forked from python/cpython
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathpystate.c
1367 lines (1178 loc) · 39.1 KB
/
pystate.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
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
/* Thread and interpreter state structures and their interfaces */
#include "Python.h"
#include "internal/pystate.h"
#define GET_TSTATE() \
((PyThreadState*)_Py_atomic_load_relaxed(&_PyThreadState_Current))
#define SET_TSTATE(value) \
_Py_atomic_store_relaxed(&_PyThreadState_Current, (uintptr_t)(value))
#define GET_INTERP_STATE() \
(GET_TSTATE()->interp)
/* --------------------------------------------------------------------------
CAUTION
Always use PyMem_RawMalloc() and PyMem_RawFree() directly in this file. A
number of these functions are advertised as safe to call when the GIL isn't
held, and in a debug build Python redirects (e.g.) PyMem_NEW (etc) to Python's
debugging obmalloc functions. Those aren't thread-safe (they rely on the GIL
to avoid the expense of doing their own locking).
-------------------------------------------------------------------------- */
#ifdef HAVE_DLOPEN
#ifdef HAVE_DLFCN_H
#include <dlfcn.h>
#endif
#if !HAVE_DECL_RTLD_LAZY
#define RTLD_LAZY 1
#endif
#endif
#ifdef __cplusplus
extern "C" {
#endif
static _PyInitError
_PyRuntimeState_Init_impl(_PyRuntimeState *runtime)
{
memset(runtime, 0, sizeof(*runtime));
_PyGC_Initialize(&runtime->gc);
_PyEval_Initialize(&runtime->ceval);
runtime->gilstate.check_enabled = 1;
/* A TSS key must be initialized with Py_tss_NEEDS_INIT
in accordance with the specification. */
Py_tss_t initial = Py_tss_NEEDS_INIT;
runtime->gilstate.autoTSSkey = initial;
runtime->interpreters.mutex = PyThread_allocate_lock();
if (runtime->interpreters.mutex == NULL) {
return _Py_INIT_ERR("Can't initialize threads for interpreter");
}
runtime->interpreters.next_id = -1;
runtime->xidregistry.mutex = PyThread_allocate_lock();
if (runtime->xidregistry.mutex == NULL) {
return _Py_INIT_ERR("Can't initialize threads for cross-interpreter data registry");
}
return _Py_INIT_OK();
}
_PyInitError
_PyRuntimeState_Init(_PyRuntimeState *runtime)
{
/* Force default allocator, since _PyRuntimeState_Fini() must
use the same allocator than this function. */
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
_PyInitError err = _PyRuntimeState_Init_impl(runtime);
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
return err;
}
void
_PyRuntimeState_Fini(_PyRuntimeState *runtime)
{
/* Force the allocator used by _PyRuntimeState_Init(). */
PyMemAllocatorEx old_alloc;
_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
if (runtime->interpreters.mutex != NULL) {
PyThread_free_lock(runtime->interpreters.mutex);
runtime->interpreters.mutex = NULL;
}
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &old_alloc);
}
#define HEAD_LOCK() PyThread_acquire_lock(_PyRuntime.interpreters.mutex, \
WAIT_LOCK)
#define HEAD_UNLOCK() PyThread_release_lock(_PyRuntime.interpreters.mutex)
static void _PyGILState_NoteThreadState(PyThreadState* tstate);
_PyInitError
_PyInterpreterState_Enable(_PyRuntimeState *runtime)
{
runtime->interpreters.next_id = 0;
/* Since we only call _PyRuntimeState_Init() once per process
(see _PyRuntime_Initialize()), we make sure the mutex is
initialized here. */
if (runtime->interpreters.mutex == NULL) {
runtime->interpreters.mutex = PyThread_allocate_lock();
if (runtime->interpreters.mutex == NULL) {
return _Py_INIT_ERR("Can't initialize threads for interpreter");
}
}
return _Py_INIT_OK();
}
PyInterpreterState *
