realtime_box.h

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/*
 * Copyright (c) 2009, Willow Garage, Inc.
 * All rights reserved.
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 *
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 *     * Neither the name of the Willow Garage, Inc. nor the names of its
 *       contributors may be used to endorse or promote products derived from
 *       this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// Author: Stuart Glaser

#ifndef REALTIME_TOOLS__REALTIME_BOX_H__
#define REALTIME_TOOLS__REALTIME_BOX_H__

#include <mutex>
#include <string>

namespace realtime_tools {

template <class T>
class RealtimeBox
{
public:
  RealtimeBox(const T &initial = T()) : thing_(initial)
  {
  }

  void set(const T &value)
  {
    std::lock_guard<std::mutex> guard(thing_lock_RT_);
    thing_ = value;
  }

  void get(T &ref)
  {
    std::lock_guard<std::mutex> guard(thing_lock_RT_);
    ref = thing_;
  }

private:
  // The thing that's in the box.
  T thing_;

  // Protects access to the thing in the box.  This mutex is
  // guaranteed to be locked for no longer than the duration of the
  // copy, so as long as the copy is realtime safe and the OS has
  // priority inheritance for mutexes, this lock can be safely locked
  // from within realtime.
  std::mutex thing_lock_RT_;
};

} // namespace

#endif