1 files changed, 39 insertions, 0 deletions
diff --git a/include/grpcpp/impl/codegen/completion_queue_tag.h b/include/grpcpp/impl/codegen/completion_queue_tag.h
new file mode 100644
index 0000000000..ffb642c56b
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+++ b/include/grpcpp/impl/codegen/completion_queue_tag.h
@@ -0,0 +1,39 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#ifndef GRPCPP_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H
+#define GRPCPP_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H
+
+namespace grpc {
+
+namespace internal {
+/// An interface allowing implementors to process and filter event tags.
+class CompletionQueueTag {
+ public:
+  virtual ~CompletionQueueTag() {}
+  /// Called prior to returning from Next(), return value is the status of the
+  /// operation (return status is the default thing to do). If this function
+  /// returns false, the tag is dropped and not returned from the completion
+  /// queue
+  virtual bool FinalizeResult(void** tag, bool* status) = 0;
+};
+}  // namespace internal
+
+}  // namespace grpc
+
+#endif  // GRPCPP_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H