Repository navigation
Expand file tree
/
Copy pathobmalloc.c
More file actions
3181 lines (2752 loc) · 101 KB
/
Copy pathobmalloc.c
File metadata and controls
3181 lines (2752 loc) · 101 KB
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
#include "Python.h"
#include "pycore_pymem.h" // _PyTraceMalloc_Config
#include <stdbool.h>
#include <stdlib.h> // malloc()
/* Defined in tracemalloc.c */
extern void _PyMem_DumpTraceback(int fd, const void *ptr);
/* Python's malloc wrappers (see pymem.h) */
#undef uint
#define uint unsigned int /* assuming >= 16 bits */
/* Forward declaration */
static void* _PyMem_DebugRawMalloc(void *ctx, size_t size);
static void* _PyMem_DebugRawCalloc(void *ctx, size_t nelem, size_t elsize);
static void* _PyMem_DebugRawRealloc(void *ctx, void *ptr, size_t size);
static void _PyMem_DebugRawFree(void *ctx, void *ptr);
static void* _PyMem_DebugMalloc(void *ctx, size_t size);
static void* _PyMem_DebugCalloc(void *ctx, size_t nelem, size_t elsize);
static void* _PyMem_DebugRealloc(void *ctx, void *ptr, size_t size);
static void _PyMem_DebugFree(void *ctx, void *p);
static void _PyObject_DebugDumpAddress(const void *p);
static void _PyMem_DebugCheckAddress(const char *func, char api_id, const void *p);
static void _PyMem_SetupDebugHooksDomain(PyMemAllocatorDomain domain);
static void _PyFreelist_DebugMallocStats(FILE *out);
#if defined(__has_feature) /* Clang */
# if __has_feature(address_sanitizer) /* is ASAN enabled? */
# define _Py_NO_SANITIZE_ADDRESS \
__attribute__((no_sanitize("address")))
# endif
# if __has_feature(thread_sanitizer) /* is TSAN enabled? */
# define _Py_NO_SANITIZE_THREAD __attribute__((no_sanitize_thread))
# endif
# if __has_feature(memory_sanitizer) /* is MSAN enabled? */
# define _Py_NO_SANITIZE_MEMORY __attribute__((no_sanitize_memory))
# endif
#elif defined(__GNUC__)
# if defined(__SANITIZE_ADDRESS__) /* GCC 4.8+, is ASAN enabled? */
# define _Py_NO_SANITIZE_ADDRESS \
__attribute__((no_sanitize_address))
# endif
// TSAN is supported since GCC 5.1, but __SANITIZE_THREAD__ macro
// is provided only since GCC 7.
# if __GNUC__ > 5 || (__GNUC__ == 5 && __GNUC_MINOR__ >= 1)
# define _Py_NO_SANITIZE_THREAD __attribute__((no_sanitize_thread))
# endif
#endif
#ifndef _Py_NO_SANITIZE_ADDRESS
# define _Py_NO_SANITIZE_ADDRESS
#endif
#ifndef _Py_NO_SANITIZE_THREAD
# define _Py_NO_SANITIZE_THREAD
#endif
#ifndef _Py_NO_SANITIZE_MEMORY
# define _Py_NO_SANITIZE_MEMORY
#endif
#ifdef WITH_PYMALLOC
#ifdef MS_WINDOWS
# include <windows.h>
#elif defined(HAVE_MMAP)
# include <sys/mman.h>
# ifdef MAP_ANONYMOUS
# define ARENAS_USE_MMAP
# endif
#endif
/* Forward declaration */
static void* _PyObject_Malloc(void *ctx, size_t size);
static void* _PyObject_Calloc(void *ctx, size_t nelem, size_t elsize);
static void _PyObject_Free(void *ctx, void *p);
static void* _PyObject_Realloc(void *ctx, void *ptr, size_t size);
#endif
/* bpo-35053: Declare tracemalloc configuration here rather than
Modules/_tracemalloc.c because _tracemalloc can be compiled as dynamic
library, whereas _Py_NewReference() requires it. */
struct _PyTraceMalloc_Config _Py_tracemalloc_config = _PyTraceMalloc_Config_INIT;
static void *
_PyMem_RawMalloc(void *ctx, size_t size)
{
/* PyMem_RawMalloc(0) means malloc(1). Some systems would return NULL
for malloc(0), which would be treated as an error. Some platforms would
return a pointer with no memory behind it, which would break pymalloc.
