IGraphicBufferAlloc.cpp revision 4cb18881b55b82a24873ccd8e298bc2d5a9c17e5 
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 <surfaceflinger/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 sp<GraphicBuffer> createGraphicBuffer(uint32_t w, uint32_t h,
46            PixelFormat format, uint32_t usage) {
47        Parcel data, reply;
48        data.writeInterfaceToken(IGraphicBufferAlloc::getInterfaceDescriptor());
49        data.writeInt32(w);
50        data.writeInt32(h);
51        data.writeInt32(format);
52        data.writeInt32(usage);
53        remote()->transact(CREATE_GRAPHIC_BUFFER, data, &reply);
54        sp<GraphicBuffer> graphicBuffer;
55        bool nonNull = (bool)reply.readInt32();
56        if (nonNull) {
57            graphicBuffer = new GraphicBuffer();
58            reply.read(*graphicBuffer);
59            // reply.readStrongBinder();
60            // here we don't even have to read the BufferReference from
61            // the parcel, it'll die with the parcel.
62        }
63        return graphicBuffer;
64    }
65};
66
67IMPLEMENT_META_INTERFACE(GraphicBufferAlloc, "android.ui.IGraphicBufferAlloc");
68
69// ----------------------------------------------------------------------
70
71status_t BnGraphicBufferAlloc::onTransact(
72    uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
73{
74    // codes that don't require permission check
75
76    /* BufferReference just keeps a strong reference to a
77     * GraphicBuffer until it is destroyed (that is, until
78     * no local or remote process have a reference to it).
79     */
80    class BufferReference : public BBinder {
81        sp<GraphicBuffer> buffer;
82    public:
83        BufferReference(const sp<GraphicBuffer>& buffer) : buffer(buffer) { }
84    };
85
86
87    switch(code) {
88        case CREATE_GRAPHIC_BUFFER: {
89            CHECK_INTERFACE(IGraphicBufferAlloc, data, reply);
90            uint32_t w = data.readInt32();
91            uint32_t h = data.readInt32();
92            PixelFormat format = data.readInt32();
93            uint32_t usage = data.readInt32();
94            sp<GraphicBuffer> result(createGraphicBuffer(w, h, format, usage));
95            reply->writeInt32(result != 0);
96            if (result != 0) {
97                reply->write(*result);
98                // We add a BufferReference to this parcel to make sure the
99                // buffer stays alive until the GraphicBuffer object on
100                // the other side has been created.
101                // This is needed so that the buffer handle can be
102                // registered before the buffer is destroyed on implementations
103                // that do not use file-descriptors to track their buffers.
104                reply->writeStrongBinder( new BufferReference(result) );
105            }
106            return NO_ERROR;
107        } break;
108        default:
109            return BBinder::onTransact(code, data, reply, flags);
110    }
111}
112
113}; // namespace android
114