/usr/include/asio/detail/win_iocp_handle_service.hpp is in libasio-dev 1.4.1-3ubuntu2.
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// win_iocp_handle_service.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2008 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_WIN_IOCP_HANDLE_SERVICE_HPP
#define ASIO_DETAIL_WIN_IOCP_HANDLE_SERVICE_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include "asio/detail/push_options.hpp"
#include "asio/detail/win_iocp_io_service_fwd.hpp"
#if defined(ASIO_HAS_IOCP)
#include "asio/detail/push_options.hpp"
#include <boost/cstdint.hpp>
#include "asio/detail/pop_options.hpp"
#include "asio/buffer.hpp"
#include "asio/error.hpp"
#include "asio/io_service.hpp"
#include "asio/detail/bind_handler.hpp"
#include "asio/detail/handler_alloc_helpers.hpp"
#include "asio/detail/handler_invoke_helpers.hpp"
#include "asio/detail/mutex.hpp"
#include "asio/detail/win_iocp_io_service.hpp"
namespace asio {
namespace detail {
class win_iocp_handle_service
: public asio::detail::service_base<win_iocp_handle_service>
{
public:
// Base class for all operations.
typedef win_iocp_io_service::operation operation;
// The native type of a stream handle.
typedef HANDLE native_type;
// The implementation type of the stream handle.
class implementation_type
{
public:
// Default constructor.
implementation_type()
: handle_(INVALID_HANDLE_VALUE),
safe_cancellation_thread_id_(0),
next_(0),
prev_(0)
{
}
private:
// Only this service will have access to the internal values.
friend class win_iocp_handle_service;
// The native stream handle representation.
native_type handle_;
// The ID of the thread from which it is safe to cancel asynchronous
// operations. 0 means no asynchronous operations have been started yet.
// ~0 means asynchronous operations have been started from more than one
// thread, and cancellation is not supported for the handle.
DWORD safe_cancellation_thread_id_;
// Pointers to adjacent handle implementations in linked list.
implementation_type* next_;
implementation_type* prev_;
};
win_iocp_handle_service(asio::io_service& io_service)
: asio::detail::service_base<win_iocp_handle_service>(io_service),
iocp_service_(asio::use_service<win_iocp_io_service>(io_service)),
mutex_(),
impl_list_(0)
{
}
// Destroy all user-defined handler objects owned by the service.
void shutdown_service()
{
// 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_;
}
}
// Construct a new handle implementation.
void construct(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;
}
// Destroy a handle implementation.
void destroy(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;
}
// Assign a native handle to a handle implementation.
asio::error_code assign(implementation_type& impl,
const native_type& native_handle, asio::error_code& ec)
{
if (is_open(impl))
{
ec = asio::error::already_open;
return ec;
}
if (iocp_service_.register_handle(native_handle, ec))
return ec;
impl.handle_ = native_handle;
ec = asio::error_code();
return ec;
}
// Determine whether the handle is open.
bool is_open(const implementation_type& impl) const
{
return impl.handle_ != INVALID_HANDLE_VALUE;
}
// Destroy a handle implementation.
asio::error_code close(implementation_type& impl,
asio::error_code& ec)
{
if (is_open(impl))
{
if (!::CloseHandle(impl.handle_))
{
DWORD last_error = ::GetLastError();
ec = asio::error_code(last_error,
asio::error::get_system_category());
return ec;
}
impl.handle_ = INVALID_HANDLE_VALUE;
impl.safe_cancellation_thread_id_ = 0;
}
ec = asio::error_code();
return ec;
}
// Get the native handle representation.
native_type native(const implementation_type& impl) const
{
return impl.handle_;
}
// Cancel all operations associated with the handle.
asio::error_code cancel(implementation_type& impl,
asio::error_code& ec)
{
if (!is_open(impl))
{
ec = asio::error::bad_descriptor;
}
else 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 = (cancel_io_ex_t)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;
}
return ec;
}
class 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 = ::CreateEvent(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.