To solve these problems, allocate an extra byte. */
if (size == 0)
size = 1;
return malloc(size);
}
static void *
_PyMem_RawCalloc(void *ctx, size_t nelem, size_t elsize)
{
/* PyMem_RawCalloc(0, 0) means calloc(1, 1). Some systems would return NULL
for calloc(0, 0), which would be treated as an error. Some platforms
would return a pointer with no memory behind it, which would break
pymalloc. To solve these problems, allocate an extra byte. */
if (nelem == 0 || elsize == 0) {
nelem = 1;
elsize = 1;
}
return calloc(nelem, elsize);
}
static void *
_PyMem_RawRealloc(void *ctx, void *ptr, size_t size)
{
if (size == 0)
size = 1;
return realloc(ptr, size);
}
static void
_PyMem_RawFree(void *ctx, void *ptr)
{
free(ptr);
}
#ifdef MS_WINDOWS
static void *
_PyObject_ArenaVirtualAlloc(void *ctx, size_t size)
{
return VirtualAlloc(NULL, size,
MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
}
static void
_PyObject_ArenaVirtualFree(void *ctx, void *ptr, size_t size)
{
VirtualFree(ptr, 0, MEM_RELEASE);
}
#elif defined(ARENAS_USE_MMAP)
static void *
_PyObject_ArenaMmap(void *ctx, size_t size)
{
void *ptr;
ptr = mmap(NULL, size, PROT_READ|PROT_WRITE,
MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
if (ptr == MAP_FAILED)
return NULL;
assert(ptr != NULL);
return ptr;
}
static void
_PyObject_ArenaMunmap(void *ctx, void *ptr, size_t size)
{
munmap(ptr, size);
}
#else
static void *
_PyObject_ArenaMalloc(void *ctx, size_t size)
{
return malloc(size);
}
static void
_PyObject_ArenaFree(void *ctx, void *ptr, size_t size)
{
free(ptr);
}
#endif
#define MALLOC_ALLOC {NULL, _PyMem_RawMalloc, _PyMem_RawCalloc, _PyMem_RawRealloc, _PyMem_RawFree}
#ifdef WITH_PYMALLOC
# define PYMALLOC_ALLOC {NULL, _PyObject_Malloc, _PyObject_Calloc, _PyObject_Realloc, _PyObject_Free}
#endif
#define PYRAW_ALLOC MALLOC_ALLOC
#ifdef WITH_PYMALLOC
# define PYOBJ_ALLOC PYMALLOC_ALLOC
#else
# define PYOBJ_ALLOC MALLOC_ALLOC
#endif
#define PYMEM_ALLOC PYOBJ_ALLOC
typedef struct {
/* We tag each block with an API ID in order to tag API violations */
char api_id;
PyMemAllocatorEx alloc;
} debug_alloc_api_t;
static struct {
debug_alloc_api_t raw;
debug_alloc_api_t mem;
debug_alloc_api_t obj;
} _PyMem_Debug = {
{'r', PYRAW_ALLOC},
{'m', PYMEM_ALLOC},
{'o', PYOBJ_ALLOC}
};
#define PYDBGRAW_ALLOC \
{&_PyMem_Debug.raw, _PyMem_DebugRawMalloc, _PyMem_DebugRawCalloc, _PyMem_DebugRawRealloc, _PyMem_DebugRawFree}
#define PYDBGMEM_ALLOC \
{&_PyMem_Debug.mem, _PyMem_DebugMalloc, _PyMem_DebugCalloc, _PyMem_DebugRealloc, _PyMem_DebugFree}
#define PYDBGOBJ_ALLOC \
{&_PyMem_Debug.obj, _PyMem_DebugMalloc, _PyMem_DebugCalloc, _PyMem_DebugRealloc, _PyMem_DebugFree}
#ifdef Py_DEBUG
static PyMemAllocatorEx _PyMem_Raw = PYDBGRAW_ALLOC;
static PyMemAllocatorEx _PyMem = PYDBGMEM_ALLOC;