PyInterpreterState_New(void)
{
PyInterpreterState *interp = (PyInterpreterState *)
PyMem_RawMalloc(sizeof(PyInterpreterState));
if (interp == NULL) {
return NULL;
}
interp->id_refcount = -1;
interp->id_mutex = NULL;
interp->modules = NULL;
interp->modules_by_index = NULL;
interp->sysdict = NULL;
interp->builtins = NULL;
interp->builtins_copy = NULL;
interp->tstate_head = NULL;
interp->check_interval = 100;
interp->num_threads = 0;
interp->pythread_stacksize = 0;
interp->codec_search_path = NULL;
interp->codec_search_cache = NULL;
interp->codec_error_registry = NULL;
interp->codecs_initialized = 0;
interp->fscodec_initialized = 0;
interp->core_config = _PyCoreConfig_INIT;
interp->config = _PyMainInterpreterConfig_INIT;
interp->importlib = NULL;
interp->import_func = NULL;
interp->eval_frame = _PyEval_EvalFrameDefault;
interp->co_extra_user_count = 0;
#ifdef HAVE_DLOPEN
#if HAVE_DECL_RTLD_NOW
interp->dlopenflags = RTLD_NOW;
#else
interp->dlopenflags = RTLD_LAZY;
#endif
#endif
#ifdef HAVE_FORK
interp->before_forkers = NULL;
interp->after_forkers_parent = NULL;
interp->after_forkers_child = NULL;
#endif
interp->pyexitfunc = NULL;
interp->pyexitmodule = NULL;
HEAD_LOCK();
interp->next = _PyRuntime.interpreters.head;
if (_PyRuntime.interpreters.main == NULL) {
_PyRuntime.interpreters.main = interp;
}
_PyRuntime.interpreters.head = interp;
if (_PyRuntime.interpreters.next_id < 0) {
/* overflow or Py_Initialize() not called! */
PyErr_SetString(PyExc_RuntimeError,
"failed to get an interpreter ID");
/* XXX deallocate! */
interp = NULL;
} else {
interp->id = _PyRuntime.interpreters.next_id;
_PyRuntime.interpreters.next_id += 1;
}
HEAD_UNLOCK();
interp->tstate_next_unique_id = 0;
return interp;
}
void
PyInterpreterState_Clear(PyInterpreterState *interp)
{
PyThreadState *p;
HEAD_LOCK();
for (p = interp->tstate_head; p != NULL; p = p->next)
PyThreadState_Clear(p);
HEAD_UNLOCK();
_PyCoreConfig_Clear(&interp->core_config);
_PyMainInterpreterConfig_Clear(&interp->config);
Py_CLEAR(interp->codec_search_path);
Py_CLEAR(interp->codec_search_cache);
Py_CLEAR(interp->codec_error_registry);
Py_CLEAR(interp->modules);
Py_CLEAR(interp->modules_by_index);
Py_CLEAR(interp->sysdict);
Py_CLEAR(interp->builtins);
Py_CLEAR(interp->builtins_copy);
Py_CLEAR(interp->importlib);
Py_CLEAR(interp->import_func);
#ifdef HAVE_FORK
Py_CLEAR(interp->before_forkers);
Py_CLEAR(interp->after_forkers_parent);
Py_CLEAR(interp->after_forkers_child);
#endif
}
static void
zapthreads(PyInterpreterState *interp)
{
PyThreadState *p;
/* No need to lock the mutex here because this should only happen
when the threads are all really dead (XXX famous last words). */
while ((p = interp->tstate_head) != NULL) {
PyThreadState_Delete(p);
}
}
void
PyInterpreterState_Delete(PyInterpreterState *interp)
{
PyInterpreterState **p;
zapthreads(interp);
HEAD_LOCK();
for (p = &_PyRuntime.interpreters.head; ; p = &(*p)->next) {
if (*p == NULL)
Py_FatalError(
"PyInterpreterState_Delete: invalid interp");
if (*p == interp)
break;
}
if (interp->tstate_head != NULL)
Py_FatalError("PyInterpreterState_Delete: remaining threads");
*p = interp->next;
if (_PyRuntime.interpreters.main == interp) {
_PyRuntime.interpreters.main = NULL;
if (_PyRuntime.interpreters.head != NULL)
Py_FatalError("PyInterpreterState_Delete: remaining subinterpreters");
}
HEAD_UNLOCK();
if (interp->id_mutex != NULL) {
PyThread_free_lock(interp->id_mutex);
}
PyMem_RawFree(interp);
}
int64_t
PyInterpreterState_GetID(PyInterpreterState *interp)
{
if (interp == NULL) {
PyErr_SetString(PyExc_RuntimeError, "no interpreter provided");
