donner::gpu::BufferMappingTable Class Reference

Tracks the host mappings a backend has open and answers the mapping hooks Device dispatches to it. More...

#include "donner/gpu/BufferMappingTable.h"

Public Member Functions
	BufferMappingTable (BufferMappingHost &host)
Status	begin (uint32_t mappingSlotIndex, uint32_t bufferSlotIndex, uint64_t offsetBytes, uint64_t byteCount, uint64_t readySerial)
	Opens a mapping over byteCount bytes of bufferSlotIndex starting at offsetBytes.
MapSliceReport	waitSlice (uint32_t mappingSlotIndex, double sliceSeconds)
	Waits up to sliceSeconds for one mapping, and reports what it found and how it waited.
Result< std::span< const uint8_t > >	bytes (uint32_t mappingSlotIndex) const
	Bytes of a completed mapping, or a failure while it is pending, released, or invalidated.
void	release (uint32_t mappingSlotIndex)
	Releases a mapping, so every remaining handle naming it reads as released.
void	invalidateBuffer (uint32_t bufferSlotIndex)
	Invalidates every mapping of bufferSlotIndex, called when the buffer is retired so a mapping cannot outlive the allocation it points into.
size_t	liveMappingCountForTest () const
	How many mappings are currently open, counting ones whose buffer was retired: those are still open handles that have to be released. Test accessor for leak checks.

Detailed Description

Tracks the host mappings a backend has open and answers the mapping hooks Device dispatches to it.

A mapping names a byte range of one buffer plus the submission that must complete before that range holds the bytes the caller asked for. Holding a mapping is not ownership of the buffer: destroying the buffer invalidates the mapping instead of keeping the allocation alive, so a read afterwards is a reported failure rather than a read of freed memory.

A mapping observes the work submitted before it was created. Writes still queued for a later submission are not part of it, because the submission that would carry them does not exist yet and waiting for it would be waiting for something the caller has not asked for.

Constructor & Destructor Documentation

BufferMappingTable()

donner::gpu::BufferMappingTable::BufferMappingTable ( BufferMappingHost & host )

inlineexplicit

Parameters

host	Supplies the backend's buffer facts; must outlive this table.

Member Function Documentation

begin()

Status donner::gpu::BufferMappingTable::begin	(	uint32_t	mappingSlotIndex,
		uint32_t	bufferSlotIndex,
		uint64_t	offsetBytes,
		uint64_t	byteCount,
		uint64_t	readySerial )

Opens a mapping over byteCount bytes of bufferSlotIndex starting at offsetBytes.

Parameters

mappingSlotIndex	Slot the mapping occupies.
bufferSlotIndex	Slot of the buffer being mapped.
offsetBytes	Byte offset of the mapped range.
byteCount	Length of the mapped range.
readySerial	Submission whose completion makes the range hold the bytes the caller asked for. Zero when the buffer has no outstanding work, which is ready immediately.

bytes()

Result< std::span< const uint8_t > > donner::gpu::BufferMappingTable::bytes

(

uint32_t

mappingSlotIndex

)

const

Bytes of a completed mapping, or a failure while it is pending, released, or invalidated.

The span aliases the backend's own allocation rather than a copy of it, so it is valid only until whichever of these comes first: the mapping is released, its buffer is retired, or the device is lost. Callers that outlive any of those copy the bytes out. The annotation states that contract to the compiler rather than enforcing it: the span is returned inside a Result, and the dangling diagnostic does not see through an unannotated class template.

Parameters

mappingSlotIndex

Slot of the mapping.

invalidateBuffer()

void donner::gpu::BufferMappingTable::invalidateBuffer

(

uint32_t

bufferSlotIndex

)

Invalidates every mapping of bufferSlotIndex, called when the buffer is retired so a mapping cannot outlive the allocation it points into.

Parameters

bufferSlotIndex

Slot of the buffer being retired.

release()

void donner::gpu::BufferMappingTable::release

(

uint32_t

mappingSlotIndex

)

Releases a mapping, so every remaining handle naming it reads as released.

Parameters

mappingSlotIndex

Slot of the mapping.

waitSlice()

MapSliceReport donner::gpu::BufferMappingTable::waitSlice	(	uint32_t	mappingSlotIndex,
		double	sliceSeconds )

Waits up to sliceSeconds for one mapping, and reports what it found and how it waited.

Parameters

mappingSlotIndex	Slot of the mapping.
sliceSeconds	Longest this call may block; zero polls without calling the host wait.

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The documentation for this class was generated from the following file:

• donner/gpu/BufferMappingTable.h