*reinterpret_cast<DWORD_PTR*>(&hEvent) |= 1;
}
else
{
DWORD last_error = ::GetLastError();
ec = asio::error_code(last_error,
asio::error::get_system_category());
}
}
~overlapped_wrapper()
{
if (hEvent)
{
::CloseHandle(hEvent);
}
}
};
// Write the given data. Returns the number of bytes written.
template <typename ConstBufferSequence>
size_t write_some(implementation_type& impl,
const ConstBufferSequence& buffers, asio::error_code& ec)
{
return write_some_at(impl, 0, buffers, ec);
}
// Write the given data at the specified offset. Returns the number of bytes
// written.
template <typename ConstBufferSequence>
size_t write_some_at(implementation_type& impl, boost::uint64_t offset,
const ConstBufferSequence& buffers, asio::error_code& ec)
{
if (!is_open(impl))
{
ec = asio::error::bad_descriptor;
return 0;
}
// Find first buffer of non-zero length.
asio::const_buffer buffer;
typename ConstBufferSequence::const_iterator iter = buffers.begin();
typename ConstBufferSequence::const_iterator end = buffers.end();
for (DWORD i = 0; iter != end; ++iter, ++i)
{
buffer = asio::const_buffer(*iter);
if (asio::buffer_size(buffer) != 0)
break;
}
// A request to write 0 bytes on a handle is a no-op.
if (asio::buffer_size(buffer) == 0)
{
ec = asio::error_code();
return 0;
}
overlapped_wrapper overlapped(ec);
if (ec)
{
return 0;
}
// Write the data.
overlapped.Offset = offset & 0xFFFFFFFF;
overlapped.OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
BOOL ok = ::WriteFile(impl.handle_,
asio::buffer_cast<LPCVOID>(buffer),
static_cast<DWORD>(asio::buffer_size(buffer)), 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());
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());
}
ec = asio::error_code();
return bytes_transferred;
}
template <typename ConstBufferSequence, typename Handler>
class write_operation
: public operation
{
public:
write_operation(win_iocp_io_service& io_service,
const ConstBufferSequence& buffers, Handler handler)
: operation(io_service,
&write_operation<ConstBufferSequence, Handler>::do_completion_impl,
&write_operation<ConstBufferSequence, Handler>::destroy_impl),
work_(io_service.get_io_service()),
buffers_(buffers),
handler_(handler)
{
}
private:
static void do_completion_impl(operation* op,
DWORD last_error, size_t bytes_transferred)
{
// Take ownership of the operation object.
typedef write_operation<ConstBufferSequence, Handler> op_type;
op_type* handler_op(static_cast<op_type*>(op));
typedef handler_alloc_traits<Handler, op_type> alloc_traits;
handler_ptr<alloc_traits> ptr(handler_op->handler_, handler_op);
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
// Check whether buffers are still valid.
typename ConstBufferSequence::const_iterator iter
= handler_op->buffers_.begin();
typename ConstBufferSequence::const_iterator end
= handler_op->buffers_.end();
while (iter != end)
{
asio::const_buffer buffer(*iter);
asio::buffer_cast<const char*>(buffer);
++iter;
}
#endif // defined(ASIO_ENABLE_BUFFER_DEBUGGING)
// Make a copy of the handler so that the memory can be deallocated before
// the upcall is made.
Handler handler(handler_op->handler_);
// Free the memory associated with the handler.
ptr.reset();
// Call the handler.
asio::error_code ec(last_error,
asio::error::get_system_category());
asio_handler_invoke_helpers::invoke(
bind_handler(handler, ec, bytes_transferred), &handler);
}
static void destroy_impl(operation* op)
{
// Take ownership of the operation object.
typedef write_operation<ConstBufferSequence, Handler> op_type;
op_type* handler_op(static_cast<op_type*>(op));
typedef handler_alloc_traits<Handler, op_type> alloc_traits;
handler_ptr<alloc_traits> ptr(handler_op->handler_, handler_op);
// A sub-object of the handler may be the true owner of the memory
// associated with the handler. Consequently, a local copy of the handler
// is required to ensure that any owning sub-object remains valid until
// after we have deallocated the memory here.
