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/BUILD b/pw_sync/BUILD
new file mode 100644
index 0000000..ceb60c6
--- /dev/null
+++ b/pw_sync/BUILD
@@ -0,0 +1,77 @@
+# Copyright 2020 The Pigweed Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+
+load(
+ "//pw_build:pigweed.bzl",
+ "pw_cc_library",
+ "pw_cc_test",
+)
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"]) # Apache License 2.0
+
+# TODO(pwbug/101): Need to add support for facades/backends to Bazel.
+PW_SYNC_SPIN_LOCK_BACKEND = "//pw_sync_stl:spin_lock"
+
+pw_cc_library(
+ name = "spin_lock_facade",
+ hdrs = [
+ "public/pw_sync/spin_lock.h",
+ ],
+ includes = ["public"],
+ srcs = [
+ "spin_lock.cc"
+ ],
+ deps = [
+ PW_SYNC_SPIN_LOCK_BACKEND + "_headers",
+ "//pw_preprocessor",
+ ],
+)
+
+pw_cc_library(
+ name = "spin_lock",
+ deps = [
+ ":spin_lock_facade",
+ PW_SYNC_SPIN_LOCK_BACKEND + "_headers",
+ ],
+)
+
+pw_cc_library(
+ name = "spin_lock_backend",
+ deps = [
+ PW_SYNC_SPIN_LOCK_BACKEND,
+ ],
+)
+
+pw_cc_library(
+ name = "yield_core",
+ hdrs = [
+ "public/pw_sync/yield_core.h",
+ ],
+ includes = ["public"],
+)
+
+pw_cc_test(
+ name = "spin_lock_facade_test",
+ srcs = [
+ "spin_lock_facade_test.cc",
+ "spin_lock_facade_test_c.c",
+ ],
+ deps = [
+ ":spin_lock",
+ "//pw_preprocessor",
+ "//pw_unit_test",
+ ],
+)