Program Listing for File realtime_box.h

↰ Return to documentation for file (/tmp/ws/src/realtime_tools/include/realtime_tools/realtime_box.h)

// Copyright (c) 2009, Willow Garage, Inc.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//    * Redistributions of source code must retain the above copyright
//      notice, this list of conditions and the following disclaimer.
//
//    * 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.
//
//    * 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"
// 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.

// 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:
  explicit 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 realtime_tools

#endif  // REALTIME_TOOLS__REALTIME_BOX_H_