Handler handler(handler_op->handler_);
(void)handler;
// Free the memory associated with the handler.
ptr.reset();
}
asio::io_service::work work_;
ConstBufferSequence buffers_;
Handler handler_;
};
// Start an asynchronous write. The data being written must be valid for the
// lifetime of the asynchronous operation.
template <typename ConstBufferSequence, typename Handler>
void async_write_some(implementation_type& impl,
const ConstBufferSequence& buffers, Handler handler)
{
async_write_some_at(impl, 0, buffers, handler);
}
// Start an asynchronous write at a specified offset. The data being written
// must be valid for the lifetime of the asynchronous operation.
template <typename ConstBufferSequence, typename Handler>
void async_write_some_at(implementation_type& impl, boost::uint64_t offset,
const ConstBufferSequence& buffers, Handler handler)
{
if (!is_open(impl))
{
this->get_io_service().post(bind_handler(handler,
asio::error::bad_descriptor, 0));
return;
}
// Update the ID of the thread from which cancellation is safe.
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);
// Allocate and construct an operation to wrap the handler.
typedef write_operation<ConstBufferSequence, Handler> value_type;
typedef handler_alloc_traits<Handler, value_type> alloc_traits;
raw_handler_ptr<alloc_traits> raw_ptr(handler);
handler_ptr<alloc_traits> ptr(raw_ptr, iocp_service_, buffers, handler);
// Find first buffer of non-zero length.
asio::const_buffer buffer;
typename ConstBufferSequence::const_iterator iter = buffers.begin();
typename ConstBufferSequence::const_iterator end = buffers.end();
for (DWORD i = 0; iter != end; ++iter, ++i)
{
buffer = asio::const_buffer(*iter);
if (asio::buffer_size(buffer) != 0)
break;
}
// A request to write 0 bytes on a handle is a no-op.
if (asio::buffer_size(buffer) == 0)
{
asio::io_service::work work(this->get_io_service());
ptr.reset();
asio::error_code error;
iocp_service_.post(bind_handler(handler, error, 0));
return;
}
// Write the data.
DWORD bytes_transferred = 0;
ptr.get()->Offset = offset & 0xFFFFFFFF;
ptr.get()->OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
BOOL ok = ::WriteFile(impl.handle_,
asio::buffer_cast<LPCVOID>(buffer),
static_cast<DWORD>(asio::buffer_size(buffer)),
&bytes_transferred, ptr.get());
DWORD last_error = ::GetLastError();
// Check if the operation completed immediately.
if (!ok && last_error != ERROR_IO_PENDING)
{
asio::io_service::work work(this->get_io_service());
ptr.reset();
asio::error_code ec(last_error,
asio::error::get_system_category());
iocp_service_.post(bind_handler(handler, ec, bytes_transferred));
}
else
{
ptr.release();
}
}
// Read some data. Returns the number of bytes received.
template <typename MutableBufferSequence>
size_t read_some(implementation_type& impl,
const MutableBufferSequence& buffers, asio::error_code& ec)
{
return read_some_at(impl, 0, buffers, ec);
}
// Read some data at a specified offset. Returns the number of bytes received.
template <typename MutableBufferSequence>
size_t read_some_at(implementation_type& impl, boost::uint64_t offset,
const MutableBufferSequence& buffers, asio::error_code& ec)
{
if (!is_open(impl))
{
ec = asio::error::bad_descriptor;
return 0;
}
// Find first buffer of non-zero length.
asio::mutable_buffer buffer;
typename MutableBufferSequence::const_iterator iter = buffers.begin();
typename MutableBufferSequence::const_iterator end = buffers.end();
for (DWORD i = 0; iter != end; ++iter, ++i)
{
buffer = asio::mutable_buffer(*iter);
if (asio::buffer_size(buffer) != 0)
break;
}
// A request to read 0 bytes on a stream handle is a no-op.
