libobjc2/selector_table.c at master · vitacy/libobjc2 · GitHub

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

/**

* Handle selector uniquing.

* When building, you may define TYPE_DEPENDENT_DISPATCH to enable message

* sends to depend on their types.

#include <string.h>

#include <stdio.h>

#include <assert.h>

#include <ctype.h>

#include "lock.h"

#include "objc/runtime.h"

#include "method.h"

#include "class.h"

#include "selector.h"

#include "visibility.h"

#ifdef TYPE_DEPENDENT_DISPATCH

# define TDD(x) x

#else

# define TDD(x)

#endif

// Define the pool allocator for selectors. This is a simple bump-the-pointer

// allocator for low-overhead allocation.

#define POOL_NAME selector

#define POOL_TYPE struct objc_selector

#include "pool.h"

/**

* The number of selectors currently registered. When a selector is

* registered, its name field is replaced with its index in the selector_list

* array.

static uint32_t selector_count = 1;

/**

* Size of the buffer.

static size_t table_size;

/**

* Mapping from selector numbers to selector names.

PRIVATE struct sel_type_list **selector_list = NULL;

#ifdef DEBUG_SELECTOR_TABLE

#define DEBUG_LOG(...) fprintf(stderr, __VA_ARGS__)

#else

#define DEBUG_LOG(...)

#endif

// Get the functions for string hashing

#include "string_hash.h"

/**

* Lock protecting the selector table.

mutex_t selector_table_lock;

static inline struct sel_type_list *selLookup_locked(uint32_t idx)

{

if (idx > selector_count)

{

return NULL;

}

return selector_list[idx];

}

static inline struct sel_type_list *selLookup(uint32_t idx)

{

LOCK_FOR_SCOPE(&selector_table_lock);

return selLookup_locked(idx);

}

PRIVATE BOOL isSelRegistered(SEL sel)

{

if ((uintptr_t)sel->name < (uintptr_t)selector_count)

{

return YES;

}

return NO;

}

static const char *sel_getNameNonUnique(SEL sel)

{

const char *name = sel->name;

if (isSelRegistered(sel))

{

struct sel_type_list * list = selLookup_locked(sel->index);

name = (list == NULL) ? NULL : list->value;

}

if (NULL == name)

{

name = "";

}

return name;

}

/**

* Skip anything in a type encoding that is irrelevant to the comparison

* between selectors, including type qualifiers and argframe info.

static const char *skip_irrelevant_type_info(const char *t)

{

switch (*t)

{

default: return t;

case 'r': case 'n': case 'N': case 'o': case 'O': case 'R':

case 'V': case 'A': case '!': case '0'...'9':

return skip_irrelevant_type_info(t+1);

}

static BOOL selector_types_equal(const char *t1, const char *t2)

{

if (t1 == NULL || t2 == NULL) { return t1 == t2; }

while (('\0' != *t1) && ('\0' != *t1))

{

t1 = skip_irrelevant_type_info(t1);

t2 = skip_irrelevant_type_info(t2);

// This is a really ugly hack. For some stupid reason, the people

// designing Objective-C type encodings decided to allow * as a

// shorthand for char*, because strings are 'special'. Unfortunately,

// FSF GCC generates "*" for @encode(BOOL*), while Clang and Apple GCC

// generate "^c" or "^C" (depending on whether BOOL is declared

// unsigned).

// The correct fix is to remove * completely from type encodings, but

// unfortunately my time machine is broken so I can't travel to 1986

// and apply a cluebat to those responsible.

if ((*t1 == '*') && (*t2 != '*'))

{

if (*t2 == '^' && (((*(t2+1) == 'C') || (*(t2+2) == 'c'))))

{

t2++;

}

else

{

return NO;

}

else if ((*t2 == '*') && (*t1 != '*'))

{

if (*t1 == '^' && (((*(t1+1) == 'C') || (*(t1+1) == 'c'))))

{

t1++;

}

else

{

return NO;

}

else if (*t1 != *t2)

{

return NO;

}

if ('\0' != *t1) { t1++; }

if ('\0' != *t2) { t2++; }

}

return YES;

}

#ifdef TYPE_DEPENDENT_DISPATCH

static BOOL selector_types_equivalent(const char *t1, const char *t2)

{

// We always treat untyped selectors as having the same type as typed

// selectors, for dispatch purposes.

if (t1 == NULL || t2 == NULL) { return YES; }

return selector_types_equal(t1, t2);

}

#endif

/**

* Compare whether two selectors are identical.

static int selector_identical(const void *k,

const SEL value)

{

SEL key = (SEL)k;

DEBUG_LOG("Comparing %s %s, %s %s\n", sel_getNameNonUnique(key), sel_getNameNonUnique(value), sel_getType_np(key), sel_getType_np(value));

return string_compare(sel_getNameNonUnique(key), sel_getNameNonUnique(value)) &&

selector_types_equal(sel_getType_np(key), sel_getType_np(value));

