Program Listing for File periodic.hpp

            

            
/*
* SPDX-FileCopyrightText: Copyright (c) 2023-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
* SPDX-License-Identifier: Apache-2.0
*
* 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 HOLOSCAN_CORE_CONDITIONS_GXF_PERIODIC_HPP
#define HOLOSCAN_CORE_CONDITIONS_GXF_PERIODIC_HPP

#include <string>
#include <chrono>

#include <gxf/std/scheduling_terms.hpp>

#include "../../gxf/gxf_condition.hpp"

namespace holoscan {

enum class PeriodicConditionPolicy {
  // scheduler will try to "catch up" on missed ticks
  // eg. assume recess period of 100ms:
  // tick 0 at 0ms -> next_target_ = 100ms
  // tick 1 at 250ms -> next_target_ = 200ms (next_target_ < timestamp)
  // tick 2 at 255ms -> next_target_ = 300ms (double tick before 300ms)
  kCatchUpMissedTicks,
  // scheduler guarantees recess period will have passed before next tick
  // eg. assume recess period of 100ms:
  // tick 0 at 0ms -> next_target_ = 100ms
  // tick 1 at 101ms -> next_target_ = 201ms
  // tick 2 at 350ms -> next_target_ = 450ms
  kMinTimeBetweenTicks,
  // scheduler will not try to "catch up" on missed ticks
  // eg. assume recess period of 100ms:
  // tick 0 at 0ms -> next_target_ = 100ms
  // tick 1 at 250ms -> next_target_ = 300ms (single tick before 300ms)
  // tick 2 at 305ms -> next_target_ = 400ms
  kNoCatchUpMissedTicks
};

class PeriodicCondition : public gxf::GXFCondition {
 public:
  HOLOSCAN_CONDITION_FORWARD_ARGS_SUPER(PeriodicCondition, GXFCondition)
  // using PeriodicConditionPolicy = nvidia::gxf::PeriodicSchedulingPolicy;
  PeriodicCondition() = default;

  explicit PeriodicCondition(
      int64_t recess_period_ns,
      PeriodicConditionPolicy policy = PeriodicConditionPolicy::kCatchUpMissedTicks);

  template <typename Rep, typename Period>
  explicit PeriodicCondition(
      std::chrono::duration<Rep, Period> recess_period_duration,
      PeriodicConditionPolicy policy = PeriodicConditionPolicy::kCatchUpMissedTicks)
      : recess_period_ns_(
            std::chrono::duration_cast<std::chrono::nanoseconds>(recess_period_duration).count()) {
    recess_period_ = std::to_string(recess_period_ns_);
    switch (policy) {
      case PeriodicConditionPolicy::kCatchUpMissedTicks:
        policy_ = YAML::Node("CatchUpMissedTicks");
        break;
      case PeriodicConditionPolicy::kMinTimeBetweenTicks:
        policy_ = YAML::Node("MinTimeBetweenTicks");
        break;
      case PeriodicConditionPolicy::kNoCatchUpMissedTicks:
        policy_ = YAML::Node("NoCatchUpMissedTicks");
        break;
      default:
        HOLOSCAN_LOG_ERROR("Unrecognized policy enum value: {}", static_cast<int>(policy));
    }
  }

  nvidia::gxf::PeriodicSchedulingPolicy convertToGXFPolicy(PeriodicConditionPolicy policy) {
    switch (policy) {
      case PeriodicConditionPolicy::kCatchUpMissedTicks:
        return nvidia::gxf::PeriodicSchedulingPolicy::kCatchUpMissedTicks;
      case PeriodicConditionPolicy::kMinTimeBetweenTicks:
        return nvidia::gxf::PeriodicSchedulingPolicy::kMinTimeBetweenTicks;
      case PeriodicConditionPolicy::kNoCatchUpMissedTicks:
        return nvidia::gxf::PeriodicSchedulingPolicy::kNoCatchUpMissedTicks;
      default:
        throw std::runtime_error("Unknown PeriodicConditionPolicy value");
    }
  }

  PeriodicCondition(const std::string& name, nvidia::gxf::PeriodicSchedulingTerm* term);

  const char* gxf_typename() const override { return "nvidia::gxf::PeriodicSchedulingTerm"; }

  void initialize() override;

  void setup(ComponentSpec& spec) override;

  PeriodicConditionPolicy policy() {
    auto gxf_policy = policy_.get().as<std::string>();
    if (gxf_policy == "CatchUpMissedTicks") {
      return PeriodicConditionPolicy::kCatchUpMissedTicks;
    } else if (gxf_policy == "MinTimeBetweenTicks") {
      return PeriodicConditionPolicy::kMinTimeBetweenTicks;
    } else if (gxf_policy == "NoCatchUpMissedTicks") {
      return PeriodicConditionPolicy::kNoCatchUpMissedTicks;
    } else {
      throw std::runtime_error(fmt::format("unknown mode: {}", gxf_policy));
    }
  }

  void recess_period(int64_t recess_period_ns);

  template <typename Rep, typename Period>
  void recess_period(std::chrono::duration<Rep, Period> recess_period_duration) {
    int64_t recess_period_ns =
        std::chrono::duration_cast<std::chrono::nanoseconds>(recess_period_duration).count();
    recess_period(recess_period_ns);
  }

  int64_t recess_period_ns();

  int64_t last_run_timestamp();

  nvidia::gxf::PeriodicSchedulingTerm* get() const;

 private:
  Parameter<std::string> recess_period_;
  int64_t recess_period_ns_ = 0;
  Parameter<YAML::Node> policy_;  // = YAML::Node("CatchUpMissedTicks");
};

}  // namespace holoscan

#endif/* HOLOSCAN_CORE_CONDITIONS_GXF_PERIODIC_HPP */