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
|
#pragma once
#include "base/logging.hpp"
#include <algorithm>
#include <mutex>
#include <utility>
#include <vector>
namespace base
{
class DummyLockable
{
public:
void lock() {}
void unlock() {}
};
template <typename Observer, typename Mutex>
class ObserverList;
/// This alias represents a thread-safe observers list. It allows to
/// add/remove observers as well as trigger them all.
template <typename Observer>
using ObserverListSafe = ObserverList<Observer, std::mutex>;
template <typename Observer>
using ObserverListUnsafe = ObserverList<Observer, DummyLockable>;
template <typename Observer, typename Mutex>
class ObserverList
{
public:
bool Add(Observer & observer)
{
std::lock_guard<Mutex> lock(m_observersLock);
auto const it = std::find(m_observers.begin(), m_observers.end(), &observer);
if (it != m_observers.end())
{
LOG(LWARNING, ("Can't add the same observer twice:", &observer));
return false;
}
m_observers.push_back(&observer);
return true;
}
bool Remove(Observer const & observer)
{
std::lock_guard<Mutex> lock(m_observersLock);
auto const it = std::find(m_observers.begin(), m_observers.end(), &observer);
if (it == m_observers.end())
{
LOG(LWARNING, ("Can't remove non-registered observer:", &observer));
return false;
}
m_observers.erase(it);
return true;
}
template <typename F, typename... Args>
void ForEach(F fn, Args const &... args)
{
std::lock_guard<Mutex> lock(m_observersLock);
for (Observer * observer : m_observers)
(observer->*fn)(args...);
}
private:
Mutex m_observersLock;
std::vector<Observer *> m_observers;
};
} // namespace base
|
