1  /* Copyright (C) 2011-2023 Free Software Foundation, Inc.
       2     Contributed by Torvald Riegel <triegel@redhat.com>.
       3  
       4     This file is part of the GNU Transactional Memory Library (libitm).
       5  
       6     Libitm is free software; you can redistribute it and/or modify it
       7     under the terms of the GNU General Public License as published by
       8     the Free Software Foundation; either version 3 of the License, or
       9     (at your option) any later version.
      10  
      11     Libitm is distributed in the hope that it will be useful, but WITHOUT ANY
      12     WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
      13     FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
      14     more details.
      15  
      16     Under Section 7 of GPL version 3, you are granted additional
      17     permissions described in the GCC Runtime Library Exception, version
      18     3.1, as published by the Free Software Foundation.
      19  
      20     You should have received a copy of the GNU General Public License and
      21     a copy of the GCC Runtime Library Exception along with this program;
      22     see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23     <http://www.gnu.org/licenses/>.  */
      24  
      25  #ifndef LIBITM_CONTAINERS_H
      26  #define LIBITM_CONTAINERS_H 1
      27  
      28  #include "common.h"
      29  
      30  namespace GTM HIDDEN {
      31  
      32  // A simple vector-like container.
      33  // If alloc_seperate_cl is true, allocations will happen on separate cache
      34  // lines.
      35  template <typename T, bool alloc_separate_cl = true>
      36  class vector
      37  {
      38   private:
      39    size_t m_capacity;
      40    size_t m_size;
      41    T* entries;
      42  
      43    // Initial capacity of the vector.
      44    static const size_t default_initial_capacity = 32;
      45    // Above that capacity, grow vector by that size for each call.
      46    static const size_t default_resize_max = 2048;
      47    // Resize vector to at least this capacity.
      48    static const size_t default_resize_min = 32;
      49  
      50    // Don't try to copy this vector.
      51    vector<T, alloc_separate_cl>(const vector<T, alloc_separate_cl>& x);
      52  
      53   public:
      54    typedef T datatype;
      55    typedef T* iterator;
      56  
      57    iterator begin() const { return entries; }
      58    iterator end() const { return entries + m_size; }
      59    T& operator[] (size_t pos) { return entries[pos]; }
      60    const T& operator[] (size_t pos) const  { return entries[pos]; }
      61  
      62    vector<T, alloc_separate_cl>(size_t initial_size = default_initial_capacity)
      63      : m_capacity(initial_size),
      64        m_size(0)
      65    {
      66      if (m_capacity > 0)
      67        entries = (T*) xmalloc(sizeof(T) * m_capacity, alloc_separate_cl);
      68      else
      69        entries = 0;
      70    }
      71    ~vector<T, alloc_separate_cl>() { if (m_capacity) free(entries); }
      72  
      73    void resize(size_t additional_capacity)
      74    {
      75      size_t target = m_capacity + additional_capacity;
      76      if (target > default_resize_max)
      77        m_capacity = ((target - 1 + default_resize_max) / default_resize_max)
      78          * default_resize_max;
      79      else
      80        while (m_capacity < target)
      81          m_capacity = m_capacity * 2;
      82      if (m_capacity < default_resize_min)
      83        m_capacity = default_resize_min;
      84      entries = (T*) xrealloc(entries, sizeof(T) * m_capacity, alloc_separate_cl);
      85    }
      86    void resize_noinline() __attribute__((noinline)) { resize(1); }
      87    void resize_noinline(size_t elements) __attribute__((noinline))
      88    {
      89      resize(elements);
      90    }
      91  
      92    size_t size() const { return m_size; }
      93    size_t capacity() const { return this->capacity; }
      94  
      95    void set_size (size_t size) { m_size = size; }
      96    void clear() { m_size = 0; }
      97  
      98    iterator push() {
      99      // We don't want inlining here since push() is often on the fast path.
     100      if (unlikely(m_size == m_capacity)) resize_noinline();
     101      return &entries[m_size++];
     102    }
     103  
     104    iterator push(size_t elements)
     105    {
     106      // We don't want inlining here since push() is often on the fast path.
     107      if (unlikely(m_size + elements > m_capacity)) resize_noinline(elements);
     108      iterator it = &entries[m_size];
     109      m_size += elements;
     110      return it;
     111    }
     112  
     113    iterator pop() {
     114      if (likely(m_size > 0))
     115        {
     116  	m_size--;
     117  	return entries + m_size;
     118        }
     119      else return 0;
     120    }
     121  };
     122  
     123  } // namespace GTM
     124  
     125  #endif // LIBITM_CONTAINERS_H