Add async exporting for OTLP gRPC exporter

api/include/opentelemetry/common/macros.h

@@ -7,9 +7,7 @@
 // GCC 9 has likely attribute but do not support declare it at the beginning of statement
 #  if defined(__has_cpp_attribute) && (defined(__clang__) || !defined(__GNUC__) || __GNUC__ > 9)
 #    if __has_cpp_attribute(likely)
-#      define OPENTELEMETRY_LIKELY_IF(...) \
-        if (__VA_ARGS__)                   \
-        [[likely]]
+#      define OPENTELEMETRY_LIKELY_IF(...) if (__VA_ARGS__) [[likely]]
 
 #    endif
 #  endif
@@ -164,16 +162,19 @@ point.
 #if defined(__clang__)
 
 #  define OPENTELEMETRY_API_SINGLETON __attribute__((visibility("default")))
+#  define OPENTELEMETRY_LOCAL_SYMBOL __attribute__((visibility("hidden")))
 
 #elif defined(__GNUC__)
 
 #  define OPENTELEMETRY_API_SINGLETON __attribute__((visibility("default")))
+#  define OPENTELEMETRY_LOCAL_SYMBOL __attribute__((visibility("hidden")))
 
 #else
 
 /* Add support for other compilers here. */
 
 #  define OPENTELEMETRY_API_SINGLETON
+#  define OPENTELEMETRY_LOCAL_SYMBOL
 
 #endif
 

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_client.h

@@ -3,10 +3,13 @@
 
 #pragma once
 
+#include <grpcpp/completion_queue.h>
 #include <grpcpp/grpcpp.h>
 
 #include <memory>
 
+#include "opentelemetry/sdk/common/exporter_utils.h"
+
 #include "opentelemetry/exporters/otlp/otlp_grpc_client_options.h"
 
 #include "opentelemetry/exporters/otlp/protobuf_include_prefix.h"
@@ -26,12 +29,21 @@ namespace otlp
 
 struct OtlpGrpcClientOptions;
 
+#ifdef ENABLE_ASYNC_EXPORT
+struct OtlpGrpcClientAsyncData;
+#endif
+
 /**
  * The OTLP gRPC client contains utility functions of gRPC.
  */
 class OtlpGrpcClient
 {
 public:
+#ifdef ENABLE_ASYNC_EXPORT
+  OtlpGrpcClient();
+  ~OtlpGrpcClient();
+#endif
+
   /**
    * Create gRPC channel from the exporter options.
    */
@@ -68,21 +80,109 @@ class OtlpGrpcClient
 
   static grpc::Status DelegateExport(
       proto::collector::trace::v1::TraceService::StubInterface *stub,
-      grpc::ClientContext *context,
-      const proto::collector::trace::v1::ExportTraceServiceRequest &request,
+      std::unique_ptr<grpc::ClientContext> &&context,
+      std::unique_ptr<google::protobuf::Arena> &&arena,
+      proto::collector::trace::v1::ExportTraceServiceRequest &&request,
       proto::collector::trace::v1::ExportTraceServiceResponse *response);
 
   static grpc::Status DelegateExport(
       proto::collector::metrics::v1::MetricsService::StubInterface *stub,
-      grpc::ClientContext *context,
-      const proto::collector::metrics::v1::ExportMetricsServiceRequest &request,
+      std::unique_ptr<grpc::ClientContext> &&context,
+      std::unique_ptr<google::protobuf::Arena> &&arena,
+      proto::collector::metrics::v1::ExportMetricsServiceRequest &&request,
       proto::collector::metrics::v1::ExportMetricsServiceResponse *response);
 
