cpython/Python/crossinterp.c at main · python/cpython · GitHub

History

3356 lines (3003 loc) · 91.4 KB

Raw

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

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

767

768

769

770

771

772

773

774

775

776

777

778

779

780

781

782

783

784

785

786

787

788

789

790

791

792

793

794

795

796

797

798

799

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

821

822

823

824

825

826

827

828

829

830

831

832

833

834

835

836

837

838

839

840

841

842

843

844

845

846

847

848

849

850

851

852

853

854

855

856

857

858

859

860

861

862

863

864

865

866

867

868

869

870

871

872

873

874

875

876

877

878

879

880

881

882

883

884

885

886

887

888

889

890

891

892

893

894

895

896

897

898

899

900

901

902

903

904

905

906

907

908

909

910

911

912

913

914

915

916

917

918

919

920

921

922

923

924

925

926

927

928

929

930

931

932

933

934

935

936

937

938

939

940

941

942

943

944

945

946

947

948

949

950

951

952

953

954

955

956

957

958

959

960

961

962

963

964

965

966

967

968

969

970

971

972

973

974

975

976

977

978

979

980

981

982

983

984

985

986

987

988

989

990

991

992

993

994

995

996

997

998

999

1000

/* API for managing interactions between isolated interpreters */

#include "Python.h"

#include "marshal.h" // PyMarshal_WriteObjectToString()

#include "osdefs.h" // MAXPATHLEN

#include "pycore_ceval.h" // _Py_simple_func

#include "pycore_crossinterp.h" // _PyXIData_t

#include "pycore_function.h" // _PyFunction_VerifyStateless()

#include "pycore_global_strings.h" // _Py_ID()

#include "pycore_import.h" // _PyImport_SetModule()

#include "pycore_initconfig.h" // _PyStatus_OK()

#include "pycore_namespace.h" // _PyNamespace_New()

#include "pycore_pythonrun.h" // _Py_SourceAsString()

#include "pycore_runtime.h" // _PyRuntime

#include "pycore_setobject.h" // _PySet_NextEntry()

#include "pycore_typeobject.h" // _PyStaticType_InitBuiltin()

static Py_ssize_t

_Py_GetMainfile(char *buffer, size_t maxlen)

{

// We don't expect subinterpreters to have the __main__ module's

// __name__ set, but proceed just in case.

PyThreadState *tstate = _PyThreadState_GET();

PyObject *module = _Py_GetMainModule(tstate);

if (_Py_CheckMainModule(module) < 0) {

Py_XDECREF(module);

return -1;

}

Py_ssize_t size = _PyModule_GetFilenameUTF8(module, buffer, maxlen);

Py_DECREF(module);

return size;

}

static PyObject *

runpy_run_path(const char *filename, const char *modname)

{

PyObject *run_path = PyImport_ImportModuleAttrString("runpy", "run_path");

if (run_path == NULL) {

return NULL;

}

PyObject *args = Py_BuildValue("(sOs)", filename, Py_None, modname);

if (args == NULL) {

Py_DECREF(run_path);

return NULL;

}

PyObject *ns = PyObject_Call(run_path, args, NULL);

Py_DECREF(run_path);

Py_DECREF(args);

return ns;

}

static void

set_exc_with_cause(PyObject *exctype, const char *msg)

{

PyObject *cause = PyErr_GetRaisedException();

PyErr_SetString(exctype, msg);

PyObject *exc = PyErr_GetRaisedException();

PyException_SetCause(exc, cause);

PyErr_SetRaisedException(exc);

}

/****************************/

/* module duplication utils */

/****************************/

struct sync_module_result {

PyObject *module;

PyObject *loaded;

PyObject *failed;

};

struct sync_module {

const char *filename;

char _filename[MAXPATHLEN+1];

struct sync_module_result cached;

};

static void

sync_module_clear(struct sync_module *data)

{

data->filename = NULL;

Py_CLEAR(data->cached.module);

