process.h

/*
 * Copyright (c) 2014-2016, Siemens AG. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef EMBB_DATAFLOW_INTERNAL_PROCESS_H_
#define EMBB_DATAFLOW_INTERNAL_PROCESS_H_

#include <embb/dataflow/internal/node.h>
#include <embb/dataflow/internal/inputs.h>
#include <embb/dataflow/internal/outputs.h>
#include <embb/dataflow/internal/process_executor.h>
#include <embb/dataflow/internal/action.h>

namespace embb {
namespace dataflow {
namespace internal {

template <int Slices, bool Serial, class INPUTS, class OUTPUTS> class Process;

template <
  int Slices, bool Serial,
  typename I1, typename I2, typename I3, typename I4, typename I5,
  typename O1, typename O2, typename O3, typename O4, typename O5>
class Process< Slices, Serial, Inputs<Slices, I1, I2, I3, I4, I5>,
  Outputs<Slices, O1, O2, O3, O4, O5> >
  : public Node
  , public ClockListener {
 public:
  typedef Inputs<Slices, I1, I2, I3, I4, I5> InputsType;
  typedef Outputs<Slices, O1, O2, O3, O4, O5> OutputsType;
  typedef ProcessExecutor< InputsType, OutputsType > ExecutorType;
  typedef typename ExecutorType::FunctionType FunctionType;

  explicit Process(FunctionType function)
    : executor_(function) {
    next_clock_ = 0;
    queued_clock_ = 0;
    bool ordered = Serial;
    if (ordered) {
      queue_id_ = GetNextProcessID();
    } else {
      queue_id_ = 0;
    }
    inputs_.SetListener(this);
  }

  virtual bool HasInputs() const {
    return inputs_.Size() > 0;
  }

  virtual bool HasOutputs() const {
    return outputs_.Size() > 0;
  }

  virtual void Run(int clock) {
    executor_.Execute(clock, inputs_, outputs_);
  }

  virtual void Init(InitData * init_data) {
    SetScheduler(init_data->sched);
    executor_.Init(init_data, outputs_);
  }

  InputsType & GetInputs() {
    return inputs_;
  }

  template <int Index>
  typename TypeAt<typename InputsType::Types, Index>::Result & GetInput() {
    return inputs_.template Get<Index>();
  }

  OutputsType & GetOutputs() {
    return outputs_;
  }

  template <int Index>
  typename TypeAt<typename OutputsType::Types, Index>::Result & GetOutput() {
    return outputs_.template Get<Index>();
  }

  template <typename T>
  T & operator >> (T & target) {
    GetOutput<0>() >> target.template GetInput<0>();
    return target;
  }

  virtual void OnClock(int clock) {
    if (!inputs_.AreAtClock(clock)) {
      EMBB_THROW(embb::base::ErrorException,
        "Some inputs are not at expected clock.")
    }

    bool ordered = Serial;
    if (ordered) {
      bool retry = true;
      while (retry) {
        int clk = next_clock_;
        int clk_end = clk + Slices;
        int clk_res = clk;
        for (int ii = clk; ii < clk_end; ii++) {
          if (!inputs_.AreAtClock(ii)) {
            break;
          }
          clk_res++;
        }
        if (clk_res > clk) {
          if (next_clock_.CompareAndSwap(clk, clk_res)) {
            while (queued_clock_.Load() < clk) continue;
            for (int ii = clk; ii < clk_res; ii++) {
              const int idx = ii % Slices;
              action_[idx] = Action(this, ii);
              sched_->Enqueue(queue_id_, action_[idx]);
            }
            queued_clock_.Store(clk_res);
            retry = false;
          }
        } else {
          retry = false;
        }
      }
    } else {
      const int idx = clock % Slices;
      action_[idx] = Action(this, clock);
      sched_->Spawn(action_[idx]);
    }
  }

  virtual void OnInit(InitData * init_data) {
    Init(init_data);
  }

 private:
  InputsType inputs_;
  OutputsType outputs_;
  ExecutorType executor_;
  Action action_[Slices];
  embb::base::Atomic<int> next_clock_;
  embb::base::Atomic<int> queued_clock_;
  int queue_id_;
};

} // namespace internal
} // namespace dataflow
} // namespace embb

#endif // EMBB_DATAFLOW_INTERNAL_PROCESS_H_