include/boost/corosio/detail/conditionally_enabled_event.hpp

31.8% Lines (7/22) 33.3% List of functions (2/6)
conditionally_enabled_event.hpp
f(x) Functions (6)
Line TLA Hits Source Code
1 //
2 // Copyright (c) 2026 Michael Vandeberg
3 //
4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7 // Official repository: https://github.com/cppalliance/corosio
8 //
9
10 #ifndef BOOST_COROSIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP
11 #define BOOST_COROSIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP
12
13 #include <boost/corosio/detail/conditionally_enabled_mutex.hpp>
14
15 #include <chrono>
16 #include <condition_variable>
17
18 namespace boost::corosio::detail {
19
20 /* Condition variable wrapper that becomes a no-op when disabled.
21
22 When enabled, notify/wait delegate to an underlying
23 std::condition_variable. When disabled, all operations
24 are no-ops. The wait paths are unreachable in
25 single-threaded mode because the task sentinel prevents
26 the empty-queue state in do_one().
27 */
28 class conditionally_enabled_event
29 {
30 std::condition_variable cond_;
31 bool enabled_;
32
33 public:
34 515x explicit conditionally_enabled_event(bool enabled = true) noexcept
35 515x : enabled_(enabled)
36 {
37 515x }
38
39 conditionally_enabled_event(conditionally_enabled_event const&) = delete;
40 conditionally_enabled_event& operator=(conditionally_enabled_event const&) = delete;
41
42 void set_enabled(bool v) noexcept
43 {
44 enabled_ = v;
45 }
46
47 void notify_one()
48 {
49 if (enabled_)
50 cond_.notify_one();
51 }
52
53 889x void notify_all()
54 {
55 889x if (enabled_)
56 889x cond_.notify_all();
57 889x }
58
59 void wait(conditionally_enabled_mutex::scoped_lock& lock)
60 {
61 if (enabled_)
62 cond_.wait(lock.underlying());
63 }
64
65 template<class Rep, class Period>
66 void wait_for(
67 conditionally_enabled_mutex::scoped_lock& lock,
68 std::chrono::duration<Rep, Period> const& d)
69 {
70 if (enabled_)
71 cond_.wait_for(lock.underlying(), d);
72 }
73 };
74
75 } // namespace boost::corosio::detail
76
77 #endif // BOOST_COROSIO_DETAIL_CONDITIONALLY_ENABLED_EVENT_HPP
78