Py_CLEAR(data->cached.loaded);

Py_CLEAR(data->cached.failed);

}

static void

sync_module_capture_exc(PyThreadState *tstate, struct sync_module *data)

{

assert(_PyErr_Occurred(tstate));

PyObject *context = data->cached.failed;

PyObject *exc = _PyErr_GetRaisedException(tstate);

_PyErr_SetRaisedException(tstate, Py_NewRef(exc));

if (context != NULL) {

PyException_SetContext(exc, context);

}

data->cached.failed = exc;

}

static int

ensure_isolated_main(PyThreadState *tstate, struct sync_module *main)

{

// Load the module from the original file (or from a cache).

// First try the local cache.

if (main->cached.failed != NULL) {

// We'll deal with this in apply_isolated_main().

assert(main->cached.module == NULL);

assert(main->cached.loaded == NULL);

return 0;

}

else if (main->cached.loaded != NULL) {

assert(main->cached.module != NULL);

return 0;

}

assert(main->cached.module == NULL);

if (main->filename == NULL) {

_PyErr_SetString(tstate, PyExc_NotImplementedError, "");

return -1;

}

// It wasn't in the local cache so we'll need to populate it.

PyObject *mod = _Py_GetMainModule(tstate);

if (_Py_CheckMainModule(mod) < 0) {

// This is probably unrecoverable, so don't bother caching the error.

assert(_PyErr_Occurred(tstate));

Py_XDECREF(mod);

return -1;

}

PyObject *loaded = NULL;

// Try the per-interpreter cache for the loaded module.

// XXX Store it in sys.modules?

PyObject *interpns = PyInterpreterState_GetDict(tstate->interp);

assert(interpns != NULL);

PyObject *key = PyUnicode_FromString("CACHED_MODULE_NS___main__");

if (key == NULL) {

// It's probably unrecoverable, so don't bother caching the error.

Py_DECREF(mod);

return -1;

}

else if (PyDict_GetItemRef(interpns, key, &loaded) < 0) {

// It's probably unrecoverable, so don't bother caching the error.

Py_DECREF(mod);

Py_DECREF(key);

return -1;

}

else if (loaded == NULL) {

// It wasn't already loaded from file.

loaded = PyModule_NewObject(&_Py_ID(__main__));

if (loaded == NULL) {

goto error;

}

PyObject *ns = _PyModule_GetDict(loaded);

// We don't want to trigger "if __name__ == '__main__':",

// so we use a bogus module name.

PyObject *loaded_ns =

runpy_run_path(main->filename, "<fake __main__>");

if (loaded_ns == NULL) {

goto error;

}

int res = PyDict_Update(ns, loaded_ns);

Py_DECREF(loaded_ns);

if (res < 0) {

goto error;

}

// Set the per-interpreter cache entry.

if (PyDict_SetItem(interpns, key, loaded) < 0) {

goto error;

}

Py_DECREF(key);

main->cached = (struct sync_module_result){

.module = mod,

.loaded = loaded,

};

return 0;

error:

sync_module_capture_exc(tstate, main);

Py_XDECREF(loaded);

Py_DECREF(mod);

Py_XDECREF(key);

return -1;

}

#ifndef NDEBUG

static int

main_mod_matches(PyObject *expected)

{

PyObject *mod = PyImport_GetModule(&_Py_ID(__main__));

Py_XDECREF(mod);

return mod == expected;

}

#endif

static int

apply_isolated_main(PyThreadState *tstate, struct sync_module *main)

{

assert((main->cached.loaded == NULL) == (main->cached.loaded == NULL));

if (main->cached.failed != NULL) {

// It must have failed previously.

assert(main->cached.loaded == NULL);

_PyErr_SetRaisedException(tstate, main->cached.failed);

return -1;

}

assert(main->cached.loaded != NULL);

assert(main_mod_matches(main->cached.module));

if (_PyImport_SetModule(&_Py_ID(__main__), main->cached.loaded) < 0) {

sync_module_capture_exc(tstate, main);

return -1;

