1/*
2 * Copyright (c) 2001-2011 Marc Alexander Lehmann <schmorp@schmorp.de>
3 *
4 * Redistribution and use in source and binary forms, with or without modifica-
5 * tion, are permitted provided that the following conditions are met:
6 *
7 * 1. Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 *
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
16 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
17 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
18 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
20 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
21 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
22 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
23 * OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 * Alternatively, the contents of this file may be used under the terms of
26 * the GNU General Public License ("GPL") version 2 or any later version,
27 * in which case the provisions of the GPL are applicable instead of
28 * the above. If you wish to allow the use of your version of this file
29 * only under the terms of the GPL and not to allow others to use your
30 * version of this file under the BSD license, indicate your decision
31 * by deleting the provisions above and replace them with the notice
32 * and other provisions required by the GPL. If you do not delete the
33 * provisions above, a recipient may use your version of this file under
34 * either the BSD or the GPL.
35 *
36 * This library is modelled strictly after Ralf S. Engelschalls article at
37 * http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
38 * go to Ralf S. Engelschall <rse@engelschall.com>.
39 */
40
41#include "coro.h"
42
43#include <stddef.h>
44#include <string.h>
45
46/*****************************************************************************/
47/* ucontext/setjmp/asm backends */
48/*****************************************************************************/
49#if CORO_UCONTEXT || CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM
50
51# if CORO_UCONTEXT
52# include <stddef.h>
53# endif
54
55# if !defined(STACK_ADJUST_PTR)
56# if __sgi
57/* IRIX is decidedly NON-unix */
58# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
59# define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
60# elif (__i386__ && CORO_LINUX) || (_M_IX86 && CORO_LOSER)
61# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
62# define STACK_ADJUST_SIZE(sp,ss) (ss)
63# elif (__amd64__ && CORO_LINUX) || ((_M_AMD64 || _M_IA64) && CORO_LOSER)
64# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
65# define STACK_ADJUST_SIZE(sp,ss) (ss)
66# else
67# define STACK_ADJUST_PTR(sp,ss) (sp)
68# define STACK_ADJUST_SIZE(sp,ss) (ss)
69# endif
70# endif
71
72# include <stdlib.h>
73
74# if CORO_SJLJ
75# include <stdio.h>
76# include <signal.h>
77# include <unistd.h>
78# endif
79
80static coro_func coro_init_func;
81static void *coro_init_arg;
82static coro_context *new_coro, *create_coro;
83
84static void
85coro_init (void)
86{
87 volatile coro_func func = coro_init_func;
88 volatile void *arg = coro_init_arg;
89
90 coro_transfer (new_coro, create_coro);
91
92#if __GCC_HAVE_DWARF2_CFI_ASM && __amd64
93 asm (".cfi_undefined rip");
94#endif
95
96 func ((void *)arg);
97
98 /* the new coro returned. bad. just abort() for now */
99 abort ();
100}
101
102# if CORO_SJLJ
103
