Initial Commit

include/asio/detail/impl/win_iocp_handle_service.ipp

@@ -0,0 +1,619 @@
+//
+// detail/impl/win_iocp_handle_service.ipp
+// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+//
+// Copyright (c) 2003-2025 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// Copyright (c) 2008 Rep Invariant Systems, Inc. (info@repinvariant.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_IMPL_WIN_IOCP_HANDLE_SERVICE_IPP
+#define ASIO_DETAIL_IMPL_WIN_IOCP_HANDLE_SERVICE_IPP
+
+#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/detail/win_iocp_handle_service.hpp"
+
+#include "asio/detail/push_options.hpp"
+
+namespace asio {
+namespace detail {
+
+class win_iocp_handle_service::overlapped_wrapper
+  : public OVERLAPPED
+{
+public:
+  explicit overlapped_wrapper(asio::error_code& ec)
+  {
+    Internal = 0;
+    InternalHigh = 0;
+    Offset = 0;
+    OffsetHigh = 0;
+
+    // Create a non-signalled manual-reset event, for GetOverlappedResult.
+    hEvent = ::CreateEventW(0, TRUE, FALSE, 0);
+    if (hEvent)
+    {
+      // As documented in GetQueuedCompletionStatus, setting the low order
+      // bit of this event prevents our synchronous writes from being treated
+      // as completion port events.
+      DWORD_PTR tmp = reinterpret_cast<DWORD_PTR>(hEvent);
+      hEvent = reinterpret_cast<HANDLE>(tmp | 1);
+    }
+    else
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+  }
+
+  ~overlapped_wrapper()
+  {
+    if (hEvent)
+    {
+      ::CloseHandle(hEvent);
+    }
+  }
+};
+
+win_iocp_handle_service::win_iocp_handle_service(execution_context& context)
+  : execution_context_service_base<win_iocp_handle_service>(context),
+    iocp_service_(asio::use_service<win_iocp_io_context>(context)),
+    nt_set_info_(0),
+    mutex_(),
+    impl_list_(0)
+{
+}
+
+void win_iocp_handle_service::shutdown()
+{
+  // Close all implementations, causing all operations to complete.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  implementation_type* impl = impl_list_;
+  while (impl)
+  {
+    close_for_destruction(*impl);
+    impl = impl->next_;
+  }
+}
+
+void win_iocp_handle_service::construct(
+    win_iocp_handle_service::implementation_type& impl)
+{
+  impl.handle_ = INVALID_HANDLE_VALUE;
+  impl.safe_cancellation_thread_id_ = 0;
+
+  // Insert implementation into linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  impl.next_ = impl_list_;
+  impl.prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = &impl;
+  impl_list_ = &impl;
+}
+
+void win_iocp_handle_service::move_construct(
+    win_iocp_handle_service::implementation_type& impl,
+    win_iocp_handle_service::implementation_type& other_impl)
+{
+  impl.handle_ = other_impl.handle_;
+  other_impl.handle_ = INVALID_HANDLE_VALUE;
+
+  impl.safe_cancellation_thread_id_ = other_impl.safe_cancellation_thread_id_;
+  other_impl.safe_cancellation_thread_id_ = 0;
+
+  // Insert implementation into linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  impl.next_ = impl_list_;
+  impl.prev_ = 0;
+  if (impl_list_)
+    impl_list_->prev_ = &impl;
+  impl_list_ = &impl;
+}
+
+void win_iocp_handle_service::move_assign(
+    win_iocp_handle_service::implementation_type& impl,
+    win_iocp_handle_service& other_service,
+    win_iocp_handle_service::implementation_type& other_impl)
+{
+  close_for_destruction(impl);
+
+  if (this != &other_service)
+  {
+    // Remove implementation from linked list of all implementations.
+    asio::detail::mutex::scoped_lock lock(mutex_);
+    if (impl_list_ == &impl)
+      impl_list_ = impl.next_;
+    if (impl.prev_)
+      impl.prev_->next_ = impl.next_;
+    if (impl.next_)
+      impl.next_->prev_= impl.prev_;
+    impl.next_ = 0;
+    impl.prev_ = 0;
+  }
+
+  impl.handle_ = other_impl.handle_;
+  other_impl.handle_ = INVALID_HANDLE_VALUE;
+
+  impl.safe_cancellation_thread_id_ = other_impl.safe_cancellation_thread_id_;
+  other_impl.safe_cancellation_thread_id_ = 0;
+
+  if (this != &other_service)
+  {
+    // Insert implementation into linked list of all implementations.
+    asio::detail::mutex::scoped_lock lock(other_service.mutex_);
+    impl.next_ = other_service.impl_list_;
+    impl.prev_ = 0;
+    if (other_service.impl_list_)
+      other_service.impl_list_->prev_ = &impl;
+    other_service.impl_list_ = &impl;
+  }
+}
+
+void win_iocp_handle_service::destroy(
+    win_iocp_handle_service::implementation_type& impl)
+{
+  close_for_destruction(impl);
+
+  // Remove implementation from linked list of all implementations.
