replicant-frameworks_native/libs/gui/IGraphicBufferAlloc.cpp
Mathias Agopian 4cb18881b5 Fix a GraphicBuffer leak in SurfaceTexture
This leak was intentional, it was there to deal with the fact that
some gralloc implementations don't track buffer handles with
file-descriptors so buffers needed to stay alive until there were
registered, which is not guaranteed by binder transactions.

In this new implementation, we use a small BBinder holding a
reference to the buffer, which with tuck into the parcel. This forces
the reference to stay alive until the parcel is destroyed, which
is guaranteed (by construction) to happen after the buffer is
registered.

this allows the public facing API to not expose the previous hack.

Change-Id: I1dd6cd83679a2b7457ad628169e2851acc027143
2011-04-08 19:28:04 -07:00

114 lines
3.8 KiB
C++

/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// tag as surfaceflinger
#define LOG_TAG "SurfaceFlinger"
#include <stdint.h>
#include <sys/types.h>
#include <binder/Parcel.h>
#include <ui/GraphicBuffer.h>
#include <surfaceflinger/IGraphicBufferAlloc.h>
// ---------------------------------------------------------------------------
namespace android {
enum {
CREATE_GRAPHIC_BUFFER = IBinder::FIRST_CALL_TRANSACTION,
};
class BpGraphicBufferAlloc : public BpInterface<IGraphicBufferAlloc>
{
public:
BpGraphicBufferAlloc(const sp<IBinder>& impl)
: BpInterface<IGraphicBufferAlloc>(impl)
{
}
virtual sp<GraphicBuffer> createGraphicBuffer(uint32_t w, uint32_t h,
PixelFormat format, uint32_t usage) {
Parcel data, reply;
data.writeInterfaceToken(IGraphicBufferAlloc::getInterfaceDescriptor());
data.writeInt32(w);
data.writeInt32(h);
data.writeInt32(format);
data.writeInt32(usage);
remote()->transact(CREATE_GRAPHIC_BUFFER, data, &reply);
sp<GraphicBuffer> graphicBuffer;
bool nonNull = (bool)reply.readInt32();
if (nonNull) {
graphicBuffer = new GraphicBuffer();
reply.read(*graphicBuffer);
// reply.readStrongBinder();
// here we don't even have to read the BufferReference from
// the parcel, it'll die with the parcel.
}
return graphicBuffer;
}
};
IMPLEMENT_META_INTERFACE(GraphicBufferAlloc, "android.ui.IGraphicBufferAlloc");
// ----------------------------------------------------------------------
status_t BnGraphicBufferAlloc::onTransact(
uint32_t code, const Parcel& data, Parcel* reply, uint32_t flags)
{
// codes that don't require permission check
/* BufferReference just keeps a strong reference to a
* GraphicBuffer until it is destroyed (that is, until
* no local or remote process have a reference to it).
*/
class BufferReference : public BBinder {
sp<GraphicBuffer> buffer;
public:
BufferReference(const sp<GraphicBuffer>& buffer) : buffer(buffer) { }
};
switch(code) {
case CREATE_GRAPHIC_BUFFER: {
CHECK_INTERFACE(IGraphicBufferAlloc, data, reply);
uint32_t w = data.readInt32();
uint32_t h = data.readInt32();
PixelFormat format = data.readInt32();
uint32_t usage = data.readInt32();
sp<GraphicBuffer> result(createGraphicBuffer(w, h, format, usage));
reply->writeInt32(result != 0);
if (result != 0) {
reply->write(*result);
// We add a BufferReference to this parcel to make sure the
// buffer stays alive until the GraphicBuffer object on
// the other side has been created.
// This is needed so that the buffer handle can be
// registered before the buffer is destroyed on implementations
// that do not use file-descriptors to track their buffers.
reply->writeStrongBinder( new BufferReference(result) );
}
return NO_ERROR;
} break;
default:
return BBinder::onTransact(code, data, reply, flags);
}
}
}; // namespace android