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>
diff --git a/pw_sync/docs.rst b/pw_sync/docs.rst
new file mode 100644
index 0000000..1dfe23f
--- /dev/null
+++ b/pw_sync/docs.rst
@@ -0,0 +1,8 @@
+.. _module-pw_sync:
+
+-------
+pw_sync
+-------
+This is a synchronization module for Pigweed. It is not ready for use, and
+is under construction.
+