return -1;
}
return interp->id;
}
PyInterpreterState *
_PyInterpreterState_LookUpID(PY_INT64_T requested_id)
{
if (requested_id < 0)
goto error;
PyInterpreterState *interp = PyInterpreterState_Head();
while (interp != NULL) {
PY_INT64_T id = PyInterpreterState_GetID(interp);
if (id < 0)
return NULL;
if (requested_id == id)
return interp;
interp = PyInterpreterState_Next(interp);
}
error:
PyErr_Format(PyExc_RuntimeError,
"unrecognized interpreter ID %lld", requested_id);
return NULL;
}
int
_PyInterpreterState_IDInitref(PyInterpreterState *interp)
{
if (interp->id_mutex != NULL) {
return 0;
}
interp->id_mutex = PyThread_allocate_lock();
if (interp->id_mutex == NULL) {
PyErr_SetString(PyExc_RuntimeError,
"failed to create init interpreter ID mutex");
return -1;
}
interp->id_refcount = 0;
return 0;
}
void
_PyInterpreterState_IDIncref(PyInterpreterState *interp)
{
if (interp->id_mutex == NULL) {
return;
}
PyThread_acquire_lock(interp->id_mutex, WAIT_LOCK);
interp->id_refcount += 1;
PyThread_release_lock(interp->id_mutex);
}
void
_PyInterpreterState_IDDecref(PyInterpreterState *interp)
{
if (interp->id_mutex == NULL) {
return;
}
PyThread_acquire_lock(interp->id_mutex, WAIT_LOCK);
assert(interp->id_refcount != 0);
interp->id_refcount -= 1;
int64_t refcount = interp->id_refcount;
PyThread_release_lock(interp->id_mutex);
if (refcount == 0) {
// XXX Using the "head" thread isn't strictly correct.
PyThreadState *tstate = PyInterpreterState_ThreadHead(interp);
// XXX Possible GILState issues?
PyThreadState *save_tstate = PyThreadState_Swap(tstate);
Py_EndInterpreter(tstate);
PyThreadState_Swap(save_tstate);
}
}
/* Default implementation for _PyThreadState_GetFrame */
static struct _frame *
threadstate_getframe(PyThreadState *self)
{
return self->frame;
}
static PyThreadState *
new_threadstate(PyInterpreterState *interp, int init)
{
PyThreadState *tstate = (PyThreadState *)PyMem_RawMalloc(sizeof(PyThreadState));
if (_PyThreadState_GetFrame == NULL)
_PyThreadState_GetFrame = threadstate_getframe;
if (tstate != NULL) {
tstate->interp = interp;
tstate->frame = NULL;
tstate->recursion_depth = 0;
tstate->overflowed = 0;
tstate->recursion_critical = 0;
tstate->stackcheck_counter = 0;
tstate->tracing = 0;
tstate->use_tracing = 0;
tstate->gilstate_counter = 0;
tstate->async_exc = NULL;
tstate->thread_id = PyThread_get_thread_ident();
tstate->dict = NULL;
tstate->curexc_type = NULL;
tstate->curexc_value = NULL;
tstate->curexc_traceback = NULL;
tstate->exc_state.exc_type = NULL;
tstate->exc_state.exc_value = NULL;
tstate->exc_state.exc_traceback = NULL;
tstate->exc_state.previous_item = NULL;
tstate->exc_info = &tstate->exc_state;
tstate->c_profilefunc = NULL;
tstate->c_tracefunc = NULL;
tstate->c_profileobj = NULL;
tstate->c_traceobj = NULL;
tstate->trash_delete_nesting = 0;
tstate->trash_delete_later = NULL;
tstate->on_delete = NULL;
tstate->on_delete_data = NULL;
tstate->coroutine_origin_tracking_depth = 0;
tstate->coroutine_wrapper = NULL;
tstate->in_coroutine_wrapper = 0;
tstate->async_gen_firstiter = NULL;
tstate->async_gen_finalizer = NULL;
tstate->context = NULL;
tstate->context_ver = 1;
tstate->id = ++interp->tstate_next_unique_id;
if (init)
_PyThreadState_Init(tstate);
HEAD_LOCK();
tstate->prev = NULL;
tstate->next = interp->tstate_head;
if (tstate->next)
tstate->next->prev = tstate;
interp->tstate_head = tstate;
HEAD_UNLOCK();
}
return tstate;
}
PyThreadState *
PyThreadState_New(PyInterpreterState *interp)
{
return new_threadstate(interp, 1);
}
PyThreadState *
_PyThreadState_Prealloc(PyInterpreterState *interp)
