resource_manager.h

// -*- mode: c++; tab-width: 4; indent-tabs-mode: t; eval: (progn (c-set-style "stroustrup") (c-set-offset 'innamespace 0)); -*-
// vi:set ts=4 sts=4 sw=4 noet :
//
// Copyright 2011, The TPIE development team
//
// This file is part of TPIE.
//
// TPIE is free software: you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License as published by the
// Free Software Foundation, either version 3 of the License, or (at your
// option) any later version.
//
// TPIE is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
// License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with TPIE.  If not, see <http://www.gnu.org/licenses/>


#ifndef __TPIE_RESOURCE_MANAGER_H__
#define __TPIE_RESOURCE_MANAGER_H__

#include <tpie/config.h>
#include <tpie/util.h>
#include <tpie/resources.h>
#include <mutex>
#include <unordered_map>
#include <type_traits>
#include <utility>
#include <memory>
#include <atomic>
#include <cstdlib>
#include <iostream>
#include <sstream>
#include <tpie/exception.h>
namespace tpie {

class resource_manager {
public:
    enum enforce_t {
        ENFORCE_IGNORE,
        ENFORCE_DEBUG,
        ENFORCE_WARN,
        ENFORCE_THROW
    };

    size_t used() const noexcept;

    size_t available() const noexcept;

    size_t limit() const noexcept {return m_limit;}

    void set_limit(size_t new_limit);

    void set_enforcement(enforce_t e);

    enforce_t enforcement() const noexcept {return m_enforce;}

    void register_increased_usage(size_t amount);

    void register_decreased_usage(size_t amount);

    virtual std::string amount_with_unit(size_t amount) const {
        std::ostringstream os;
        os << amount << " amount of " << resource_managed;
        return os.str();
    }

    resource_manager(resource_type type);

    virtual ~resource_manager() = default;

private:
    void print_resource_complaint(std::ostream & os, size_t amount, size_t usage);
protected:
    virtual void throw_out_of_resource_error(const std::string & s) = 0;

    std::atomic<size_t> m_used;
    size_t m_limit;
    size_t m_maxExceeded;
    size_t m_nextWarning;
    enforce_t m_enforce;

    resource_type resource_managed;
};

} //namespace tpie

#endif //__TPIE_RESOURCE_MANAGER_H__