11debfc3dSmrg /* Shared pool of memory blocks for pool allocators. 2*8feb0f0bSmrg Copyright (C) 2015-2020 Free Software Foundation, Inc. 31debfc3dSmrg 41debfc3dSmrg This file is part of GCC. 51debfc3dSmrg 61debfc3dSmrg GCC is free software; you can redistribute it and/or modify 71debfc3dSmrg it under the terms of the GNU General Public License as published by 81debfc3dSmrg the Free Software Foundation; either version 3, or (at your option) 91debfc3dSmrg any later version. 101debfc3dSmrg 111debfc3dSmrg GCC is distributed in the hope that it will be useful, 121debfc3dSmrg but WITHOUT ANY WARRANTY; without even the implied warranty of 131debfc3dSmrg MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 141debfc3dSmrg GNU General Public License for more details. 151debfc3dSmrg 161debfc3dSmrg You should have received a copy of the GNU General Public License 171debfc3dSmrg along with GCC; see the file COPYING3. If not see 181debfc3dSmrg <http://www.gnu.org/licenses/>. */ 191debfc3dSmrg 201debfc3dSmrg 211debfc3dSmrg #ifndef MEMORY_BLOCK_H 221debfc3dSmrg #define MEMORY_BLOCK_H 231debfc3dSmrg 241debfc3dSmrg /* Shared pool which allows other memory pools to reuse each others' allocated 251debfc3dSmrg memory blocks instead of calling free/malloc again. */ 261debfc3dSmrg class memory_block_pool 271debfc3dSmrg { 281debfc3dSmrg public: 291debfc3dSmrg /* Blocks have fixed size. This is necessary for sharing. */ 301debfc3dSmrg static const size_t block_size = 64 * 1024; 31*8feb0f0bSmrg /* Number of blocks we keep in the freelists. */ 32*8feb0f0bSmrg static const size_t freelist_size = 1024 * 1024 / block_size; 331debfc3dSmrg 341debfc3dSmrg memory_block_pool (); 351debfc3dSmrg 361debfc3dSmrg static inline void *allocate () ATTRIBUTE_MALLOC; 371debfc3dSmrg static inline void release (void *); 38*8feb0f0bSmrg static void trim (int nblocks = freelist_size); 39*8feb0f0bSmrg void reduce_free_list (int); 401debfc3dSmrg 411debfc3dSmrg private: 421debfc3dSmrg /* memory_block_pool singleton instance, defined in memory-block.cc. */ 431debfc3dSmrg static memory_block_pool instance; 441debfc3dSmrg 451debfc3dSmrg struct block_list 461debfc3dSmrg { 471debfc3dSmrg block_list *m_next; 481debfc3dSmrg }; 491debfc3dSmrg 501debfc3dSmrg /* Free list. */ 511debfc3dSmrg block_list *m_blocks; 521debfc3dSmrg }; 531debfc3dSmrg 541debfc3dSmrg /* Allocate a single block. Reuse a previously returned block, if possible. */ 551debfc3dSmrg inline void * allocate()561debfc3dSmrgmemory_block_pool::allocate () 571debfc3dSmrg { 581debfc3dSmrg if (instance.m_blocks == NULL) 591debfc3dSmrg return XNEWVEC (char, block_size); 601debfc3dSmrg 611debfc3dSmrg void *result = instance.m_blocks; 621debfc3dSmrg instance.m_blocks = instance.m_blocks->m_next; 631debfc3dSmrg VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (result, block_size)); 641debfc3dSmrg return result; 651debfc3dSmrg } 661debfc3dSmrg 671debfc3dSmrg /* Return UNCAST_BLOCK to the pool. */ 681debfc3dSmrg inline void release(void * uncast_block)691debfc3dSmrgmemory_block_pool::release (void *uncast_block) 701debfc3dSmrg { 711debfc3dSmrg block_list *block = new (uncast_block) block_list; 721debfc3dSmrg block->m_next = instance.m_blocks; 731debfc3dSmrg instance.m_blocks = block; 74c0a68be4Smrg 75c0a68be4Smrg VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS ((char *)uncast_block 76c0a68be4Smrg + sizeof (block_list), 77c0a68be4Smrg block_size 78c0a68be4Smrg - sizeof (block_list))); 791debfc3dSmrg } 801debfc3dSmrg 811debfc3dSmrg extern void *mempool_obstack_chunk_alloc (size_t) ATTRIBUTE_MALLOC; 821debfc3dSmrg extern void mempool_obstack_chunk_free (void *); 831debfc3dSmrg 841debfc3dSmrg #endif /* MEMORY_BLOCK_H */ 85