static PyMemAllocatorEx _PyObject = PYDBGOBJ_ALLOC;
#else
static PyMemAllocatorEx _PyMem_Raw = PYRAW_ALLOC;
static PyMemAllocatorEx _PyMem = PYMEM_ALLOC;
static PyMemAllocatorEx _PyObject = PYOBJ_ALLOC;
#endif
static int
pymem_set_default_allocator(PyMemAllocatorDomain domain, int debug,
PyMemAllocatorEx *old_alloc)
{
if (old_alloc != NULL) {
PyMem_GetAllocator(domain, old_alloc);
}
PyMemAllocatorEx new_alloc;
switch(domain)
{
case PYMEM_DOMAIN_RAW:
new_alloc = (PyMemAllocatorEx)PYRAW_ALLOC;
break;
case PYMEM_DOMAIN_MEM:
new_alloc = (PyMemAllocatorEx)PYMEM_ALLOC;
break;
case PYMEM_DOMAIN_OBJ:
new_alloc = (PyMemAllocatorEx)PYOBJ_ALLOC;
break;
default:
/* unknown domain */
return -1;
}
PyMem_SetAllocator(domain, &new_alloc);
if (debug) {
_PyMem_SetupDebugHooksDomain(domain);
}
return 0;
}
int
_PyMem_SetDefaultAllocator(PyMemAllocatorDomain domain,
PyMemAllocatorEx *old_alloc)
{
#ifdef Py_DEBUG
const int debug = 1;
#else
const int debug = 0;
#endif
return pymem_set_default_allocator(domain, debug, old_alloc);
}
int
_PyMem_GetAllocatorName(const char *name, PyMemAllocatorName *allocator)
{
if (name == NULL || *name == '\0') {
/* PYTHONMALLOC is empty or is not set or ignored (-E/-I command line
nameions): use default memory allocators */
*allocator = PYMEM_ALLOCATOR_DEFAULT;
}
else if (strcmp(name, "default") == 0) {
*allocator = PYMEM_ALLOCATOR_DEFAULT;
}
else if (strcmp(name, "debug") == 0) {
*allocator = PYMEM_ALLOCATOR_DEBUG;
}
#ifdef WITH_PYMALLOC
else if (strcmp(name, "pymalloc") == 0) {
*allocator = PYMEM_ALLOCATOR_PYMALLOC;
}
else if (strcmp(name, "pymalloc_debug") == 0) {
*allocator = PYMEM_ALLOCATOR_PYMALLOC_DEBUG;
}
#endif
else if (strcmp(name, "malloc") == 0) {
*allocator = PYMEM_ALLOCATOR_MALLOC;
}
else if (strcmp(name, "malloc_debug") == 0) {
*allocator = PYMEM_ALLOCATOR_MALLOC_DEBUG;
}
else {
/* unknown allocator */
return -1;
}
return 0;
}
int
_PyMem_SetupAllocators(PyMemAllocatorName allocator)
{
switch (allocator) {
case PYMEM_ALLOCATOR_NOT_SET:
/* do nothing */
break;
case PYMEM_ALLOCATOR_DEFAULT:
(void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_RAW, NULL);
(void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_MEM, NULL);
(void)_PyMem_SetDefaultAllocator(PYMEM_DOMAIN_OBJ, NULL);
break;
case PYMEM_ALLOCATOR_DEBUG:
(void)pymem_set_default_allocator(PYMEM_DOMAIN_RAW, 1, NULL);
(void)pymem_set_default_allocator(PYMEM_DOMAIN_MEM, 1, NULL);
(void)pymem_set_default_allocator(PYMEM_DOMAIN_OBJ, 1, NULL);
break;
#ifdef WITH_PYMALLOC
case PYMEM_ALLOCATOR_PYMALLOC:
case PYMEM_ALLOCATOR_PYMALLOC_DEBUG:
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &malloc_alloc);
PyMemAllocatorEx pymalloc = PYMALLOC_ALLOC;
PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &pymalloc);
PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &pymalloc);
