include/boost/corosio/native/detail/iocp/win_timers.hpp

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win_timers.hpp

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boost::corosio::detail::win_timers::win_timers(long*) :38 1121x 100.0% – 100.0% boost::corosio::detail::win_timers::~win_timers() :43 1121x 100.0% – 100.0% boost::corosio::detail::make_win_timers(void*, long*) :61 1121x 100.0% 100.0% 100.0%

Line	Branch	Hits	Source Code
1			//
2			// Copyright (c) 2025 Vinnie Falco ([email protected])
3			// Copyright (c) 2026 Steve Gerbino
4			//
5			// Distributed under the Boost Software License, Version 1.0. (See accompanying
6			// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7			//
8			// Official repository: https://github.com/cppalliance/corosio
9			//
10
11			#ifndef BOOST_COROSIO_NATIVE_DETAIL_IOCP_WIN_TIMERS_HPP
12			#define BOOST_COROSIO_NATIVE_DETAIL_IOCP_WIN_TIMERS_HPP
13
14			#include <boost/corosio/detail/platform.hpp>
15
16			#if BOOST_COROSIO_HAS_IOCP
17
18			#include <boost/corosio/native/detail/iocp/win_completion_key.hpp>
19			#include <boost/corosio/native/detail/iocp/win_windows.hpp>
20
21			#include <chrono>
22			#include <memory>
23
24			namespace boost::corosio::detail {
25
26			/** Abstract interface for timer wakeup mechanisms.
27
28			Posts key_wake_dispatch to the IOCP to trigger timer processing.
29			*/
30			class win_timers
31			{
32			protected:
33			long* dispatch_required_;
34
35			public:
36			using time_point = std::chrono::steady_clock::time_point;
37
38		1121x	explicit win_timers(long* dispatch_required) noexcept
39		1121x	: dispatch_required_(dispatch_required)
40			{
41		1121x	}
42
43		1121x	virtual ~win_timers() = default;
44
45			virtual void start() = 0;
46			virtual void stop() = 0;
47			virtual void update_timeout(time_point next_expiry) = 0;
48			};
49
50			std::unique_ptr<win_timers>
51			make_win_timers(void* iocp_handle, long* dispatch_required);
52
53			} // namespace boost::corosio::detail
54
55			// Include concrete implementations needed by make_win_timers
56			#include <boost/corosio/native/detail/iocp/win_timers_thread.hpp>
57
58			namespace boost::corosio::detail {
59
60			inline std::unique_ptr<win_timers>
61		1121x	make_win_timers(void* iocp_handle, long* dispatch_required)
62			{
63			// Thread-based over NtAssociateWaitCompletionPacket: the NT wait
64			// packet is one-shot, so it must be re-associated (SetWaitableTimer
65			// + NtAssociateWaitCompletionPacket) after every scheduler wakeup
66			// even in timer-free workloads, costing ~60% CPU overhead. Skipping
67			// the re-association is not a fix: a spent packet never fires again
68			// and pending timers hang the scheduler.
69	1/1 ✓ Branch 2 → 3 taken 1121 times.	1121x	return std::make_unique<win_timers_thread>(iocp_handle, dispatch_required);
70			}
71
72			} // namespace boost::corosio::detail
73
74			#endif // BOOST_COROSIO_HAS_IOCP
75
76			#endif // BOOST_COROSIO_NATIVE_DETAIL_IOCP_WIN_TIMERS_HPP
77