1 files changed, 87 insertions, 0 deletions
diff --git a/contrib/epee/include/mlocker.h b/contrib/epee/include/mlocker.h
new file mode 100644
index 000000000..d2fc2ed58
--- /dev/null
+++ b/contrib/epee/include/mlocker.h
@@ -0,0 +1,87 @@
+// 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,
+// 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.
+
+#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() { mlocker::unlock(this, sizeof(T)); }
+  };
+
+  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>>;
+}