{
return new_threadstate(interp, 0);
}
void
_PyThreadState_Init(PyThreadState *tstate)
{
_PyGILState_NoteThreadState(tstate);
}
PyObject*
PyState_FindModule(struct PyModuleDef* module)
{
Py_ssize_t index = module->m_base.m_index;
PyInterpreterState *state = GET_INTERP_STATE();
PyObject *res;
if (module->m_slots) {
return NULL;
}
if (index == 0)
return NULL;
if (state->modules_by_index == NULL)
return NULL;
if (index >= PyList_GET_SIZE(state->modules_by_index))
return NULL;
res = PyList_GET_ITEM(state->modules_by_index, index);
return res==Py_None ? NULL : res;
}
int
_PyState_AddModule(PyObject* module, struct PyModuleDef* def)
{
PyInterpreterState *state;
if (!def) {
assert(PyErr_Occurred());
return -1;
}
if (def->m_slots) {
PyErr_SetString(PyExc_SystemError,
"PyState_AddModule called on module with slots");
return -1;
}
state = GET_INTERP_STATE();
if (!state->modules_by_index) {
state->modules_by_index = PyList_New(0);
if (!state->modules_by_index)
return -1;
}
while(PyList_GET_SIZE(state->modules_by_index) <= def->m_base.m_index)
if (PyList_Append(state->modules_by_index, Py_None) < 0)
return -1;
Py_INCREF(module);
return PyList_SetItem(state->modules_by_index,
def->m_base.m_index, module);
}
int
PyState_AddModule(PyObject* module, struct PyModuleDef* def)
{
Py_ssize_t index;
PyInterpreterState *state = GET_INTERP_STATE();
if (!def) {
Py_FatalError("PyState_AddModule: Module Definition is NULL");
return -1;
}
index = def->m_base.m_index;
if (state->modules_by_index) {
if(PyList_GET_SIZE(state->modules_by_index) >= index) {
if(module == PyList_GET_ITEM(state->modules_by_index, index)) {
Py_FatalError("PyState_AddModule: Module already added!");
return -1;
}
}
}
return _PyState_AddModule(module, def);
}
int
PyState_RemoveModule(struct PyModuleDef* def)
{
PyInterpreterState *state;
Py_ssize_t index = def->m_base.m_index;
if (def->m_slots) {
PyErr_SetString(PyExc_SystemError,
"PyState_RemoveModule called on module with slots");
return -1;
}
state = GET_INTERP_STATE();
if (index == 0) {
Py_FatalError("PyState_RemoveModule: Module index invalid.");
return -1;
}
if (state->modules_by_index == NULL) {
Py_FatalError("PyState_RemoveModule: Interpreters module-list not acessible.");
return -1;
}
if (index > PyList_GET_SIZE(state->modules_by_index)) {
Py_FatalError("PyState_RemoveModule: Module index out of bounds.");
return -1;
}
return PyList_SetItem(state->modules_by_index, index, Py_None);
}
/* used by import.c:PyImport_Cleanup */
void
_PyState_ClearModules(void)
{
PyInterpreterState *state = GET_INTERP_STATE();
if (state->modules_by_index) {
Py_ssize_t i;
for (i = 0; i < PyList_GET_SIZE(state->modules_by_index); i++) {
PyObject *m = PyList_GET_ITEM(state->modules_by_index, i);
if (PyModule_Check(m)) {
/* cleanup the saved copy of module dicts */
PyModuleDef *md = PyModule_GetDef(m);
if (md)
Py_CLEAR(md->m_base.m_copy);
}
}
/* Setting modules_by_index to NULL could be dangerous, so we
clear the list instead. */
if (PyList_SetSlice(state->modules_by_index,
0, PyList_GET_SIZE(state->modules_by_index),
NULL))
PyErr_WriteUnraisable(state->modules_by_index);
}
}
void
PyThreadState_Clear(PyThreadState *tstate)
{
if (Py_VerboseFlag && tstate->frame != NULL)
fprintf(stderr,
"PyThreadState_Clear: warning: thread still has a frame\n");
Py_CLEAR(tstate->frame);
Py_CLEAR(tstate->dict);
Py_CLEAR(tstate->async_exc);
Py_CLEAR(tstate->curexc_type);
Py_CLEAR(tstate->curexc_value);
Py_CLEAR(tstate->curexc_traceback);
Py_CLEAR(tstate->exc_state.exc_type);
Py_CLEAR(tstate->exc_state.exc_value);
