Add Shutdown method to TracerProvider (open-telemetry#394)

sdk/include/opentelemetry/sdk/trace/simple_processor.h

@@ -57,12 +57,14 @@ class SimpleSpanProcessor : public SpanProcessor
   void Shutdown(std::chrono::microseconds timeout = std::chrono::microseconds(0)) noexcept override
   {
     // We only call shutdown ONCE.
-    if (!shutdown_latch_.test_and_set(std::memory_order_acquire))
+    if (exporter_ != nullptr && !shutdown_latch_.test_and_set(std::memory_order_acquire))
     {
       exporter_->Shutdown(timeout);
     }
   }
 
+  ~SimpleSpanProcessor() { Shutdown(); }
+
 private:
   std::unique_ptr<SpanExporter> exporter_;
   opentelemetry::common::SpinLockMutex lock_;

sdk/include/opentelemetry/sdk/trace/tracer_provider.h

@@ -52,6 +52,11 @@ class TracerProvider final : public opentelemetry::trace::TracerProvider
    */
   std::shared_ptr<Sampler> GetSampler() const noexcept;
 
+  /**
+   * Shutdown the span processor associated with this tracer provider.
+   */
+  void Shutdown() noexcept;
+
 private:
   opentelemetry::sdk::AtomicSharedPtr<SpanProcessor> processor_;
   std::shared_ptr<opentelemetry::trace::Tracer> tracer_;

sdk/src/trace/batch_span_processor.cc

@@ -175,12 +175,14 @@ void BatchSpanProcessor::DrainQueue()
 
 void BatchSpanProcessor::Shutdown(std::chrono::microseconds timeout) noexcept
 {
-  is_shutdown_ = true;
+  is_shutdown_.store(true);
 
   cv_.notify_one();
   worker_thread_.join();
-
-  exporter_->Shutdown();
+  if (exporter_ != nullptr)
+  {
+    exporter_->Shutdown();
+  }
 }
 
 BatchSpanProcessor::~BatchSpanProcessor()

sdk/src/trace/tracer_provider.cc

@@ -34,6 +34,11 @@ std::shared_ptr<Sampler> TracerProvider::GetSampler() const noexcept
 {
   return sampler_;
 }
+
+void TracerProvider::Shutdown() noexcept
+{
+  GetProcessor()->Shutdown();
+}
 }  // namespace trace
 }  // namespace sdk
 OPENTELEMETRY_END_NAMESPACE

sdk/test/trace/tracer_provider_test.cc

@@ -59,3 +59,15 @@ TEST(TracerProvider, GetSampler)
 
   ASSERT_EQ("AlwaysOffSampler", t3->GetDescription());
 }
+
+TEST(TracerProvider, Shutdown)
+{
+  std::shared_ptr<SpanProcessor> processor1(new SimpleSpanProcessor(nullptr));
+
+  TracerProvider tp1(processor1);
+
+  tp1.Shutdown();
+
+  // Verify Shutdown returns.
+  ASSERT_TRUE(true);
+}