adb_legacy_io_completion.cpp revision 39164844f16c2c63d52a71652d53b233c5f28e14 
1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17/** \file
18  This file consists of implementation of class AdbLegacyIOCompletion that
19  encapsulates a wrapper around OVERLAPPED Win32 structure returned from
20  asynchronous I/O requests issued via legacy USB API.
21*/
22
23#include "stdafx.h"
24#include "adb_legacy_io_completion.h"
25
26AdbLegacyIOCompletion::AdbLegacyIOCompletion(
27    AdbLegacyEndpointObject* parent_io_obj,
28    ULONG expected_trans_size,
29    HANDLE event_hndl,
30    bool is_write_ctl)
31    : AdbIOCompletion(parent_io_obj, expected_trans_size, event_hndl),
32      transferred_bytes_(0),
33      is_write_ioctl_(is_write_ctl) {
34}
35
36AdbLegacyIOCompletion::~AdbLegacyIOCompletion() {
37}
38
39bool AdbLegacyIOCompletion::GetOvelappedIoResult(LPOVERLAPPED ovl_data,
40                                                 ULONG* bytes_transferred,
41                                                 bool wait) {
42  if (NULL != bytes_transferred) {
43    *bytes_transferred = 0;
44  }
45
46  if (!IsOpened()) {
47    SetLastError(ERROR_INVALID_HANDLE);
48    return false;
49  }
50
51  ULONG transfer;
52  bool ret = GetOverlappedResult(parent_legacy_io_object()->usb_handle(),
53                                 overlapped(),
54                                 &transfer,
55                                 wait) ? true :
56                                         false;
57
58  // TODO: This is bizzare but I've seen it happening
59  // that GetOverlappedResult with wait set to true returns "prematurely",
60  // with wrong transferred bytes value and GetLastError reporting
61  // ERROR_IO_PENDING. So, lets give it an up to a 20 ms loop!
62  ULONG error = GetLastError();
63
64  if (wait && ret && (0 == transfer) && (0 != expected_transfer_size_) &&
65      ((ERROR_IO_INCOMPLETE == error) || (ERROR_IO_PENDING == error))) {
66    for (int trying = 0; trying < 10; trying++) {
67      Sleep(2);
68      ret = GetOverlappedResult(parent_legacy_io_object()->usb_handle(),
69                                overlapped(),
70                                &transfer,
71                                wait) ? true :
72                                        false;
73      error = GetLastError();
74      if (!ret || (0 != transfer) ||
75          ((ERROR_IO_INCOMPLETE != error) && (ERROR_IO_PENDING != error))) {
76        break;
77      }
78    }
79  }
80
81  if (NULL != ovl_data) {
82    CopyMemory(ovl_data, overlapped(), sizeof(OVERLAPPED));
83  }
84
85  if (NULL != bytes_transferred) {
86    *bytes_transferred = is_write_ioctl() ? transferred_bytes_ : transfer;
87  }
88
89  return ret;
90}
91