}

return 0;

}

static void

restore_main(PyThreadState *tstate, struct sync_module *main)

{

assert(main->cached.failed == NULL);

assert(main->cached.module != NULL);

assert(main->cached.loaded != NULL);

PyObject *exc = _PyErr_GetRaisedException(tstate);

assert(main_mod_matches(main->cached.loaded));

int res = _PyImport_SetModule(&_Py_ID(__main__), main->cached.module);

assert(res == 0);

if (res < 0) {

PyErr_FormatUnraisable("Exception ignored while restoring __main__");

}

_PyErr_SetRaisedException(tstate, exc);

}

/**************/

/* exceptions */

/**************/

typedef struct xi_exceptions exceptions_t;

static int init_static_exctypes(exceptions_t *, PyInterpreterState *);

static void fini_static_exctypes(exceptions_t *, PyInterpreterState *);

static int init_heap_exctypes(exceptions_t *);

static void fini_heap_exctypes(exceptions_t *);

#include "crossinterp_exceptions.h"

/***************************/

/* cross-interpreter calls */

/***************************/

int

_Py_CallInInterpreter(PyInterpreterState *interp,

_Py_simple_func func, void *arg)

{

if (interp == PyInterpreterState_Get()) {

return func(arg);

}

// XXX Emit a warning if this fails?

_PyEval_AddPendingCall(interp, (_Py_pending_call_func)func, arg, 0);

return 0;

}

int

_Py_CallInInterpreterAndRawFree(PyInterpreterState *interp,

_Py_simple_func func, void *arg)

{

if (interp == PyInterpreterState_Get()) {

int res = func(arg);

PyMem_RawFree(arg);

return res;

}

// XXX Emit a warning if this fails?

_PyEval_AddPendingCall(interp, func, arg, _Py_PENDING_RAWFREE);

return 0;

}

/**************************/

/* cross-interpreter data */

/**************************/

/* registry of {type -> _PyXIData_getdata_t} */

/* For now we use a global registry of shareable classes.

An alternative would be to add a tp_* slot for a class's

_PyXIData_getdata_t. It would be simpler and more efficient. */

static void xid_lookup_init(_PyXIData_lookup_t *);

static void xid_lookup_fini(_PyXIData_lookup_t *);

struct _dlcontext;

static _PyXIData_getdata_t lookup_getdata(struct _dlcontext *, PyObject *);

#include "crossinterp_data_lookup.h"

/* lifecycle */

_PyXIData_t *

_PyXIData_New(void)

{

_PyXIData_t *xid = PyMem_RawCalloc(1, sizeof(_PyXIData_t));

if (xid == NULL) {

PyErr_NoMemory();

}

return xid;

}

void

_PyXIData_Free(_PyXIData_t *xid)

{

PyInterpreterState *interp = PyInterpreterState_Get();

_PyXIData_Clear(interp, xid);

PyMem_RawFree(xid);

}

/* defining cross-interpreter data */

static inline void

_xidata_init(_PyXIData_t *xidata)

{

// If the value is being reused

// then _xidata_clear() should have been called already.

assert(xidata->data == NULL);

assert(xidata->obj == NULL);

*xidata = (_PyXIData_t){0};

_PyXIData_INTERPID(xidata) = -1;

}

static inline void

_xidata_clear(_PyXIData_t *xidata)

{

// _PyXIData_t only has two members that need to be

// cleaned up, if set: "xidata" must be freed and "obj" must be decref'ed.

// In both cases the original (owning) interpreter must be used,

// which is the caller's responsibility to ensure.

if (xidata->data != NULL) {

if (xidata->free != NULL) {

xidata->free(xidata->data);

}

xidata->data = NULL;

}

Py_CLEAR(xidata->obj);

}

void

_PyXIData_Init(_PyXIData_t *xidata,

PyInterpreterState *interp,

void *shared, PyObject *obj,

xid_newobjfunc new_object)

{

assert(xidata != NULL);

assert(new_object != NULL);

_xidata_init(xidata);

xidata->data = shared;

if (obj != NULL) {

assert(interp != NULL);

// released in _PyXIData_Clear()

xidata->obj = Py_NewRef(obj);

}

// Ideally every object would know its owning interpreter.

