mmap Format

Structure of version 1 mmstat’s mmaps:

version number	fields...
byte = 01	...

Fields

There are two types of field structures so far in mmstats:

1. buffered
2. unbuffered

Buffered fields use multiple buffers for handling values which cannot be written atomically.

Unbuffered structures have ff in the write buffer field.

Buffered

label size	label	type size	type	write buffer	buffer 1	buffer 2
ushort	char[]	ushort	char[]	byte	varies	varies

The buffers field length = sizeof(type) * buffers.

The current write buffer is referenced by: write_buffer * sizeof(type)

TODO: field for total number of buffers?

Unbuffered

label size	label	type size	type	write buffer	value
ushort	char[]	ushort	char[]	byte = ff	varies

The value field length = sizeof(type).