if (allocator == PYMEM_ALLOCATOR_PYMALLOC_DEBUG) {
PyMem_SetupDebugHooks();
}
break;
}
#endif
case PYMEM_ALLOCATOR_MALLOC:
case PYMEM_ALLOCATOR_MALLOC_DEBUG:
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &malloc_alloc);
PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &malloc_alloc);
PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &malloc_alloc);
if (allocator == PYMEM_ALLOCATOR_MALLOC_DEBUG) {
PyMem_SetupDebugHooks();
}
break;
}
default:
/* unknown allocator */
return -1;
}
return 0;
}
static int
pymemallocator_eq(PyMemAllocatorEx *a, PyMemAllocatorEx *b)
{
return (memcmp(a, b, sizeof(PyMemAllocatorEx)) == 0);
}
const char*
_PyMem_GetCurrentAllocatorName(void)
{
PyMemAllocatorEx malloc_alloc = MALLOC_ALLOC;
#ifdef WITH_PYMALLOC
PyMemAllocatorEx pymalloc = PYMALLOC_ALLOC;
#endif
if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) &&
pymemallocator_eq(&_PyMem, &malloc_alloc) &&
pymemallocator_eq(&_PyObject, &malloc_alloc))
{
return "malloc";
}
#ifdef WITH_PYMALLOC
if (pymemallocator_eq(&_PyMem_Raw, &malloc_alloc) &&
pymemallocator_eq(&_PyMem, &pymalloc) &&
pymemallocator_eq(&_PyObject, &pymalloc))
{
return "pymalloc";
}
#endif
PyMemAllocatorEx dbg_raw = PYDBGRAW_ALLOC;
PyMemAllocatorEx dbg_mem = PYDBGMEM_ALLOC;
PyMemAllocatorEx dbg_obj = PYDBGOBJ_ALLOC;
if (pymemallocator_eq(&_PyMem_Raw, &dbg_raw) &&
pymemallocator_eq(&_PyMem, &dbg_mem) &&
pymemallocator_eq(&_PyObject, &dbg_obj))
{
/* Debug hooks installed */
if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &malloc_alloc) &&
pymemallocator_eq(&_PyMem_Debug.mem.alloc, &malloc_alloc) &&
pymemallocator_eq(&_PyMem_Debug.obj.alloc, &malloc_alloc))
{
return "malloc_debug";
}
#ifdef WITH_PYMALLOC
if (pymemallocator_eq(&_PyMem_Debug.raw.alloc, &malloc_alloc) &&
pymemallocator_eq(&_PyMem_Debug.mem.alloc, &pymalloc) &&
pymemallocator_eq(&_PyMem_Debug.obj.alloc, &pymalloc))
{
return "pymalloc_debug";
}
#endif
}
return NULL;
}
#undef MALLOC_ALLOC
#undef PYMALLOC_ALLOC
#undef PYRAW_ALLOC
#undef PYMEM_ALLOC
#undef PYOBJ_ALLOC
#undef PYDBGRAW_ALLOC
#undef PYDBGMEM_ALLOC
#undef PYDBGOBJ_ALLOC
static PyObjectArenaAllocator _PyObject_Arena = {NULL,
#ifdef MS_WINDOWS
_PyObject_ArenaVirtualAlloc, _PyObject_ArenaVirtualFree
#elif defined(ARENAS_USE_MMAP)
_PyObject_ArenaMmap, _PyObject_ArenaMunmap
#else
_PyObject_ArenaMalloc, _PyObject_ArenaFree
#endif
};
#ifdef WITH_PYMALLOC
static int
_PyMem_DebugEnabled(void)
{
return (_PyObject.malloc == _PyMem_DebugMalloc);
}
static int
_PyMem_PymallocEnabled(void)
{
if (_PyMem_DebugEnabled()) {
return (_PyMem_Debug.obj.alloc.malloc == _PyObject_Malloc);
}
else {
return (_PyObject.malloc == _PyObject_Malloc);
}
}
#endif
static void
_PyMem_SetupDebugHooksDomain(PyMemAllocatorDomain domain)
{
PyMemAllocatorEx alloc;
if (domain == PYMEM_DOMAIN_RAW) {
