1/*
2 * Copyright (C) 2008 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_IBINDER_H
18#define ANDROID_IBINDER_H
19
20#include <utils/Errors.h>
21#include <utils/RefBase.h>
22#include <utils/String16.h>
23#include <utils/Vector.h>
24
25
26// linux/binder.h already defines this, but we can't just include it from there
27// because there are host builds that include this file.
28#ifndef B_PACK_CHARS
29#define B_PACK_CHARS(c1, c2, c3, c4) \
30    ((((c1)<<24)) | (((c2)<<16)) | (((c3)<<8)) | (c4))
31#endif  // B_PACK_CHARS
32
33// ---------------------------------------------------------------------------
34namespace android {
35
36class BBinder;
37class BpBinder;
38class IInterface;
39class Parcel;
40class IResultReceiver;
41
42/**
43 * Base class and low-level protocol for a remotable object.
44 * You can derive from this class to create an object for which other
45 * processes can hold references to it.  Communication between processes
46 * (method calls, property get and set) is down through a low-level
47 * protocol implemented on top of the transact() API.
48 */
49class IBinder : public virtual RefBase
50{
51public:
52    enum {
53        FIRST_CALL_TRANSACTION  = 0x00000001,
54        LAST_CALL_TRANSACTION   = 0x00ffffff,
55
56        PING_TRANSACTION        = B_PACK_CHARS('_','P','N','G'),
57        DUMP_TRANSACTION        = B_PACK_CHARS('_','D','M','P'),
58        SHELL_COMMAND_TRANSACTION = B_PACK_CHARS('_','C','M','D'),
59        INTERFACE_TRANSACTION   = B_PACK_CHARS('_', 'N', 'T', 'F'),
60        SYSPROPS_TRANSACTION    = B_PACK_CHARS('_', 'S', 'P', 'R'),
61
62        // Corresponds to TF_ONE_WAY -- an asynchronous call.
63        FLAG_ONEWAY             = 0x00000001
64    };
65
66                          IBinder();
67
68    /**
69     * Check if this IBinder implements the interface named by
70     * @a descriptor.  If it does, the base pointer to it is returned,
71     * which you can safely static_cast<> to the concrete C++ interface.
72     */
73    virtual sp<IInterface>  queryLocalInterface(const String16& descriptor);
74
75    /**
76     * Return the canonical name of the interface provided by this IBinder
77     * object.
78     */
79    virtual const String16& getInterfaceDescriptor() const = 0;
80
81    virtual bool            isBinderAlive() const = 0;
82    virtual status_t        pingBinder() = 0;
83    virtual status_t        dump(int fd, const Vector<String16>& args) = 0;
84    static  status_t        shellCommand(const sp<IBinder>& target, int in, int out, int err,
85                                         Vector<String16>& args,
86                                         const sp<IResultReceiver>& resultReceiver);
87
88    virtual status_t        transact(   uint32_t code,
89                                        const Parcel& data,
90                                        Parcel* reply,
91                                        uint32_t flags = 0) = 0;
92
93    class DeathRecipient : public virtual RefBase
94    {
95    public:
96        virtual void binderDied(const wp<IBinder>& who) = 0;
97    };
98
99    /**
100     * Register the @a recipient for a notification if this binder
101     * goes away.  If this binder object unexpectedly goes away
102     * (typically because its hosting process has been killed),
103     * then DeathRecipient::binderDied() will be called with a reference
104     * to this.
105     *
106     * The @a cookie is optional -- if non-NULL, it should be a
107     * memory address that you own (that is, you know it is unique).
108     *
109     * @note You will only receive death notifications for remote binders,
110     * as local binders by definition can't die without you dying as well.
111     * Trying to use this function on a local binder will result in an
112     * INVALID_OPERATION code being returned and nothing happening.
113     *
114     * @note This link always holds a weak reference to its recipient.
115     *
116     * @note You will only receive a weak reference to the dead
117     * binder.  You should not try to promote this to a strong reference.
118     * (Nor should you need to, as there is nothing useful you can
119     * directly do with it now that it has passed on.)
120     */
121    virtual status_t        linkToDeath(const sp<DeathRecipient>& recipient,
122                                        void* cookie = NULL,
123                                        uint32_t flags = 0) = 0;
124
125    /**
126     * Remove a previously registered death notification.
127     * The @a recipient will no longer be called if this object
128     * dies.  The @a cookie is optional.  If non-NULL, you can
129     * supply a NULL @a recipient, and the recipient previously
130     * added with that cookie will be unlinked.
131     */
132    virtual status_t        unlinkToDeath(  const wp<DeathRecipient>& recipient,
133                                            void* cookie = NULL,
134                                            uint32_t flags = 0,
135                                            wp<DeathRecipient>* outRecipient = NULL) = 0;
136
137    virtual bool            checkSubclass(const void* subclassID) const;
138
139    typedef void (*object_cleanup_func)(const void* id, void* obj, void* cleanupCookie);
140
141    virtual void            attachObject(   const void* objectID,
142                                            void* object,
143                                            void* cleanupCookie,
144                                            object_cleanup_func func) = 0;
145    virtual void*           findObject(const void* objectID) const = 0;
146    virtual void            detachObject(const void* objectID) = 0;
147
148    virtual BBinder*        localBinder();
149    virtual BpBinder*       remoteBinder();
150
151protected:
152    virtual          ~IBinder();
153
154private:
155};
156
157}; // namespace android
158
159// ---------------------------------------------------------------------------
160
161#endif // ANDROID_IBINDER_H
162