-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathcont.c
1474 lines (1316 loc) · 38.1 KB
/
cont.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
/**********************************************************************
cont.c -
$Author$
created at: Thu May 23 09:03:43 2007
Copyright (C) 2007 Koichi Sasada
**********************************************************************/
#include "ruby/ruby.h"
#include "internal.h"
#include "vm_core.h"
#include "gc.h"
#include "eval_intern.h"
#if ((defined(_WIN32) && _WIN32_WINNT >= 0x0400) || defined(HAVE_SETCONTEXT)) && !defined(__NetBSD__) && !defined(FIBER_USE_NATIVE)
#define FIBER_USE_NATIVE 1
/* FIBER_USE_NATIVE enables Fiber performance improvement using system
* dependent method such as make/setcontext on POSIX system or
* CreateFiber() API on Windows.
* This hack make Fiber context switch faster (x2 or more).
* However, it decrease maximum number of Fiber. For example, on the
* 32bit POSIX OS, ten or twenty thousands Fiber can be created.
*
* Details is reported in the paper "A Fast Fiber Implementation for Ruby 1.9"
* in Proc. of 51th Programming Symposium, pp.21--28 (2010) (in Japanese).
*/
/* On our experience, NetBSD doesn't support using setcontext() and pthread
* simultaneously. This is because pthread_self(), TLS and other information
* are represented by stack pointer (higher bits of stack pointer).
* TODO: check such constraint on configure.
*/
#elif !defined(FIBER_USE_NATIVE)
#define FIBER_USE_NATIVE 0
#endif
#if FIBER_USE_NATIVE
#ifndef _WIN32
#include <unistd.h>
#include <sys/mman.h>
#include <ucontext.h>
#endif
#define RB_PAGE_SIZE (pagesize)
#define RB_PAGE_MASK (~(RB_PAGE_SIZE - 1))
static long pagesize;
#define FIBER_MACHINE_STACK_ALLOCATION_SIZE (0x10000 / sizeof(VALUE))
#endif
#define CAPTURE_JUST_VALID_VM_STACK 1
enum context_type {
CONTINUATION_CONTEXT = 0,
FIBER_CONTEXT = 1,
ROOT_FIBER_CONTEXT = 2
};
typedef struct rb_context_struct {
enum context_type type;
VALUE self;
int argc;
VALUE value;
VALUE *vm_stack;
#ifdef CAPTURE_JUST_VALID_VM_STACK
size_t vm_stack_slen; /* length of stack (head of th->stack) */
size_t vm_stack_clen; /* length of control frames (tail of th->stack) */
#endif
VALUE *machine_stack;
VALUE *machine_stack_src;
#ifdef __ia64
VALUE *machine_register_stack;
VALUE *machine_register_stack_src;
int machine_register_stack_size;
#endif
rb_thread_t saved_thread;
rb_jmpbuf_t jmpbuf;
size_t machine_stack_size;
} rb_context_t;
enum fiber_status {
CREATED,
RUNNING,
TERMINATED
};
#if FIBER_USE_NATIVE && !defined(_WIN32)
#define MAX_MAHINE_STACK_CACHE 10
static int machine_stack_cache_index = 0;
typedef struct machine_stack_cache_struct {
void *ptr;
size_t size;
} machine_stack_cache_t;
static machine_stack_cache_t machine_stack_cache[MAX_MAHINE_STACK_CACHE];
static machine_stack_cache_t terminated_machine_stack;
#endif
typedef struct rb_fiber_struct {
rb_context_t cont;
VALUE prev;
enum fiber_status status;
struct rb_fiber_struct *prev_fiber;
struct rb_fiber_struct *next_fiber;
#if FIBER_USE_NATIVE