if (_PyMem_Raw.malloc == _PyMem_DebugRawMalloc) {
return;
}
PyMem_GetAllocator(PYMEM_DOMAIN_RAW, &_PyMem_Debug.raw.alloc);
alloc.ctx = &_PyMem_Debug.raw;
alloc.malloc = _PyMem_DebugRawMalloc;
alloc.calloc = _PyMem_DebugRawCalloc;
alloc.realloc = _PyMem_DebugRawRealloc;
alloc.free = _PyMem_DebugRawFree;
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &alloc);
}
else if (domain == PYMEM_DOMAIN_MEM) {
if (_PyMem.malloc == _PyMem_DebugMalloc) {
return;
}
PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &_PyMem_Debug.mem.alloc);
alloc.ctx = &_PyMem_Debug.mem;
alloc.malloc = _PyMem_DebugMalloc;
alloc.calloc = _PyMem_DebugCalloc;
alloc.realloc = _PyMem_DebugRealloc;
alloc.free = _PyMem_DebugFree;
PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc);
}
else if (domain == PYMEM_DOMAIN_OBJ) {
if (_PyObject.malloc == _PyMem_DebugMalloc) {
return;
}
PyMem_GetAllocator(PYMEM_DOMAIN_OBJ, &_PyMem_Debug.obj.alloc);
alloc.ctx = &_PyMem_Debug.obj;
alloc.malloc = _PyMem_DebugMalloc;
alloc.calloc = _PyMem_DebugCalloc;
alloc.realloc = _PyMem_DebugRealloc;
alloc.free = _PyMem_DebugFree;
PyMem_SetAllocator(PYMEM_DOMAIN_OBJ, &alloc);
}
}
void
PyMem_SetupDebugHooks(void)
{
_PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_RAW);
_PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_MEM);
_PyMem_SetupDebugHooksDomain(PYMEM_DOMAIN_OBJ);
}
void
PyMem_GetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator)
{
switch(domain)
{
case PYMEM_DOMAIN_RAW: *allocator = _PyMem_Raw; break;
case PYMEM_DOMAIN_MEM: *allocator = _PyMem; break;
case PYMEM_DOMAIN_OBJ: *allocator = _PyObject; break;
default:
/* unknown domain: set all attributes to NULL */
allocator->ctx = NULL;
allocator->malloc = NULL;
allocator->calloc = NULL;
allocator->realloc = NULL;
allocator->free = NULL;
}
}
void
PyMem_SetAllocator(PyMemAllocatorDomain domain, PyMemAllocatorEx *allocator)
{
switch(domain)
{
case PYMEM_DOMAIN_RAW: _PyMem_Raw = *allocator; break;
case PYMEM_DOMAIN_MEM: _PyMem = *allocator; break;
case PYMEM_DOMAIN_OBJ: _PyObject = *allocator; break;
/* ignore unknown domain */
}
}
void
PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator)
{
*allocator = _PyObject_Arena;
}
void *
_PyObject_VirtualAlloc(size_t size)
{
return _PyObject_Arena.alloc(_PyObject_Arena.ctx, size);
}
void
_PyObject_VirtualFree(void *obj, size_t size)
{
_PyObject_Arena.free(_PyObject_Arena.ctx, obj, size);
}
void
PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator)
{
_PyObject_Arena = *allocator;
}
void *
PyMem_RawMalloc(size_t size)
{
/*
* Limit ourselves to PY_SSIZE_T_MAX bytes to prevent security holes.
* Most python internals blindly use a signed Py_ssize_t to track
* things without checking for overflows or negatives.
* As size_t is unsigned, checking for size < 0 is not required.
