// Copyright 2023 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 GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_PING_RATE_POLICY_H #define GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_PING_RATE_POLICY_H #include #include #include #include #include "absl/types/variant.h" #include "src/core/lib/channel/channel_args.h" #include "src/core/util/time.h" namespace grpc_core { class Chttp2PingRatePolicy { public: explicit Chttp2PingRatePolicy(const ChannelArgs& args, bool is_client); static void SetDefaults(const ChannelArgs& args); struct SendGranted { bool operator==(const SendGranted&) const { return true; } }; struct TooManyRecentPings { bool operator==(const TooManyRecentPings&) const { return true; } }; struct TooSoon { Duration next_allowed_ping_interval; Timestamp last_ping; Duration wait; bool operator==(const TooSoon& other) const { return next_allowed_ping_interval == other.next_allowed_ping_interval && last_ping == other.last_ping && wait == other.wait; } }; using RequestSendPingResult = absl::variant; // Request that one ping be sent. // Returns: // - SendGranted if a ping can be sent. // - TooManyRecentPings if too many pings have been sent recently and we // should wait for some future write. // - TooSoon if we should wait for some time before sending the ping. RequestSendPingResult RequestSendPing(Duration next_allowed_ping_interval, size_t inflight_pings) const; // Notify the policy that one ping has been sent. void SentPing(); // Notify the policy that some data has been sent and so we should no longer // block pings on that basis. void ResetPingsBeforeDataRequired(); // Notify the policy that we've received some data. void ReceivedDataFrame(); std::string GetDebugString() const; int TestOnlyMaxPingsWithoutData() const { return max_pings_without_data_sent_; } private: const int max_pings_without_data_sent_; const int max_inflight_pings_; int pings_before_data_sending_required_ = 0; Timestamp last_ping_sent_time_ = Timestamp::InfPast(); }; std::ostream& operator<<(std::ostream& out, const Chttp2PingRatePolicy::RequestSendPingResult& r); } // namespace grpc_core #endif // GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_PING_RATE_POLICY_H