// Until then, we have to rely on the caller to identify it

// (but we don't need it in all cases).

_PyXIData_INTERPID(xidata) = (interp != NULL)

? PyInterpreterState_GetID(interp)

: -1;

xidata->new_object = new_object;

}

int

_PyXIData_InitWithSize(_PyXIData_t *xidata,

PyInterpreterState *interp,

const size_t size, PyObject *obj,

xid_newobjfunc new_object)

{

assert(size > 0);

// For now we always free the shared data in the same interpreter

// where it was allocated, so the interpreter is required.

assert(interp != NULL);

_PyXIData_Init(xidata, interp, NULL, obj, new_object);

xidata->data = PyMem_RawCalloc(1, size);

if (xidata->data == NULL) {

return -1;

}

xidata->free = PyMem_RawFree;

return 0;

}

void

_PyXIData_Clear(PyInterpreterState *interp, _PyXIData_t *xidata)

{

assert(xidata != NULL);

// This must be called in the owning interpreter.

assert(interp == NULL

|| _PyXIData_INTERPID(xidata) == -1

|| _PyXIData_INTERPID(xidata) == PyInterpreterState_GetID(interp));

_xidata_clear(xidata);

}

/* getting cross-interpreter data */

static inline void

_set_xid_lookup_failure(PyThreadState *tstate, PyObject *obj, const char *msg,

PyObject *cause)

{

if (msg != NULL) {

assert(obj == NULL);

set_notshareableerror(tstate, cause, 0, msg);

}

else if (obj == NULL) {

msg = "object does not support cross-interpreter data";

set_notshareableerror(tstate, cause, 0, msg);

}

else {

msg = "%R does not support cross-interpreter data";

format_notshareableerror(tstate, cause, 0, msg, obj);

}

int

_PyObject_CheckXIData(PyThreadState *tstate, PyObject *obj)

{

dlcontext_t ctx;

if (get_lookup_context(tstate, &ctx) < 0) {

return -1;

}

_PyXIData_getdata_t getdata = lookup_getdata(&ctx, obj);

if (getdata.basic == NULL && getdata.fallback == NULL) {

if (!_PyErr_Occurred(tstate)) {

_set_xid_lookup_failure(tstate, obj, NULL, NULL);

}

return -1;

}

return 0;

}

static int

_check_xidata(PyThreadState *tstate, _PyXIData_t *xidata)

{

// xidata->data can be anything, including NULL, so we don't check it.

// xidata->obj may be NULL, so we don't check it.

if (_PyXIData_INTERPID(xidata) < 0) {

PyErr_SetString(PyExc_SystemError, "missing interp");

return -1;

}

if (xidata->new_object == NULL) {

PyErr_SetString(PyExc_SystemError, "missing new_object func");

return -1;

}

// xidata->free may be NULL, so we don't check it.

return 0;

}

static int

_get_xidata(PyThreadState *tstate,

PyObject *obj, xidata_fallback_t fallback, _PyXIData_t *xidata)

{

PyInterpreterState *interp = tstate->interp;

assert(xidata->data == NULL);

assert(xidata->obj == NULL);

if (xidata->data != NULL || xidata->obj != NULL) {

_PyErr_SetString(tstate, PyExc_ValueError, "xidata not cleared");

return -1;

}

// Call the "getdata" func for the object.

dlcontext_t ctx;

if (get_lookup_context(tstate, &ctx) < 0) {

return -1;

}

Py_INCREF(obj);

_PyXIData_getdata_t getdata = lookup_getdata(&ctx, obj);

if (getdata.basic == NULL && getdata.fallback == NULL) {

if (PyErr_Occurred()) {

Py_DECREF(obj);

return -1;