104static volatile int trampoline_done;
105
106/* trampoline signal handler */
107static void
108trampoline (int sig)
109{
110 if (coro_setjmp (new_coro->env))
111 coro_init (); /* start it */
112 else
113 trampoline_done = 1;
114}
115
116# endif
117
118# if CORO_ASM
119
120 #if __arm__ && \
121 (defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
122 || defined __ARM_ARCH_7R__ || defined __ARM_ARCH_7M__ \
123 || __ARCH_ARCH == 7)
124 #define CORO_ARM 1
125 #endif
126
127 #if _WIN32 || __CYGWIN__
128 #define CORO_WIN_TIB 1
129 #endif
130
131 asm (
132 "\t.text\n"
133 #if _WIN32 || __CYGWIN__
134 "\t.globl _coro_transfer\n"
135 "_coro_transfer:\n"
136 #else
137 "\t.globl coro_transfer\n"
138 "coro_transfer:\n"
139 #endif
140 /* windows, of course, gives a shit on the amd64 ABI and uses different registers */
141 /* http://blogs.msdn.com/freik/archive/2005/03/17/398200.aspx */
142 #if __amd64
143
144 #if _WIN32 || __CYGWIN__
145 #define NUM_SAVED 29
146 "\tsubq $168, %rsp\t" /* one dummy qword to improve alignment */
147 "\tmovaps %xmm6, (%rsp)\n"
148 "\tmovaps %xmm7, 16(%rsp)\n"
149 "\tmovaps %xmm8, 32(%rsp)\n"
150 "\tmovaps %xmm9, 48(%rsp)\n"
151 "\tmovaps %xmm10, 64(%rsp)\n"
152 "\tmovaps %xmm11, 80(%rsp)\n"
153 "\tmovaps %xmm12, 96(%rsp)\n"
154 "\tmovaps %xmm13, 112(%rsp)\n"
155 "\tmovaps %xmm14, 128(%rsp)\n"
156 "\tmovaps %xmm15, 144(%rsp)\n"
157 "\tpushq %rsi\n"
158 "\tpushq %rdi\n"
159 "\tpushq %rbp\n"
160 "\tpushq %rbx\n"
161 "\tpushq %r12\n"
162 "\tpushq %r13\n"
163 "\tpushq %r14\n"
164 "\tpushq %r15\n"
165 #if CORO_WIN_TIB
166 "\tpushq %fs:0x0\n"
167 "\tpushq %fs:0x8\n"
168 "\tpushq %fs:0xc\n"
169 #endif
170 "\tmovq %rsp, (%rcx)\n"
171 "\tmovq (%rdx), %rsp\n"
172 #if CORO_WIN_TIB
173 "\tpopq %fs:0xc\n"
174 "\tpopq %fs:0x8\n"
175 "\tpopq %fs:0x0\n"
176 #endif
177 "\tpopq %r15\n"
178 "\tpopq %r14\n"
179 "\tpopq %r13\n"
180 "\tpopq %r12\n"
181 "\tpopq %rbx\n"
182 "\tpopq %rbp\n"
183 "\tpopq %rdi\n"
184 "\tpopq %rsi\n"
185 "\tmovaps (%rsp), %xmm6\n"
186 "\tmovaps 16(%rsp), %xmm7\n"
187 "\tmovaps 32(%rsp), %xmm8\n"
188 "\tmovaps 48(%rsp), %xmm9\n"
189 "\tmovaps 64(%rsp), %xmm10\n"
190 "\tmovaps 80(%rsp), %xmm11\n"
191 "\tmovaps 96(%rsp), %xmm12\n"
192 "\tmovaps 112(%rsp), %xmm13\n"
193 "\tmovaps 128(%rsp), %xmm14\n"
194 "\tmovaps 144(%rsp), %xmm15\n"
195 "\taddq $168, %rsp\n"
196 #else
197 #define NUM_SAVED 6
198 "\tpushq %rbp\n"
199 "\tpushq %rbx\n"
200 "\tpushq %r12\n"
201 "\tpushq %r13\n"
202 "\tpushq %r14\n"
203 "\tpushq %r15\n"
204 "\tmovq %rsp, (%rdi)\n"
205 "\tmovq (%rsi), %rsp\n"
206 "\tpopq %r15\n"
207 "\tpopq %r14\n"
208 "\tpopq %r13\n"
209 "\tpopq %r12\n"
210 "\tpopq %rbx\n"
211 "\tpopq %rbp\n"
212 #endif
213 "\tpopq %rcx\n"
214 "\tjmpq *%rcx\n"
215
216 #elif __i386__
217
218 #define NUM_SAVED 4
219 "\tpushl %ebp\n"
220 "\tpushl %ebx\n"
221 "\tpushl %esi\n"
222 "\tpushl %edi\n"
223 #if CORO_WIN_TIB
224 #undef NUM_SAVED
225 #define NUM_SAVED 7
226 "\tpushl %fs:0\n"
227 "\tpushl %fs:4\n"
228 "\tpushl %fs:8\n"
229 #endif
230 "\tmovl %esp, (%eax)\n"
231 "\tmovl (%edx), %esp\n"
232 #if CORO_WIN_TIB
233 "\tpopl %fs:8\n"
234 "\tpopl %fs:4\n"
235 "\tpopl %fs:0\n"
236 #endif
237 "\tpopl %edi\n"
238 "\tpopl %esi\n"
239 "\tpopl %ebx\n"
240 "\tpopl %ebp\n"
241 "\tpopl %ecx\n"
242 "\tjmpl *%ecx\n"
243
244 #elif CORO_ARM /* untested, what about thumb, neon, iwmmxt? */
245
246 #if __ARM_PCS_VFP