#ifdef _WIN32
void *fib_handle;
#else
ucontext_t context;
#endif
#endif
} rb_fiber_t;
static const rb_data_type_t cont_data_type, fiber_data_type;
static VALUE rb_cContinuation;
static VALUE rb_cFiber;
static VALUE rb_eFiberError;
#define GetContPtr(obj, ptr) \
TypedData_Get_Struct((obj), rb_context_t, &cont_data_type, (ptr))
#define GetFiberPtr(obj, ptr) do {\
TypedData_Get_Struct((obj), rb_fiber_t, &fiber_data_type, (ptr)); \
if (!(ptr)) rb_raise(rb_eFiberError, "uninitialized fiber"); \
} while(0)
NOINLINE(static VALUE cont_capture(volatile int *stat));
#define THREAD_MUST_BE_RUNNING(th) do { \
if (!(th)->tag) rb_raise(rb_eThreadError, "not running thread"); \
} while (0)
static void
cont_mark(void *ptr)
{
RUBY_MARK_ENTER("cont");
if (ptr) {
rb_context_t *cont = ptr;
rb_gc_mark(cont->value);
rb_thread_mark(&cont->saved_thread);
if (cont->vm_stack) {
#ifdef CAPTURE_JUST_VALID_VM_STACK
rb_gc_mark_locations(cont->vm_stack,
cont->vm_stack + cont->vm_stack_slen + cont->vm_stack_clen);
#else
rb_gc_mark_localtion(cont->vm_stack,
cont->vm_stack, cont->saved_thread.stack_size);
#endif
}
if (cont->machine_stack) {
if (cont->type == CONTINUATION_CONTEXT) {
/* cont */
rb_gc_mark_locations(cont->machine_stack,
cont->machine_stack + cont->machine_stack_size);
}
else {
/* fiber */
rb_thread_t *th;
rb_fiber_t *fib = (rb_fiber_t*)cont;
GetThreadPtr(cont->saved_thread.self, th);
if ((th->fiber != cont->self) && fib->status == RUNNING) {
rb_gc_mark_locations(cont->machine_stack,
cont->machine_stack + cont->machine_stack_size);
}
}
}
#ifdef __ia64
if (cont->machine_register_stack) {
rb_gc_mark_locations(cont->machine_register_stack,
cont->machine_register_stack + cont->machine_register_stack_size);
}
#endif
}
RUBY_MARK_LEAVE("cont");
}
static void
cont_free(void *ptr)
{
RUBY_FREE_ENTER("cont");
if (ptr) {
rb_context_t *cont = ptr;
RUBY_FREE_UNLESS_NULL(cont->saved_thread.stack); fflush(stdout);
#if FIBER_USE_NATIVE
if (cont->type == CONTINUATION_CONTEXT) {
/* cont */
RUBY_FREE_UNLESS_NULL(cont->machine_stack);
}
else {
/* fiber */
#ifdef _WIN32
if (GET_THREAD()->fiber != cont->self && cont->type != ROOT_FIBER_CONTEXT) {
/* don't delete root fiber handle */
rb_fiber_t *fib = (rb_fiber_t*)cont;
if (fib->fib_handle) {
DeleteFiber(fib->fib_handle);
}
}
#else /* not WIN32 */
if (GET_THREAD()->fiber != cont->self) {
rb_fiber_t *fib = (rb_fiber_t*)cont;
if (fib->context.uc_stack.ss_sp) {
if (cont->type == ROOT_FIBER_CONTEXT) {
rb_bug("Illegal root fiber parameter");
}
munmap((void*)fib->context.uc_stack.ss_sp, fib->context.uc_stack.ss_size);
}
}
else {
/* It may reached here when finalize */
/* TODO examine whether it is a bug */
/* rb_bug("cont_free: release self"); */
}
#endif
}
#else /* not FIBER_USE_NATIVE */
RUBY_FREE_UNLESS_NULL(cont->machine_stack);
#endif
#ifdef __ia64
RUBY_FREE_UNLESS_NULL(cont->machine_register_stack);
#endif
RUBY_FREE_UNLESS_NULL(cont->vm_stack);
/* free rb_cont_t or rb_fiber_t */
ruby_xfree(ptr);
}
RUBY_FREE_LEAVE("cont");
}
static size_t
cont_memsize(const void *ptr)
{
