base/async_socket_io_handler_win.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/async_socket_io_handler.h"
   6
   7 namespace base {
   8
   9 AsyncSocketIoHandler::AsyncSocketIoHandler()
  10     : socket_(base::SyncSocket::kInvalidHandle),
  11       context_(NULL),
  12       is_pending_(false) {}
  13
  14 AsyncSocketIoHandler::~AsyncSocketIoHandler() {
  15   // We need to be deleted on the correct thread to avoid racing with the
  16   // message loop thread.
  17   DCHECK(CalledOnValidThread());
  18
  19   if (context_) {
  20     if (is_pending_) {
  21       // Make the context be deleted by the message pump when done.
  22       context_->handler = NULL;
  23     } else {
  24       delete context_;
  25     }
  26   }
  27 }
  28
  29 // Implementation of IOHandler on Windows.
  30 void AsyncSocketIoHandler::OnIOCompleted(
  31     base::MessageLoopForIO::IOContext* context,
  32     DWORD bytes_transfered,
  33     DWORD error) {
  34   DCHECK(CalledOnValidThread());
  35   DCHECK_EQ(context_, context);
  36   DCHECK(!read_complete_.is_null());
  37   is_pending_ = false;
  38   read_complete_.Run(error == ERROR_SUCCESS ? bytes_transfered : 0);
  39 }
  40
  41 bool AsyncSocketIoHandler::Read(char* buffer, int buffer_len) {
  42   DCHECK(CalledOnValidThread());
  43   DCHECK(!read_complete_.is_null());
  44   DCHECK(!is_pending_);
  45   DCHECK_NE(socket_, base::SyncSocket::kInvalidHandle);
  46
  47   DWORD bytes_read = 0;
  48   BOOL ok = ::ReadFile(socket_, buffer, buffer_len, &bytes_read,
  49                        &context_->overlapped);
  50   // The completion port will be signaled regardless of completing the read
  51   // straight away or asynchronously (ERROR_IO_PENDING). OnIOCompleted() will
  52   // be called regardless and we don't need to explicitly run the callback
  53   // in the case where ok is FALSE and GLE==ERROR_IO_PENDING.
  54   is_pending_ = !ok && (GetLastError() == ERROR_IO_PENDING);
  55   return ok || is_pending_;
  56 }
  57
  58 bool AsyncSocketIoHandler::Initialize(base::SyncSocket::Handle socket,
  59                                       const ReadCompleteCallback& callback) {
  60   DCHECK(!context_);
  61   DCHECK_EQ(socket_, base::SyncSocket::kInvalidHandle);
  62
  63   DetachFromThread();
  64
  65   socket_ = socket;
  66   read_complete_ = callback;
  67
  68   base::MessageLoopForIO::current()->RegisterIOHandler(socket, this);
  69
  70   context_ = new base::MessageLoopForIO::IOContext();
  71   context_->handler = this;
  72   memset(&context_->overlapped, 0, sizeof(context_->overlapped));
  73
  74   return true;
  75 }
  76
  77 }  // namespace base.