HTML Diff invocation/prioritised

src/examples/cpp03/invocation/prioritised_handlers.cpp		src/examples/cpp11/invocation/prioritised_handlers.cpp
⋮		⋮
1	//	1	//
2	//·prioritised_handlers.cpp	2	//·prioritised_handlers.cpp
3	//·~~~~~~~~~~~~~~~~~~~~~~~~	3	//·~~~~~~~~~~~~~~~~~~~~~~~~
4	//	4	//
5	//·Copyright·(c)·2003-2020·Christopher·M.·Kohlhoff·(chris·at·kohlhoff·dot·com)	5	//·Copyright·(c)·2003-2020·Christopher·M.·Kohlhoff·(chris·at·kohlhoff·dot·com)
6	//	6	//
7	//·Distributed·under·the·Boost·Software·License,·Version·1.0.·(See·accompanying	7	//·Distributed·under·the·Boost·Software·License,·Version·1.0.·(See·accompanying
8	//·file·LICENSE_1_0.txt·or·copy·at·http://www.boost.org/LICENSE_1_0.txt)	8	//·file·LICENSE_1_0.txt·or·copy·at·http://www.boost.org/LICENSE_1_0.txt)
9	//	9	//
10		10
11	#include·"asio.hpp"	11	#include·"asio.hpp"
12	#include·<boost/function.hpp>
13	#include·<iostream>	12	#include·<iostream>
		13	#include·<memory>
14	#include·<queue>	14	#include·<queue>
15		15
16	using·asio::ip::tcp;	16	using·asio::ip::tcp;
17		17
18	class·handler_priority_queue·:·public·asio::execution_context	18	class·handler_priority_queue·:·public·asio::execution_context
19	{	19	{
20	public:	20	public:
21	··void·add(int·priority,·boost::function<void()>·function)	21	··template·<typename·Function>
		22	··void·add(int·priority,·Function·function)
22	··{	23	··{
23	····handlers_.push(queued_handler(priority,·function));	24	····std::unique_ptr<queued_handler_base>·handler(
		25	········new·queued_handler<Function>(
		26	··········priority,·std::move(function)));
		27
		28	····handlers_.push(std::move(handler));
24	··}	29	··}
25		30
26	··void·execute_all()	31	··void·execute_all()
27	··{	32	··{
28	····while·(!handlers_.empty())	33	····while·(!handlers_.empty())
29	····{	34	····{
30	······queued_handler·handler·=·handlers_.top();	35	······handlers_.top()->execute();
31	······handler.execute();
32	······handlers_.pop();	36	······handlers_.pop();
33	····}	37	····}
34	··}	38	··}
35		39
36	··class·executor	40	··class·executor
37	··{	41	··{
38	··public:	42	··public:
39	····executor(handler_priority_queue&·q,·int·p)	43	····executor(handler_priority_queue&·q,·int·p)
40	······:·context_(q),·priority_(p)	44	······:·context_(q),·priority_(p)
41	····{	45	····{
42	····}	46	····}
43		47
44	····handler_priority_queue&·context()·const	48	····handler_priority_queue&·context()·const·noexcept
45	····{	49	····{
46	······return·context_;	50	······return·context_;
47	····}	51	····}
48		52
49	····template·<typename·Function,·typename·Allocator>	53	····template·<typename·Function,·typename·Allocator>
50	····void·dispatch(const·Function&·f,·const·Allocator&)·const	54	····void·dispatch(Function·f,·const·Allocator&)·const
51	····{	55	····{
52	······context_.add(priority_,·f);	56	······context_.add(priority_,·std::move(f));
53	····}	57	····}
54		58
55	····template·<typename·Function,·typename·Allocator>	59	····template·<typename·Function,·typename·Allocator>
56	····void·post(const·Function&·f,·const·Allocator&)·const	60	····void·post(Function·f,·const·Allocator&)·const
57	····{	61	····{
58	······context_.add(priority_,·f);	62	······context_.add(priority_,·std::move(f));
59	····}	63	····}
60		64
61	····template·<typename·Function,·typename·Allocator>	65	····template·<typename·Function,·typename·Allocator>
62	····void·defer(const·Function&·f,·const·Allocator&)·const	66	····void·defer(Function·f,·const·Allocator&)·const
63	····{	67	····{
64	······context_.add(priority_,·f);	68	······context_.add(priority_,·std::move(f));
65	····}	69	····}
66		70
67	····void·on_work_started()·const·{}	71	····void·on_work_started()·const·noexcept·{}