247 "\tvpush {d8-d15}\n"
248 #define NUM_SAVED (9 + 8 * 2)
249 #else
250 #define NUM_SAVED 9
251 #endif
252 "\tpush {r4-r11,lr}\n"
253 "\tstr sp, [r0]\n"
254 "\tldr sp, [r1]\n"
255 "\tpop {r4-r11,lr}\n"
256 #if __ARM_PCS_VFP
257 "\tvpop {d8-d15}\n"
258 #endif
259 "\tmov r15, lr\n"
260
261 #elif __mips__ && 0 /* untested, 32 bit only */
262
263 #define NUM_SAVED (12 + 8 * 2)
264 /* TODO: n64/o64, lw=>ld */
265
266 "\t.set nomips16\n"
267 "\t.frame $sp,112,$31\n"
268 #if __mips_soft_float
269 "\taddiu $sp,$sp,-44\n"
270 #else
271 "\taddiu $sp,$sp,-112\n"
272 "\ts.d $f30,88($sp)\n"
273 "\ts.d $f28,80($sp)\n"
274 "\ts.d $f26,72($sp)\n"
275 "\ts.d $f24,64($sp)\n"
276 "\ts.d $f22,56($sp)\n"
277 "\ts.d $f20,48($sp)\n"
278 #endif
279 "\tsw $28,40($sp)\n"
280 "\tsw $31,36($sp)\n"
281 "\tsw $fp,32($sp)\n"
282 "\tsw $23,28($sp)\n"
283 "\tsw $22,24($sp)\n"
284 "\tsw $21,20($sp)\n"
285 "\tsw $20,16($sp)\n"
286 "\tsw $19,12($sp)\n"
287 "\tsw $18,8($sp)\n"
288 "\tsw $17,4($sp)\n"
289 "\tsw $16,0($sp)\n"
290 "\tsw $sp,0($4)\n"
291 "\tlw $sp,0($5)\n"
292 #if !__mips_soft_float
293 "\tl.d $f30,88($sp)\n"
294 "\tl.d $f28,80($sp)\n"
295 "\tl.d $f26,72($sp)\n"
296 "\tl.d $f24,64($sp)\n"
297 "\tl.d $f22,56($sp)\n"
298 "\tl.d $f20,48($sp)\n"
299 #endif
300 "\tlw $28,40($sp)\n"
301 "\tlw $31,36($sp)\n"
302 "\tlw $fp,32($sp)\n"
303 "\tlw $23,28($sp)\n"
304 "\tlw $22,24($sp)\n"
305 "\tlw $21,20($sp)\n"
306 "\tlw $20,16($sp)\n"
307 "\tlw $19,12($sp)\n"
308 "\tlw $18,8($sp)\n"
309 "\tlw $17,4($sp)\n"
310 "\tlw $16,0($sp)\n"
311 "\tj $31\n"
312 #if __mips_soft_float
313 "\taddiu $sp,$sp,44\n"
314 #else
315 "\taddiu $sp,$sp,112\n"
316 #endif
317
318 #else
319 #error unsupported architecture
320 #endif
321 );
322
323# endif
324
325void
326coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, size_t ssize)
327{
328 coro_context nctx;
329# if CORO_SJLJ
330 stack_t ostk, nstk;
331 struct sigaction osa, nsa;
332 sigset_t nsig, osig;
333# endif
334
335 if (!coro)
336 return;
337
338 coro_init_func = coro;
339 coro_init_arg = arg;
340
341 new_coro = ctx;
342 create_coro = &nctx;
343
344# if CORO_SJLJ
345 /* we use SIGUSR2. first block it, then fiddle with it. */
346
347 sigemptyset (&nsig);
348 sigaddset (&nsig, SIGUSR2);
349 sigprocmask (SIG_BLOCK, &nsig, &osig);
350
351 nsa.sa_handler = trampoline;
352 sigemptyset (&nsa.sa_mask);
353 nsa.sa_flags = SA_ONSTACK;
354
355 if (sigaction (SIGUSR2, &nsa, &osa))
356 {
357 perror ("sigaction");
358 abort ();
359 }
360
361 /* set the new stack */
362 nstk.ss_sp = STACK_ADJUST_PTR (sptr, ssize); /* yes, some platforms (IRIX) get this wrong. */
363 nstk.ss_size = STACK_ADJUST_SIZE (sptr, ssize);
364 nstk.ss_flags = 0;
365
366 if (sigaltstack (&nstk, &ostk) < 0)
367 {
368 perror ("sigaltstack");
369 abort ();
370 }
371
372 trampoline_done = 0;
373 kill (getpid (), SIGUSR2);
374 sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
375
376 while (!trampoline_done)
377 sigsuspend (&nsig);
378
379 sigaltstack (0, &nstk);
380 nstk.ss_flags = SS_DISABLE;
381 if (sigaltstack (&nstk, 0) < 0)
382 perror ("sigaltstack");
383
384 sigaltstack (0, &nstk);
385 if (~nstk.ss_flags & SS_DISABLE)
386 abort ();
387
388 if (~ostk.ss_flags & SS_DISABLE)
389 sigaltstack (&ostk, 0);
390
391 sigaction (SIGUSR2, &osa, 0);
392 sigprocmask (SIG_SETMASK, &osig, 0);
393
394# elif CORO_LOSER
395
