adb_winusb_endpoint_object.h revision f855c4e8469e31114fccca4c28aeb01a806a9a48 
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#ifndef ANDROID_USB_API_ADB_WINUSB_ENDPOINT_OBJECT_H__
18#define ANDROID_USB_API_ADB_WINUSB_ENDPOINT_OBJECT_H__
19/** \file
20  This file consists of declaration of class AdbWinUsbEndpointObject that
21  encapsulates a handle opened to a WinUsb endpoint on our device.
22*/
23
24#include "..\api\adb_endpoint_object.h"
25#include "adb_winusb_interface.h"
26
27/** Class AdbWinUsbEndpointObject encapsulates a handle opened to an endpoint on
28  our device.
29*/
30class AdbWinUsbEndpointObject : public AdbEndpointObject {
31 public:
32  /** \brief Constructs the object
33
34    @param[in] interface Parent WinUsb interface for this object.
35    @param[in] endpoint_id Endpoint ID (endpoint address) on the device.
36    @param[in] endpoint_index Zero-based endpoint index in the interface's
37          array of endpoints.
38  */
39  AdbWinUsbEndpointObject(AdbWinUsbInterfaceObject* parent_interf,
40                          UCHAR endpoint_id,
41                          UCHAR endpoint_index);
42
43 protected:
44  /** \brief Destructs the object.
45
46    We hide destructor in order to prevent ourseves from accidentaly allocating
47    instances on the stack. If such attemp occur, compiler will error.
48  */
49  virtual ~AdbWinUsbEndpointObject();
50
51  //
52  // Virtual overrides
53  //
54
55 public:
56  /** \brief Releases the object.
57
58    If refcount drops to zero as the result of this release, the object is
59    destroyed in this method. As a general rule, objects must not be touched
60    after this method returns even if returned value is not zero. We override
61    this method in order to make sure that objects of this class are deleted
62    in contect of the DLL they were created in. The problem is that since
63    objects of this class were created in context of AdbWinUsbApi module, they
64    are allocated from the heap assigned to that module. Now, if these objects
65    are deleted outside of AdbWinUsbApi module, this will lead to the heap
66    corruption in the module that deleted these objects. Since all objects of
67    this class are deleted in the Release method only, by overriding it we make
68    sure that we free memory in the context of the module where it was
69    allocated.
70    @return Value of the reference counter after object is released in this
71            method.
72  */
73  virtual LONG Release();
74
75  //
76  // Abstract overrides
77  //
78
79 protected:
80  /** \brief Common code for async read / write
81
82    @param[in] is_read Read or write selector.
83    @param[in,out] buffer Pointer to the buffer for read / write.
84    @param[in] bytes_to_transfer Number of bytes to be read / written.
85    @param[out] bytes_transferred Number of bytes read / written. Can be NULL.
86    @param[in] event_handle Event handle that should be signaled when async I/O
87           completes. Can be NULL. If it's not NULL this handle will be used to
88           initialize OVERLAPPED structure for this I/O.
89    @param[in] time_out A timeout (in milliseconds) required for this I/O to
90           complete. Zero value in this parameter means that there is no
91           timeout set for this I/O.
92    @return A handle to IO completion object or NULL on failure. If NULL is
93            returned GetLastError() provides extended error information.
94  */
95  virtual ADBAPIHANDLE CommonAsyncReadWrite(bool is_read,
96                                            void* buffer,
97                                            ULONG bytes_to_transfer,
98                                            ULONG* bytes_transferred,
99                                            HANDLE event_handle,
100                                            ULONG time_out);
101
102  /** \brief Common code for sync read / write
103
104    @param[in] is_read Read or write selector.
105    @param[in,out] buffer Pointer to the buffer for read / write.
106    @param[in] bytes_to_transfer Number of bytes to be read / written.
107    @param[out] bytes_transferred Number of bytes read / written. Can be NULL.
108    @param[in] time_out A timeout (in milliseconds) required for this I/O to
109           complete. Zero value in this parameter means that there is no
110           timeout set for this I/O.
111    @return true on success, false on failure. If false is returned
112            GetLastError() provides extended error information.
113  */
114  virtual bool CommonSyncReadWrite(bool is_read,
115                                   void* buffer,
116                                   ULONG bytes_to_transfer,
117                                   ULONG* bytes_transferred,
118                                   ULONG time_out);
119
120  //
121  // Operations
122  //
123
124 protected:
125  /** \brief Sets read / write operation timeout.
126
127    @param[in] timeout Timeout value in milliseconds to use for current read
128          or write operation. Zero value passed in this parameters indicate
129          not timeout at all. Note that timeout that is set with this method is
130          global per endpoint (pipe). I.e. once set, it will be used against
131          all read / write operations performed on this endpoint, untill
132          another call to this method modifies it. This is a WinUsb design
133          flaw. Microsoft is aware of this and (hopefuly) future versions of
134          WinUsb framework will accept a timeout parameter in WinUsb_Read/Write
135          routines. For the purposes of ADB this flaw doesn't apperar to be an
136          issue, since we use single-threaded synchronous read / writes, so
137          there is no conflict in setting per-endpoint timeouts.
138    @return true on success, false on failure. If false is returned
139            GetLastError() provides extended error information.
140  */
141  virtual bool SetTimeout(ULONG timeout);
142
143 public:
144  /// Gets parent WinUsb interface
145  AdbWinUsbInterfaceObject* parent_winusb_interface() const {
146    return reinterpret_cast<AdbWinUsbInterfaceObject*>(parent_interface());
147  }
148
149  /// Gets parent interface WinUsb handle
150  WINUSB_INTERFACE_HANDLE winusb_handle() const {
151    return parent_winusb_interface()->winusb_handle();
152  }
153};
154
155#endif  // ANDROID_USB_API_ADB_WINUSB_ENDPOINT_OBJECT_H__
156