Initial Commit

include/asio/detail/thread_group.hpp

@@ -0,0 +1,104 @@
+//
+// detail/thread_group.hpp
+// ~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2025 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)
+//
+
+#ifndef ASIO_DETAIL_THREAD_GROUP_HPP
+#define ASIO_DETAIL_THREAD_GROUP_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+#include "asio/detail/memory.hpp"
+#include "asio/detail/thread.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+template <typename Allocator>
+class thread_group
+{
+public:
+  // Constructor initialises an empty thread group.
+  explicit thread_group(const Allocator& a)
+    : allocator_(a),
+      first_(0)
+  {
+  }
+
+  // Destructor joins any remaining threads in the group.
+  ~thread_group()
+  {
+    join();
+  }
+
+  // Create a new thread in the group.
+  template <typename Function>
+  void create_thread(Function f)
+  {
+    first_ = allocate_object<item>(allocator_, allocator_, f, first_);
+  }
+
+  // Create new threads in the group.
+  template <typename Function>
+  void create_threads(Function f, std::size_t num_threads)
+  {
+    for (std::size_t i = 0; i < num_threads; ++i)
+      create_thread(f);
+  }
+
+  // Wait for all threads in the group to exit.
+  void join()
+  {
+    while (first_)
+    {
+      first_->thread_.join();
+      item* tmp = first_;
+      first_ = first_->next_;
+      deallocate_object(allocator_, tmp);
+    }
+  }
+
+  // Test whether the group is empty.
+  bool empty() const
+  {
+    return first_ == 0;
+  }
+
+private:
+  // Structure used to track a single thread in the group.
+  struct item
+  {
+    template <typename Function>
+    explicit item(const Allocator& a, Function f, item* next)
+      : thread_(std::allocator_arg, a, f),
+        next_(next)
+    {
+    }
+
+    asio::detail::thread thread_;
+    item* next_;
+  };
+
+  // The allocator to be used to create items in the group.
+  Allocator allocator_;
+
+  // The first thread in the group.
+  item* first_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // ASIO_DETAIL_THREAD_GROUP_HPP