+  asio::detail::mutex::scoped_lock lock(mutex_);
+  if (impl_list_ == &impl)
+    impl_list_ = impl.next_;
+  if (impl.prev_)
+    impl.prev_->next_ = impl.next_;
+  if (impl.next_)
+    impl.next_->prev_= impl.prev_;
+  impl.next_ = 0;
+  impl.prev_ = 0;
+}
+
+asio::error_code win_iocp_handle_service::assign(
+    win_iocp_handle_service::implementation_type& impl,
+    const native_handle_type& handle, asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ec = asio::error::already_open;
+    ASIO_ERROR_LOCATION(ec);
+    return ec;
+  }
+
+  if (iocp_service_.register_handle(handle, ec))
+  {
+    ASIO_ERROR_LOCATION(ec);
+    return ec;
+  }
+
+  impl.handle_ = handle;
+  ec = asio::error_code();
+  return ec;
+}
+
+asio::error_code win_iocp_handle_service::close(
+    win_iocp_handle_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((iocp_service_.context(), "handle",
+          &impl, reinterpret_cast<uintmax_t>(impl.handle_), "close"));
+
+    if (!::CloseHandle(impl.handle_))
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+    else
+    {
+      ec = asio::error_code();
+    }
+
+    impl.handle_ = INVALID_HANDLE_VALUE;
+    impl.safe_cancellation_thread_id_ = 0;
+  }
+  else
+  {
+    ec = asio::error_code();
+  }
+
+  ASIO_ERROR_LOCATION(ec);
+  return ec;
+}
+
+win_iocp_handle_service::native_handle_type win_iocp_handle_service::release(
+    win_iocp_handle_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+    return INVALID_HANDLE_VALUE;
+
+  cancel(impl, ec);
+  if (ec)
+  {
+    ASIO_ERROR_LOCATION(ec);
+    return INVALID_HANDLE_VALUE;
+  }
+
+  nt_set_info_fn fn = get_nt_set_info();
+  if (fn == 0)
+  {
+    ec = asio::error::operation_not_supported;
+    ASIO_ERROR_LOCATION(ec);
+    return INVALID_HANDLE_VALUE;
+  }
+
+  ULONG_PTR iosb[2] = { 0, 0 };
+  void* info[2] = { 0, 0 };
+  if (fn(impl.handle_, iosb, &info, sizeof(info),
+        61 /* FileReplaceCompletionInformation */))
+  {
+    ec = asio::error::operation_not_supported;
+    ASIO_ERROR_LOCATION(ec);
+    return INVALID_HANDLE_VALUE;
+  }
+
+  native_handle_type tmp = impl.handle_;
+  impl.handle_ = INVALID_HANDLE_VALUE;
+  return tmp;
+}
+
+asio::error_code win_iocp_handle_service::cancel(
+    win_iocp_handle_service::implementation_type& impl,
+    asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    ASIO_ERROR_LOCATION(ec);
+    return ec;
+  }
+
+  ASIO_HANDLER_OPERATION((iocp_service_.context(), "handle",
+        &impl, reinterpret_cast<uintmax_t>(impl.handle_), "cancel"));
+
+  if (FARPROC cancel_io_ex_ptr = ::GetProcAddress(
+        ::GetModuleHandleA("KERNEL32"), "CancelIoEx"))
+  {
+    // The version of Windows supports cancellation from any thread.
+    typedef BOOL (WINAPI* cancel_io_ex_t)(HANDLE, LPOVERLAPPED);
+    cancel_io_ex_t cancel_io_ex = reinterpret_cast<cancel_io_ex_t>(
+        reinterpret_cast<void*>(cancel_io_ex_ptr));
+    if (!cancel_io_ex(impl.handle_, 0))
+    {
+      DWORD last_error = ::GetLastError();
+      if (last_error == ERROR_NOT_FOUND)
+      {
+        // ERROR_NOT_FOUND means that there were no operations to be
+        // cancelled. We swallow this error to match the behaviour on other
+        // platforms.
+        ec = asio::error_code();
+      }
+      else
+      {
+        ec = asio::error_code(last_error,
+            asio::error::get_system_category());
+      }
+    }
+    else
+    {
+      ec = asio::error_code();
+    }
+  }
+  else if (impl.safe_cancellation_thread_id_ == 0)
+  {
+    // No operations have been started, so there's nothing to cancel.
+    ec = asio::error_code();
+  }
+  else if (impl.safe_cancellation_thread_id_ == ::GetCurrentThreadId())
+  {
+    // Asynchronous operations have been started from the current thread only,
+    // so it is safe to try to cancel them using CancelIo.