}

// Fall back to obj

Py_DECREF(obj);

if (!_PyErr_Occurred(tstate)) {

_set_xid_lookup_failure(tstate, obj, NULL, NULL);

}

return -1;

}

int res = getdata.basic != NULL

? getdata.basic(tstate, obj, xidata)

: getdata.fallback(tstate, obj, fallback, xidata);

Py_DECREF(obj);

if (res != 0) {

PyObject *cause = _PyErr_GetRaisedException(tstate);

assert(cause != NULL);

_set_xid_lookup_failure(tstate, obj, NULL, cause);

Py_XDECREF(cause);

return -1;

}

// Fill in the blanks and validate the result.

_PyXIData_INTERPID(xidata) = PyInterpreterState_GetID(interp);

if (_check_xidata(tstate, xidata) != 0) {

(void)_PyXIData_Release(xidata);

return -1;

}

return 0;

}

int

_PyObject_GetXIDataNoFallback(PyThreadState *tstate,

PyObject *obj, _PyXIData_t *xidata)

{

return _get_xidata(tstate, obj, _PyXIDATA_XIDATA_ONLY, xidata);

}

int

_PyObject_GetXIData(PyThreadState *tstate,

PyObject *obj, xidata_fallback_t fallback,

_PyXIData_t *xidata)

{

switch (fallback) {

case _PyXIDATA_XIDATA_ONLY:

return _get_xidata(tstate, obj, fallback, xidata);

case _PyXIDATA_FULL_FALLBACK:

if (_get_xidata(tstate, obj, fallback, xidata) == 0) {

return 0;

}

PyObject *exc = _PyErr_GetRaisedException(tstate);

if (PyFunction_Check(obj)) {

if (_PyFunction_GetXIData(tstate, obj, xidata) == 0) {

Py_DECREF(exc);

return 0;

}

_PyErr_Clear(tstate);

}

// We could try _PyMarshal_GetXIData() but we won't for now.

if (_PyPickle_GetXIData(tstate, obj, xidata) == 0) {

Py_DECREF(exc);

return 0;

}

// Raise the original exception.

_PyErr_SetRaisedException(tstate, exc);

return -1;

default:

#ifdef Py_DEBUG

Py_FatalError("unsupported xidata fallback option");

#endif

_PyErr_SetString(tstate, PyExc_SystemError,

"unsupported xidata fallback option");

return -1;

}

/* pickle C-API */

/* Per-interpreter cache for pickle.dumps and pickle.loads.

* Each interpreter has its own cache in _PyXI_state_t.pickle, preserving

* interpreter isolation. The cache is populated lazily on first use and

* cleared during interpreter finalization in _Py_xi_state_fini().

* Note: the cached references are captured at first use and not invalidated

* on module reload. This matches the caching pattern used elsewhere in

* CPython (e.g. arraymodule.c, _decimal.c). */

static PyObject *

_get_pickle_dumps(PyThreadState *tstate)

{

_PyXI_state_t *state = _PyXI_GET_STATE(tstate->interp);

PyObject *dumps = state->pickle.dumps;

if (dumps != NULL) {

return dumps;

}

dumps = PyImport_ImportModuleAttrString("pickle", "dumps");

if (dumps == NULL) {

return NULL;

}

state->pickle.dumps = dumps; // owns the reference

return dumps;

}

static PyObject *

_get_pickle_loads(PyThreadState *tstate)

{

_PyXI_state_t *state = _PyXI_GET_STATE(tstate->interp);

PyObject *loads = state->pickle.loads;

if (loads != NULL) {

return loads;

}

loads = PyImport_ImportModuleAttrString("pickle", "loads");

if (loads == NULL) {

return NULL;

}

state->pickle.loads = loads; // owns the reference

return loads;

}

struct _pickle_context {

PyThreadState *tstate;

};

static PyObject *

_PyPickle_Dumps(struct _pickle_context *ctx, PyObject *obj)

