arena.cpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 1998, 2002, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25#include "adlc.hpp" 26 27void* Chunk::operator new(size_t requested_size, size_t length) { 28 return CHeapObj::operator new(requested_size + length); 29} 30 31void Chunk::operator delete(void* p, size_t length) { 32 CHeapObj::operator delete(p); 33} 34 35Chunk::Chunk(size_t length) { 36 _next = NULL; // Chain on the linked list 37 _len = length; // Save actual size 38} 39 40//------------------------------chop------------------------------------------- 41void Chunk::chop() { 42 Chunk *k = this; 43 while( k ) { 44 Chunk *tmp = k->_next; 45 // clear out this chunk (to detect allocation bugs) 46 memset(k, 0xBAADBABE, k->_len); 47 free(k); // Free chunk (was malloc'd) 48 k = tmp; 49 } 50} 51 52void Chunk::next_chop() { 53 _next->chop(); 54 _next = NULL; 55} 56 57//------------------------------Arena------------------------------------------ 58Arena::Arena( size_t init_size ) { 59 init_size = (init_size+3) & ~3; 60 _first = _chunk = new (init_size) Chunk(init_size); 61 _hwm = _chunk->bottom(); // Save the cached hwm, max 62 _max = _chunk->top(); 63 set_size_in_bytes(init_size); 64} 65 66Arena::Arena() { 67 _first = _chunk = new (Chunk::init_size) Chunk(Chunk::init_size); 68 _hwm = _chunk->bottom(); // Save the cached hwm, max 69 _max = _chunk->top(); 70 set_size_in_bytes(Chunk::init_size); 71} 72 73Arena::Arena( Arena *a ) 74: _chunk(a->_chunk), _hwm(a->_hwm), _max(a->_max), _first(a->_first) { 75 set_size_in_bytes(a->size_in_bytes()); 76} 77 78//------------------------------used------------------------------------------- 79// Total of all Chunks in arena 80size_t Arena::used() const { 81 size_t sum = _chunk->_len - (_max-_hwm); // Size leftover in this Chunk 82 register Chunk *k = _first; 83 while( k != _chunk) { // Whilst have Chunks in a row 84 sum += k->_len; // Total size of this Chunk 85 k = k->_next; // Bump along to next Chunk 86 } 87 return sum; // Return total consumed space. 88} 89 90//------------------------------grow------------------------------------------- 91// Grow a new Chunk 92void* Arena::grow( size_t x ) { 93 // Get minimal required size. Either real big, or even bigger for giant objs 94 size_t len = max(x, Chunk::size); 95 96 register Chunk *k = _chunk; // Get filled-up chunk address 97 _chunk = new (len) Chunk(len); 98 99 if( k ) k->_next = _chunk; // Append new chunk to end of linked list 100 else _first = _chunk; 101 _hwm = _chunk->bottom(); // Save the cached hwm, max 102 _max = _chunk->top(); 103 set_size_in_bytes(size_in_bytes() + len); 104 void* result = _hwm; 105 _hwm += x; 106 return result; 107} 108 109//------------------------------calloc----------------------------------------- 110// Allocate zeroed storage in Arena 111void *Arena::Acalloc( size_t items, size_t x ) { 112 size_t z = items*x; // Total size needed 113 void *ptr = Amalloc(z); // Get space 114 memset( ptr, 0, z ); // Zap space 115 return ptr; // Return space 116} 117 118//------------------------------realloc---------------------------------------- 119// Reallocate storage in Arena. 120void *Arena::Arealloc( void *old_ptr, size_t old_size, size_t new_size ) { 121 char *c_old = (char*)old_ptr; // Handy name 122 // Stupid fast special case 123 if( new_size <= old_size ) { // Shrink in-place 124 if( c_old+old_size == _hwm) // Attempt to free the excess bytes 125 _hwm = c_old+new_size; // Adjust hwm 126 return c_old; 127 } 128 129 // See if we can resize in-place 130 if( (c_old+old_size == _hwm) && // Adjusting recent thing 131 (c_old+new_size <= _max) ) { // Still fits where it sits 132 _hwm = c_old+new_size; // Adjust hwm 133 return c_old; // Return old pointer 134 } 135 136 // Oops, got to relocate guts 137 void *new_ptr = Amalloc(new_size); 138 memcpy( new_ptr, c_old, old_size ); 139 Afree(c_old,old_size); // Mostly done to keep stats accurate 140 return new_ptr; 141} 142 143//------------------------------reset------------------------------------------ 144// Reset this Arena to empty, and return this Arenas guts in a new Arena. 145Arena *Arena::reset(void) { 146 Arena *a = new Arena(this); // New empty arena 147 _first = _chunk = NULL; // Normal, new-arena initialization 148 _hwm = _max = NULL; 149 return a; // Return Arena with guts 150} 151 152//------------------------------contains--------------------------------------- 153// Determine if pointer belongs to this Arena or not. 154bool Arena::contains( const void *ptr ) const { 155 if( (void*)_chunk->bottom() <= ptr && ptr < (void*)_hwm ) 156 return true; // Check for in this chunk 157 for( Chunk *c = _first; c; c = c->_next ) 158 if( (void*)c->bottom() <= ptr && ptr < (void*)c->top()) 159 return true; // Check for every chunk in Arena 160 return false; // Not in any Chunk, so not in Arena 161} 162 163//----------------------------------------------------------------------------- 164// CHeapObj 165 166void* CHeapObj::operator new(size_t size){ 167 return (void *) malloc(size); 168} 169 170void CHeapObj::operator delete(void* p){ 171 free(p); 172} 173