1/*
2 *
3 * Copyright 2015 gRPC authors.
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19#ifndef GRPCPP_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H
20#define GRPCPP_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H
21
22namespace grpc {
23
24namespace internal {
25/// An interface allowing implementors to process and filter event tags.
26class CompletionQueueTag {
27 public:
28 virtual ~CompletionQueueTag() {}
29
30 /// FinalizeResult must be called before informing user code that the
31 /// operation bound to the underlying core completion queue tag has
32 /// completed. In practice, this means:
33 ///
34 /// 1. For the sync API - before returning from Pluck
35 /// 2. For the CQ-based async API - before returning from Next
36 /// 3. For the callback-based API - before invoking the user callback
37 ///
38 /// This is the method that translates from core-side tag/status to
39 /// C++ API-observable tag/status.
40 ///
41 /// The return value is the status of the operation (returning status is the
42 /// general behavior of this function). If this function returns false, the
43 /// tag is dropped and not returned from the completion queue: this concept is
44 /// for events that are observed at core but not requested by the user
45 /// application (e.g., server shutdown, for server unimplemented method
46 /// responses, or for cases where a server-side RPC doesn't have a completion
47 /// notification registered using AsyncNotifyWhenDone)
48 virtual bool FinalizeResult(void** tag, bool* status) = 0;
49};
50} // namespace internal
51
52} // namespace grpc
53
54#endif // GRPCPP_IMPL_CODEGEN_COMPLETION_QUEUE_TAG_H
55

source code of include/grpcpp/impl/codegen/completion_queue_tag.h