summaryrefslogtreecommitdiffstats
path: root/lib/base/loader.hpp
blob: f1c775928878020045747fc9e23e89a9b9e97130 (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
57
58
59
60
61
/* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */

#ifndef LOADER_H
#define LOADER_H

#include "base/i2-base.hpp"
#include "base/initialize.hpp"
#include "base/string.hpp"
#include <boost/thread/tss.hpp>
#include <queue>

namespace icinga
{

struct DeferredInitializer
{
public:
	DeferredInitializer(std::function<void ()> callback, InitializePriority priority)
		: m_Callback(std::move(callback)), m_Priority(priority)
	{ }

	bool operator>(const DeferredInitializer& other) const
	{
		return m_Priority > other.m_Priority;
	}

	void operator()()
	{
		m_Callback();
	}

private:
	std::function<void ()> m_Callback;
	InitializePriority m_Priority;
};

/**
 * Loader helper functions.
 *
 * @ingroup base
 */
class Loader
{
public:
	static void AddDeferredInitializer(const std::function<void ()>& callback, InitializePriority priority = InitializePriority::Default);
	static void ExecuteDeferredInitializers();

private:
	Loader();

	// Deferred initializers are run in the order of the definition of their enum values.
	// Therefore, initializers that should be run first have lower enum values and
	// the order of the std::priority_queue has to be reversed using std::greater.
	using DeferredInitializerPriorityQueue = std::priority_queue<DeferredInitializer, std::vector<DeferredInitializer>, std::greater<>>;

	static boost::thread_specific_ptr<DeferredInitializerPriorityQueue>& GetDeferredInitializers();
};

}

#endif /* LOADER_H */