Commit Graph

2 Commits (94415e80296cdb445ea228bdae3864f3d5ddc64a)

Author SHA1 Message Date
Maisem Ali 36e8e8cd64 wgengine/magicsock: use math/rands/v2
Updates #11058

Co-authored-by: James Tucker <james@tailscale.com>
Signed-off-by: Maisem Ali <maisem@tailscale.com>
6 months ago
James Tucker 24bac27632 util/rands: add Shuffle and Perm functions with on-stack RNG state
The new math/rand/v2 package includes an m-local global random number
generator that can not be reseeded by the user, which is suitable for
most uses without the RNG pools we have in a number of areas of the code
base.

The new API still does not have an allocation-free way of performing a
seeded operations, due to the long term compiler bug around interface
parameter escapes, and the Source interface.

This change introduces the two APIs that math/rand/v2 can not yet
replace efficiently: seeded Perm() and Shuffle() operations. This
implementation chooses to use the PCG random source from math/rand/v2,
as with sufficient compiler optimization, this source should boil down
to only two on-stack registers for random state under ideal conditions.

Updates #17243

Signed-off-by: James Tucker <james@tailscale.com>
9 months ago