1 files changed, 60 insertions, 0 deletions
diff --git a/src/tracer.cpp b/src/tracer.cpp
new file mode 100644
index 0000000..52f2f46
--- /dev/null
+++ b/src/tracer.cpp
@@ -0,0 +1,60 @@
+#include <opentracing/noop.h>
+#include <opentracing/tracer.h>
+
+#include <mutex>
+
+namespace opentracing {
+BEGIN_OPENTRACING_ABI_NAMESPACE
+namespace {
+class TracerRegistry {
+ public:
+  static TracerRegistry& instance() noexcept {
+    static TracerRegistry result;
+    return result;
+  }
+
+  static std::shared_ptr<Tracer> RegisterTracer(
+      std::shared_ptr<Tracer>& tracer) noexcept {
+    std::lock_guard<std::mutex> lock_guard{mutex_};
+    is_registered_ = true;
+    tracer_.swap(tracer);
+    return tracer;
+  }
+
+  static std::shared_ptr<Tracer> tracer() noexcept {
+    std::lock_guard<std::mutex> lock_guard{mutex_};
+    return tracer_;
+  }
+
+  static bool is_registered() noexcept {
+    std::lock_guard<std::mutex> lock_guard{mutex_};
+    return is_registered_;
+  }
+
+ private:
+  static std::mutex mutex_;
+  static bool is_registered_;
+  static std::shared_ptr<Tracer> tracer_;
+};
+
+std::mutex TracerRegistry::mutex_;
+
+bool TracerRegistry::is_registered_{false};
+
+std::shared_ptr<Tracer> TracerRegistry::tracer_{MakeNoopTracer()};
+}  // namespace
+
+std::shared_ptr<Tracer> Tracer::Global() noexcept {
+  return TracerRegistry::instance().tracer();
+}
+
+std::shared_ptr<Tracer> Tracer::InitGlobal(
+    std::shared_ptr<Tracer> tracer) noexcept {
+  return TracerRegistry::instance().RegisterTracer(tracer);
+}
+
+bool Tracer::IsGlobalTracerRegistered() noexcept {
+  return TracerRegistry::instance().is_registered();
+}
+END_OPENTRACING_ABI_NAMESPACE
+}  // namespace opentracing