| /* |
| * |
| * 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. |
| * |
| */ |
| |
| /// An Alarm posts the user provided tag to its associated completion queue upon |
| /// expiry or cancellation. |
| #ifndef GRPCXX_ALARM_H |
| #define GRPCXX_ALARM_H |
| |
| #include <grpc++/impl/codegen/completion_queue.h> |
| #include <grpc++/impl/codegen/completion_queue_tag.h> |
| #include <grpc++/impl/codegen/grpc_library.h> |
| #include <grpc++/impl/codegen/time.h> |
| #include <grpc++/impl/grpc_library.h> |
| #include <grpc/grpc.h> |
| |
| struct grpc_alarm; |
| |
| namespace grpc { |
| |
| class CompletionQueue; |
| |
| /// A thin wrapper around \a grpc_alarm (see / \a / src/core/surface/alarm.h). |
| class Alarm : private GrpcLibraryCodegen { |
| public: |
| /// Create an unset completion queue alarm |
| Alarm() : tag_(nullptr), alarm_(grpc_alarm_create(nullptr)) {} |
| |
| /// DEPRECATED: Create and set a completion queue alarm instance associated to |
| /// \a cq. |
| /// This form is deprecated because it is inherently racy. |
| /// \internal We rely on the presence of \a cq for grpc initialization. If \a |
| /// cq were ever to be removed, a reference to a static |
| /// internal::GrpcLibraryInitializer instance would need to be introduced |
| /// here. \endinternal. |
| template <typename T> |
| Alarm(CompletionQueue* cq, const T& deadline, void* tag) |
| : tag_(tag), alarm_(grpc_alarm_create(nullptr)) { |
| grpc_alarm_set(alarm_, cq->cq(), TimePoint<T>(deadline).raw_time(), |
| static_cast<void*>(&tag_), nullptr); |
| } |
| |
| /// Trigger an alarm instance on completion queue \a cq at the specified time. |
| /// Once the alarm expires (at \a deadline) or it's cancelled (see \a Cancel), |
| /// an event with tag \a tag will be added to \a cq. If the alarm expired, the |
| /// event's success bit will be true, false otherwise (ie, upon cancellation). |
| template <typename T> |
| void Set(CompletionQueue* cq, const T& deadline, void* tag) { |
| tag_.Set(tag); |
| grpc_alarm_set(alarm_, cq->cq(), TimePoint<T>(deadline).raw_time(), |
| static_cast<void*>(&tag_), nullptr); |
| } |
| |
| /// Alarms aren't copyable. |
| Alarm(const Alarm&) = delete; |
| Alarm& operator=(const Alarm&) = delete; |
| |
| /// Alarms are movable. |
| Alarm(Alarm&& rhs) : tag_(rhs.tag_), alarm_(rhs.alarm_) { |
| rhs.alarm_ = nullptr; |
| } |
| Alarm& operator=(Alarm&& rhs) { |
| tag_ = rhs.tag_; |
| alarm_ = rhs.alarm_; |
| rhs.alarm_ = nullptr; |
| return *this; |
| } |
| |
| /// Destroy the given completion queue alarm, cancelling it in the process. |
| ~Alarm() { |
| if (alarm_ != nullptr) grpc_alarm_destroy(alarm_, nullptr); |
| } |
| |
| /// Cancel a completion queue alarm. Calling this function over an alarm that |
| /// has already fired has no effect. |
| void Cancel() { |
| if (alarm_ != nullptr) grpc_alarm_cancel(alarm_, nullptr); |
| } |
| |
| private: |
| class AlarmEntry : public internal::CompletionQueueTag { |
| public: |
| AlarmEntry(void* tag) : tag_(tag) {} |
| void Set(void* tag) { tag_ = tag; } |
| bool FinalizeResult(void** tag, bool* status) override { |
| *tag = tag_; |
| return true; |
| } |
| |
| private: |
| void* tag_; |
| }; |
| |
| AlarmEntry tag_; |
| grpc_alarm* alarm_; // owned |
| }; |
| |
| } // namespace grpc |
| |
| #endif // GRPCXX_ALARM_H |