const rb_context_t *cont = ptr;
size_t size = 0;
if (cont) {
size = sizeof(*cont);
if (cont->vm_stack) {
#ifdef CAPTURE_JUST_VALID_VM_STACK
size_t n = (cont->vm_stack_slen + cont->vm_stack_clen);
#else
size_t n = cont->saved_thread.stack_size;
#endif
size += n * sizeof(*cont->vm_stack);
}
if (cont->machine_stack) {
size += cont->machine_stack_size * sizeof(*cont->machine_stack);
}
#ifdef __ia64
if (cont->machine_register_stack) {
size += cont->machine_register_stack_size * sizeof(*cont->machine_register_stack);
}
#endif
}
return size;
}
static void
fiber_mark(void *ptr)
{
RUBY_MARK_ENTER("cont");
if (ptr) {
rb_fiber_t *fib = ptr;
rb_gc_mark(fib->prev);
cont_mark(&fib->cont);
}
RUBY_MARK_LEAVE("cont");
}
static void
fiber_link_join(rb_fiber_t *fib)
{
VALUE current_fibval = rb_fiber_current();
rb_fiber_t *current_fib;
GetFiberPtr(current_fibval, current_fib);
/* join fiber link */
fib->next_fiber = current_fib->next_fiber;
fib->prev_fiber = current_fib;
current_fib->next_fiber->prev_fiber = fib;
current_fib->next_fiber = fib;
}
static void
fiber_link_remove(rb_fiber_t *fib)
{
fib->prev_fiber->next_fiber = fib->next_fiber;
fib->next_fiber->prev_fiber = fib->prev_fiber;
}
static void
fiber_free(void *ptr)
{
RUBY_FREE_ENTER("fiber");
if (ptr) {
rb_fiber_t *fib = ptr;
if (fib->cont.type != ROOT_FIBER_CONTEXT &&
fib->cont.saved_thread.local_storage) {
st_free_table(fib->cont.saved_thread.local_storage);
}
fiber_link_remove(fib);
cont_free(&fib->cont);
}
RUBY_FREE_LEAVE("fiber");
}
static size_t
fiber_memsize(const void *ptr)
{
const rb_fiber_t *fib = ptr;
size_t size = 0;
if (ptr) {
size = sizeof(*fib);
if (fib->cont.type != ROOT_FIBER_CONTEXT) {
size += st_memsize(fib->cont.saved_thread.local_storage);
}
size += cont_memsize(&fib->cont);
}
return size;
}
static void
cont_save_machine_stack(rb_thread_t *th, rb_context_t *cont)
{
size_t size;
SET_MACHINE_STACK_END(&th->machine_stack_end);
#ifdef __ia64
th->machine_register_stack_end = rb_ia64_bsp();
#endif
if (th->machine_stack_start > th->machine_stack_end) {
size = cont->machine_stack_size = th->machine_stack_start - th->machine_stack_end;
cont->machine_stack_src = th->machine_stack_end;
}
else {
size = cont->machine_stack_size = th->machine_stack_end - th->machine_stack_start;
cont->machine_stack_src = th->machine_stack_start;
}
if (cont->machine_stack) {
REALLOC_N(cont->machine_stack, VALUE, size);
}
else {
cont->machine_stack = ALLOC_N(VALUE, size);
}
FLUSH_REGISTER_WINDOWS;
MEMCPY(cont->machine_stack, cont->machine_stack_src, VALUE, size);
#ifdef __ia64
rb_ia64_flushrs();
size = cont->machine_register_stack_size = th->machine_register_stack_end - th->machine_register_stack_start;
cont->machine_register_stack_src = th->machine_register_stack_start;
if (cont->machine_register_stack) {
REALLOC_N(cont->machine_register_stack, VALUE, size);
}
else {
cont->machine_register_stack = ALLOC_N(VALUE, size);
}
MEMCPY(cont->machine_register_stack, cont->machine_register_stack_src, VALUE, size);
#endif
}
static const rb_data_type_t cont_data_type = {
"continuation",
