Merge branch 'google3'

Change-Id: Ibebf84b98939ee8e5006beedc34d225e8c2dd413

cpp/platform/impl/g3/atomic_reference_impl.h

@@ -0,0 +1,38 @@
+#ifndef PLATFORM_IMPL_G3_ATOMIC_REFERENCE_IMPL_H_
+#define PLATFORM_IMPL_G3_ATOMIC_REFERENCE_IMPL_H_
+
+#include "platform/api/atomic_reference.h"
+#include "platform/ptr.h"
+#include "absl/synchronization/mutex.h"
+#include "absl/types/any.h"
+
+namespace location {
+namespace nearby {
+namespace platform {
+
+// Provide implementation for absl::any.
+class AtomicReferenceImpl : public AtomicReference<absl::any> {
+ public:
+  explicit AtomicReferenceImpl(absl::any initial_value)
+      : value_(std::move(initial_value)) {}
+  ~AtomicReferenceImpl() override = default;
+
+  absl::any get() override {
+    absl::MutexLock lock(&mutex_);
+    return value_;
+  }
+  void set(absl::any value) override {
+    absl::MutexLock lock(&mutex_);
+    value_ = std::move(value);
+  }
+
+ private:
+  absl::Mutex mutex_;
+  absl::any value_;
+};
+
+}  // namespace platform
+}  // namespace nearby
+}  // namespace location
+
+#endif  // PLATFORM_IMPL_G3_ATOMIC_REFERENCE_IMPL_H_