GCC Code Coverage Report

Directory: ./
File: libs/capy/src/ex/thread_pool.cpp
Date: 2026-01-15 23:24:40
Exec Total Coverage
Lines: 56 61 91.8%
Functions: 11 12 91.7%
Branches: 28 36 77.8%
Line Branch Exec Source
1 //
2 // Copyright (c) 2025 Vinnie Falco (vinnie.falco@gmail.com)
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/boostorg/capy
8 //
9
10 #include <boost/capy/ex/thread_pool.hpp>
11 #include <boost/capy/core/intrusive_queue.hpp>
12 #include <condition_variable>
13 #include <mutex>
14 #include <thread>
15 #include <vector>
16
17 namespace boost {
18 namespace capy {
19
20 //------------------------------------------------------------------------------
21
22 // Pimpl implementation hides threading details from the header
23 class thread_pool::impl
24 {
25 // Wraps a coroutine handle for queue storage
26 struct work : intrusive_queue<work>::node
27 {
28 any_coro h_;
29
30 83 explicit work(any_coro h) noexcept
31 83 : h_(h)
32 {
33 83 }
34
35 83 void run()
36 {
37 // delete before dispatch
38 83 auto h = h_;
39
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 83 delete this;
40
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 83 h.resume();
41 83 }
42
43 ✗ void destroy()
44 {
45 ✗ delete this;
46 ✗ }
47 };
48
49 std::mutex mutex_;
50 std::condition_variable cv_;
51 intrusive_queue<work> q_;
52 std::vector<std::thread> threads_;
53 bool stop_;
54
55 public:
56 14 ~impl()
57 {
58 {
59 14 std::lock_guard<std::mutex> lock(mutex_);
60 14 stop_ = true;
61 14 }
62 14 cv_.notify_all();
63
64
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 35 for(auto& t : threads_)
65 21 t.join();
66
67 // Destroy any work items that were never executed
68
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 14 while(auto* w = q_.pop())
69 ✗ w->destroy();
70 14 }
71
72 explicit
73 14 impl(std::size_t num_threads)
74 14 : stop_(false)
75 {
76
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 14 if( num_threads == 0)
77 1 num_threads = std::thread::hardware_concurrency();
78 // Fallback
79
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 14 if( num_threads == 0)
80 ✗ num_threads = 1;
81
82
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 14 threads_.reserve(num_threads);
83
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 35 for(std::size_t i = 0; i < num_threads; ++i)
84
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 42 threads_.emplace_back([this]{ run(); });
85 14 }
86
87 void
88 83 post(any_coro h)
89 {
90 83 auto* w = new work(h);
91 {
92
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 83 std::lock_guard<std::mutex> lock(mutex_);
93 83 q_.push(w);
94 83 }
95 83 cv_.notify_one();
96 83 }
97
98 private:
99 void
100 21 run()
101 {
102 for(;;)
103 {
104 104 work* w = nullptr;
105 {
106
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 104 std::unique_lock<std::mutex> lock(mutex_);
107
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 104 cv_.wait(lock, [this]{
108
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 151 return stop_ || !q_.empty();
109 });
110
111 // Only exit when stopped AND queue is drained
112
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 104 if(stop_ && q_.empty())
113 42 return;
114
115 83 w = q_.pop();
116 104 }
117
118 83 w->run();
119 83 }
120 }
121 };
122
123 //------------------------------------------------------------------------------
124
125 14 thread_pool::
126 ~thread_pool()
127 {
128 // Order matters: shutdown services, then impl, then base
129 14 shutdown();
130
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 14 delete impl_;
131 14 destroy();
132 14 }
133
134 14 thread_pool::
135 14 thread_pool(std::size_t num_threads)
136
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 14 : impl_(new impl(num_threads))
137 {
138 14 }
139
140 //------------------------------------------------------------------------------
141
142 void
143 83 thread_pool::executor_type::
144 post(any_coro h) const
145 {
146 83 pool_->impl_->post(h);
147 83 }
148
149 } // capy
150 } // boost
151