{cont_mark, cont_free, cont_memsize,},
};
static void
cont_save_thread(rb_context_t *cont, rb_thread_t *th)
{
/* save thread context */
cont->saved_thread = *th;
/* saved_thread->machine_stack_(start|end) should be NULL */
/* because it may happen GC afterward */
cont->saved_thread.machine_stack_start = 0;
cont->saved_thread.machine_stack_end = 0;
#ifdef __ia64
cont->saved_thread.machine_register_stack_start = 0
cont->saved_thread.machine_register_stack_end = 0
#endif
}
static void
cont_init(rb_context_t *cont, rb_thread_t *th)
{
/* save thread context */
cont_save_thread(cont, th);
cont->saved_thread.local_storage = 0;
}
static rb_context_t *
cont_new(VALUE klass)
{
rb_context_t *cont;
volatile VALUE contval;
rb_thread_t *th = GET_THREAD();
THREAD_MUST_BE_RUNNING(th);
contval = TypedData_Make_Struct(klass, rb_context_t, &cont_data_type, cont);
cont->self = contval;
cont_init(cont, th);
return cont;
}
static VALUE
cont_capture(volatile int *stat)
{
rb_context_t *cont;
rb_thread_t *th = GET_THREAD(), *sth;
volatile VALUE contval;
THREAD_MUST_BE_RUNNING(th);
rb_vm_stack_to_heap(th);
cont = cont_new(rb_cContinuation);
contval = cont->self;
sth = &cont->saved_thread;
#ifdef CAPTURE_JUST_VALID_VM_STACK
cont->vm_stack_slen = th->cfp->sp + th->mark_stack_len - th->stack;
cont->vm_stack_clen = th->stack + th->stack_size - (VALUE*)th->cfp;
cont->vm_stack = ALLOC_N(VALUE, cont->vm_stack_slen + cont->vm_stack_clen);
MEMCPY(cont->vm_stack, th->stack, VALUE, cont->vm_stack_slen);
MEMCPY(cont->vm_stack + cont->vm_stack_slen, (VALUE*)th->cfp, VALUE, cont->vm_stack_clen);
#else
cont->vm_stack = ALLOC_N(VALUE, th->stack_size);
MEMCPY(cont->vm_stack, th->stack, VALUE, th->stack_size);
#endif
sth->stack = 0;
cont_save_machine_stack(th, cont);
if (ruby_setjmp(cont->jmpbuf)) {
VALUE value;
value = cont->value;
if (cont->argc == -1) rb_exc_raise(value);
cont->value = Qnil;
*stat = 1;
return value;
}
else {
*stat = 0;
return cont->self;
}
}
static void
cont_restore_thread(rb_context_t *cont)
{
rb_thread_t *th = GET_THREAD(), *sth = &cont->saved_thread;
/* restore thread context */
if (cont->type == CONTINUATION_CONTEXT) {
/* continuation */
VALUE fib;
th->fiber = sth->fiber;
fib = th->fiber ? th->fiber : th->root_fiber;
if (fib) {
rb_fiber_t *fcont;
GetFiberPtr(fib, fcont);
th->stack_size = fcont->cont.saved_thread.stack_size;
th->stack = fcont->cont.saved_thread.stack;
}
#ifdef CAPTURE_JUST_VALID_VM_STACK
MEMCPY(th->stack, cont->vm_stack, VALUE, cont->vm_stack_slen);
MEMCPY(th->stack + sth->stack_size - cont->vm_stack_clen,
cont->vm_stack + cont->vm_stack_slen, VALUE, cont->vm_stack_clen);
#else
MEMCPY(th->stack, cont->vm_stack, VALUE, sth->stack_size);
#endif
}
else {
/* fiber */
th->stack = sth->stack;
th->stack_size = sth->stack_size;
th->local_storage = sth->local_storage;
th->fiber = cont->self;
}
th->cfp = sth->cfp;
th->safe_level = sth->safe_level;
th->raised_flag = sth->raised_flag;
th->state = sth->state;
th->status = sth->status;
th->tag = sth->tag;
th->protect_tag = sth->protect_tag;
th->errinfo = sth->errinfo;
