Module wgpu_core::init_tracker
source · Expand description
Lazy initialization of texture and buffer memory.
The WebGPU specification requires all texture & buffer memory to be zero initialized on first read. To avoid unnecessary inits, we track the initialization status of every resource and perform inits lazily.
The granularity is different for buffers and textures:
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Buffer: Byte granularity to support usecases with large, partially bound buffers well.
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Texture: Mip-level per layer. That is, a 2D surface is either completely initialized or not, subrects are not tracked.
Every use of a buffer/texture generates a InitTrackerAction which are recorded and later resolved at queue submit by merging them with the current state and each other in execution order.
It is important to note that from the point of view of the memory init system there are two kind of writes:
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Full writes: Any kind of memcpy operation. These cause a
MemoryInitKind.ImplicitlyInitializedaction. -
(Potentially) partial writes: For example, write use in a Shader. The system is not able to determine if a resource is fully initialized afterwards but is no longer allowed to perform any clears, therefore this leads to a
MemoryInitKind.ImplicitlyInitializedaction, exactly like a read would.
Modules
Structs
- Tracks initialization status of a linear range from 0..size