VKSHARINGMODECONCURRENT

VK_SHARING_MODE_CONCURRENT is a value in the Vulkan API that indicates a resource may be accessed by multiple queue families without explicit ownership transfer. In Vulkan, resources such as buffers and images are created with a sharing mode that defines how they are shared among queue families. There are two supported modes: VK_SHARING_MODE_EXCLUSIVE and VK_SHARING_MODE_CONCURRENT.

In EXCLUSIVE mode, a resource is owned by a single queue family at a time. Access by other queue families requires an explicit ownership transfer via a pipeline barrier that updates the srcQueueFamilyIndex and dstQueueFamilyIndex. This mode yields lower overhead and best performance when the resource is operated on by one queue family at a time or ownership changes are managed by the application.

In CONCURRENT mode, the resource can be concurrently accessed by multiple queue families as specified at creation time. No explicit ownership transfer is required when different queues access the resource, but synchronization is still necessary to avoid hazards. The app must list the queue families that can access the resource via the queueFamilyIndices and queueFamilyIndexCount fields in the resource creation structure. This mode simplifies sharing when a single resource is used by graphics, transfer, or presentation queues.

Choosing between modes depends on usage patterns and hardware: EXCLUSIVE is preferred for performance when a single queue family predominates, while CONCURRENT is convenient when multiple queues need frequent access without ownership transfers. Ensure compatibility with device queue families and consult the Vulkan specification for exact behavior.