Expose mBufferId for GraphicBuffer

Bug: 118844974
Test: GraphicBuffer_test
Change-Id: I75a58b21e9943ffed9219a37e0d05c6697232bf4

3 files changed, 31 insertions, 0 deletions

diff --git a/libs/ui/GraphicBuffer.cpp b/libs/ui/GraphicBuffer.cpp
index e606e26f8b..f408fcbe84 100644
--- a/libs/ui/GraphicBuffer.cpp
+++ b/libs/ui/GraphicBuffer.cpp
@@ -104,6 +104,7 @@ GraphicBuffer::GraphicBuffer(std::unique_ptr<BufferHubBuffer> buffer) : GraphicB
                                 buffer->desc().width, buffer->desc().height,
                                 static_cast<PixelFormat>(buffer->desc().format),
                                 buffer->desc().layers, buffer->desc().usage, buffer->desc().stride);
+    mBufferId = buffer->id();
     mBufferHubBuffer = std::move(buffer);
 }
 #endif // LIBUI_IN_VNDK
diff --git a/libs/ui/include/ui/GraphicBuffer.h b/libs/ui/include/ui/GraphicBuffer.h
index 81f6cd9061..b73ca2b793 100644
--- a/libs/ui/include/ui/GraphicBuffer.h
+++ b/libs/ui/include/ui/GraphicBuffer.h
@@ -153,6 +153,7 @@ public:
     uint32_t getLayerCount() const      { return static_cast<uint32_t>(layerCount); }
     Rect getBounds() const              { return Rect(width, height); }
     uint64_t getId() const              { return mId; }
+    int32_t getBufferId() const { return mBufferId; }
 
     uint32_t getGenerationNumber() const { return mGenerationNumber; }
     void setGenerationNumber(uint32_t generation) {
@@ -247,6 +248,12 @@ private:
 
     uint64_t mId;
 
+    // System unique buffer ID. Note that this is different from mId, which is process unique. For
+    // GraphicBuffer backed by BufferHub, the mBufferId is a system unique identifier that stays the
+    // same cross process for the same chunck of underlying memory. Also note that this only applies
+    // to GraphicBuffers that are backed by BufferHub.
+    int32_t mBufferId = -1;
+
     // Stores the generation number of this buffer. If this number does not
     // match the BufferQueue's internal generation number (set through
     // IGBP::setGenerationNumber), attempts to attach the buffer will fail.
diff --git a/libs/ui/tests/GraphicBuffer_test.cpp b/libs/ui/tests/GraphicBuffer_test.cpp
index 95ca2c16b3..81ab3acfe4 100644
--- a/libs/ui/tests/GraphicBuffer_test.cpp
+++ b/libs/ui/tests/GraphicBuffer_test.cpp
@@ -39,6 +39,7 @@ TEST_F(GraphicBufferTest, CreateFromBufferHubBuffer) {
     std::unique_ptr<BufferHubBuffer> b1 =
             BufferHubBuffer::Create(kTestWidth, kTestHeight, kTestLayerCount, kTestFormat,
                                     kTestUsage, /*userMetadataSize=*/0);
+    EXPECT_NE(b1, nullptr);
     EXPECT_TRUE(b1->IsValid());
 
     sp<GraphicBuffer> gb(new GraphicBuffer(std::move(b1)));
@@ -51,4 +52,26 @@ TEST_F(GraphicBufferTest, CreateFromBufferHubBuffer) {
     EXPECT_EQ(gb->getLayerCount(), kTestLayerCount);
 }
 
+TEST_F(GraphicBufferTest, InvalidBufferIdForNoneBufferHubBuffer) {
+    sp<GraphicBuffer> gb(
+            new GraphicBuffer(kTestWidth, kTestHeight, kTestFormat, kTestLayerCount, kTestUsage));
+    EXPECT_FALSE(gb->isBufferHubBuffer());
+    EXPECT_EQ(gb->getBufferId(), -1);
+}
+
+TEST_F(GraphicBufferTest, BufferIdMatchesBufferHubBufferId) {
+    std::unique_ptr<BufferHubBuffer> b1 =
+            BufferHubBuffer::Create(kTestWidth, kTestHeight, kTestLayerCount, kTestFormat,
+                                    kTestUsage, /*userMetadataSize=*/0);
+    EXPECT_NE(b1, nullptr);
+    EXPECT_TRUE(b1->IsValid());
+
+    int b1_id = b1->id();
+    EXPECT_GE(b1_id, 0);
+
+    sp<GraphicBuffer> gb(new GraphicBuffer(std::move(b1)));
+    EXPECT_TRUE(gb->isBufferHubBuffer());
+    EXPECT_EQ(gb->getBufferId(), b1_id);
+}
+
 } // namespace android