{

PyObject *dumps = _get_pickle_dumps(ctx->tstate);

if (dumps == NULL) {

return NULL;

}

// dumps is a borrowed reference from the cache.

return PyObject_CallOneArg(dumps, obj);

}

struct _unpickle_context {

PyThreadState *tstate;

// We only special-case the __main__ module,

// since other modules behave consistently.

struct sync_module main;

};

static void

_unpickle_context_clear(struct _unpickle_context *ctx)

{

sync_module_clear(&ctx->main);

}

static int

check_missing___main___attr(PyObject *exc)

{

assert(!PyErr_Occurred());

if (!PyErr_GivenExceptionMatches(exc, PyExc_AttributeError)) {

return 0;

}

// Get the error message.

PyObject *args = PyException_GetArgs(exc);

if (args == NULL || args == Py_None || PyObject_Size(args) < 1) {

Py_XDECREF(args);

assert(!PyErr_Occurred());

return 0;

}

PyObject *msgobj = args;

if (!PyUnicode_Check(msgobj)) {

msgobj = PySequence_GetItem(args, 0);

Py_DECREF(args);

if (msgobj == NULL) {

PyErr_Clear();

return 0;

}

const char *err = PyUnicode_AsUTF8(msgobj);

// Check if it's a missing __main__ attr.

int cmp = strncmp(err, "module '__main__' has no attribute '", 36);

Py_DECREF(msgobj);

return cmp == 0;

}

static PyObject *

_PyPickle_Loads(struct _unpickle_context *ctx, PyObject *pickled)

{

PyThreadState *tstate = ctx->tstate;

PyObject *exc = NULL;

// loads is a borrowed reference from the per-interpreter cache.

PyObject *loads = _get_pickle_loads(tstate);

if (loads == NULL) {

return NULL;

}

// Make an initial attempt to unpickle.

PyObject *obj = PyObject_CallOneArg(loads, pickled);

if (obj != NULL) {

goto finally;

}

assert(_PyErr_Occurred(tstate));

if (ctx == NULL) {

goto finally;

}

exc = _PyErr_GetRaisedException(tstate);

if (!check_missing___main___attr(exc)) {

goto finally;

}

// Temporarily swap in a fake __main__ loaded from the original

// file and cached. Note that functions will use the cached ns

// for __globals__, // not the actual module.

if (ensure_isolated_main(tstate, &ctx->main) < 0) {

goto finally;

}

if (apply_isolated_main(tstate, &ctx->main) < 0) {

goto finally;

}

// Try to unpickle once more.

obj = PyObject_CallOneArg(loads, pickled);

restore_main(tstate, &ctx->main);

if (obj == NULL) {

goto finally;

}

Py_CLEAR(exc);

finally:

if (exc != NULL) {

if (_PyErr_Occurred(tstate)) {

sync_module_capture_exc(tstate, &ctx->main);

}

// We restore the original exception.

// It might make sense to chain it (__context__).

_PyErr_SetRaisedException(tstate, exc);

}

return obj;

}

/* pickle wrapper */

struct _pickle_xid_context {

// __main__.__file__

struct {

const char *utf8;

size_t len;

char _utf8[MAXPATHLEN+1];

} mainfile;

};

static int

_set_pickle_xid_context(PyThreadState *tstate, struct _pickle_xid_context *ctx)

{

// Set mainfile if possible.

Py_ssize_t len = _Py_GetMainfile(ctx->mainfile._utf8, MAXPATHLEN);

if (len < 0) {

// For now we ignore any exceptions.

PyErr_Clear();

}

else if (len > 0) {

ctx->mainfile.utf8 = ctx->mainfile._utf8;

ctx->mainfile.len = (size_t)len;

}

return 0;

}

struct _shared_pickle_data {

_PyBytes_data_t pickled; // Must be first if we use _PyBytes_FromXIData().

struct _pickle_xid_context ctx;

};

PyObject *

_PyPickle_LoadFromXIData(_PyXIData_t *xidata)

{

PyThreadState *tstate = _PyThreadState_GET();

struct _shared_pickle_data *shared =

(struct _shared_pickle_data *)xidata->data;

// We avoid copying the pickled data by wrapping it in a memoryview.

