[SDK] Handle instrumentation object construction failures safely

CHANGELOG.md

@@ -15,6 +15,11 @@ Increment the:
 
 ## [Unreleased]
 
+* [SDK] Allow SDK provider and instrumentation constructors to throw during
+  initialization. `GetTracer`, `GetLogger`, and `GetMeter` stay `noexcept` and
+  return a pre-allocated noop object if constructing a new instrumentation
+  object fails, without caching the failure.
+  [#4361](https://github.com/open-telemetry/opentelemetry-cpp/issues/4361)
 * [CONFIGURATION] Add a configuration builder for the host resource detector
   [#4451](https://github.com/open-telemetry/opentelemetry-cpp/issues/4451)
 * [CONFIGURATION] Build the configured resource detectors in SdkBuilder, apply

sdk/include/opentelemetry/sdk/logs/logger.h

@@ -42,7 +42,7 @@ class Logger final : public opentelemetry::logs::Logger
       opentelemetry::nostd::string_view name,
       std::shared_ptr<LoggerContext> context,
       std::unique_ptr<instrumentationscope::InstrumentationScope> instrumentation_scope =
-          instrumentationscope::InstrumentationScope::Create("")) noexcept;
+          instrumentationscope::InstrumentationScope::Create(""));
 
   /**
    * Returns the name of this logger.

sdk/include/opentelemetry/sdk/logs/logger_provider.h

@@ -45,7 +45,7 @@ class OPENTELEMETRY_EXPORT LoggerProvider final : public opentelemetry::logs::Lo
           std::make_unique<instrumentationscope::ScopeConfigurator<LoggerConfig>>(
               instrumentationscope::ScopeConfigurator<LoggerConfig>::Builder(
                   LoggerConfig::Default())
-                  .Build())) noexcept;
+                  .Build()));
 
   /**
    * Initialize a new logger provider.
@@ -62,19 +62,19 @@ class OPENTELEMETRY_EXPORT LoggerProvider final : public opentelemetry::logs::Lo
           std::make_unique<instrumentationscope::ScopeConfigurator<LoggerConfig>>(
               instrumentationscope::ScopeConfigurator<LoggerConfig>::Builder(
                   LoggerConfig::Default())
-                  .Build())) noexcept;
+                  .Build()));
 
   /**
    * Initialize a new logger provider. A processor must later be assigned
    * to this logger provider via the AddProcessor() method.
    */
-  explicit LoggerProvider() noexcept;
+  explicit LoggerProvider();
 
   /**
    * Initialize a new logger provider with a specified context
    * @param context The owned logger configuration/pipeline for this provider.
    */
-  explicit LoggerProvider(std::unique_ptr<LoggerContext> context) noexcept;
+  explicit LoggerProvider(std::unique_ptr<LoggerContext> context);
 
   LoggerProvider(const LoggerProvider &)            = delete;
   LoggerProvider(LoggerProvider &&)                 = delete;
@@ -144,6 +144,8 @@ class OPENTELEMETRY_EXPORT LoggerProvider final : public opentelemetry::logs::Lo
   std::vector<std::shared_ptr<opentelemetry::sdk::logs::Logger>> loggers_;
   std::shared_ptr<LoggerContext> context_;
   std::mutex lock_;
+  // Allocated during provider construction so GetLogger can return it without allocating.
+  nostd::shared_ptr<opentelemetry::logs::Logger> noop_logger_;
 };
 }  // namespace logs
 }  // namespace sdk

sdk/include/opentelemetry/sdk/metrics/meter.h

@@ -45,7 +45,7 @@ class Meter final : public opentelemetry::metrics::Meter
   explicit Meter(
       std::weak_ptr<sdk::metrics::MeterContext> meter_context,
       std::unique_ptr<opentelemetry::sdk::instrumentationscope::InstrumentationScope> scope =
-          opentelemetry::sdk::instrumentationscope::InstrumentationScope::Create("")) noexcept;
+          opentelemetry::sdk::instrumentationscope::InstrumentationScope::Create(""));
 
   nostd::unique_ptr<opentelemetry::metrics::Counter<uint64_t>> CreateUInt64Counter(
       nostd::string_view name,

sdk/include/opentelemetry/sdk/metrics/meter_provider.h

@@ -59,13 +59,13 @@ class OPENTELEMETRY_EXPORT MeterProvider final : public opentelemetry::metrics::
       std::unique_ptr<instrumentationscope::ScopeConfigurator<MeterConfig>> meter_configurator =
           std::make_unique<instrumentationscope::ScopeConfigurator<MeterConfig>>(
               instrumentationscope::ScopeConfigurator<MeterConfig>::Builder(MeterConfig::Default())
-                  .Build())) noexcept;
+                  .Build()));
 
   /**
    * Initialize a new meter provider with a specified context
    * @param context The owned meter configuration/pipeline for this provider.
    */
-  explicit MeterProvider(std::unique_ptr<MeterContext> context) noexcept;
+  explicit MeterProvider(std::unique_ptr<MeterContext> context);
 