th->first_proc = sth->first_proc;
}
#if FIBER_USE_NATIVE
#ifdef _WIN32
static void
fiber_set_stack_location(void)
{
rb_thread_t *th = GET_THREAD();
VALUE *ptr;
SET_MACHINE_STACK_END(&ptr);
th->machine_stack_start = (void*)(((VALUE)ptr & RB_PAGE_MASK) + STACK_UPPER((void *)&ptr, 0, RB_PAGE_SIZE));
}
static VOID CALLBACK
fiber_entry(void *arg)
{
fiber_set_stack_location();
rb_fiber_start();
}
#else
static VALUE*
fiber_machine_stack_alloc(size_t size)
{
VALUE *ptr;
if (machine_stack_cache_index > 0) {
if (machine_stack_cache[machine_stack_cache_index - 1].size == (size / sizeof(VALUE))) {
ptr = machine_stack_cache[machine_stack_cache_index - 1].ptr;
machine_stack_cache_index--;
machine_stack_cache[machine_stack_cache_index].ptr = NULL;
machine_stack_cache[machine_stack_cache_index].size = 0;
}
else{
/* TODO handle multiple machine stack size */
rb_bug("machine_stack_cache size is not canonicalized");
}
}
else {
void *page;
STACK_GROW_DIR_DETECTION;
ptr = (VALUE*)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
if (ptr == (VALUE*)(SIGNED_VALUE)-1) {
rb_raise(rb_eFiberError, "can't alloc machine stack to fiber");
}
page = ptr + STACK_DIR_UPPER((size - RB_PAGE_SIZE) / sizeof(VALUE), 0);
if (mprotect(page, RB_PAGE_SIZE, PROT_READ | PROT_WRITE) < 0) {
rb_raise(rb_eFiberError, "mprotect failed");
}
}
return ptr;
}
#endif
static void
fiber_initialize_machine_stack_context(rb_fiber_t *fib, size_t size)
{
rb_thread_t *sth = &fib->cont.saved_thread;
#ifdef _WIN32
fib->fib_handle = CreateFiberEx(size - 1, size, 0, fiber_entry, NULL);
if (!fib->fib_handle) {
/* try to release unnecessary fibers & retry to create */
rb_gc();
fib->fib_handle = CreateFiberEx(size - 1, size, 0, fiber_entry, NULL);
if (!fib->fib_handle) {
rb_raise(rb_eFiberError, "can't create fiber");
}
}
#else /* not WIN32 */
ucontext_t *context = &fib->context;
VALUE *ptr;
STACK_GROW_DIR_DETECTION;
getcontext(context);
ptr = fiber_machine_stack_alloc(size);
context->uc_link = NULL;
context->uc_stack.ss_sp = (char *)ptr;
context->uc_stack.ss_size = size;
makecontext(context, rb_fiber_start, 0);
sth->machine_stack_start = ptr + STACK_DIR_UPPER(0, size / sizeof(VALUE));
#endif
sth->machine_stack_maxsize = size;
#ifdef __ia64
sth->machine_register_stack_maxsize = sth->machine_stack_maxsize;
#endif
}
NOINLINE(static void fiber_setcontext(rb_fiber_t *newfib, rb_fiber_t *oldfib));
static void
fiber_setcontext(rb_fiber_t *newfib, rb_fiber_t *oldfib)
{
rb_thread_t *th = GET_THREAD(), *sth = &newfib->cont.saved_thread;
if (newfib->status != RUNNING) {
fiber_initialize_machine_stack_context(newfib, FIBER_MACHINE_STACK_ALLOCATION_SIZE * sizeof(VALUE));
}
/* restore thread context */
cont_restore_thread(&newfib->cont);
th->machine_stack_maxsize = sth->machine_stack_maxsize;
if (sth->machine_stack_end && (newfib != oldfib)) {
rb_bug("fiber_setcontext: sth->machine_stack_end has non zero value");
}
/* save oldfib's machine stack */
if (oldfib->status != TERMINATED) {
STACK_GROW_DIR_DETECTION;
SET_MACHINE_STACK_END(&th->machine_stack_end);