Py_CLEAR(tstate->exc_state.exc_traceback);
/* The stack of exception states should contain just this thread. */
assert(tstate->exc_info->previous_item == NULL);
if (Py_VerboseFlag && tstate->exc_info != &tstate->exc_state) {
fprintf(stderr,
"PyThreadState_Clear: warning: thread still has a generator\n");
}
tstate->c_profilefunc = NULL;
tstate->c_tracefunc = NULL;
Py_CLEAR(tstate->c_profileobj);
Py_CLEAR(tstate->c_traceobj);
Py_CLEAR(tstate->coroutine_wrapper);
Py_CLEAR(tstate->async_gen_firstiter);
Py_CLEAR(tstate->async_gen_finalizer);
Py_CLEAR(tstate->context);
}
/* Common code for PyThreadState_Delete() and PyThreadState_DeleteCurrent() */
static void
tstate_delete_common(PyThreadState *tstate)
{
PyInterpreterState *interp;
if (tstate == NULL)
Py_FatalError("PyThreadState_Delete: NULL tstate");
interp = tstate->interp;
if (interp == NULL)
Py_FatalError("PyThreadState_Delete: NULL interp");
HEAD_LOCK();
if (tstate->prev)
tstate->prev->next = tstate->next;
else
interp->tstate_head = tstate->next;
if (tstate->next)
tstate->next->prev = tstate->prev;
HEAD_UNLOCK();
if (tstate->on_delete != NULL) {
tstate->on_delete(tstate->on_delete_data);
}
PyMem_RawFree(tstate);
}
void
PyThreadState_Delete(PyThreadState *tstate)
{
if (tstate == GET_TSTATE())
Py_FatalError("PyThreadState_Delete: tstate is still current");
if (_PyRuntime.gilstate.autoInterpreterState &&
PyThread_tss_get(&_PyRuntime.gilstate.autoTSSkey) == tstate)
{
PyThread_tss_set(&_PyRuntime.gilstate.autoTSSkey, NULL);
}
tstate_delete_common(tstate);
}
void
PyThreadState_DeleteCurrent()
{
PyThreadState *tstate = GET_TSTATE();
if (tstate == NULL)
Py_FatalError(
"PyThreadState_DeleteCurrent: no current tstate");
tstate_delete_common(tstate);
if (_PyRuntime.gilstate.autoInterpreterState &&
PyThread_tss_get(&_PyRuntime.gilstate.autoTSSkey) == tstate)
{
PyThread_tss_set(&_PyRuntime.gilstate.autoTSSkey, NULL);
}
SET_TSTATE(NULL);
PyEval_ReleaseLock();
}
/*
* Delete all thread states except the one passed as argument.
* Note that, if there is a current thread state, it *must* be the one
* passed as argument. Also, this won't touch any other interpreters
* than the current one, since we don't know which thread state should
* be kept in those other interpreteres.
*/
void
_PyThreadState_DeleteExcept(PyThreadState *tstate)
{
PyInterpreterState *interp = tstate->interp;
PyThreadState *p, *next, *garbage;
HEAD_LOCK();
/* Remove all thread states, except tstate, from the linked list of
thread states. This will allow calling PyThreadState_Clear()
without holding the lock. */
garbage = interp->tstate_head;
if (garbage == tstate)
garbage = tstate->next;
if (tstate->prev)
tstate->prev->next = tstate->next;
if (tstate->next)
tstate->next->prev = tstate->prev;
tstate->prev = tstate->next = NULL;
interp->tstate_head = tstate;
HEAD_UNLOCK();
/* Clear and deallocate all stale thread states. Even if this
executes Python code, we should be safe since it executes
in the current thread, not one of the stale threads. */
for (p = garbage; p; p = next) {
next = p->next;
PyThreadState_Clear(p);
PyMem_RawFree(p);
}
}
PyThreadState *
_PyThreadState_UncheckedGet(void)
{
return GET_TSTATE();
}
PyThreadState *
PyThreadState_Get(void)
{
PyThreadState *tstate = GET_TSTATE();
if (tstate == NULL)
Py_FatalError("PyThreadState_Get: no current thread");
return tstate;
}
PyThreadState *
PyThreadState_Swap(PyThreadState *newts)
{
PyThreadState *oldts = GET_TSTATE();
SET_TSTATE(newts);
/* It should not be possible for more than one thread state
to be used for a thread. Check this the best we can in debug
builds.