// The alternative is to get a bytes object using _PyBytes_FromXIData().

PyObject *pickled = PyMemoryView_FromMemory(

(char *)shared->pickled.bytes, shared->pickled.len, PyBUF_READ);

if (pickled == NULL) {

return NULL;

}

// Unpickle the object.

struct _unpickle_context ctx = {

.tstate = tstate,

.main = {

.filename = shared->ctx.mainfile.utf8,

};

PyObject *obj = _PyPickle_Loads(&ctx, pickled);

Py_DECREF(pickled);

_unpickle_context_clear(&ctx);

if (obj == NULL) {

PyObject *cause = _PyErr_GetRaisedException(tstate);

assert(cause != NULL);

_set_xid_lookup_failure(

tstate, NULL, "object could not be unpickled", cause);

Py_DECREF(cause);

}

return obj;

}

int

_PyPickle_GetXIData(PyThreadState *tstate, PyObject *obj, _PyXIData_t *xidata)

{

// Pickle the object.

struct _pickle_context ctx = {

.tstate = tstate,

};

PyObject *bytes = _PyPickle_Dumps(&ctx, obj);

if (bytes == NULL) {

PyObject *cause = _PyErr_GetRaisedException(tstate);

assert(cause != NULL);

_set_xid_lookup_failure(

tstate, NULL, "object could not be pickled", cause);

Py_DECREF(cause);

return -1;

}

// If we had an "unwrapper" mechnanism, we could call

// _PyObject_GetXIData() on the bytes object directly and add

// a simple unwrapper to call pickle.loads() on the bytes.

size_t size = sizeof(struct _shared_pickle_data);

struct _shared_pickle_data *shared =

(struct _shared_pickle_data *)_PyBytes_GetXIDataWrapped(

tstate, bytes, size, _PyPickle_LoadFromXIData, xidata);

Py_DECREF(bytes);

if (shared == NULL) {

return -1;

}

// If it mattered, we could skip getting __main__.__file__

// when "__main__" doesn't show up in the pickle bytes.

if (_set_pickle_xid_context(tstate, &shared->ctx) < 0) {

_xidata_clear(xidata);

return -1;

}

return 0;

}

/* marshal wrapper */

PyObject *

_PyMarshal_ReadObjectFromXIData(_PyXIData_t *xidata)

{

PyThreadState *tstate = _PyThreadState_GET();

_PyBytes_data_t *shared = (_PyBytes_data_t *)xidata->data;

PyObject *obj = PyMarshal_ReadObjectFromString(shared->bytes, shared->len);

if (obj == NULL) {

PyObject *cause = _PyErr_GetRaisedException(tstate);

assert(cause != NULL);

_set_xid_lookup_failure(

tstate, NULL, "object could not be unmarshalled", cause);

Py_DECREF(cause);

return NULL;

}

return obj;

}

int

_PyMarshal_GetXIData(PyThreadState *tstate, PyObject *obj, _PyXIData_t *xidata)

{

PyObject *bytes = PyMarshal_WriteObjectToString(obj, Py_MARSHAL_VERSION);

if (bytes == NULL) {

PyObject *cause = _PyErr_GetRaisedException(tstate);

assert(cause != NULL);

_set_xid_lookup_failure(

tstate, NULL, "object could not be marshalled", cause);

Py_DECREF(cause);

return -1;

}

size_t size = sizeof(_PyBytes_data_t);

_PyBytes_data_t *shared = _PyBytes_GetXIDataWrapped(

tstate, bytes, size, _PyMarshal_ReadObjectFromXIData, xidata);

Py_DECREF(bytes);

if (shared == NULL) {

return -1;

}

return 0;

}

/* script wrapper */

static int

verify_script(PyThreadState *tstate, PyCodeObject *co, int checked, int pure)

{

// Make sure it isn't a closure and (optionally) doesn't use globals.