+    if (!::CancelIo(impl.handle_))
+    {
+      DWORD last_error = ::GetLastError();
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+    else
+    {
+      ec = asio::error_code();
+    }
+  }
+  else
+  {
+    // Asynchronous operations have been started from more than one thread,
+    // so cancellation is not safe.
+    ec = asio::error::operation_not_supported;
+  }
+
+  ASIO_ERROR_LOCATION(ec);
+  return ec;
+}
+
+size_t win_iocp_handle_service::do_write(
+    win_iocp_handle_service::implementation_type& impl, uint64_t offset,
+    const asio::const_buffer& buffer, asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    ASIO_ERROR_LOCATION(ec);
+    return 0;
+  }
+
+  // A request to write 0 bytes on a handle is a no-op.
+  if (buffer.size() == 0)
+  {
+    ec = asio::error_code();
+    return 0;
+  }
+
+  overlapped_wrapper overlapped(ec);
+  if (ec)
+  {
+    ASIO_ERROR_LOCATION(ec);
+    return 0;
+  }
+
+  // Write the data.
+  overlapped.Offset = offset & 0xFFFFFFFF;
+  overlapped.OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
+  BOOL ok = ::WriteFile(impl.handle_, buffer.data(),
+      static_cast<DWORD>(buffer.size()), 0, &overlapped);
+  if (!ok)
+  {
+    DWORD last_error = ::GetLastError();
+    if (last_error != ERROR_IO_PENDING)
+    {
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+      ASIO_ERROR_LOCATION(ec);
+      return 0;
+    }
+  }
+
+  // Wait for the operation to complete.
+  DWORD bytes_transferred = 0;
+  ok = ::GetOverlappedResult(impl.handle_,
+      &overlapped, &bytes_transferred, TRUE);
+  if (!ok)
+  {
+    DWORD last_error = ::GetLastError();
+    ec = asio::error_code(last_error,
+        asio::error::get_system_category());
+    ASIO_ERROR_LOCATION(ec);
+    return 0;
+  }
+
+  ec = asio::error_code();
+  return bytes_transferred;
+}
+
+void win_iocp_handle_service::start_write_op(
+    win_iocp_handle_service::implementation_type& impl, uint64_t offset,
+    const asio::const_buffer& buffer, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (!is_open(impl))
+  {
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  }
+  else if (buffer.size() == 0)
+  {
+    // A request to write 0 bytes on a handle is a no-op.
+    iocp_service_.on_completion(op);
+  }
+  else
+  {
+    DWORD bytes_transferred = 0;
+    op->Offset = offset & 0xFFFFFFFF;
+    op->OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
+    BOOL ok = ::WriteFile(impl.handle_, buffer.data(),
+        static_cast<DWORD>(buffer.size()),
+        &bytes_transferred, op);
+    DWORD last_error = ::GetLastError();
+    if (!ok && last_error != ERROR_IO_PENDING
+        && last_error != ERROR_MORE_DATA)
+    {
+      iocp_service_.on_completion(op, last_error, bytes_transferred);
+    }
+    else
+    {
+      iocp_service_.on_pending(op);
+    }
+  }
+}
+
+size_t win_iocp_handle_service::do_read(
+    win_iocp_handle_service::implementation_type& impl, uint64_t offset,
+    const asio::mutable_buffer& buffer, asio::error_code& ec)
+{
+  if (!is_open(impl))
+  {
+    ec = asio::error::bad_descriptor;
+    ASIO_ERROR_LOCATION(ec);
+    return 0;
+  }
+
+  // A request to read 0 bytes on a stream handle is a no-op.
+  if (buffer.size() == 0)
+  {
+    ec = asio::error_code();
+    return 0;
+  }
+
+  overlapped_wrapper overlapped(ec);
+  if (ec)
+  {
+    ASIO_ERROR_LOCATION(ec);
+    return 0;
+  }
+
+  // Read some data.
+  overlapped.Offset = offset & 0xFFFFFFFF;
+  overlapped.OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
+  BOOL ok = ::ReadFile(impl.handle_, buffer.data(),
+      static_cast<DWORD>(buffer.size()), 0, &overlapped);
+  if (!ok)
+  {
+    DWORD last_error = ::GetLastError();
+    if (last_error != ERROR_IO_PENDING && last_error != ERROR_MORE_DATA)
+    {
+      if (last_error == ERROR_HANDLE_EOF)
+      {
+        ec = asio::error::eof;
+      }
+      else
+      {
+        ec = asio::error_code(last_error,
+            asio::error::get_system_category());
+      }
+      ASIO_ERROR_LOCATION(ec);
+      return 0;
+    }
+  }
+
+  // Wait for the operation to complete.