*/
#if defined(Py_DEBUG)
if (newts) {
/* This can be called from PyEval_RestoreThread(). Similar
to it, we need to ensure errno doesn't change.
*/
int err = errno;
PyThreadState *check = PyGILState_GetThisThreadState();
if (check && check->interp == newts->interp && check != newts)
Py_FatalError("Invalid thread state for this thread");
errno = err;
}
#endif
return oldts;
}
/* An extension mechanism to store arbitrary additional per-thread state.
PyThreadState_GetDict() returns a dictionary that can be used to hold such
state; the caller should pick a unique key and store its state there. If
PyThreadState_GetDict() returns NULL, an exception has *not* been raised
and the caller should assume no per-thread state is available. */
PyObject *
PyThreadState_GetDict(void)
{
PyThreadState *tstate = GET_TSTATE();
if (tstate == NULL)
return NULL;
if (tstate->dict == NULL) {
PyObject *d;
tstate->dict = d = PyDict_New();
if (d == NULL)
PyErr_Clear();
}
return tstate->dict;
}
/* Asynchronously raise an exception in a thread.
Requested by Just van Rossum and Alex Martelli.
To prevent naive misuse, you must write your own extension
to call this, or use ctypes. Must be called with the GIL held.
Returns the number of tstates modified (normally 1, but 0 if `id` didn't
match any known thread id). Can be called with exc=NULL to clear an
existing async exception. This raises no exceptions. */
int
PyThreadState_SetAsyncExc(unsigned long id, PyObject *exc)
{
PyInterpreterState *interp = GET_INTERP_STATE();
PyThreadState *p;
/* Although the GIL is held, a few C API functions can be called
* without the GIL held, and in particular some that create and
* destroy thread and interpreter states. Those can mutate the
* list of thread states we're traversing, so to prevent that we lock
* head_mutex for the duration.
*/
HEAD_LOCK();
for (p = interp->tstate_head; p != NULL; p = p->next) {
if (p->thread_id == id) {
/* Tricky: we need to decref the current value
* (if any) in p->async_exc, but that can in turn
* allow arbitrary Python code to run, including
* perhaps calls to this function. To prevent
* deadlock, we need to release head_mutex before
* the decref.
*/
PyObject *old_exc = p->async_exc;
Py_XINCREF(exc);
p->async_exc = exc;
HEAD_UNLOCK();
Py_XDECREF(old_exc);
_PyEval_SignalAsyncExc();
return 1;
}
}
HEAD_UNLOCK();
return 0;
}
/* Routines for advanced debuggers, requested by David Beazley.
Don't use unless you know what you are doing! */
PyInterpreterState *
PyInterpreterState_Head(void)
{
return _PyRuntime.interpreters.head;
}
PyInterpreterState *
PyInterpreterState_Main(void)
{
return _PyRuntime.interpreters.main;
}
PyInterpreterState *
PyInterpreterState_Next(PyInterpreterState *interp) {
return interp->next;
}
PyThreadState *
PyInterpreterState_ThreadHead(PyInterpreterState *interp) {
return interp->tstate_head;
}
PyThreadState *
PyThreadState_Next(PyThreadState *tstate) {
return tstate->next;
}
/* The implementation of sys._current_frames(). This is intended to be
called with the GIL held, as it will be when called via
sys._current_frames(). It's possible it would work fine even without
the GIL held, but haven't thought enough about that.
*/
PyObject *
_PyThread_CurrentFrames(void)
{
PyObject *result;
PyInterpreterState *i;
result = PyDict_New();
if (result == NULL)
return NULL;
/* for i in all interpreters:
* for t in all of i's thread states:
* if t's frame isn't NULL, map t's id to its frame
* Because these lists can mutate even when the GIL is held, we
* need to grab head_mutex for the duration.
*/
HEAD_LOCK();
for (i = _PyRuntime.interpreters.head; i != NULL; i = i->next) {
PyThreadState *t;
for (t = i->tstate_head; t != NULL; t = t->next) {
PyObject *id;
int stat;
struct _frame *frame = t->frame;
if (frame == NULL)
continue;
id = PyLong_FromUnsignedLong(t->thread_id);
if (id == NULL)
goto Fail;
stat = PyDict_SetItem(result, id, (PyObject *)frame);
Py_DECREF(id);
if (stat < 0)
goto Fail;
}
}
HEAD_UNLOCK();
return result;
Fail:
HEAD_UNLOCK();
Py_DECREF(result);
return NULL;
}
/* Python "auto thread state" API. */
/* Keep this as a static, as it is not reliable! It can only
ever be compared to the state for the *current* thread.
