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#include "collector.h"
00023
00024
#include "value.h"
00025
#include "internal.h"
00026
00027
#include "collector.h"
00028
#include "value.h"
00029
#include "internal.h"
00030
00031
#ifndef MAX
00032
#define MAX(a,b) ((a) > (b) ? (a) : (b))
00033
#endif
00034
00035
namespace KJS {
00036
00037
00038
const int MINIMUM_CELL_SIZE = 56;
00039
const int BLOCK_SIZE = (8 * 4096);
00040
const int SPARE_EMPTY_BLOCKS = 2;
00041
const int MIN_ARRAY_SIZE = 14;
00042
const int GROWTH_FACTOR = 2;
00043
const int LOW_WATER_FACTOR = 4;
00044
const int ALLOCATIONS_PER_COLLECTION = 1000;
00045
00046
00047
const int CELL_ARRAY_LENGTH = (MINIMUM_CELL_SIZE /
sizeof(
double)) + (MINIMUM_CELL_SIZE %
sizeof(
double) != 0 ?
sizeof(
double) : 0);
00048
const int CELL_SIZE = CELL_ARRAY_LENGTH *
sizeof(
double);
00049
const int CELLS_PER_BLOCK = ((BLOCK_SIZE * 8 -
sizeof(
int) * 8 -
sizeof(
void *) * 8) / (CELL_SIZE * 8));
00050
00051
00052
00053
struct CollectorCell {
00054
double memory[CELL_ARRAY_LENGTH];
00055 };
00056
00057
00058
struct CollectorBlock {
00059 CollectorCell cells[CELLS_PER_BLOCK];
00060
int usedCells;
00061 CollectorCell *freeList;
00062 };
00063
00064
struct CollectorHeap {
00065 CollectorBlock **blocks;
00066
int numBlocks;
00067
int usedBlocks;
00068
int firstBlockWithPossibleSpace;
00069
00070 CollectorCell **oversizeCells;
00071
int numOversizeCells;
00072
int usedOversizeCells;
00073
00074
int numLiveObjects;
00075
int numAllocationsSinceLastCollect;
00076 };
00077
00078
static CollectorHeap heap = {NULL, 0, 0, 0, NULL, 0, 0, 0, 0};
00079
00080
bool Collector::memoryFull =
false;
00081
00082 void* Collector::allocate(size_t s)
00083 {
00084
if (s == 0)
00085
return 0L;
00086
00087
00088
if (++heap.numAllocationsSinceLastCollect >= ALLOCATIONS_PER_COLLECTION) {
00089
collect();
00090 }
00091
00092
if (s > (
unsigned)CELL_SIZE) {
00093
00094
if (heap.usedOversizeCells == heap.numOversizeCells) {
00095 heap.numOversizeCells = MAX(MIN_ARRAY_SIZE, heap.numOversizeCells * GROWTH_FACTOR);
00096 heap.oversizeCells = (CollectorCell **)realloc(heap.oversizeCells, heap.numOversizeCells *
sizeof(CollectorCell *));
00097 }
00098
00099
void *newCell = malloc(s);
00100 heap.oversizeCells[heap.usedOversizeCells] = (CollectorCell *)newCell;
00101 heap.usedOversizeCells++;
00102 heap.numLiveObjects++;
00103
00104 ((
ValueImp *)(newCell))->_flags = 0;
00105
return newCell;
00106 }
00107
00108
00109
00110 CollectorBlock *targetBlock = NULL;
00111
00112
int i;
00113
for (i = heap.firstBlockWithPossibleSpace; i < heap.usedBlocks; i++) {
00114
if (heap.blocks[i]->usedCells < CELLS_PER_BLOCK) {
00115 targetBlock = heap.blocks[i];
00116
break;
00117 }
00118 }
00119
00120 heap.firstBlockWithPossibleSpace = i;
00121
00122
if (targetBlock == NULL) {
00123
00124
00125
if (heap.usedBlocks == heap.numBlocks) {
00126 heap.numBlocks = MAX(MIN_ARRAY_SIZE, heap.numBlocks * GROWTH_FACTOR);
00127 heap.blocks = (CollectorBlock **)realloc(heap.blocks, heap.numBlocks *
sizeof(CollectorBlock *));
00128 }
00129
00130 targetBlock = (CollectorBlock *)calloc(1,
sizeof(CollectorBlock));
00131 targetBlock->freeList = targetBlock->cells;
00132 heap.blocks[heap.usedBlocks] = targetBlock;
00133 heap.usedBlocks++;
00134 }
00135
00136
00137 CollectorCell *newCell = targetBlock->freeList;
00138
00139
ValueImp *imp = (
ValueImp*)newCell;
00140
if (imp->
_vd != NULL) {
00141 targetBlock->freeList = (CollectorCell*)(imp->
_vd);
00142 }
else if (targetBlock->usedCells == (CELLS_PER_BLOCK - 1)) {
00143
00144 targetBlock->freeList = NULL;
00145 }
else {
00146
00147 targetBlock->freeList = newCell + 1;
00148 }
00149
00150 targetBlock->usedCells++;
00151 heap.numLiveObjects++;
00152
00153 ((
ValueImp *)(newCell))->_flags = 0;
00154
return (
void *)(newCell);
00155 }
00156
00157 bool Collector::collect()
00158 {
00159
bool deleted =
false;
00160
00161
00162
00163
if (InterpreterImp::s_hook) {
00164 InterpreterImp *scr = InterpreterImp::s_hook;
00165
do {
00166
00167 scr->mark();
00168 scr = scr->next;
00169 }
while (scr != InterpreterImp::s_hook);