   MeterProvider(const MeterProvider &)            = delete;
   MeterProvider(MeterProvider &&)                 = delete;
@@ -152,6 +152,8 @@ class OPENTELEMETRY_EXPORT MeterProvider final : public opentelemetry::metrics::
 private:
   std::shared_ptr<MeterContext> context_;
   std::mutex lock_;
+  // Allocated during provider construction so GetMeter can return it without allocating.
+  nostd::shared_ptr<opentelemetry::metrics::Meter> noop_meter_;
 
 #if defined(__cpp_lib_atomic_value_initialization) && \
     __cpp_lib_atomic_value_initialization >= 201911L

sdk/include/opentelemetry/sdk/trace/tracer.h

@@ -40,7 +40,7 @@ class Tracer final : public opentelemetry::trace::Tracer,
   /** Construct a new Tracer with the given context pipeline. */
   explicit Tracer(std::shared_ptr<TracerContext> context,
                   std::unique_ptr<InstrumentationScope> instrumentation_scope =
-                      InstrumentationScope::Create("")) noexcept;
+                      InstrumentationScope::Create(""));
 
   nostd::shared_ptr<opentelemetry::trace::Span> StartSpan(
       nostd::string_view name,

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

@@ -56,7 +56,7 @@ class OPENTELEMETRY_EXPORT TracerProvider final : public opentelemetry::trace::T
               instrumentationscope::ScopeConfigurator<TracerConfig>::Builder(
                   TracerConfig::Default())
                   .Build()),
-      SpanLimits span_limits = SpanLimits::NoLimits()) noexcept;
+      SpanLimits span_limits = SpanLimits::NoLimits());
 
   explicit TracerProvider(
       std::vector<std::unique_ptr<SpanProcessor>> &&processors,
@@ -70,13 +70,13 @@ class OPENTELEMETRY_EXPORT TracerProvider final : public opentelemetry::trace::T
               instrumentationscope::ScopeConfigurator<TracerConfig>::Builder(
                   TracerConfig::Default())
                   .Build()),
-      SpanLimits span_limits = SpanLimits::NoLimits()) noexcept;
+      SpanLimits span_limits = SpanLimits::NoLimits());
 
   /**
    * Initialize a new tracer provider with a specified context
    * @param context The owned tracer configuration/pipeline for this provider.
    */
-  explicit TracerProvider(std::unique_ptr<TracerContext> context) noexcept;
+  explicit TracerProvider(std::unique_ptr<TracerContext> context);
 
   TracerProvider(const TracerProvider &)            = delete;
   TracerProvider(TracerProvider &&)                 = delete;
@@ -155,6 +155,8 @@ class OPENTELEMETRY_EXPORT TracerProvider final : public opentelemetry::trace::T
   std::vector<std::shared_ptr<Tracer>> tracers_;
   std::shared_ptr<TracerContext> context_;
   std::mutex lock_;
+  // Allocated during provider construction so GetTracer can return it without allocating.
+  nostd::shared_ptr<opentelemetry::trace::Tracer> noop_tracer_;
 };
 }  // namespace trace
 }  // namespace sdk

sdk/src/logs/logger.cc

@@ -96,10 +96,9 @@ void StampSpanContextFromVariant(
 
 opentelemetry::logs::NoopLogger Logger::kNoopLogger = opentelemetry::logs::NoopLogger();
 
-Logger::Logger(
-    opentelemetry::nostd::string_view name,
-    std::shared_ptr<LoggerContext> context,
-    std::unique_ptr<instrumentationscope::InstrumentationScope> instrumentation_scope) noexcept
+Logger::Logger(opentelemetry::nostd::string_view name,
+               std::shared_ptr<LoggerContext> context,
+               std::unique_ptr<instrumentationscope::InstrumentationScope> instrumentation_scope)
     : logger_name_(std::string(name)),
       instrumentation_scope_(std::move(instrumentation_scope)),
       context_(std::move(context))

sdk/src/logs/logger_provider.cc

@@ -2,10 +2,14 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #include <chrono>
+#include <exception>
 #include <mutex>
+#include <ostream>
 #include <utility>
 #include <vector>
 
+#include "opentelemetry/logs/logger.h"
+#include "opentelemetry/logs/noop.h"
 #include "opentelemetry/nostd/shared_ptr.h"
 #include "opentelemetry/nostd/string_view.h"
 #include "opentelemetry/sdk/common/global_log_handler.h"
@@ -25,11 +29,39 @@ namespace sdk
 namespace logs
 {
 
