FMjShmRegion¶

Owning wrapper around a file-backed mmap region.

Lifetime: Open() truncates / creates the file, mmaps the full size, and writes the initial FMjShmHeader. Close() unmaps and (optionally) deletes the file. Move-only; no copies. Thread safety: GetData() returns a raw pointer that is valid until Close() is called. Concurrent reads / writes through that pointer are the caller's responsibility (the publisher uses the double-buffer pattern below).

Attribute	Value
Kind	`Class`

Properties Functions

Properties¶

Public Properties¶

Property	Type	Description
`default`	``
`delete`	``
`operator`	FMjShmRegion&
`size`	`* * Total mapped`
`const`	``
`FilePath`	`private: FString`

default¶

Type:

delete¶

Type:

operator¶

Type: FMjShmRegion&

size¶

Type: * * Total mapped

const¶

Type:

FilePath¶

Type: private: FString

Private Properties¶

Property	Type	Description
`MappedAddr`	`void*`
`MappedSize`	`uint64`
`BufferStride`	`uint32`
`NumBuffers`	`uint32`
`PlatformFileHandle`	`void*`
`HANDLE`	`Win:`
`PlatformMappingHandle`	`void*`
`HANDLE`	`Win:`

MappedAddr¶

Type: void*

MappedSize¶

Type: uint64

BufferStride¶

Type: uint32

NumBuffers¶

Type: uint32

PlatformFileHandle¶

Type: void*

HANDLE¶

Type: Win:

PlatformMappingHandle¶

Type: void*

HANDLE¶

Type: Win:

Functions¶

Public Functions¶

General¶

Function	Returns	Description
`Open()`	`bool`	Create / truncate the file at `Path`, mmap header + n_buffers slots,
`Close()`	void	Unmap, close handles, optionally remove the backing file.
`GetData()`	`void*`	Pointer to the start of the mapped region (header lives at offset 0).
`GetSlot()`	`uint8*`	Pointer to buffer slot index `Idx` (0 .. NBuffers-1).

Open¶

Create / truncate the file at Path, mmap header + n_buffers slots,

Signature: Open(const FString& Path, uint32 BufferStride, uint32 NBuffers)
Returns: bool

Close¶

Unmap, close handles, optionally remove the backing file.

Signature: Close(bool bDeleteFile)

GetData¶

Pointer to the start of the mapped region (header lives at offset 0).

Signature: GetData()
Returns: void*

GetSlot¶

Pointer to buffer slot index Idx (0 .. NBuffers-1).

Signature: GetSlot(uint32 Idx)
Returns: uint8*