if (STACK_DIR_UPPER(0, 1)) {
oldfib->cont.machine_stack_size = th->machine_stack_start - th->machine_stack_end;
oldfib->cont.machine_stack = th->machine_stack_end;
}
else {
oldfib->cont.machine_stack_size = th->machine_stack_end - th->machine_stack_start;
oldfib->cont.machine_stack = th->machine_stack_start;
}
}
/* exchange machine_stack_start between oldfib and newfib */
oldfib->cont.saved_thread.machine_stack_start = th->machine_stack_start;
th->machine_stack_start = sth->machine_stack_start;
/* oldfib->machine_stack_end should be NULL */
oldfib->cont.saved_thread.machine_stack_end = 0;
#ifndef _WIN32
if (!newfib->context.uc_stack.ss_sp && th->root_fiber != newfib->cont.self) {
rb_bug("non_root_fiber->context.uc_stac.ss_sp should not be NULL");
}
#endif
/* swap machine context */
#ifdef _WIN32
SwitchToFiber(newfib->fib_handle);
#else
swapcontext(&oldfib->context, &newfib->context);
#endif
}
#endif
NOINLINE(NORETURN(static void cont_restore_1(rb_context_t *)));
static void
cont_restore_1(rb_context_t *cont)
{
cont_restore_thread(cont);
/* restore machine stack */
#ifdef _M_AMD64
{
/* workaround for x64 SEH */
jmp_buf buf;
setjmp(buf);
((_JUMP_BUFFER*)(&cont->jmpbuf))->Frame =
((_JUMP_BUFFER*)(&buf))->Frame;
}
#endif
if (cont->machine_stack_src) {
FLUSH_REGISTER_WINDOWS;
MEMCPY(cont->machine_stack_src, cont->machine_stack,
VALUE, cont->machine_stack_size);
}
#ifdef __ia64
if (cont->machine_register_stack_src) {
MEMCPY(cont->machine_register_stack_src, cont->machine_register_stack,
VALUE, cont->machine_register_stack_size);
}
#endif
ruby_longjmp(cont->jmpbuf, 1);
}
NORETURN(NOINLINE(static void cont_restore_0(rb_context_t *, VALUE *)));
#ifdef __ia64
#define C(a) rse_##a##0, rse_##a##1, rse_##a##2, rse_##a##3, rse_##a##4
#define E(a) rse_##a##0= rse_##a##1= rse_##a##2= rse_##a##3= rse_##a##4
static volatile int C(a), C(b), C(c), C(d), C(e);
static volatile int C(f), C(g), C(h), C(i), C(j);
static volatile int C(k), C(l), C(m), C(n), C(o);
static volatile int C(p), C(q), C(r), C(s), C(t);
#if 0
{/* the above lines make cc-mode.el confused so much */}
#endif
int rb_dummy_false = 0;
NORETURN(NOINLINE(static void register_stack_extend(rb_context_t *, VALUE *, VALUE *)));
static void
register_stack_extend(rb_context_t *cont, VALUE *vp, VALUE *curr_bsp)
{
if (rb_dummy_false) {
/* use registers as much as possible */
E(a) = E(b) = E(c) = E(d) = E(e) =
E(f) = E(g) = E(h) = E(i) = E(j) =
E(k) = E(l) = E(m) = E(n) = E(o) =
E(p) = E(q) = E(r) = E(s) = E(t) = 0;
E(a) = E(b) = E(c) = E(d) = E(e) =
E(f) = E(g) = E(h) = E(i) = E(j) =
E(k) = E(l) = E(m) = E(n) = E(o) =
E(p) = E(q) = E(r) = E(s) = E(t) = 0;
}
if (curr_bsp < cont->machine_register_stack_src+cont->machine_register_stack_size) {
register_stack_extend(cont, vp, (VALUE*)rb_ia64_bsp());
}
cont_restore_0(cont, vp);
}
#undef C
#undef E
#endif
static void
cont_restore_0(rb_context_t *cont, VALUE *addr_in_prev_frame)
{
if (cont->machine_stack_src) {
#ifdef HAVE_ALLOCA
#define STACK_PAD_SIZE 1
#else
#define STACK_PAD_SIZE 1024
#endif