+namespace
+{
+
+nostd::shared_ptr<opentelemetry::logs::Logger> CreateNoopLoggerFallback()
+{
+  return nostd::shared_ptr<opentelemetry::logs::Logger>(new opentelemetry::logs::NoopLogger());
+}
+
+void LogGetLoggerConstructionFailure(const char *detail) noexcept
+{
+#if OPENTELEMETRY_HAVE_EXCEPTIONS
+  try
+  {
+#endif
+    OTEL_INTERNAL_LOG_ERROR("[LoggerProvider::GetLogger] Failed to construct logger: "
+                            << detail << "; returning noop logger.");
+#if OPENTELEMETRY_HAVE_EXCEPTIONS
+  }
+  catch (const std::exception &)  // NOLINT(bugprone-empty-catch)
+  {
+    // Logging can throw (typically std::bad_alloc from the string stream).
+    // Swallow it so the noexcept GetLogger path cannot throw.
+  }
+#endif
+}
+
+}  // namespace
+
 LoggerProvider::LoggerProvider(
     std::unique_ptr<LogRecordProcessor> &&processor,
     const opentelemetry::sdk::resource::Resource &resource,
-    std::unique_ptr<instrumentationscope::ScopeConfigurator<LoggerConfig>>
-        logger_configurator) noexcept
+    std::unique_ptr<instrumentationscope::ScopeConfigurator<LoggerConfig>> logger_configurator)
+    : noop_logger_(CreateNoopLoggerFallback())
 {
   std::vector<std::unique_ptr<LogRecordProcessor>> processors;
   processors.emplace_back(std::move(processor));
@@ -41,19 +73,20 @@ LoggerProvider::LoggerProvider(
 LoggerProvider::LoggerProvider(
     std::vector<std::unique_ptr<LogRecordProcessor>> &&processors,
     const opentelemetry::sdk::resource::Resource &resource,
-    std::unique_ptr<instrumentationscope::ScopeConfigurator<LoggerConfig>>
-        logger_configurator) noexcept
+    std::unique_ptr<instrumentationscope::ScopeConfigurator<LoggerConfig>> logger_configurator)
     : context_{std::make_shared<LoggerContext>(std::move(processors),
                                                resource,
-                                               std::move(logger_configurator))}
+                                               std::move(logger_configurator))},
+      noop_logger_(CreateNoopLoggerFallback())
 {}
 
-LoggerProvider::LoggerProvider() noexcept
-    : context_{std::make_shared<LoggerContext>(std::vector<std::unique_ptr<LogRecordProcessor>>{})}
+LoggerProvider::LoggerProvider()
+    : context_{std::make_shared<LoggerContext>(std::vector<std::unique_ptr<LogRecordProcessor>>{})},
+      noop_logger_(CreateNoopLoggerFallback())
 {}
 
-LoggerProvider::LoggerProvider(std::unique_ptr<LoggerContext> context) noexcept
-    : context_(std::move(context))
+LoggerProvider::LoggerProvider(std::unique_ptr<LoggerContext> context)
+    : context_(std::move(context)), noop_logger_(CreateNoopLoggerFallback())
 {}
 
 LoggerProvider::~LoggerProvider()
@@ -94,12 +127,31 @@ opentelemetry::nostd::shared_ptr<opentelemetry::logs::Logger> LoggerProvider::Ge
     }
   }
 
-  std::unique_ptr<instrumentationscope::InstrumentationScope> lib =
-      instrumentationscope::InstrumentationScope::Create(name, version, schema_url, attributes);
-
-  loggers_.push_back(std::shared_ptr<opentelemetry::sdk::logs::Logger>(
-      new Logger(logger_name, context_, std::move(lib))));
-  return opentelemetry::nostd::shared_ptr<opentelemetry::logs::Logger>{loggers_.back()};
+#if OPENTELEMETRY_HAVE_EXCEPTIONS
+  try
+  {
+#endif
+    std::unique_ptr<instrumentationscope::InstrumentationScope> lib =
+        instrumentationscope::InstrumentationScope::Create(name, version, schema_url, attributes);
+
+    auto logger = std::make_shared<Logger>(logger_name, context_, std::move(lib));
+    loggers_.push_back(logger);
+    return opentelemetry::nostd::shared_ptr<opentelemetry::logs::Logger>{logger};
+#if OPENTELEMETRY_HAVE_EXCEPTIONS
+  }
+  catch (const std::exception &ex)
+  {
+    LogGetLoggerConstructionFailure(ex.what());
+    return noop_logger_;
+  }
+  // User-provided scope configurators can throw any exception type, not just
+  // std::exception. Catch everything so GetLogger stays noexcept.
+  catch (...)
+  {
+    LogGetLoggerConstructionFailure("unknown exception");
+    return noop_logger_;
+  }
+#endif
 }
 
 void LoggerProvider::AddProcessor(std::unique_ptr<LogRecordProcessor> processor) noexcept

sdk/src/metrics/meter.cc

@@ -95,9 +95,8 @@ namespace metrics = opentelemetry::metrics;
 
 metrics::NoopMeter Meter::kNoopMeter = metrics::NoopMeter();
 
-Meter::Meter(
-    std::weak_ptr<MeterContext> meter_context,
-    std::unique_ptr<sdk::instrumentationscope::InstrumentationScope> instrumentation_scope) noexcept
+Meter::Meter(std::weak_ptr<MeterContext> meter_context,
+             std::unique_ptr<sdk::instrumentationscope::InstrumentationScope> instrumentation_scope)
     : scope_{std::move(instrumentation_scope)},
       meter_context_{std::move(meter_context)},
       observable_registry_(new ObservableRegistry()),