queueFlags

queueFlags is a field used to describe the capabilities of a queue family in certain graphics and compute APIs. In Vulkan, for example, queueFlags is a member of VkQueueFamilyProperties and is typed as VkQueueFlags, a bitmask that indicates which operations the queues in a given family can perform. The value helps applications select appropriate queue families when creating a logical device.

The bits commonly defined in queueFlags include VK_QUEUE_GRAPHICS_BIT, VK_QUEUE_COMPUTE_BIT, VK_QUEUE_TRANSFER_BIT, and VK_QUEUE_SPARSE_BINDING_BIT. The GRAPHICS_BIT indicates support for rendering and presenting graphics commands, the COMPUTE_BIT indicates support for general-purpose compute operations, the TRANSFER_BIT covers data transfer and copy operations, and the SPARSE_BINDING_BIT indicates support for sparse resource binding such as sparse textures and buffers. A single queue family may expose multiple bits, meaning its queues can handle several kinds of work; a dedicated transfer queue, by contrast, might only have the TRANSFER_BIT set.

In practice, applications query the physical device for queue family properties and examine the queueFlags to find a family that supports the required operations. When creating a logical device or submitting work, the application may request a queue from a family that has the necessary bits. The flags are hardware- and driver-defined, so developers should test for the presence of required bits and plan for alternative configurations if a preferred capability is unavailable.

Overall, queueFlags serves as a concise descriptor of a queue family’s capabilities, guiding resource and task allocation in GPU-accelerated and parallel computation environments.