I want to add feature, which will delete mesh from the scene, so I am trying to perform a possibility of deleting vk::Buffer and vk::Memory while scene is running. Whenever the vertices data is nullptr, the recreation of a buffer causes an error: “Cannot call vkFreeMemory on VkDeviceMemory that is currently in use by a command buffer.”. However, when vertices data holds something, there is no error. Only if I call transferQueue.waitIdle() or device.waitIdle() before the recreation the error will disappear.

Pseudo-code of recreation:

auto temp = m_Buffer;

m_Buffer = Buffer(...);

temp.Cleanup(...);

The code of buffer:

    void CopyBuffer(

        const vk::Buffer& srcBuffer,

        const vk::Buffer& dstBuffer,

        const vk::DeviceSize& size,

        const vk::Device& device,

        const vk::CommandPool& transferPool,

        const vk::Queue& transferQueue

    )

    {

        const vk::CommandBufferAllocateInfo allocInfo(

            transferPool,

            vk::CommandBufferLevel::ePrimary,

            1

        );



        const auto cBuffer = device.allocateCommandBuffers(allocInfo)[0];



        const vk::CommandBufferBeginInfo beginInfo{vk::CommandBufferUsageFlagBits::eOneTimeSubmit};

        GE_ASSERT_FN(cBuffer.begin(&beginInfo) == vk::Result::eSuccess, "cannot begin command buffer when copying buffer");



        const vk::BufferCopy copy{0, 0, size};

        cBuffer.copyBuffer(srcBuffer, dstBuffer, 1, &copy);

        cBuffer.end();



        vk::SubmitInfo submitInfo{};

        submitInfo.commandBufferCount = 1;

        submitInfo.pCommandBuffers = &cBuffer;



        GE_ASSERT_FN(transferQueue.submit(1, &submitInfo, nullptr) == vk::Result::eSuccess, "cannot submit on transfer queue");

        transferQueue.waitIdle();



        device.freeCommandBuffers(transferPool, 1, &cBuffer);

    }

    VertexBuffer::VertexBuffer(

        const vk::Device& device,

        const vk::PhysicalDevice& physicalDevice,

        const QueueFamilyIndices& queueFamilyIndices,

        const vk::CommandPool& transferPool,

        const vk::Queue& transferQueue,

        const void* data,

        const uint& sizeOfAllData

    )

    {

        m_Size = sizeOfAllData;

        if(m_Size)

        {

            vk::BufferCreateInfo info{ vk::BufferCreateFlagBits(),

                sizeOfAllData,

                vk::BufferUsageFlagBits::eVertexBuffer | vk::BufferUsageFlagBits::eTransferDst

            };



            if(queueFamilyIndices.GetGraphicsFamily() != queueFamilyIndices.GetTransferFamily())

            {

                const uint uniqueIndices[] = { queueFamilyIndices.GetGraphicsFamily(), queueFamilyIndices.GetTransferFamily() };

                info.queueFamilyIndexCount = 2;

                info.pQueueFamilyIndices = uniqueIndices;

                info.sharingMode = vk::SharingMode::eConcurrent;

            }

            else

                info.sharingMode = vk::SharingMode::eExclusive;



            m_Buffer = device.createBuffer(info);



            const auto memRequirements = device.getBufferMemoryRequirements(m_Buffer);



            vk::MemoryAllocateInfo allocInfo{

                memRequirements.size,

                    IBuffer::FindMemoryType(

                        physicalDevice,

                        memRequirements.memoryTypeBits,

                        vk::MemoryPropertyFlagBits::eDeviceLocal

                    )

            };



            m_BufferMemory = device.allocateMemory(allocInfo);

            device.bindBufferMemory(m_Buffer, m_BufferMemory, 0);



            const auto stagingBuffer = StagingBuffer(device, physicalDevice, queueFamilyIndices, data, sizeOfAllData);

            CopyBuffer(stagingBuffer.GetBuffer(), m_Buffer, m_Size, device, transferPool, transferQueue);

            stagingBuffer.Cleanup(device);

        }

    }

So, why the error is thrown only when vertices data is nullptr?

PS: I am a beginner with Vulkan.