VALUE space[STACK_PAD_SIZE];
#if !STACK_GROW_DIRECTION
if (addr_in_prev_frame > &space[0]) {
/* Stack grows downward */
#endif
#if STACK_GROW_DIRECTION <= 0
volatile VALUE *const end = cont->machine_stack_src;
if (&space[0] > end) {
# ifdef HAVE_ALLOCA
volatile VALUE *sp = ALLOCA_N(VALUE, &space[0] - end);
(void)sp;
# else
cont_restore_0(cont, &space[0]);
# endif
}
#endif
#if !STACK_GROW_DIRECTION
}
else {
/* Stack grows upward */
#endif
#if STACK_GROW_DIRECTION >= 0
volatile VALUE *const end = cont->machine_stack_src + cont->machine_stack_size;
if (&space[STACK_PAD_SIZE] < end) {
# ifdef HAVE_ALLOCA
volatile VALUE *sp = ALLOCA_N(VALUE, end - &space[STACK_PAD_SIZE]);
(void)sp;
# else
cont_restore_0(cont, &space[STACK_PAD_SIZE-1]);
# endif
}
#endif
#if !STACK_GROW_DIRECTION
}
#endif
}
cont_restore_1(cont);
}
#ifdef __ia64
#define cont_restore_0(cont, vp) register_stack_extend((cont), (vp), (VALUE*)rb_ia64_bsp());
#endif
/*
* Document-class: Continuation
*
* Continuation objects are generated by <code>Kernel#callcc</code>,
* after having <code>require</code>d <i>continuation</i>. They hold
* a return address and execution context, allowing a nonlocal return
* to the end of the <code>callcc</code> block from anywhere within a
* program. Continuations are somewhat analogous to a structured
* version of C's <code>setjmp/longjmp</code> (although they contain
* more state, so you might consider them closer to threads).
*
* For instance:
*
* require "continuation"
* arr = [ "Freddie", "Herbie", "Ron", "Max", "Ringo" ]
* callcc{|cc| $cc = cc}
* puts(message = arr.shift)
* $cc.call unless message =~ /Max/
*
* <em>produces:</em>
*
* Freddie
* Herbie
* Ron
* Max
*
* This (somewhat contrived) example allows the inner loop to abandon
* processing early:
*
* require "continuation"
* callcc {|cont|
* for i in 0..4
* print "\n#{i}: "
* for j in i*5...(i+1)*5
* cont.call() if j == 17
* printf "%3d", j
* end
* end
* }
* puts
*
* <em>produces:</em>
*
* 0: 0 1 2 3 4
* 1: 5 6 7 8 9
* 2: 10 11 12 13 14
* 3: 15 16
*/
/*
* call-seq:
* callcc {|cont| block } -> obj
*
* Generates a <code>Continuation</code> object, which it passes to
* the associated block. You need to <code>require
* 'continuation'</code> before using this method. Performing a
* <em>cont</em><code>.call</code> will cause the <code>callcc</code>
* to return (as will falling through the end of the block). The
* value returned by the <code>callcc</code> is the value of the
* block, or the value passed to <em>cont</em><code>.call</code>. See
* class <code>Continuation</code> for more details. Also see
* <code>Kernel::throw</code> for an alternative mechanism for
* unwinding a call stack.
*/
static VALUE
rb_callcc(VALUE self)
{
volatile int called;
volatile VALUE val = cont_capture(&called);
if (called) {
return val;
}
else {
return rb_yield(val);
}
}
static VALUE
make_passing_arg(int argc, VALUE *argv)
{
switch(argc) {
case 0:
return Qnil;
case 1:
return argv[0];
default:
return rb_ary_new4(argc, argv);
}
}
/*
* call-seq:
* cont.call(args, ...)
* cont[args, ...]
