tree fb1a29de6813302bcf3e17c3a6e041f6d5107293
parent 00efe188a1fb361067d3bf73d4ad5885b2cfc453
author Ewout van Bekkum <ewout@google.com> 1604954812 -0800
committer CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com> 1606244563 +0000

pw_sync: Adds initial SpinLock primitive

Adds the first synchronization primitive to Pigweed: the
pw::sync::SpinLock with integrated local interrupt
masking.

This also provides the first backend for the SpinLock facade
backed by an STL implementation. Note that signals are considered
"NMIs" while spin locks are only supported up to IRQs, ergo no
local interrupt/signal masking is done in the STL implementation.

Change-Id: I34204835c55e54597077d40665f61715964803f9
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/25802
Reviewed-by: Ewout van Bekkum <ewout@google.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>
Reviewed-by: Keir Mierle <keir@google.com>
Commit-Queue: Ewout van Bekkum <ewout@google.com>