if (asio::buffer_size(buffer) == 0)
{
ec = asio::error_code();
return 0;
}
overlapped_wrapper overlapped(ec);
if (ec)
{
return 0;
}
// Read some data.
overlapped.Offset = offset & 0xFFFFFFFF;
overlapped.OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
BOOL ok = ::ReadFile(impl.handle_,
asio::buffer_cast<LPVOID>(buffer),
static_cast<DWORD>(asio::buffer_size(buffer)), 0, &overlapped);
if (!ok)
{
DWORD last_error = ::GetLastError();
if (last_error != ERROR_IO_PENDING)
{
if (last_error == ERROR_HANDLE_EOF)
{
ec = asio::error::eof;
}
else
{
ec = asio::error_code(last_error,
asio::error::get_system_category());
}
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());
}
}
ec = asio::error_code();
return bytes_transferred;
}
template <typename MutableBufferSequence, typename Handler>
class read_operation
: public operation
{
public:
read_operation(win_iocp_io_service& io_service,
const MutableBufferSequence& buffers, Handler handler)
: operation(io_service,
&read_operation<
MutableBufferSequence, Handler>::do_completion_impl,
&read_operation<
MutableBufferSequence, Handler>::destroy_impl),
work_(io_service.get_io_service()),
buffers_(buffers),
handler_(handler)
{
}
private:
static void do_completion_impl(operation* op,
DWORD last_error, size_t bytes_transferred)
{
// Take ownership of the operation object.
typedef read_operation<MutableBufferSequence, Handler> op_type;
op_type* handler_op(static_cast<op_type*>(op));
typedef handler_alloc_traits<Handler, op_type> alloc_traits;
handler_ptr<alloc_traits> ptr(handler_op->handler_, handler_op);
#if defined(ASIO_ENABLE_BUFFER_DEBUGGING)
// Check whether buffers are still valid.
typename MutableBufferSequence::const_iterator iter
= handler_op->buffers_.begin();
typename MutableBufferSequence::const_iterator end
= handler_op->buffers_.end();
while (iter != end)
{
asio::mutable_buffer buffer(*iter);
asio::buffer_cast<char*>(buffer);
++iter;
}
#endif // defined(ASIO_ENABLE_BUFFER_DEBUGGING)
// Check for the end-of-file condition.
asio::error_code ec(last_error,
asio::error::get_system_category());
if (!ec && bytes_transferred == 0 || last_error == ERROR_HANDLE_EOF)
{
ec = asio::error::eof;
}
// Make a copy of the handler so that the memory can be deallocated before
// the upcall is made.
Handler handler(handler_op->handler_);
// Free the memory associated with the handler.
ptr.reset();
// Call the handler.
asio_handler_invoke_helpers::invoke(
bind_handler(handler, ec, bytes_transferred), &handler);
}
static void destroy_impl(operation* op)
{
// Take ownership of the operation object.
typedef read_operation<MutableBufferSequence, Handler> op_type;
op_type* handler_op(static_cast<op_type*>(op));
typedef asio::detail::handler_alloc_traits<
Handler, op_type> alloc_traits;
asio::detail::handler_ptr<alloc_traits> ptr(
handler_op->handler_, handler_op);
// A sub-object of the handler may be the true owner of the memory
// associated with the handler. Consequently, a local copy of the handler
// is required to ensure that any owning sub-object remains valid until
// after we have deallocated the memory here.
Handler handler(handler_op->handler_);
(void)handler;
// Free the memory associated with the handler.
ptr.reset();
}
asio::io_service::work work_;
MutableBufferSequence buffers_;
Handler handler_;
};
// Start an asynchronous read. The buffer for the data being received must be
// valid for the lifetime of the asynchronous operation.
template <typename MutableBufferSequence, typename Handler>
void async_read_some(implementation_type& impl,
const MutableBufferSequence& buffers, Handler handler)
{
async_read_some_at(impl, 0, buffers, handler);
}
// Start an asynchronous read at a specified offset. The buffer for the data
// being received must be valid for the lifetime of the asynchronous
// operation.
template <typename MutableBufferSequence, typename Handler>
void async_read_some_at(implementation_type& impl, boost::uint64_t offset,
const MutableBufferSequence& buffers, Handler handler)
{
if (!is_open(impl))
{
this->get_io_service().post(bind_handler(handler,
asio::error::bad_descriptor, 0));
return;
}
// Update the ID of the thread from which cancellation is safe.
