gcc/memory-block.cc

   1 /* Shared pool of memory blocks for pool allocators.
   2    Copyright (C) 2015-2017 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "memory-block.h"
  24 #include "obstack.h"
  25
  26 /* Global singleton-like instance.  */
  27 memory_block_pool memory_block_pool::instance;
  28
  29 memory_block_pool::memory_block_pool () : m_blocks (NULL) {}
  30
  31 /* Return all blocks from free list to the OS.  */
  32 void
  33 memory_block_pool::clear_free_list ()
  34 {
  35   while (m_blocks)
  36     {
  37       block_list *next = m_blocks->m_next;
  38       XDELETEVEC (m_blocks);
  39       m_blocks = next;
  40     }
  41 }
  42
  43 /* Allocate a chunk for obstack.  Use the pool if requested chunk size matches
  44    the size of blocks in the pool.  */
  45 void *
  46 mempool_obstack_chunk_alloc (size_t size)
  47 {
  48   if (size == memory_block_pool::block_size)
  49     return memory_block_pool::allocate ();
  50   else
  51     return XNEWVEC (char, size);
  52 }
  53
  54 /* Free previously allocated obstack chunk.  */
  55 void
  56 mempool_obstack_chunk_free (void *chunk)
  57 {
  58   size_t size = (reinterpret_cast<_obstack_chunk *> (chunk)->limit
  59                  - reinterpret_cast<char *> (chunk));
  60   if (size == memory_block_pool::block_size)
  61     memory_block_pool::release (chunk);
  62   else
  63     XDELETEVEC (chunk);
  64 }