*/
if (size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyMem_Raw.malloc(_PyMem_Raw.ctx, size);
}
void *
PyMem_RawCalloc(size_t nelem, size_t elsize)
{
/* see PyMem_RawMalloc() */
if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize)
return NULL;
return _PyMem_Raw.calloc(_PyMem_Raw.ctx, nelem, elsize);
}
void*
PyMem_RawRealloc(void *ptr, size_t new_size)
{
/* see PyMem_RawMalloc() */
if (new_size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyMem_Raw.realloc(_PyMem_Raw.ctx, ptr, new_size);
}
void PyMem_RawFree(void *ptr)
{
_PyMem_Raw.free(_PyMem_Raw.ctx, ptr);
}
void *
PyMem_Malloc(size_t size)
{
/* see PyMem_RawMalloc() */
if (size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyMem.malloc(_PyMem.ctx, size);
}
void *
PyMem_Calloc(size_t nelem, size_t elsize)
{
/* see PyMem_RawMalloc() */
if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize)
return NULL;
return _PyMem.calloc(_PyMem.ctx, nelem, elsize);
}
void *
PyMem_Realloc(void *ptr, size_t new_size)
{
/* see PyMem_RawMalloc() */
if (new_size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyMem.realloc(_PyMem.ctx, ptr, new_size);
}
void
PyMem_Free(void *ptr)
{
_PyMem.free(_PyMem.ctx, ptr);
}
wchar_t*
_PyMem_RawWcsdup(const wchar_t *str)
{
assert(str != NULL);
size_t len = wcslen(str);
if (len > (size_t)PY_SSIZE_T_MAX / sizeof(wchar_t) - 1) {
return NULL;
}
size_t size = (len + 1) * sizeof(wchar_t);
wchar_t *str2 = PyMem_RawMalloc(size);
if (str2 == NULL) {
return NULL;
}
memcpy(str2, str, size);
return str2;
}
char *
_PyMem_RawStrdup(const char *str)
{
assert(str != NULL);
size_t size = strlen(str) + 1;
char *copy = PyMem_RawMalloc(size);
if (copy == NULL) {
return NULL;
}
memcpy(copy, str, size);
return copy;
}
char *
_PyMem_Strdup(const char *str)
{
assert(str != NULL);
size_t size = strlen(str) + 1;
char *copy = PyMem_Malloc(size);
if (copy == NULL) {
return NULL;
}
memcpy(copy, str, size);
return copy;
}
void *
PyObject_Malloc(size_t size)
{
/* see PyMem_RawMalloc() */
if (size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyObject.malloc(_PyObject.ctx, size);
}
void *
PyObject_Calloc(size_t nelem, size_t elsize)
{
/* see PyMem_RawMalloc() */
if (elsize != 0 && nelem > (size_t)PY_SSIZE_T_MAX / elsize)
return NULL;
return _PyObject.calloc(_PyObject.ctx, nelem, elsize);
}
void *
PyObject_Realloc(void *ptr, size_t new_size)
{
/* see PyMem_RawMalloc() */
if (new_size > (size_t)PY_SSIZE_T_MAX)
return NULL;
return _PyObject.realloc(_PyObject.ctx, ptr, new_size);
}
void
PyObject_Free(void *ptr)
{
_PyObject.free(_PyObject.ctx, ptr);
}
/* If we're using GCC, use __builtin_expect() to reduce overhead of
the valgrind checks */
#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
# define UNLIKELY(value) __builtin_expect((value), 0)
# define LIKELY(value) __builtin_expect((value), 1)
#else
# define UNLIKELY(value) (value)
# define LIKELY(value) (value)
#endif
#ifdef WITH_PYMALLOC
#ifdef WITH_VALGRIND
#include <valgrind/valgrind.h>
/* -1 indicates that we haven't checked that we're running on valgrind yet. */
static int running_on_valgrind = -1;
#endif
/* An object allocator for Python.
Here is an introduction to the layers of the Python memory architecture,
showing where the object allocator is actually used (layer +2), It is
called for every object allocation and deallocation (PyObject_New/Del),
unless the object-specific allocators implement a proprietary allocation
scheme (ex.: ints use a simple free list). This is also the place where
the cyclic garbage collector operates selectively on container objects.
Object-specific allocators
_____ ______ ______ ________
[ int ] [ dict ] [ list ] ... [ string ] Python core |
+3 | <----- Object-specific memory -----> | <-- Non-object memory --> |
_______________________________ | |
[ Python's object allocator ] | |
+2 | ####### Object memory ####### | <------ Internal buffers ------> |
______________________________________________________________ |
[ Python's raw memory allocator (PyMem_ API) ] |
+1 | <----- Python memory (under PyMem manager's control) ------> | |
__________________________________________________________________
[ Underlying general-purpose allocator (ex: C library malloc) ]
0 | <------ Virtual memory allocated for the python process -------> |
=========================================================================
_______________________________________________________________________
[ OS-specific Virtual Memory Manager (VMM) ]
-1 | <--- Kernel dynamic storage allocation & management (page-based) ---> |
__________________________________ __________________________________
[ ] [ ]
-2 | <-- Physical memory: ROM/RAM --> | | <-- Secondary storage (swap) --> |
*/
/*==========================================================================*/
/* A fast, special-purpose memory allocator for small blocks, to be used
on top of a general-purpose malloc -- heavily based on previous art. */
/* Vladimir Marangozov -- August 2000 */
/*
* "Memory management is where the rubber meets the road -- if we do the wrong
* thing at any level, the results will not be good. And if we don't make the
* levels work well together, we are in serious trouble." (1)
*
* (1) Paul R. Wilson, Mark S. Johnstone, Michael Neely, and David Boles,
* "Dynamic Storage Allocation: A Survey and Critical Review",
* in Proc. 1995 Int'l. Workshop on Memory Management, September 1995.