68	····void·on_work_finished()·const·{}	72	····void·on_work_finished()·const·noexcept·{}
69		73
70	····bool·operator==(const·executor&·other)·const	74	····bool·operator==(const·executor&·other)·const·noexcept
71	····{	75	····{
72	······return·&context_·==·&other.context_·&&·priority_·==·other.priority_;	76	······return·&context_·==·&other.context_·&&·priority_·==·other.priority_;
73	····}	77	····}
74		78
75	····bool·operator!=(const·executor&·other)·const	79	····bool·operator!=(const·executor&·other)·const·noexcept
76	····{	80	····{
77	······return·!operator==(other);	81	······return·!operator==(other);
78	····}	82	····}
79		83
80	··private:	84	··private:
81	····handler_priority_queue&·context_;	85	····handler_priority_queue&·context_;
82	····int·priority_;	86	····int·priority_;
83	··};	87	··};
84		88
85	··template·<typename·Handler>	89	··template·<typename·Handler>
86	··asio::executor_binder<Handler,·executor>	90	··asio::executor_binder<Handler,·executor>
87	··wrap(int·priority,·Handler·handler)	91	··wrap(int·priority,·Handler·handler)
88	··{	92	··{
89	····return·asio::bind_executor(executor(*this,·priority),·handler);	93	····return·asio::bind_executor(
		94	········executor(*this,·priority),·std::move(handler));
90	··}	95	··}
91		96
92	private:	97	private:
93	··class·queued_handler	98	··class·queued_handler_base
94	··{	99	··{
95	··public:	100	··public:
96	····queued_handler(int·p,·boost::function<void()>·f)	101	····queued_handler_base(int·p)
97	······:·priority_(p),·function_(f)	102	······:·priority_(p)
98	····{	103	····{
99	····}	104	····}
100		105
101	····void·execute()	106	····virtual·~queued_handler_base()
102	····{	107	····{
103	······function_();
104	····}	108	····}
105		109
106	····friend·bool·operator<(const·queued_handler&·a,	110	····virtual·void·execute()·=·0;
107	········const·queued_handler&·b)	111
		112	····friend·bool·operator<(const·std::unique_ptr<queued_handler_base>&·a,
		113	········const·std::unique_ptr<queued_handler_base>&·b)·noexcept
108	····{	114	····{
109	······return·a.priority_·<·b.priority_;	115	······return·a->priority_·<·b->priority_;
110	····}	116	····}
111		117
112	··private:	118	··private:
113	····int·priority_;	119	····int·priority_;
114	····boost::function<void()>·function_;
115	··};	120	··};
116		121
117	··std::priority_queue<queued_handler>·handlers_;	122	··template·<typename·Function>
		123	··class·queued_handler·:·public·queued_handler_base
		124	··{
		125	··public:
		126	····queued_handler(int·p,·Function·f)
		127	······:·queued_handler_base(p),·function_(std::move(f))
		128	····{
		129	····}
		130
		131	····void·execute()·override
		132	····{
		133	······function_();
		134	····}
		135
		136	··private:
		137	····Function·function_;
		138	··};
		139
		140	··std::priority_queue<std::unique_ptr<queued_handler_base>>·handlers_;
118	};	141	};
119		142
120	//----------------------------------------------------------------------	143	//----------------------------------------------------------------------
121		144
122	void·high_priority_handler(const·asio::error_code&·/ec/)	145	void·high_priority_handler(const·asio::error_code&·/ec/,
		146	····tcp::socket·/socket/)
123	{	147	{
124	··std::cout·<<·"High·priority·handler\n";	148	··std::cout·<<·"High·priority·handler\n";
125	}	149	}
126		150
127	void·middle_priority_handler(const·asio::error_code&·/ec/)	151	void·middle_priority_handler(const·asio::error_code&·/ec/)
128	{	152	{
129	··std::cout·<<·"Middle·priority·handler\n";	153	··std::cout·<<·"Middle·priority·handler\n";
130	}	154	}
131		155
132	void·low_priority_handler()	156	struct·low_priority_handler
133	{	157	{
134	··std::cout·<<·"Low·priority·handler\n";	158	··//·Make·the·handler·a·move-only·type.