*
* Invokes the continuation. The program continues from the end of the
* <code>callcc</code> block. If no arguments are given, the original
* <code>callcc</code> returns <code>nil</code>. If one argument is
* given, <code>callcc</code> returns it. Otherwise, an array
* containing <i>args</i> is returned.
*
* callcc {|cont| cont.call } #=> nil
* callcc {|cont| cont.call 1 } #=> 1
* callcc {|cont| cont.call 1, 2, 3 } #=> [1, 2, 3]
*/
static VALUE
rb_cont_call(int argc, VALUE *argv, VALUE contval)
{
rb_context_t *cont;
rb_thread_t *th = GET_THREAD();
GetContPtr(contval, cont);
if (cont->saved_thread.self != th->self) {
rb_raise(rb_eRuntimeError, "continuation called across threads");
}
if (cont->saved_thread.protect_tag != th->protect_tag) {
rb_raise(rb_eRuntimeError, "continuation called across stack rewinding barrier");
}
if (cont->saved_thread.fiber) {
rb_fiber_t *fcont;
GetFiberPtr(cont->saved_thread.fiber, fcont);
if (th->fiber != cont->saved_thread.fiber) {
rb_raise(rb_eRuntimeError, "continuation called across fiber");
}
}
cont->argc = argc;
cont->value = make_passing_arg(argc, argv);
cont_restore_0(cont, &contval);
return Qnil; /* unreachable */
}
/*********/
/* fiber */
/*********/
/*
* Document-class: Fiber
*
* Fibers are primitives for implementing light weight cooperative
* concurrency in Ruby. Basically they are a means of creating code blocks
* that can be paused and resumed, much like threads. The main difference
* is that they are never preempted and that the scheduling must be done by
* the programmer and not the VM.
*
* As opposed to other stackless light weight concurrency models, each fiber
* comes with a small 4KB stack. This enables the fiber to be paused from deeply
* nested function calls within the fiber block.
*
* When a fiber is created it will not run automatically. Rather it must be
* be explicitly asked to run using the <code>Fiber#resume</code> method.
* The code running inside the fiber can give up control by calling
* <code>Fiber.yield</code> in which case it yields control back to caller
* (the caller of the <code>Fiber#resume</code>).
*
* Upon yielding or termination the Fiber returns the value of the last
* executed expression
*
* For instance:
*
* fiber = Fiber.new do
* Fiber.yield 1
* 2
* end
*
* puts fiber.resume
* puts fiber.resume
* puts fiber.resume
*
* <em>produces</em>
*
* 1
* 2
* FiberError: dead fiber called
*
* The <code>Fiber#resume</code> method accepts an arbitrary number of
* parameters, if it is the first call to <code>resume</code> then they
* will be passed as block arguments. Otherwise they will be the return
* value of the call to <code>Fiber.yield</code>
*
* Example:
*
* fiber = Fiber.new do |first|
* second = Fiber.yield first + 2
* end
*
* puts fiber.resume 10
* puts fiber.resume 14
* puts fiber.resume 18
*
* <em>produces</em>
*
* 12
* 14
* FiberError: dead fiber called
*
*/
#define FIBER_VM_STACK_SIZE (4 * 1024)
static const rb_data_type_t fiber_data_type = {
"fiber",
{fiber_mark, fiber_free, fiber_memsize,},
};
static VALUE
fiber_alloc(VALUE klass)
{
return TypedData_Wrap_Struct(klass, &fiber_data_type, 0);
}
static rb_fiber_t*
fiber_t_alloc(VALUE fibval)
{
rb_fiber_t *fib;
rb_thread_t *th = GET_THREAD();
if (DATA_PTR(fibval) != 0) {
rb_raise(rb_eRuntimeError, "cannot initialize twice");
}
THREAD_MUST_BE_RUNNING(th);
fib = ALLOC(rb_fiber_t);
memset(fib, 0, sizeof(rb_fiber_t));
fib->cont.self = fibval;
fib->cont.type = FIBER_CONTEXT;
cont_init(&fib->cont, th);
fib->prev = Qnil;
fib->status = CREATED;
DATA_PTR(fibval) = fib;
return fib;
}