Initial Commit

include/asio/detail/win_iocp_overlapped_ptr.hpp

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+//
+// detail/win_iocp_overlapped_ptr.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_WIN_IOCP_OVERLAPPED_PTR_HPP
+#define ASIO_DETAIL_WIN_IOCP_OVERLAPPED_PTR_HPP
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1200)
+# pragma once
+#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
+
+#include "asio/detail/config.hpp"
+
+#if defined(ASIO_HAS_IOCP)
+
+#include "asio/io_context.hpp"
+#include "asio/query.hpp"
+#include "asio/detail/handler_alloc_helpers.hpp"
+#include "asio/detail/memory.hpp"
+#include "asio/detail/noncopyable.hpp"
+#include "asio/detail/win_iocp_overlapped_op.hpp"
+#include "asio/detail/win_iocp_io_context.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+// Wraps a handler to create an OVERLAPPED object for use with overlapped I/O.
+class win_iocp_overlapped_ptr
+  : private noncopyable
+{
+public:
+  // Construct an empty win_iocp_overlapped_ptr.
+  win_iocp_overlapped_ptr()
+    : ptr_(0),
+      iocp_service_(0)
+  {
+  }
+
+  // Construct an win_iocp_overlapped_ptr to contain the specified handler.
+  template <typename Executor, typename Handler>
+  explicit win_iocp_overlapped_ptr(const Executor& ex,
+      Handler&& handler)
+    : ptr_(0),
+      iocp_service_(0)
+  {
+    this->reset(ex, static_cast<Handler&&>(handler));
+  }
+
+  // Destructor automatically frees the OVERLAPPED object unless released.
+  ~win_iocp_overlapped_ptr()
+  {
+    reset();
+  }
+
+  // Reset to empty.
+  void reset()
+  {
+    if (ptr_)
+    {
+      ptr_->destroy();
+      ptr_ = 0;
+      iocp_service_->work_finished();
+      iocp_service_ = 0;
+    }
+  }
+
+  // Reset to contain the specified handler, freeing any current OVERLAPPED
+  // object.
+  template <typename Executor, typename Handler>
+  void reset(const Executor& ex, Handler handler)
+  {
+    win_iocp_io_context* iocp_service = this->get_iocp_service(ex);
+
+    typedef win_iocp_overlapped_op<Handler, Executor> op;
+    typename op::ptr p = { asio::detail::addressof(handler),
+      op::ptr::allocate(handler), 0 };
+    p.p = new (p.v) op(handler, ex);
+
+    ASIO_HANDLER_CREATION((ex.context(), *p.p,
+          "iocp_service", iocp_service, 0, "overlapped"));
+
+    iocp_service->work_started();
+    reset();
+    ptr_ = p.p;
+    p.v = p.p = 0;
+    iocp_service_ = iocp_service;
+  }
+
+  // Get the contained OVERLAPPED object.
+  OVERLAPPED* get()
+  {
+    return ptr_;
+  }
+
+  // Get the contained OVERLAPPED object.
+  const OVERLAPPED* get() const
+  {
+    return ptr_;
+  }
+
+  // Release ownership of the OVERLAPPED object.
+  OVERLAPPED* release()
+  {
+    if (ptr_)
+      iocp_service_->on_pending(ptr_);
+
+    OVERLAPPED* tmp = ptr_;
+    ptr_ = 0;
+    iocp_service_ = 0;
+    return tmp;
+  }
+
+  // Post completion notification for overlapped operation. Releases ownership.
+  void complete(const asio::error_code& ec,
+      std::size_t bytes_transferred)
+  {
+    if (ptr_)
+    {
+      iocp_service_->on_completion(ptr_, ec,
+          static_cast<DWORD>(bytes_transferred));
+      ptr_ = 0;
+      iocp_service_ = 0;
+    }
+  }
+
+private:
+  template <typename Executor>
+  static win_iocp_io_context* get_iocp_service(const Executor& ex,
+      enable_if_t<
+        can_query<const Executor&, execution::context_t>::value
+      >* = 0)
+  {
+    return &use_service<win_iocp_io_context>(
+        asio::query(ex, execution::context));
+  }
+
+  template <typename Executor>
+  static win_iocp_io_context* get_iocp_service(const Executor& ex,
+      enable_if_t<
+        !can_query<const Executor&, execution::context_t>::value
+      >* = 0)
+  {
+    return &use_service<win_iocp_io_context>(ex.context());
+  }
+
+  static win_iocp_io_context* get_iocp_service(
+      const io_context::executor_type& ex)
+  {
+    return &asio::query(ex, execution::context).impl_;
+  }
+
+  win_iocp_operation* ptr_;
+  win_iocp_io_context* iocp_service_;
+};
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP)
+
+#endif // ASIO_DETAIL_WIN_IOCP_OVERLAPPED_PTR_HPP