// Copyright (c) 2018, The Monero Project
//
// 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.
//
// 3. Neither the name of the copyright holder 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,
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// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#pragma once
#include <map>
#include <boost/thread/mutex.hpp>
namespace epee
{
class mlocker
{
public:
mlocker(void *ptr, size_t len);
~mlocker();
static size_t get_page_size();
static size_t get_num_locked_pages();
static size_t get_num_locked_objects();
static void lock(void *ptr, size_t len);
static void unlock(void *ptr, size_t len);
private:
static size_t page_size;
static size_t num_locked_objects;
static boost::mutex &mutex();
static std::map<size_t, unsigned int> &map();
static void lock_page(size_t page);
static void unlock_page(size_t page);
void *ptr;
size_t len;
};
/// Locks memory while in scope
///
/// Primarily useful for making sure that private keys don't get swapped out
// to disk
template <class T>
struct mlocked : public T {
using type = T;
mlocked(): T() { mlocker::lock(this, sizeof(T)); }
mlocked(const T &t): T(t) { mlocker::lock(this, sizeof(T)); }
mlocked(const mlocked<T> &mt): T(mt) { mlocker::lock(this, sizeof(T)); }
mlocked(const T &&t): T(t) { mlocker::lock(this, sizeof(T)); }
mlocked(const mlocked<T> &&mt): T(mt) { mlocker::lock(this, sizeof(T)); }
mlocked<T> &operator=(const mlocked<T> &mt) { T::operator=(mt); return *this; }
~mlocked() { try { mlocker::unlock(this, sizeof(T)); } catch (...) { /* do not propagate */ } }
};
template<typename T>
T& unwrap(mlocked<T>& src) { return src; }
template<typename T>
const T& unwrap(mlocked<T> const& src) { return src; }
template <class T, size_t N>
using mlocked_arr = mlocked<std::array<T, N>>;
}
