Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 01142fc6 authored by Patrick Williams's avatar Patrick Williams
Browse files

Test that notifyBufferRelease doesn't deadlock when deleting BBQ 

Bug: 410458641
Flag: TEST_ONLY
Test: BLASTBufferQueueTest
Change-Id: Ifbdb911e28aa81498fdac2555fb2646d61ddf6c4
parent 4f3ff0fa

libs/gui/tests/BLASTBufferQueue_test.cpp

+46 −0
Original line number Diff line number Diff line
@@ -195,6 +195,8 @@ public: 
        mBlastBufferQueueAdapter->setApplyToken(std::move(applyToken));

    }



    void dropBbq() { mBlastBufferQueueAdapter.clear(); }



private:

    sp<TestBLASTBufferQueue> mBlastBufferQueueAdapter;

};
@@ -1440,6 +1442,50 @@ TEST_F(BLASTBufferQueueTest, TransformHint) { 
    adapter.waitForCallbacks();

}



// Verifies that we don't deadlock if BufferQueueProducer::cancelBuffer is called on a thread

// right before the owner of BBQ drops its strong pointer (b/410458641). This test is

// non-deterministic and sensitive to timings. The owning BBQ pointer may be dropped before,

// during, or after notifyBufferReleased is called. This test could be improved by mocking

// the BufferReleaseReader, forcing it to wait until after we drop the BBQ pointer. Doing so

// would require injecting a mock BufferReleaseReader into BBQ which is difficult to do with the

// current code structure.

TEST_F(BLASTBufferQueueTest, CancelBuffer_NoDeadlock) {

    for (int i = 0; i < 100; i++) {

        BLASTBufferQueueHelper adapter(mSurfaceControl, mDisplayWidth, mDisplayHeight);

        sp<IGraphicBufferProducer> producer;

        setUpProducer(adapter, producer);



        int slot;

        sp<Fence> fence;

        sp<GraphicBuffer> buf;

        status_t status = producer->dequeueBuffer(&slot, &fence, mDisplayWidth, mDisplayHeight,

                                                  PIXEL_FORMAT_RGBA_8888,

                                                  GRALLOC_USAGE_SW_WRITE_OFTEN, nullptr, nullptr);

        ASSERT_EQ(IGraphicBufferProducer::BUFFER_NEEDS_REALLOCATION, status);

        ASSERT_EQ(OK, producer->requestBuffer(slot, &buf));



        bool threadComplete = false;

        std::mutex threadCompleteMutex;

        std::condition_variable threadCompleteCondition;



        std::thread thread([&]() {

            producer->cancelBuffer(slot, fence);

            std::lock_guard lock{threadCompleteMutex};

            threadComplete = true;

            threadCompleteCondition.notify_one();

        });



        // Give the background thread some time to start up before dropping the BBQ pointer.

        std::this_thread::sleep_for(1ms);



        adapter.dropBbq();

        std::unique_lock lock{threadCompleteMutex};

        ASSERT_TRUE(threadCompleteCondition.wait_for(lock, 5s, [&]() { return threadComplete; }))

                << "Failed to join background thread, likely indicates deadlock";

        thread.join();

    }

}



class BLASTBufferQueueTransformTest : public BLASTBufferQueueTest {

public:

    void test(uint32_t tr) {