Fix MeterProvider destructor warning when Shutdown() called manually

sdk/include/opentelemetry/sdk/metrics/meter_context.h

@@ -170,6 +170,11 @@ class MeterContext : public std::enable_shared_from_this<MeterContext>
    */
   bool Shutdown(std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept;
 
+  /**
+   * Check if this meter context has been shut down.
+   */
+  bool IsShutdown() const noexcept;
+
 private:
   friend class ::testing::MetricCollectorTest;
 
@@ -187,8 +192,10 @@ class MeterContext : public std::enable_shared_from_this<MeterContext>
 #if defined(__cpp_lib_atomic_value_initialization) && \
     __cpp_lib_atomic_value_initialization >= 201911L
   std::atomic_flag shutdown_latch_{};
+  std::atomic<bool> is_shutdown_{false};
 #else
   std::atomic_flag shutdown_latch_ = ATOMIC_FLAG_INIT;
+  std::atomic<bool> is_shutdown_{false};
 #endif
   opentelemetry::common::SpinLockMutex forceflush_lock_;
   opentelemetry::common::SpinLockMutex meter_lock_;

sdk/src/metrics/meter_context.cc

@@ -163,6 +163,7 @@ bool MeterContext::Shutdown(std::chrono::microseconds timeout) noexcept
   // Shutdown only once.
   if (!shutdown_latch_.test_and_set(std::memory_order_acquire))
   {
+    is_shutdown_.store(true, std::memory_order_release);
     for (auto &collector : collectors_)
     {
       bool status = std::static_pointer_cast<MetricCollector>(collector)->Shutdown(timeout);
@@ -180,6 +181,11 @@ bool MeterContext::Shutdown(std::chrono::microseconds timeout) noexcept
   return result;
 }
 
+bool MeterContext::IsShutdown() const noexcept
+{
+  return is_shutdown_.load(std::memory_order_acquire);
+}
+
 bool MeterContext::ForceFlush(std::chrono::microseconds timeout) noexcept
 {
   bool result = true;

sdk/src/metrics/meter_provider.cc

@@ -161,7 +161,7 @@ bool MeterProvider::ForceFlush(std::chrono::microseconds timeout) noexcept
  */
 MeterProvider::~MeterProvider()
 {
-  if (context_)
+  if (context_ && !context_->IsShutdown())
   {
     context_->Shutdown();
   }

sdk/test/metrics/meter_provider_sdk_test.cc

@@ -323,3 +323,17 @@ TEST(MeterProvider, GetMeterInequalityCheckAbiv2)
 }
 
 #endif /* OPENTELEMETRY_ABI_VERSION_NO >= 2 */
+
+TEST(MeterProvider, ShutdownTwice)
+{
+  // Test that calling Shutdown twice doesn't emit warnings
+  MeterProvider mp;
+
+  // First shutdown should succeed
+  EXPECT_TRUE(mp.Shutdown());
+
+  // Second shutdown should also succeed without warnings
+  EXPECT_TRUE(mp.Shutdown());
+
+  // Destructor should not emit warnings either since we already shut down
+}