arpadboda commented on a change in pull request #735: WIP: MINIFICPP-1158 - Event driven processors can starve each other URL: https://github.com/apache/nifi-minifi-cpp/pull/735#discussion_r382103331
########## File path: libminifi/include/utils/Monitors.h ########## @@ -0,0 +1,172 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 NIFI_MINIFI_CPP_MONITORS_H +#define NIFI_MINIFI_CPP_MONITORS_H + +#include <chrono> +#include <atomic> + +namespace org { +namespace apache { +namespace nifi { +namespace minifi { +namespace utils { + +/** + * Worker task helper that determines + * whether or not we will run + */ +template<typename T> +class AfterExecute { + public: + virtual ~AfterExecute() { + + } + + explicit AfterExecute() { + + } + + explicit AfterExecute(AfterExecute &&other) { + + } + virtual bool isFinished(const T &result) = 0; + virtual bool isCancelled(const T &result) = 0; + /** + * Time to wait before re-running this task if necessary + * @return milliseconds since epoch after which we are eligible to re-run this task. + */ + virtual std::chrono::milliseconds wait_time() = 0; +}; + +/** + * Uses the wait time for a given worker to determine if it is eligible to run + */ +class TimerAwareMonitor : public utils::AfterExecute<std::chrono::milliseconds> { + public: + TimerAwareMonitor(std::atomic<bool> *run_monitor) + : current_wait_(std::chrono::milliseconds(0)), + run_monitor_(run_monitor) { + } + explicit TimerAwareMonitor(TimerAwareMonitor &&other) = default; + virtual bool isFinished(const std::chrono::milliseconds &result) override { + current_wait_.store(result); + if (*run_monitor_) { + return false; + } + return true; + } + virtual bool isCancelled(const std::chrono::milliseconds &result) override { + if (*run_monitor_) { + return false; + } + return true; + } + /** + * Time to wait before re-running this task if necessary + * @return milliseconds since epoch after which we are eligible to re-run this task. + */ + virtual std::chrono::milliseconds wait_time() override { + return current_wait_.load(); + } + protected: + + std::atomic<std::chrono::milliseconds> current_wait_; + std::atomic<bool> *run_monitor_; +}; + +class SingleRunMonitor : public utils::AfterExecute<bool>{ + public: + SingleRunMonitor(std::chrono::milliseconds retry_interval = std::chrono::milliseconds(100)) + : retry_interval_(retry_interval) { + } + explicit SingleRunMonitor(SingleRunMonitor &&other) = default; + + virtual bool isFinished(const bool &result) override { + return result; + } + virtual bool isCancelled(const bool &result) override { + return false; + } + virtual std::chrono::milliseconds wait_time() override { + return retry_interval_; + } + protected: + const std::chrono::milliseconds retry_interval_; +}; + + +struct ComplexResult { + ComplexResult(bool result, std::chrono::milliseconds wait_time) + : finished_(result), wait_time_(wait_time){} + std::chrono::milliseconds wait_time_; + bool finished_; +}; + +class ComplexMonitor : public utils::AfterExecute<ComplexResult> { + public: + ComplexMonitor(std::atomic<bool> *run_monitor) + : current_wait_(std::chrono::milliseconds(0)), + run_monitor_(run_monitor) { + } + explicit ComplexMonitor(ComplexMonitor &&other) = default; + + virtual bool isFinished(const ComplexResult &result) override { + if (result.finished_) { + return true; + } + if (*run_monitor_) { + current_wait_.store(result.wait_time_); + return false; + } + return true; + } + virtual bool isCancelled(const ComplexResult &result) override { + if (*run_monitor_) { + return false; + } + return true; + } + /** + * Time to wait before re-running this task if necessary + * @return milliseconds since epoch after which we are eligible to re-run this task. + */ + virtual std::chrono::milliseconds wait_time() override { + return current_wait_.load(); + } + + private: + std::atomic<std::chrono::milliseconds> current_wait_; + std::atomic<bool> *run_monitor_; +}; + +static ComplexResult Done() { + return ComplexResult(true, std::chrono::milliseconds(0)); +} + +static ComplexResult Retry(std::chrono::milliseconds interval) { + return ComplexResult(false, interval); +} Review comment: Moved them to the class as static members, no more warnings. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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