}

/**

* Compare selectors based on whether they are treated as equivalent for the

* purpose of dispatch.

static int selector_equal(const void *k,

const SEL value)

{

#ifdef TYPE_DEPENDENT_DISPATCH

return selector_identical(k, value);

#else

SEL key = (SEL)k;

return string_compare(sel_getNameNonUnique(key), sel_getNameNonUnique(value));

#endif

}

/**

* Hash a selector.

static inline uint32_t hash_selector(const void *s)

{

SEL sel = (SEL)s;

uint32_t hash = 5381;

const char *str = sel_getNameNonUnique(sel);

uint32_t c;

while((c = (uint32_t)*str++))

{

hash = hash * 33 + c;

}

#ifdef TYPE_DEPENDENT_DISPATCH

// We can't use all of the values in the type encoding for the hash,

// because our equality test is a bit more complex than simple string

// encoding (for example, * and ^C have to be considered equivalent, since

// they are both used as encodings for C strings in different situations)

if ((str = sel_getType_np(sel)))

{

while((c = (uint32_t)*str++))

{

switch (c)

{

case '@': case 'i': case 'I': case 'l': case 'L':

case 'q': case 'Q': case 's': case 'S':

hash = hash * 33 + c;

}

#endif

return hash;

}

#define MAP_TABLE_NAME selector

#define MAP_TABLE_SINGLE_THREAD

#define MAP_TABLE_COMPARE_FUNCTION selector_identical

#define MAP_TABLE_HASH_KEY hash_selector

#define MAP_TABLE_HASH_VALUE hash_selector

#include "hash_table.h"

/**

* Table of registered selector. Maps from selector to selector.

static selector_table *sel_table;

static int selector_name_copies;

PRIVATE void log_selector_memory_usage(void)

{

fprintf(stderr, "%lu bytes in selector name list.\n", (unsigned long)(table_size * sizeof(void*)));

fprintf(stderr, "%d bytes in selector names.\n", selector_name_copies);

fprintf(stderr, "%d bytes (%d entries) in selector hash table.\n", (int)(sel_table->table_size *

sizeof(struct selector_table_cell_struct)), sel_table->table_size);

fprintf(stderr, "%d selectors registered.\n", selector_count);

fprintf(stderr, "%d hash table cells per selector (%.2f%% full)\n", sel_table->table_size / selector_count, ((float)selector_count) / sel_table->table_size * 100);

}

/**

* Resizes the dtables to ensure that they can store as many selectors as

* exist.

void objc_resize_dtables(uint32_t);

/**

* Create data structures to store selectors.

PRIVATE void init_selector_tables()

{

selector_list = calloc(sizeof(void*), 4096);

table_size = 4096;

INIT_LOCK(selector_table_lock);

selector_initialize(&sel_table, 4096);

}

static SEL selector_lookup(const char *name, const char *types)

{

struct objc_selector sel = {{name}, types};

LOCK_FOR_SCOPE(&selector_table_lock);

return selector_table_get(sel_table, &sel);

}

static inline void add_selector_to_table(SEL aSel, int32_t uid, uint32_t idx)

{

DEBUG_LOG("Sel %s uid: %d, idx: %d, hash: %d\n", sel_getNameNonUnique(aSel), uid, idx, hash_selector(aSel));

struct sel_type_list *typeList =

(struct sel_type_list *)selector_pool_alloc();

typeList->value = aSel->name;

typeList->next = 0;

// Store the name.

if (idx >= table_size)

{

table_size *= 2;

struct sel_type_list **newList = calloc(sizeof(struct sel_type_list*), table_size);

if (newList == NULL)

{

abort();

}

memcpy(newList, selector_list, sizeof(void*)*(table_size/2));

free(selector_list);

selector_list = newList;

}

selector_list[idx] = typeList;

// Store the selector.

selector_insert(sel_table, aSel);

// Set the selector's name to the uid.

aSel->name = (const char*)(uintptr_t)uid;

}

/**

* Really registers a selector. Must be called with the selector table locked.

static inline void register_selector_locked(SEL aSel)

{

uintptr_t idx = selector_count++;

if (NULL == aSel->types)

{

DEBUG_LOG("Registering selector %d %s\n", (int)idx, sel_getNameNonUnique(aSel));

add_selector_to_table(aSel, idx, idx);

objc_resize_dtables(selector_count);

return;

}

SEL untyped = selector_lookup(aSel->name, 0);

// If this has a type encoding, store the untyped version too.

if (untyped == NULL)

{

untyped = selector_pool_alloc();

untyped->name = aSel->name;

untyped->types = 0;

DEBUG_LOG("Registering selector %d %s\n", (int)idx, sel_getNameNonUnique(aSel));

add_selector_to_table(untyped, idx, idx);

// If we are in type dependent dispatch mode, the uid for the typed

// and untyped versions will be different

idx++; selector_count++;

}

else

{

// Make sure we only store one name

aSel->name = sel_getNameNonUnique(untyped);

}

uintptr_t uid = (uintptr_t)untyped->name;

TDD(uid = idx);

DEBUG_LOG("Registering typed selector %d %s %s\n", (int)uid, sel_getNameNonUnique(aSel), sel_getType_np(aSel));

add_selector_to_table(aSel, uid, idx);

// Add this set of types to the list.