135	}	159	··low_priority_handler()·=·default;
		160	··low_priority_handler(const·low_priority_handler&)·=·delete;
		161	··low_priority_handler(low_priority_handler&&)·=·default;
		162
		163	··void·operator()()
		164	··{
		165	····std::cout·<<·"Low·priority·handler\n";
		166	··}
		167	};
136		168
137	int·main()	169	int·main()
138	{	170	{
139	··asio::io_context·io_context;	171	··asio::io_context·io_context;
140		172
141	··handler_priority_queue·pri_queue;	173	··handler_priority_queue·pri_queue;
142		174
143	··//·Post·a·completion·handler·to·be·run·immediately.	175	··//·Post·a·completion·handler·to·be·run·immediately.
144	··asio::post(io_context,·pri_queue.wrap(0,·low_priority_handler));	176	··asio::post(io_context,·pri_queue.wrap(0,·low_priority_handler()));
145		177
146	··//·Start·an·asynchronous·accept·that·will·complete·immediately.	178	··//·Start·an·asynchronous·accept·that·will·complete·immediately.
147	··tcp::endpoint·endpoint(asio::ip::address_v4::loopback(),·0);	179	··tcp::endpoint·endpoint(asio::ip::address_v4::loopback(),·0);
148	··tcp::acceptor·acceptor(io_context,·endpoint);	180	··tcp::acceptor·acceptor(io_context,·endpoint);
149	··tcp::socket·server_socket(io_context);	181	··tcp::socket·server_socket(io_context);
150	··acceptor.async_accept(server_socket,	182	··acceptor.async_accept(pri_queue.wrap(100,·high_priority_handler));
151	······pri_queue.wrap(100,·high_priority_handler));
152	··tcp::socket·client_socket(io_context);	183	··tcp::socket·client_socket(io_context);
153	··client_socket.connect(acceptor.local_endpoint());	184	··client_socket.connect(acceptor.local_endpoint());
154		185
155	··//·Set·a·deadline·timer·to·expire·immediately.	186	··//·Set·a·deadline·timer·to·expire·immediately.
156	··asio::steady_timer·timer(io_context);	187	··asio::steady_timer·timer(io_context);
157	··timer.expires_at(asio::steady_timer::time_point::min());	188	··timer.expires_at(asio::steady_timer::clock_type::time_point::min());
158	··timer.async_wait(pri_queue.wrap(42,·middle_priority_handler));	189	··timer.async_wait(pri_queue.wrap(42,·middle_priority_handler));
159		190
160	··while·(io_context.run_one())	191	··while·(io_context.run_one())
161	··{	192	··{
162	····//·The·custom·invocation·hook·adds·the·handlers·to·the·priority·queue	193	····//·The·custom·invocation·hook·adds·the·handlers·to·the·priority·queue
163	····//·rather·than·executing·them·from·within·the·poll_one()·call.	194	····//·rather·than·executing·them·from·within·the·poll_one()·call.
164	····while·(io_context.poll_one())	195	····while·(io_context.poll_one())
165	······;	196	······;
166		197
167	····pri_queue.execute_all();	198	····pri_queue.execute_all();
168	··}	199	··}
169		200
170	··return·0;	201	··return·0;
171	}	202	}