ceph/src/boost/boost/asio/detail/thread_group.hpp

   1 //
   2 // detail/thread_group.hpp
   3 // ~~~~~~~~~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2019 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   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)
   9 //
  10
  11 #ifndef BOOST_ASIO_DETAIL_THREAD_GROUP_HPP
  12 #define BOOST_ASIO_DETAIL_THREAD_GROUP_HPP
  13
  14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  15 # pragma once
  16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  17
  18 #include <boost/asio/detail/config.hpp>
  19 #include <boost/asio/detail/scoped_ptr.hpp>
  20 #include <boost/asio/detail/thread.hpp>
  21
  22 namespace boost {
  23 namespace asio {
  24 namespace detail {
  25
  26 class thread_group
  27 {
  28 public:
  29   // Constructor initialises an empty thread group.
  30   thread_group()
  31     : first_(0)
  32   {
  33   }
  34
  35   // Destructor joins any remaining threads in the group.
  36   ~thread_group()
  37   {
  38     join();
  39   }
  40
  41   // Create a new thread in the group.
  42   template <typename Function>
  43   void create_thread(Function f)
  44   {
  45     first_ = new item(f, first_);
  46   }
  47
  48   // Create new threads in the group.
  49   template <typename Function>
  50   void create_threads(Function f, std::size_t num_threads)
  51   {
  52     for (std::size_t i = 0; i < num_threads; ++i)
  53       create_thread(f);
  54   }
  55
  56   // Wait for all threads in the group to exit.
  57   void join()
  58   {
  59     while (first_)
  60     {
  61       first_->thread_.join();
  62       item* tmp = first_;
  63       first_ = first_->next_;
  64       delete tmp;
  65     }
  66   }
  67
  68   // Test whether the group is empty.
  69   bool empty() const
  70   {
  71     return first_ == 0;
  72   }
  73
  74 private:
  75   // Structure used to track a single thread in the group.
  76   struct item
  77   {
  78     template <typename Function>
  79     explicit item(Function f, item* next)
  80       : thread_(f),
  81         next_(next)
  82     {
  83     }
  84
  85     boost::asio::detail::thread thread_;
  86     item* next_;
  87   };
  88
  89   // The first thread in the group.
  90   item* first_;
  91 };
  92
  93 } // namespace detail
  94 } // namespace asio
  95 } // namespace boost
  96
  97 #endif // BOOST_ASIO_DETAIL_THREAD_GROUP_HPP