// This is quite horrible. Most selectors will only have one type

// encoding, so we're wasting a lot of memory like this.

struct sel_type_list *typeListHead = selLookup_locked(untyped->index);

struct sel_type_list *typeList =

(struct sel_type_list *)selector_pool_alloc();

typeList->value = aSel->types;

typeList->next = typeListHead->next;

typeListHead->next = typeList;

objc_resize_dtables(selector_count);

}

/**

* Registers a selector. This assumes that the argument is never deallocated.

PRIVATE SEL objc_register_selector(SEL aSel)

{

if (isSelRegistered(aSel))

{

return aSel;

}

// Check that this isn't already registered, before we try

SEL registered = selector_lookup(aSel->name, aSel->types);

if (NULL != registered && selector_equal(aSel, registered))

{

aSel->name = registered->name;

return registered;

}

assert(!(aSel->types && (strstr(aSel->types, "@\"") != NULL)));

LOCK(&selector_table_lock);

register_selector_locked(aSel);

UNLOCK(&selector_table_lock);

return aSel;

}

/**

* Registers a selector by copying the argument.

static SEL objc_register_selector_copy(SEL aSel, BOOL copyArgs)

{

// If an identical selector is already registered, return it.

SEL copy = selector_lookup(aSel->name, aSel->types);

DEBUG_LOG("Checking if old selector is registered: %d (%d)\n", NULL != copy ? selector_equal(aSel, copy) : 0, ((NULL != copy) && selector_equal(aSel, copy)));

if ((NULL != copy) && selector_identical(aSel, copy))

{

DEBUG_LOG("Not adding new copy\n");

return copy;

}

LOCK_FOR_SCOPE(&selector_table_lock);

copy = selector_lookup(aSel->name, aSel->types);

if (NULL != copy && selector_identical(aSel, copy))

{

return copy;

}

assert(!(aSel->types && (strstr(aSel->types, "@\"") != NULL)));

// Create a copy of this selector.

copy = selector_pool_alloc();

copy->name = aSel->name;

copy->types = (NULL == aSel->types) ? NULL : aSel->types;

if (copyArgs)

{

SEL untyped = selector_lookup(aSel->name, 0);

if (untyped != NULL)

{

copy->name = sel_getName(untyped);

}

else

{

copy->name = strdup(aSel->name);

selector_name_copies += strlen(copy->name);

}

if (copy->types != NULL)

{

copy->types = strdup(copy->types);

selector_name_copies += strlen(copy->types);

}

// Try to register the copy as the authoritative version

register_selector_locked(copy);

return copy;

}

PRIVATE uint32_t sel_nextTypeIndex(uint32_t untypedIdx, uint32_t idx)

{

struct sel_type_list *list = selLookup(untypedIdx);

if (NULL == list) { return 0; }

const char *selName = list->value;

list = list->next;

BOOL found = untypedIdx == idx;

while (NULL != list)

{

SEL sel = selector_lookup(selName, list->value);

if (sel->index == untypedIdx) { return 0; }

if (found)

{

return sel->index;

}

found = (sel->index == idx);

}

return 0;

}

/**

* Public API functions.

const char *sel_getName(SEL sel)

{

if (NULL == sel) { return "<null selector>"; }

const char *name = sel->name;

if (isSelRegistered(sel))

{

struct sel_type_list * list = selLookup(sel->index);

name = (list == NULL) ? NULL : list->value;

}

else

{

SEL old = selector_lookup(sel->name, sel->types);

if (NULL != old)

{

return sel_getName(old);

}

if (NULL == name)

{

name = "";

}

return name;

}

SEL sel_getUid(const char *selName)

{

return sel_registerName(selName);

}

BOOL sel_isEqual(SEL sel1, SEL sel2)

{

if ((0 == sel1) || (0 == sel2))

{

return sel1 == sel2;

}

if (sel1->name == sel2->name)

{

return YES;

}

// Otherwise, do a slow compare

return string_compare(sel_getNameNonUnique(sel1), sel_getNameNonUnique(sel2)) TDD(&&

(sel1->types == NULL || sel2->types == NULL ||

selector_types_equivalent(sel_getType_np(sel1), sel_getType_np(sel2))));