00170 }
00171
00172
00173
for (
int block = 0; block < heap.usedBlocks; block++) {
00174
00175
int minimumCellsToProcess = heap.blocks[block]->usedCells;
00176 CollectorBlock *curBlock = heap.blocks[block];
00177
00178
for (
int cell = 0; cell < CELLS_PER_BLOCK; cell++) {
00179
if (minimumCellsToProcess < cell) {
00180
goto skip_block_mark;
00181 }
00182
00183
ValueImp *imp = (
ValueImp *)(curBlock->cells + cell);
00184
00185
if (!(imp->
_flags & ValueImp::VI_DESTRUCTED)) {
00186
00187
if ((imp->
_flags & (ValueImp::VI_CREATED|ValueImp::VI_MARKED)) == ValueImp::VI_CREATED &&
00188 ((imp->
_flags & ValueImp::VI_GCALLOWED) == 0 || imp->
refcount != 0)) {
00189 imp->
mark();
00190 }
00191 }
else {
00192 minimumCellsToProcess++;
00193 }
00194 }
00195 skip_block_mark: ;
00196 }
00197
00198
for (
int cell = 0; cell < heap.usedOversizeCells; cell++) {
00199
ValueImp *imp = (
ValueImp *)heap.oversizeCells[cell];
00200
if ((imp->
_flags & (ValueImp::VI_CREATED|ValueImp::VI_MARKED)) == ValueImp::VI_CREATED &&
00201 ((imp->
_flags & ValueImp::VI_GCALLOWED) == 0 || imp->
refcount != 0)) {
00202 imp->
mark();
00203 }
00204 }
00205
00206
00207
00208
int emptyBlocks = 0;
00209
00210
for (
int block = 0; block < heap.usedBlocks; block++) {
00211 CollectorBlock *curBlock = heap.blocks[block];
00212
00213
int minimumCellsToProcess = curBlock->usedCells;
00214
00215
for (
int cell = 0; cell < CELLS_PER_BLOCK; cell++) {
00216
if (minimumCellsToProcess < cell) {
00217
goto skip_block_sweep;
00218 }
00219
00220
ValueImp *imp = (
ValueImp *)(curBlock->cells + cell);
00221
00222
if (!(imp->
_flags & ValueImp::VI_DESTRUCTED)) {
00223
if (!imp->
refcount && imp->
_flags == (ValueImp::VI_GCALLOWED | ValueImp::VI_CREATED)) {
00224
00225
00226 imp->
~ValueImp();
00227 curBlock->usedCells--;
00228 heap.numLiveObjects--;
00229 deleted =
true;
00230
00231
00232 imp->
_vd = (ValueImpPrivate*)curBlock->freeList;
00233 curBlock->freeList = (CollectorCell *)imp;
00234
00235 }
else {
00236 imp->
_flags &= ~
ValueImp::VI_MARKED;
00237 }
00238 }
else {
00239 minimumCellsToProcess++;
00240 }
00241 }
00242
00243 skip_block_sweep:
00244
00245
if (heap.blocks[block]->usedCells == 0) {
00246 emptyBlocks++;
00247
if (emptyBlocks > SPARE_EMPTY_BLOCKS) {
00248
#ifndef DEBUG_COLLECTOR
00249
free(heap.blocks[block]);
00250
#endif
00251
00252 heap.blocks[block] = heap.blocks[heap.usedBlocks - 1];
00253 heap.usedBlocks--;
00254 block--;
00255
00256
if (heap.numBlocks > MIN_ARRAY_SIZE && heap.usedBlocks < heap.numBlocks / LOW_WATER_FACTOR) {
00257 heap.numBlocks = heap.numBlocks / GROWTH_FACTOR;
00258 heap.blocks = (CollectorBlock **)realloc(heap.blocks, heap.numBlocks *
sizeof(CollectorBlock *));
00259 }
00260 }
00261 }
00262 }
00263
00264
if (deleted) {
00265 heap.firstBlockWithPossibleSpace = 0;
00266 }
00267
00268
int cell = 0;
00269
while (cell < heap.usedOversizeCells) {
00270
ValueImp *imp = (
ValueImp *)heap.oversizeCells[cell];
00271
00272
if (!imp->
refcount &&
00273 imp->
_flags == (ValueImp::VI_GCALLOWED | ValueImp::VI_CREATED)) {
00274
00275 imp->
~ValueImp();
00276
#ifndef DEBUG_COLLECTOR
00277
free((
void *)imp);
00278
#endif
00279
00280
00281 heap.oversizeCells[cell] = heap.oversizeCells[heap.usedOversizeCells - 1];
00282
00283 heap.usedOversizeCells--;
00284 deleted =
true;
00285 heap.numLiveObjects--;
00286
00287
if (heap.numOversizeCells > MIN_ARRAY_SIZE && heap.usedOversizeCells < heap.numOversizeCells / LOW_WATER_FACTOR) {
00288 heap.numOversizeCells = heap.numOversizeCells / GROWTH_FACTOR;
00289 heap.oversizeCells = (CollectorCell **)realloc(heap.oversizeCells, heap.numOversizeCells *
sizeof(CollectorCell *));
00290 }
00291
00292 }
else {
00293 imp->
_flags &= ~
ValueImp::VI_MARKED;
00294 cell++;
00295 }
00296 }
00297
00298 heap.numAllocationsSinceLastCollect = 0;
00299
00300 memoryFull = (heap.numLiveObjects >= KJS_MEM_LIMIT);
00301
00302
return deleted;
00303 }
00304
00305
int Collector::size()
00306 {
00307
return heap.numLiveObjects;
00308 }
00309
00310
#ifdef KJS_DEBUG_MEM
00311
void Collector::finalCheck()
00312 {
00313 }
00314
#endif
00315
00316 }