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);
// Allocate and construct an operation to wrap the handler.
typedef read_operation<MutableBufferSequence, Handler> value_type;
typedef handler_alloc_traits<Handler, value_type> alloc_traits;
raw_handler_ptr<alloc_traits> raw_ptr(handler);
handler_ptr<alloc_traits> ptr(raw_ptr, iocp_service_, buffers, handler);
// Find first buffer of non-zero length.
asio::mutable_buffer buffer;
typename MutableBufferSequence::const_iterator iter = buffers.begin();
typename MutableBufferSequence::const_iterator end = buffers.end();
for (DWORD i = 0; iter != end; ++iter, ++i)
{
buffer = asio::mutable_buffer(*iter);
if (asio::buffer_size(buffer) != 0)
break;
}
// A request to receive 0 bytes on a stream handle is a no-op.
if (asio::buffer_size(buffer) == 0)
{
asio::io_service::work work(this->get_io_service());
ptr.reset();
asio::error_code error;
iocp_service_.post(bind_handler(handler, error, 0));
return;
}
// Read some data.
DWORD bytes_transferred = 0;
ptr.get()->Offset = offset & 0xFFFFFFFF;
ptr.get()->OffsetHigh = (offset >> 32) & 0xFFFFFFFF;
BOOL ok = ::ReadFile(impl.handle_,
asio::buffer_cast<LPVOID>(buffer),
static_cast<DWORD>(asio::buffer_size(buffer)),
&bytes_transferred, ptr.get());
DWORD last_error = ::GetLastError();
if (!ok && last_error != ERROR_IO_PENDING)
{
asio::io_service::work work(this->get_io_service());
ptr.reset();
asio::error_code ec(last_error,
asio::error::get_system_category());
iocp_service_.post(bind_handler(handler, ec, bytes_transferred));
}
else
{
ptr.release();
}
}
private:
// Prevent the use of the null_buffers type with this service.
size_t write_some(implementation_type& impl,
const null_buffers& buffers, asio::error_code& ec);
size_t write_some_at(implementation_type& impl, boost::uint64_t offset,
const null_buffers& buffers, asio::error_code& ec);
template <typename Handler>
void async_write_some(implementation_type& impl,
const null_buffers& buffers, Handler handler);
template <typename Handler>
void async_write_some_at(implementation_type& impl, boost::uint64_t offset,
const null_buffers& buffers, Handler handler);
size_t read_some(implementation_type& impl,
const null_buffers& buffers, asio::error_code& ec);
size_t read_some_at(implementation_type& impl, boost::uint64_t offset,
const null_buffers& buffers, asio::error_code& ec);
template <typename Handler>
void async_read_some(implementation_type& impl,
const null_buffers& buffers, Handler handler);
template <typename Handler>
void async_read_some_at(implementation_type& impl, boost::uint64_t offset,
const null_buffers& buffers, Handler handler);
// Helper function to close a handle when the associated object is being
// destroyed.
void close_for_destruction(implementation_type& impl)
{
if (is_open(impl))
{
::CloseHandle(impl.handle_);
impl.handle_ = INVALID_HANDLE_VALUE;
impl.safe_cancellation_thread_id_ = 0;
}
}
// The IOCP service used for running asynchronous operations and dispatching
// handlers.
win_iocp_io_service& iocp_service_;
// Mutex to protect access to the linked list of implementations.
asio::detail::mutex mutex_;
// The head of a linked list of all implementations.
implementation_type* impl_list_;
};
} // namespace detail
} // namespace asio
#endif // defined(ASIO_HAS_IOCP)
#include "asio/detail/pop_options.hpp"
#endif // ASIO_DETAIL_WIN_IOCP_HANDLE_SERVICE_HPP
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