396 coro_setjmp (ctx->env);
397 #if __CYGWIN__ && __i386__
398 ctx->env[8] = (long) coro_init;
399 ctx->env[7] = (long) ((char *)sptr + ssize) - sizeof (long);
400 #elif __CYGWIN__ && __x86_64__
401 ctx->env[7] = (long) coro_init;
402 ctx->env[6] = (long) ((char *)sptr + ssize) - sizeof (long);
403 #elif defined __MINGW32__
404 ctx->env[5] = (long) coro_init;
405 ctx->env[4] = (long) ((char *)sptr + ssize) - sizeof (long);
406 #elif defined _M_IX86
407 ((_JUMP_BUFFER *)&ctx->env)->Eip = (long) coro_init;
408 ((_JUMP_BUFFER *)&ctx->env)->Esp = (long) STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
409 #elif defined _M_AMD64
410 ((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64) coro_init;
411 ((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
412 #elif defined _M_IA64
413 ((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64) coro_init;
414 ((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
415 #else
416 #error "microsoft libc or architecture not supported"
417 #endif
418
419# elif CORO_LINUX
420
421 coro_setjmp (ctx->env);
422 #if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
423 ctx->env[0].__jmpbuf[JB_PC] = (long) coro_init;
424 ctx->env[0].__jmpbuf[JB_SP] = (long) STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
425 #elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
426 ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
427 ctx->env[0].__jmpbuf[0].__sp = (int *) ((char *)sptr + ssize) - sizeof (long);
428 #elif defined (__GNU_LIBRARY__) && defined (__i386__)
429 ctx->env[0].__jmpbuf[0].__pc = (char *) coro_init;
430 ctx->env[0].__jmpbuf[0].__sp = (void *) ((char *)sptr + ssize) - sizeof (long);
431 #elif defined (__GNU_LIBRARY__) && defined (__x86_64__)
432 ctx->env[0].__jmpbuf[JB_PC] = (long) coro_init;
433 ctx->env[0].__jmpbuf[0].__sp = (void *) ((char *)sptr + ssize) - sizeof (long);
434 #else
435 #error "linux libc or architecture not supported"
436 #endif
437
438# elif CORO_IRIX
439
440 coro_setjmp (ctx->env, 0);
441 ctx->env[JB_PC] = (__uint64_t)coro_init;
442 ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
443
444# elif CORO_ASM
445
446 #if __i386__ || __x86_64__
447 ctx->sp = (void **)(ssize + (char *)sptr);
448 *--ctx->sp = (void *)abort; /* needed for alignment only */
449 *--ctx->sp = (void *)coro_init;
450 #if CORO_WIN_TIB
451 *--ctx->sp = 0; /* ExceptionList */
452 *--ctx->sp = (char *)sptr + ssize; /* StackBase */
453 *--ctx->sp = sptr; /* StackLimit */
454 #endif
455 #elif CORO_ARM
456 /* return address stored in lr register, don't push anything */
457 #else
458 #error unsupported architecture
459 #endif
460
461 ctx->sp -= NUM_SAVED;
462 memset (ctx->sp, 0, sizeof (*ctx->sp) * NUM_SAVED);
463
464 #if __i386__ || __x86_64__
465 /* done already */
466 #elif CORO_ARM
467 ctx->sp[0] = coro; /* r4 */
468 ctx->sp[1] = arg; /* r5 */
469 ctx->sp[8] = (char *)coro_init; /* lr */
470 #else
471 #error unsupported architecture
472 #endif
473
474# elif CORO_UCONTEXT
475
476 getcontext (&(ctx->uc));
477
478 ctx->uc.uc_link = 0;
479 ctx->uc.uc_stack.ss_sp = sptr;
480 ctx->uc.uc_stack.ss_size = (size_t)ssize;
481 ctx->uc.uc_stack.ss_flags = 0;
482
483 makecontext (&(ctx->uc), (void (*)())coro_init, 0);
484
485# endif
486
487 coro_transfer (create_coro, new_coro);
488}
489
490/*****************************************************************************/
