IGraphicBufferAlloc.cpp revision 3be1c6b60a188dc10025e2ce156c11fac050625d 
1/*
2 * Copyright (C) 2011 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// tag as surfaceflinger
18#define LOG_TAG "SurfaceFlinger"
19
20#include <stdint.h>
21#include <sys/types.h>
22
23#include <binder/Parcel.h>
24
25#include <ui/GraphicBuffer.h>
26
27#include <gui/IGraphicBufferAlloc.h>
28
29// ---------------------------------------------------------------------------
30
31namespace android {
32
33enum {
34    CREATE_GRAPHIC_BUFFER = IBinder::FIRST_CALL_TRANSACTION,
35};
36
37class BpGraphicBufferAlloc : public BpInterface<IGraphicBufferAlloc>
38{
39public:
40    BpGraphicBufferAlloc(const sp<IBinder>& impl)
41        : BpInterface<IGraphicBufferAlloc>(impl)
42    {
43    }
44
45    virtual ~BpGraphicBufferAlloc();
46
47    virtual sp<GraphicBuffer> createGraphicBuffer(uint32_t width,
48            uint32_t height, PixelFormat format, uint32_t usage,
49            status_t* error) {
50        Parcel data, reply;
51        data.writeInterfaceToken(IGraphicBufferAlloc::getInterfaceDescriptor());
52        data.writeUint32(width);
53        data.writeUint32(height);
54        data.writeInt32(static_cast<int32_t>(format));
55        data.writeUint32(usage);
56        remote()->transact(CREATE_GRAPHIC_BUFFER, data, &reply);
57        sp<GraphicBuffer> graphicBuffer;
58        status_t result = reply.readInt32();
59        if (result == NO_ERROR) {
60            graphicBuffer = new GraphicBuffer();
61            result = reply.read(*graphicBuffer);
62            // reply.readStrongBinder();
63            // here we don't even have to read the BufferReference from
64            // the parcel, it'll die with the parcel.
65        }
66        *error = result;
67        return graphicBuffer;
68    }
69};
70
71// Out-of-line virtual method definition to trigger vtable emission in this
72// translation unit (see clang warning -Wweak-vtables)
73BpGraphicBufferAlloc::~BpGraphicBufferAlloc() {}
74
75IMPLEMENT_META_INTERFACE(GraphicBufferAlloc, "android.ui.IGraphicBufferAlloc");
76
77// ----------------------------------------------------------------------
78
79status_t BnGraphicBufferAlloc::onTransact(
80    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
81{
82    // codes that don't require permission check
83
84    // BufferReference just keeps a strong reference to a GraphicBuffer until it
85    // is destroyed (that is, until no local or remote process have a reference
86    // to it).
87    class BufferReference : public BBinder {
88        sp<GraphicBuffer> mBuffer;
89    public:
90        BufferReference(const sp<GraphicBuffer>& buffer) : mBuffer(buffer) {}
91    };
92
93
94    switch (code) {
95        case CREATE_GRAPHIC_BUFFER: {
96            CHECK_INTERFACE(IGraphicBufferAlloc, data, reply);
97            uint32_t width = data.readUint32();
98            uint32_t height = data.readUint32();
99            PixelFormat format = static_cast<PixelFormat>(data.readInt32());
100            uint32_t usage = data.readUint32();
101            status_t error;
102            sp<GraphicBuffer> result =
103                    createGraphicBuffer(width, height, format, usage, &error);
104            reply->writeInt32(error);
105            if (result != 0) {
106                reply->write(*result);
107                // We add a BufferReference to this parcel to make sure the
108                // buffer stays alive until the GraphicBuffer object on
109                // the other side has been created.
110                // This is needed so that the buffer handle can be
111                // registered before the buffer is destroyed on implementations
112                // that do not use file-descriptors to track their buffers.
113                reply->writeStrongBinder( new BufferReference(result) );
114            }
115            return NO_ERROR;
116        }
117        default:
118            return BBinder::onTransact(code, data, reply, flags);
119    }
120}
121
122}; // namespace android
123