+  DWORD bytes_transferred = 0;
+  ok = ::GetOverlappedResult(impl.handle_,
+      &overlapped, &bytes_transferred, TRUE);
+  if (!ok)
+  {
+    DWORD last_error = ::GetLastError();
+    if (last_error == ERROR_HANDLE_EOF)
+    {
+      ec = asio::error::eof;
+    }
+    else
+    {
+      ec = asio::error_code(last_error,
+          asio::error::get_system_category());
+    }
+    ASIO_ERROR_LOCATION(ec);
+    return (last_error == ERROR_MORE_DATA) ? bytes_transferred : 0;
+  }
+
+  ec = asio::error_code();
+  return bytes_transferred;
+}
+
+void win_iocp_handle_service::start_read_op(
+    win_iocp_handle_service::implementation_type& impl, uint64_t offset,
+    const asio::mutable_buffer& buffer, operation* op)
+{
+  update_cancellation_thread_id(impl);
+  iocp_service_.work_started();
+
+  if (!is_open(impl))
+  {
+    iocp_service_.on_completion(op, asio::error::bad_descriptor);
+  }
+  else if (buffer.size() == 0)
+  {
+    // A request to read 0 bytes on a handle is a no-op.
+    iocp_service_.on_completion(op);
+  }
+  else
+  {
+    DWORD bytes_transferred = 0;
+    op->Offset = offset & 0xFFFFFFFF;
+    op->OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
+    BOOL ok = ::ReadFile(impl.handle_, buffer.data(),
+        static_cast<DWORD>(buffer.size()),
+        &bytes_transferred, op);
+    DWORD last_error = ::GetLastError();
+    if (!ok && last_error != ERROR_IO_PENDING
+        && last_error != ERROR_MORE_DATA)
+    {
+      iocp_service_.on_completion(op, last_error, bytes_transferred);
+    }
+    else
+    {
+      iocp_service_.on_pending(op);
+    }
+  }
+}
+
+void win_iocp_handle_service::update_cancellation_thread_id(
+    win_iocp_handle_service::implementation_type& impl)
+{
+  if (impl.safe_cancellation_thread_id_ == 0)
+    impl.safe_cancellation_thread_id_ = ::GetCurrentThreadId();
+  else if (impl.safe_cancellation_thread_id_ != ::GetCurrentThreadId())
+    impl.safe_cancellation_thread_id_ = ~DWORD(0);
+}
+
+void win_iocp_handle_service::close_for_destruction(implementation_type& impl)
+{
+  if (is_open(impl))
+  {
+    ASIO_HANDLER_OPERATION((iocp_service_.context(), "handle",
+          &impl, reinterpret_cast<uintmax_t>(impl.handle_), "close"));
+
+    ::CloseHandle(impl.handle_);
+    impl.handle_ = INVALID_HANDLE_VALUE;
+    impl.safe_cancellation_thread_id_ = 0;
+  }
+}
+
+win_iocp_handle_service::nt_set_info_fn
+win_iocp_handle_service::get_nt_set_info()
+{
+  void* ptr = interlocked_compare_exchange_pointer(&nt_set_info_, 0, 0);
+  if (!ptr)
+  {
+    if (HMODULE h = ::GetModuleHandleA("NTDLL.DLL"))
+      ptr = reinterpret_cast<void*>(GetProcAddress(h, "NtSetInformationFile"));
+
+    // On failure, set nt_set_info_ to a special value to indicate that the
+    // NtSetInformationFile function is unavailable. That way we won't bother
+    // trying to look it up again.
+    interlocked_exchange_pointer(&nt_set_info_, ptr ? ptr : this);
+  }
+
+  return reinterpret_cast<nt_set_info_fn>(ptr == this ? 0 : ptr);
+}
+
+void* win_iocp_handle_service::interlocked_compare_exchange_pointer(
+    void** dest, void* exch, void* cmp)
+{
+#if defined(_M_IX86)
+  return reinterpret_cast<void*>(InterlockedCompareExchange(
+        reinterpret_cast<PLONG>(dest), reinterpret_cast<LONG>(exch),
+        reinterpret_cast<LONG>(cmp)));
+#else
+  return InterlockedCompareExchangePointer(dest, exch, cmp);
+#endif
+}
+
+void* win_iocp_handle_service::interlocked_exchange_pointer(
+    void** dest, void* val)
+{
+#if defined(_M_IX86)
+  return reinterpret_cast<void*>(InterlockedExchange(
+        reinterpret_cast<PLONG>(dest), reinterpret_cast<LONG>(val)));
+#else
+  return InterlockedExchangePointer(dest, val);
+#endif
+}
+
+} // namespace detail
+} // namespace asio
+
+#include "asio/detail/pop_options.hpp"
+
+#endif // defined(ASIO_HAS_IOCP)
+
+#endif // ASIO_DETAIL_IMPL_WIN_IOCP_HANDLE_SERVICE_IPP