* If not equal, then it doesn't matter that the actual
value may change immediately after comparison, as it can't
possibly change to the current thread's state.
* If equal, then the current thread holds the lock, so the value can't
change until we yield the lock.
*/
static int
PyThreadState_IsCurrent(PyThreadState *tstate)
{
/* Must be the tstate for this thread */
assert(PyGILState_GetThisThreadState()==tstate);
return tstate == GET_TSTATE();
}
/* Internal initialization/finalization functions called by
Py_Initialize/Py_FinalizeEx
*/
void
_PyGILState_Init(PyInterpreterState *i, PyThreadState *t)
{
assert(i && t); /* must init with valid states */
if (PyThread_tss_create(&_PyRuntime.gilstate.autoTSSkey) != 0) {
Py_FatalError("Could not allocate TSS entry");
}
_PyRuntime.gilstate.autoInterpreterState = i;
assert(PyThread_tss_get(&_PyRuntime.gilstate.autoTSSkey) == NULL);
assert(t->gilstate_counter == 0);
_PyGILState_NoteThreadState(t);
}
PyInterpreterState *
_PyGILState_GetInterpreterStateUnsafe(void)
{
return _PyRuntime.gilstate.autoInterpreterState;
}
void
_PyGILState_Fini(void)
{
PyThread_tss_delete(&_PyRuntime.gilstate.autoTSSkey);
_PyRuntime.gilstate.autoInterpreterState = NULL;
}
/* Reset the TSS key - called by PyOS_AfterFork_Child().
* This should not be necessary, but some - buggy - pthread implementations
* don't reset TSS upon fork(), see issue #10517.
*/
void
_PyGILState_Reinit(void)
{
_PyRuntime.interpreters.mutex = PyThread_allocate_lock();
if (_PyRuntime.interpreters.mutex == NULL)
Py_FatalError("Can't initialize threads for interpreter");
PyThreadState *tstate = PyGILState_GetThisThreadState();
PyThread_tss_delete(&_PyRuntime.gilstate.autoTSSkey);
if (PyThread_tss_create(&_PyRuntime.gilstate.autoTSSkey) != 0) {
Py_FatalError("Could not allocate TSS entry");
}
/* If the thread had an associated auto thread state, reassociate it with
* the new key. */
if (tstate &&
PyThread_tss_set(&_PyRuntime.gilstate.autoTSSkey, (void *)tstate) != 0)
{
Py_FatalError("Couldn't create autoTSSkey mapping");
}
}
/* When a thread state is created for a thread by some mechanism other than
PyGILState_Ensure, it's important that the GILState machinery knows about
it so it doesn't try to create another thread state for the thread (this is
a better fix for SF bug #1010677 than the first one attempted).
*/
static void
_PyGILState_NoteThreadState(PyThreadState* tstate)
{
/* If autoTSSkey isn't initialized, this must be the very first
threadstate created in Py_Initialize(). Don't do anything for now
(we'll be back here when _PyGILState_Init is called). */
if (!_PyRuntime.gilstate.autoInterpreterState)
return;
/* Stick the thread state for this thread in thread specific storage.
The only situation where you can legitimately have more than one
thread state for an OS level thread is when there are multiple
interpreters.
You shouldn't really be using the PyGILState_ APIs anyway (see issues
#10915 and #15751).
The first thread state created for that given OS level thread will
"win", which seems reasonable behaviour.
*/
if (PyThread_tss_get(&_PyRuntime.gilstate.autoTSSkey) == NULL) {
if ((PyThread_tss_set(&_PyRuntime.gilstate.autoTSSkey, (void *)tstate)
) != 0)
{
Py_FatalError("Couldn't create autoTSSkey mapping");
}
}
/* PyGILState_Release must not try to delete this thread state. */
tstate->gilstate_counter = 1;
}
/* The public functions */
PyThreadState *
PyGILState_GetThisThreadState(void)
{
if (_PyRuntime.gilstate.autoInterpreterState == NULL)
return NULL;
return (PyThreadState *)PyThread_tss_get(&_PyRuntime.gilstate.autoTSSkey);
}