PyObject *builtins = NULL;

if (pure) {

builtins = _PyEval_GetBuiltins(tstate);

assert(builtins != NULL);

}

if (checked) {

assert(_PyCode_VerifyStateless(tstate, co, NULL, NULL, builtins) == 0);

}

else if (_PyCode_VerifyStateless(tstate, co, NULL, NULL, builtins) < 0) {

return -1;

}

// Make sure it doesn't have args.

if (co->co_argcount > 0

|| co->co_posonlyargcount > 0

|| co->co_kwonlyargcount > 0

|| co->co_flags & (CO_VARARGS | CO_VARKEYWORDS))

{

_PyErr_SetString(tstate, PyExc_ValueError,

"code with args not supported");

return -1;

}

// Make sure it doesn't return anything.

if (!_PyCode_ReturnsOnlyNone(co)) {

_PyErr_SetString(tstate, PyExc_ValueError,

"code that returns a value is not a script");

return -1;

}

return 0;

}

static int

get_script_xidata(PyThreadState *tstate, PyObject *obj, int pure,

_PyXIData_t *xidata)

{

// Get the corresponding code object.

PyObject *code = NULL;

int checked = 0;

if (PyCode_Check(obj)) {

code = obj;

Py_INCREF(code);

}

else if (PyFunction_Check(obj)) {

code = PyFunction_GET_CODE(obj);

assert(code != NULL);

Py_INCREF(code);

if (pure) {

if (_PyFunction_VerifyStateless(tstate, obj) < 0) {

goto error;

}

checked = 1;

}

else {

const char *filename = "<script>";

int optimize = 0;

PyCompilerFlags cf = _PyCompilerFlags_INIT;

cf.cf_flags = PyCF_SOURCE_IS_UTF8;

PyObject *ref = NULL;

const char *script = _Py_SourceAsString(obj, "???", "???", &cf, &ref);

if (script == NULL) {

if (!_PyObject_SupportedAsScript(obj)) {

// We discard the raised exception.

_PyErr_Format(tstate, PyExc_TypeError,

"unsupported script %R", obj);

}

goto error;

}

#ifdef Py_GIL_DISABLED

// Don't immortalize code constants to avoid memory leaks.

((_PyThreadStateImpl *)tstate)->suppress_co_const_immortalization++;

#endif

code = Py_CompileStringExFlags(

script, filename, Py_file_input, &cf, optimize);

#ifdef Py_GIL_DISABLED

((_PyThreadStateImpl *)tstate)->suppress_co_const_immortalization--;

#endif

Py_XDECREF(ref);

if (code == NULL) {

goto error;

}

// Compiled text can't have args or any return statements,

// nor be a closure. It can use globals though.

if (!pure) {

// We don't need to check for globals either.

checked = 1;

}

// Make sure it's actually a script.

if (verify_script(tstate, (PyCodeObject *)code, checked, pure) < 0) {

goto error;

}

// Convert the code object.

int res = _PyCode_GetXIData(tstate, code, xidata);

Py_DECREF(code);

if (res < 0) {

return -1;

}

return 0;

error:

Py_XDECREF(code);

PyObject *cause = _PyErr_GetRaisedException(tstate);

assert(cause != NULL);

_set_xid_lookup_failure(

tstate, NULL, "object not a valid script", cause);

Py_DECREF(cause);

return -1;

}

int

_PyCode_GetScriptXIData(PyThreadState *tstate,

View remainder of file in raw view

cpython/Python/crossinterp.c at main · python/cpython · GitHub

Uh oh!

Uh oh!

cpython/Python/crossinterp.c at main · python/cpython · GitHub

Uh oh!

Uh oh!

Expand file tree

Breadcrumbs

crossinterp.c

Latest commit

History

Breadcrumbs

crossinterp.c

File metadata and controls