmail.com>
// This file is part of the "winapi-common" project.
// For details, see https://github.com/egor-tensin/winapi-common.
// Distributed under the MIT License.
#pragma once
#include "handle.hpp"
#include <cstddef>
#include <memory>
#include <string>
#include <type_traits>
#include <utility>
namespace winapi {
class SharedMemory {
public:
static SharedMemory create(const std::string& name, std::size_t nb);
static SharedMemory open(const std::string& name);
void* get() const { return m_addr.get(); }
void* ptr() const { return get(); }
private:
struct Unmap {
void operator()(void*) const;
};
SharedMemory() = default;
SharedMemory(Handle&& handle, void* addr) : m_handle{std::move(handle)}, m_addr{addr} {}
Handle m_handle;
std::unique_ptr<void, Unmap> m_addr;
};
template <typename T>
class SharedObject {
public:
typedef typename std::aligned_storage<sizeof(T), __alignof(T)>::type AlignedType;
template <typename... Args>
static SharedObject create(const std::string& name, Args&&... args) {
SharedObject obj{SharedMemory::create(name, sizeof(AlignedType))};
new (obj.ptr()) T(std::forward<Args>(args)...);
obj.m_destruct = true;
return obj;
}
static SharedObject open(const std::string& name) {
SharedObject obj{SharedMemory::open(name)};
return obj;
}
SharedObject(SharedObject&& other) noexcept = default;
SharedObject& operator=(const SharedObject& other) noexcept = default;
SharedObject(const SharedObject&) = delete;
~SharedObject() {
if (m_destruct && ptr()) {
ptr()->~T();
}
}
T* ptr() const { return reinterpret_cast<T*>(m_shmem.ptr()); }
T& get() const { return *ptr(); }
T* operator->() const { return ptr(); }
T& operator*() const { return get(); }
private:
explicit SharedObject(SharedMemory&& shmem) : m_shmem(std::move(shmem)) {}
SharedMemory m_shmem;
// Destruct only once, no matter the number of mappings.
bool m_destruct = false;
};
} // namespace winapi
|