*/
/* #undef WITH_MEMORY_LIMITS */ /* disable mem limit checks */
/*==========================================================================*/
/*
* Allocation strategy abstract:
*
* For small requests, the allocator sub-allocates <Big> blocks of memory.
* Requests greater than SMALL_REQUEST_THRESHOLD bytes are routed to the
* system's allocator.
*
* Small requests are grouped in size classes spaced 8 bytes apart, due
* to the required valid alignment of the returned address. Requests of
* a particular size are serviced from memory pools of 4K (one VMM page).
* Pools are fragmented on demand and contain free lists of blocks of one
* particular size class. In other words, there is a fixed-size allocator
* for each size class. Free pools are shared by the different allocators
* thus minimizing the space reserved for a particular size class.
*
* This allocation strategy is a variant of what is known as "simple
* segregated storage based on array of free lists". The main drawback of
* simple segregated storage is that we might end up with lot of reserved
* memory for the different free lists, which degenerate in time. To avoid
* this, we partition each free list in pools and we share dynamically the
* reserved space between all free lists. This technique is quite efficient
* for memory intensive programs which allocate mainly small-sized blocks.
*
* For small requests we have the following table:
*
* Request in bytes Size of allocated block Size class idx
* ----------------------------------------------------------------
* 1-8 8 0
* 9-16 16 1
* 17-24 24 2
* 25-32 32 3
* 33-40 40 4
* 41-48 48 5
* 49-56 56 6
* 57-64 64 7
* 65-72 72 8
* ... ... ...
* 497-504 504 62
* 505-512 512 63
*
* 0, SMALL_REQUEST_THRESHOLD + 1 and up: routed to the underlying
* allocator.
*/
/*==========================================================================*/
/*
* -- Main tunable settings section --
*/
/*
* Alignment of addresses returned to the user. 8-bytes alignment works
* on most current architectures (with 32-bit or 64-bit address buses).
* The alignment value is also used for grouping small requests in size
* classes spaced ALIGNMENT bytes apart.
*
* You shouldn't change this unless you know what you are doing.
*/
#if SIZEOF_VOID_P > 4
#define ALIGNMENT 16 /* must be 2^N */
#define ALIGNMENT_SHIFT 4
#else
#define ALIGNMENT 8 /* must be 2^N */
#define ALIGNMENT_SHIFT 3
#endif
/* Return the number of bytes in size class I, as a uint. */
#define INDEX2SIZE(I) (((uint)(I) + 1) << ALIGNMENT_SHIFT)
/*
* Max size threshold below which malloc requests are considered to be
* small enough in order to use preallocated memory pools. You can tune
* this value according to your application behaviour and memory needs.
*
* Note: a size threshold of 512 guarantees that newly created dictionaries
* will be allocated from preallocated memory pools on 64-bit.
*
* The following invariants must hold:
* 1) ALIGNMENT <= SMALL_REQUEST_THRESHOLD <= 512
* 2) SMALL_REQUEST_THRESHOLD is evenly divisible by ALIGNMENT
*
* Although not required, for better performance and space efficiency,
* it is recommended that SMALL_REQUEST_THRESHOLD is set to a power of 2.
*/
#define SMALL_REQUEST_THRESHOLD 512
#define NB_SMALL_SIZE_CLASSES (SMALL_REQUEST_THRESHOLD / ALIGNMENT)
/*
* The system's VMM page size can be obtained on most unices with a
* getpagesize() call or deduced from various header files. To make
* things simpler, we assume that it is 4K, which is OK for most systems.
