summaryrefslogtreecommitdiffstatshomepage
path: root/3rdparty/asio/src/examples/cpp11/http/server2/io_context_pool.cpp
blob: bea089030873e0b73821b8f0d3979f4b93575764 (plain) (blame)
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
62
63
64
//
// io_context_pool.cpp
// ~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#include "server.hpp"
#include <stdexcept>
#include <thread>

namespace http {
namespace server2 {

io_context_pool::io_context_pool(std::size_t pool_size)
  : next_io_context_(0)
{
  if (pool_size == 0)
    throw std::runtime_error("io_context_pool size is 0");

  // Give all the io_contexts work to do so that their run() functions will not
  // exit until they are explicitly stopped.
  for (std::size_t i = 0; i < pool_size; ++i)
  {
    io_context_ptr io_context(new asio::io_context);
    io_contexts_.push_back(io_context);
    work_.push_back(asio::make_work_guard(*io_context));
  }
}

void io_context_pool::run()
{
  // Create a pool of threads to run all of the io_contexts.
  std::vector<std::thread> threads;
  for (std::size_t i = 0; i < io_contexts_.size(); ++i)
    threads.emplace_back([this, i]{ io_contexts_[i]->run(); });

  // Wait for all threads in the pool to exit.
  for (std::size_t i = 0; i < threads.size(); ++i)
    threads[i].join();
}

void io_context_pool::stop()
{
  // Explicitly stop all io_contexts.
  for (std::size_t i = 0; i < io_contexts_.size(); ++i)
    io_contexts_[i]->stop();
}

asio::io_context& io_context_pool::get_io_context()
{
  // Use a round-robin scheme to choose the next io_context to use.
  asio::io_context& io_context = *io_contexts_[next_io_context_];
  ++next_io_context_;
  if (next_io_context_ == io_contexts_.size())
    next_io_context_ = 0;
  return io_context;
}

} // namespace server2
} // namespace http