}

SEL sel_registerName(const char *selName)

{

if (NULL == selName) { return NULL; }

struct objc_selector sel = {{selName}, 0};

return objc_register_selector_copy(&sel, YES);

}

SEL sel_registerTypedName_np(const char *selName, const char *types)

{

if (NULL == selName) { return NULL; }

struct objc_selector sel = {{selName}, types};

return objc_register_selector_copy(&sel, YES);

}

const char *sel_getType_np(SEL aSel)

{

if (NULL == aSel) { return NULL; }

return aSel->types;

}

unsigned sel_copyTypes_np(const char *selName, const char **types, unsigned count)

{

if (NULL == selName) { return 0; }

SEL untyped = selector_lookup(selName, 0);

if (untyped == NULL) { return 0; }

struct sel_type_list *l = selLookup(untyped->index);

// Skip the head, which just contains the name, not the types.

l = l->next;

if (count == 0)

{

while (NULL != l)

{

count++;

l = l->next;

}

return count;

}

unsigned found = 0;

while (NULL != l)

{

if (found<count)

{

types[found] = l->value;

}

found++;

l = l->next;

}

return found;

}

unsigned sel_copyTypedSelectors_np(const char *selName, SEL *const sels, unsigned count)

{

if (NULL == selName) { return 0; }

SEL untyped = selector_lookup(selName, 0);

if (untyped == NULL) { return 0; }

struct sel_type_list *l = selLookup(untyped->index);

// Skip the head, which just contains the name, not the types.

l = l->next;

if (count == 0)

{

while (NULL != l)

{

count++;

l = l->next;

}

return count;

}

unsigned found = 0;

while (NULL != l && found<count)

{

sels[found++] = selector_lookup(selName, l->value);

l = l->next;

}

return found;

}

PRIVATE void objc_register_selectors_from_list(struct objc_method_list *l)

{

for (int i=0 ; i<l->count ; i++)

{

Method m = method_at_index(l, i);

struct objc_selector sel = { {(const char*)m->selector}, m->types };

m->selector = objc_register_selector_copy(&sel, NO);

}

/**

* Register all of the (unregistered) selectors that are used in a class.

PRIVATE void objc_register_selectors_from_class(Class class)

{

for (struct objc_method_list *l=class->methods ; NULL!=l ; l=l->next)

{

objc_register_selectors_from_list(l);

}

PRIVATE void objc_register_selector_array(SEL selectors, unsigned long count)

{

// GCC is broken and always sets the count to 0, so we ignore count until

// we can throw stupid and buggy compilers in the bin.

for (unsigned long i=0 ; (NULL != selectors[i].name) ; i++)

{

objc_register_selector(&selectors[i]);

}

/**

* Legacy GNU runtime compatibility.

* All of the functions in this section are deprecated and should not be used

* in new code.

#ifndef NO_LEGACY

SEL sel_get_typed_uid (const char *name, const char *types)

{

if (NULL == name) { return NULL; }

SEL sel = selector_lookup(name, types);

if (NULL == sel) { return sel_registerTypedName_np(name, types); }

struct sel_type_list *l = selLookup(sel->index);

// Skip the head, which just contains the name, not the types.

l = l->next;

if (NULL != l)

{

sel = selector_lookup(name, l->value);

}

return sel;

}

SEL sel_get_any_typed_uid (const char *name)

{

if (NULL == name) { return NULL; }

SEL sel = selector_lookup(name, 0);

if (NULL == sel) { return sel_registerName(name); }

struct sel_type_list *l = selLookup(sel->index);

// Skip the head, which just contains the name, not the types.

l = l->next;

if (NULL != l)

{

sel = selector_lookup(name, l->value);

}

return sel;

}

SEL sel_get_any_uid (const char *name)

{

return selector_lookup(name, 0);

}

SEL sel_get_uid(const char *name)

{

return selector_lookup(name, 0);

}

const char *sel_get_name(SEL selector)

{

return sel_getNameNonUnique(selector);

}

BOOL sel_is_mapped(SEL selector)

{

return isSelRegistered(selector);

}

const char *sel_get_type(SEL selector)

{

return sel_getType_np(selector);

}

SEL sel_register_name(const char *name)

{

return sel_registerName(name);

}

SEL sel_register_typed_name(const char *name, const char *type)

{

return sel_registerTypedName_np(name, type);

}

BOOL sel_eq(SEL s1, SEL s2)

{

return sel_isEqual(s1, s2);

}

#endif // NO_LEGACY

libobjc2/selector_table.c at master · vitacy/libobjc2 · GitHub

Repository navigation

Expand file tree

Breadcrumbs

selector_table.c

Latest commit

History

Breadcrumbs

selector_table.c

File metadata and controls