   static grpc::Status DelegateExport(
       proto::collector::logs::v1::LogsService::StubInterface *stub,
-      grpc::ClientContext *context,
-      const proto::collector::logs::v1::ExportLogsServiceRequest &request,
+      std::unique_ptr<grpc::ClientContext> &&context,
+      std::unique_ptr<google::protobuf::Arena> &&arena,
+      proto::collector::logs::v1::ExportLogsServiceRequest &&request,
       proto::collector::logs::v1::ExportLogsServiceResponse *response);
+
+#ifdef ENABLE_ASYNC_EXPORT
+
+  /**
+   * Async export
+   * @param options Options used to message to create gRPC context and stub(if necessary)
+   * @param arena Protobuf arena to hold lifetime of all messages
+   * @param request Request for this RPC
+   * @param result_callback callback to call when the exporting is done
+   * @return return the status of this operation
+   */
+  sdk::common::ExportResult DelegateAsyncExport(
+      const OtlpGrpcClientOptions &options,
+      proto::collector::trace::v1::TraceService::StubInterface *stub,
+      std::unique_ptr<grpc::ClientContext> &&context,
+      std::unique_ptr<google::protobuf::Arena> &&arena,
+      proto::collector::trace::v1::ExportTraceServiceRequest &&request,
+      std::function<bool(opentelemetry::sdk::common::ExportResult,
+                         std::unique_ptr<google::protobuf::Arena> &&,
+                         const proto::collector::trace::v1::ExportTraceServiceRequest &,
+                         proto::collector::trace::v1::ExportTraceServiceResponse *)>
+          &&result_callback) noexcept;
+
+  /**
+   * Async export
+   * @param options Options used to message to create gRPC context and stub(if necessary)
+   * @param arena Protobuf arena to hold lifetime of all messages
+   * @param request Request for this RPC
+   * @param result_callback callback to call when the exporting is done
+   * @return return the status of this operation
+   */
+  sdk::common::ExportResult DelegateAsyncExport(
+      const OtlpGrpcClientOptions &options,
+      proto::collector::metrics::v1::MetricsService::StubInterface *stub,
+      std::unique_ptr<grpc::ClientContext> &&context,
+      std::unique_ptr<google::protobuf::Arena> &&arena,
+      proto::collector::metrics::v1::ExportMetricsServiceRequest &&request,
+      std::function<bool(opentelemetry::sdk::common::ExportResult,
+                         std::unique_ptr<google::protobuf::Arena> &&,
+                         const proto::collector::metrics::v1::ExportMetricsServiceRequest &,
+                         proto::collector::metrics::v1::ExportMetricsServiceResponse *)>
+          &&result_callback) noexcept;
+
+  /**
+   * Async export
+   * @param options Options used to message to create gRPC context and stub(if necessary)
+   * @param arena Protobuf arena to hold lifetime of all messages
+   * @param request Request for this RPC
+   * @param result_callback callback to call when the exporting is done
+   * @return return the status of this operation
+   */
+  sdk::common::ExportResult DelegateAsyncExport(
+      const OtlpGrpcClientOptions &options,
+      proto::collector::logs::v1::LogsService::StubInterface *stub,
+      std::unique_ptr<grpc::ClientContext> &&context,
+      std::unique_ptr<google::protobuf::Arena> &&arena,
+      proto::collector::logs::v1::ExportLogsServiceRequest &&request,
+      std::function<bool(opentelemetry::sdk::common::ExportResult,
+                         std::unique_ptr<google::protobuf::Arena> &&,
+                         const proto::collector::logs::v1::ExportLogsServiceRequest &,
+                         proto::collector::logs::v1::ExportLogsServiceResponse *)>
+          &&result_callback) noexcept;
+
+  /**
+   * Force flush the gRPC client.
+   */
+  bool ForceFlush(std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept;
+
+  /**
+   * Shut down the gRPC client.
+   * @param timeout an optional timeout, the default timeout of 0 means that no
+   * timeout is applied.
+   * @return return the status of this operation
+   */
+  bool Shutdown(std::chrono::microseconds timeout = std::chrono::microseconds(0)) noexcept;
+
+  std::shared_ptr<OtlpGrpcClientAsyncData> MutableAsyncData(const OtlpGrpcClientOptions &options);
+
+private:
+  // Stores if this gRPC client had its Shutdown() method called
+  bool is_shutdown_;
+
+  // Stores shared data between threads of this gRPC client
+  std::shared_ptr<OtlpGrpcClientAsyncData> async_data_;
+#endif
 };
 }  // namespace otlp
 }  // namespace exporter

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_client_options.h

@@ -51,6 +51,14 @@ struct OtlpGrpcClientOptions
 
   /** User agent. */
   std::string user_agent;
+
+  /** max number of threads that can be allocated from this */
+  std::size_t max_threads;
+
+#ifdef ENABLE_ASYNC_EXPORT
+  // Concurrent requests
+  std::size_t max_concurrent_requests;
+#endif
 };
 
 }  // namespace otlp

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_exporter.h

@@ -23,6 +23,8 @@ namespace exporter
 namespace otlp
 {
 
+class OtlpGrpcClient;
+
 /**
  * The OTLP exporter exports span data in OpenTelemetry Protocol (OTLP) format.
  */
@@ -73,6 +75,10 @@ class OtlpGrpcExporter final : public opentelemetry::sdk::trace::SpanExporter
   // The configuration options associated with this exporter.
   const OtlpGrpcExporterOptions options_;
 
+#ifdef ENABLE_ASYNC_EXPORT
+  std::shared_ptr<OtlpGrpcClient> client_;
+#endif
+
   // For testing
   friend class OtlpGrpcExporterTestPeer;
   friend class OtlpGrpcLogRecordExporterTestPeer;

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_log_record_exporter.h

@@ -22,6 +22,8 @@ namespace exporter
 namespace otlp
 {
 
+class OtlpGrpcClient;
+
 /**
  * The OTLP exporter exports log data in OpenTelemetry Protocol (OTLP) format in gRPC.
  */
@@ -73,6 +75,10 @@ class OtlpGrpcLogRecordExporter : public opentelemetry::sdk::logs::LogRecordExpo
   // Configuration options for the exporter
   const OtlpGrpcLogRecordExporterOptions options_;
 
+#ifdef ENABLE_ASYNC_EXPORT
+  std::shared_ptr<OtlpGrpcClient> client_;
+#endif
+
   // For testing
   friend class OtlpGrpcLogRecordExporterTestPeer;
 

exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_metric_exporter.h

@@ -22,6 +22,8 @@ namespace exporter
 namespace otlp
 {
 
+class OtlpGrpcClient;
+
 /**
  * The OTLP exporter exports metrics data in OpenTelemetry Protocol (OTLP) format in gRPC.
  */
@@ -59,6 +61,10 @@ class OtlpGrpcMetricExporter : public opentelemetry::sdk::metrics::PushMetricExp
   // The configuration options associated with this exporter.
   const OtlpGrpcMetricExporterOptions options_;
 
+#ifdef ENABLE_ASYNC_EXPORT
+  std::shared_ptr<OtlpGrpcClient> client_;
+#endif
+
   // Aggregation Temporality selector
   const sdk::metrics::AggregationTemporalitySelector aggregation_temporality_selector_;