Line data    Source code

       1             : // Copyright (c) 2009-2010 Satoshi Nakamoto
       2             : // Copyright (c) 2009-2018 The Bitcoin Core developers
       3             : // Distributed under the MIT software license, see the accompanying
       4             : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
       5             : 
       6             : #ifndef BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H
       7             : #define BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H
       8             : 
       9             : #include <support/cleanse.h>
      10             : 
      11             : #include <memory>
      12             : #include <vector>
      13             : 
      14             : template <typename T>
      15             : struct zero_after_free_allocator : public std::allocator<T> {
      16             :     // MSVC8 default copy constructor is broken
      17             :     typedef std::allocator<T> base;
      18             :     typedef typename base::size_type size_type;
      19             :     typedef typename base::difference_type difference_type;
      20             :     typedef typename base::pointer pointer;
      21             :     typedef typename base::const_pointer const_pointer;
      22             :     typedef typename base::reference reference;
      23             :     typedef typename base::const_reference const_reference;
      24             :     typedef typename base::value_type value_type;
      25     7716209 :     zero_after_free_allocator() noexcept {}
      26      175137 :     zero_after_free_allocator(const zero_after_free_allocator& a) noexcept : base(a) {}
      27             :     template <typename U>
      28             :     zero_after_free_allocator(const zero_after_free_allocator<U>& a) noexcept : base(a)
      29             :     {
      30             :     }
      31     7891347 :     ~zero_after_free_allocator() noexcept {}
      32             :     template <typename _Other>
      33             :     struct rebind {
      34             :         typedef zero_after_free_allocator<_Other> other;
      35             :     };
      36             : 
      37     9936510 :     void deallocate(T* p, std::size_t n)
      38             :     {
      39     9936510 :         if (p != nullptr)
      40     9936510 :             memory_cleanse(p, sizeof(T) * n);
      41     9936508 :         std::allocator<T>::deallocate(p, n);
      42     9936508 :     }
      43             : };
      44             : 
      45             : // Byte-vector that clears its contents before deletion.
      46             : typedef std::vector<char, zero_after_free_allocator<char> > CSerializeData;
      47             : 
      48             : #endif // BITCOIN_SUPPORT_ALLOCATORS_ZEROAFTERFREE_H