Import of the watch repository from Pebble

src/fw/services/runlevel_impl.h

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * 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
+ *
+ *     http://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.
+ */
+
+#pragma once
+
+// Definitions used to implement runlevels.
+//
+// The set of runlevels is defined in the runlevel.def X-Macro file. These
+// definitions are used to construct two enums, RunLevel (in runlevel.h) and
+// RunLevelBit (in this header).
+//
+// The set of runlevels for which a service should be enabled is defined by
+// bitwise-OR-ing the RunLevelBit constants for every runlevel that the service
+// should be enabled in to form an enable-mask. Testing whether a service should
+// be enabled for a given runlevel is simply
+// (enable_mask & (1 << runlevel) != 0).
+//
+// The RunLevelBit constants take the form R_<name> to minimize visual clutter
+// when defining enable-masks. Since this header is only included in the source
+// files for which enable-masks are defined, the potential for namespace
+// pollution is minimized.
+
+#define RUNLEVEL(number, name) _Static_assert( \
+      0 <= number && number <= 31, \
+      "The numeric value of runlevel " #name " (" #number ")" \
+      " is out of range. Only runlevels in the range 0 <= level <= 31" \
+      " are supported.");
+#include "runlevel.def"
+#undef RUNLEVEL
+
+typedef enum RunLevelBit {
+#define RUNLEVEL(number, name) R_##name = (1 << number),
+#include "runlevel.def"
+#undef RUNLEVEL
+} RunLevelBit;
+
+struct ServiceRunLevelSetting {
+  void (*set_enable_fn)(bool);
+  RunLevelBit enable_mask;
+};