* It is probably better if this is the native page size, but it doesn't
* have to be. In theory, if SYSTEM_PAGE_SIZE is larger than the native page
* size, then `POOL_ADDR(p)->arenaindex' could rarely cause a segmentation
* violation fault. 4K is apparently OK for all the platforms that python
* currently targets.
*/
#define SYSTEM_PAGE_SIZE (4 * 1024)
#define SYSTEM_PAGE_SIZE_MASK (SYSTEM_PAGE_SIZE - 1)
/*
* Maximum amount of memory managed by the allocator for small requests.
*/
#ifdef WITH_MEMORY_LIMITS
#ifndef SMALL_MEMORY_LIMIT
#define SMALL_MEMORY_LIMIT (64 * 1024 * 1024) /* 64 MB -- more? */
#endif
#endif
#if !defined(WITH_PYMALLOC_RADIX_TREE)
/* Use radix-tree to track arena memory regions, for address_in_range().
* Enable by default since it allows larger pool sizes. Can be disabled
* using -DWITH_PYMALLOC_RADIX_TREE=0 */
#define WITH_PYMALLOC_RADIX_TREE 1
#endif
#if SIZEOF_VOID_P > 4
/* on 64-bit platforms use larger pools and arenas if we can */
#define USE_LARGE_ARENAS
#if WITH_PYMALLOC_RADIX_TREE
/* large pools only supported if radix-tree is enabled */
#define USE_LARGE_POOLS
#endif
#endif
/*
* The allocator sub-allocates <Big> blocks of memory (called arenas) aligned
* on a page boundary. This is a reserved virtual address space for the
* current process (obtained through a malloc()/mmap() call). In no way this
* means that the memory arenas will be used entirely. A malloc(<Big>) is
* usually an address range reservation for <Big> bytes, unless all pages within
* this space are referenced subsequently. So malloc'ing big blocks and not
* using them does not mean "wasting memory". It's an addressable range
* wastage...
*
* Arenas are allocated with mmap() on systems supporting anonymous memory
* mappings to reduce heap fragmentation.
*/
#ifdef USE_LARGE_ARENAS
#define ARENA_BITS 20 /* 1 MiB */
#else
#define ARENA_BITS 18 /* 256 KiB */
#endif
#define ARENA_SIZE (1 << ARENA_BITS)
#define ARENA_SIZE_MASK (ARENA_SIZE - 1)
#ifdef WITH_MEMORY_LIMITS
#define MAX_ARENAS (SMALL_MEMORY_LIMIT / ARENA_SIZE)
#endif
/*
* Size of the pools used for small blocks. Must be a power of 2.
*/
#ifdef USE_LARGE_POOLS
#define POOL_BITS 14 /* 16 KiB */
#else
#define POOL_BITS 12 /* 4 KiB */
#endif
#define POOL_SIZE (1 << POOL_BITS)
#define POOL_SIZE_MASK (POOL_SIZE - 1)
#if !WITH_PYMALLOC_RADIX_TREE
#if POOL_SIZE != SYSTEM_PAGE_SIZE
# error "pool size must be equal to system page size"
#endif
#endif
#define MAX_POOLS_IN_ARENA (ARENA_SIZE / POOL_SIZE)
#if MAX_POOLS_IN_ARENA * POOL_SIZE != ARENA_SIZE
# error "arena size not an exact multiple of pool size"
#endif
/*
* -- End of tunable settings section --
*/
/*==========================================================================*/
/* When you say memory, my mind reasons in terms of (pointers to) blocks */
typedef uint8_t block;
/* Pool for small blocks. */
struct pool_header {
union { block *_padding;
uint count; } ref; /* number of allocated blocks */
block *freeblock; /* pool's free list head */
struct pool_header *nextpool; /* next pool of this size class */
struct pool_header *prevpool; /* previous pool "" */
uint arenaindex; /* index into arenas of base adr */
uint szidx; /* block size class index */
uint nextoffset; /* bytes to virgin block */
uint maxnextoffset; /* largest valid nextoffset */
};
typedef struct pool_header *poolp;
/* Record keeping for arenas. */
struct arena_object {
/* The address of the arena, as returned by malloc. Note that 0