491/* pthread backend */
492/*****************************************************************************/
493#elif CORO_PTHREAD
494
495/* this mutex will be locked by the running coroutine */
496pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
497
498struct coro_init_args
499{
500 coro_func func;
501 void *arg;
502 coro_context *self, *main;
503};
504
505static pthread_t null_tid;
506
507/* I'd so love to cast pthread_mutex_unlock to void (*)(void *)... */
508static void
509mutex_unlock_wrapper (void *arg)
510{
511 pthread_mutex_unlock ((pthread_mutex_t *)arg);
512}
513
514static void *
515coro_init (void *args_)
516{
517 struct coro_init_args *args = (struct coro_init_args *)args_;
518 coro_func func = args->func;
519 void *arg = args->arg;
520
521 pthread_mutex_lock (&coro_mutex);
522
523 /* we try to be good citizens and use deferred cancellation and cleanup handlers */
524 pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
525 coro_transfer (args->self, args->main);
526 func (arg);
527 pthread_cleanup_pop (1);
528
529 return 0;
530}
531
532void
533coro_transfer (coro_context *prev, coro_context *next)
534{
535 pthread_cond_signal (&next->cv);
536 pthread_cond_wait (&prev->cv, &coro_mutex);
537#if __FreeBSD__ /* freebsd is of course broken and needs manual testcancel calls... yay... */
538 pthread_testcancel ();
539#endif
540}
541
542void
543coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, size_t ssize)
544{
545 static coro_context nctx;
546 static int once;
547
548 if (!once)
549 {
550 once = 1;
551
552 pthread_mutex_lock (&coro_mutex);
553 pthread_cond_init (&nctx.cv, 0);
554 null_tid = pthread_self ();
555 }
556
557 pthread_cond_init (&ctx->cv, 0);
558
559 if (coro)
560 {
561 pthread_attr_t attr;
562 struct coro_init_args args;
563
564 args.func = coro;
565 args.arg = arg;
566 args.self = ctx;
567 args.main = &nctx;
568
569 pthread_attr_init (&attr);
570#if __UCLIBC__
571 /* exists, but is borked */
572 /*pthread_attr_setstacksize (&attr, (size_t)ssize);*/
573#elif __CYGWIN__
574 /* POSIX, not here */
575 pthread_attr_setstacksize (&attr, (size_t)ssize);
576#else
577 pthread_attr_setstack (&attr, sptr, (size_t)ssize);
578#endif
579 pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
580 pthread_create (&ctx->id, &attr, coro_init, &args);
581
582 coro_transfer (args.main, args.self);
583 }
584 else
585 ctx->id = null_tid;
586}
587
588void
589coro_destroy (coro_context *ctx)
590{
591 if (!pthread_equal (ctx->id, null_tid))
592 {
593 pthread_cancel (ctx->id);
594 pthread_mutex_unlock (&coro_mutex);
595 pthread_join (ctx->id, 0);
596 pthread_mutex_lock (&coro_mutex);
597 }
598
599 pthread_cond_destroy (&ctx->cv);
600}
601
602/*****************************************************************************/
603/* fiber backend */
604/*****************************************************************************/
605#elif CORO_FIBER
606
607#define WIN32_LEAN_AND_MEAN
608#if _WIN32_WINNT < 0x0400
609 #undef _WIN32_WINNT
610 #define _WIN32_WINNT 0x0400
611#endif
612#include <windows.h>
613
614VOID CALLBACK
615coro_init (PVOID arg)
616{
617 coro_context *ctx = (coro_context *)arg;
618
619 ctx->coro (ctx->arg);
620}
621
622void
623coro_transfer (coro_context *prev, coro_context *next)
624{
625 if (!prev->fiber)
626 {
627 prev->fiber = GetCurrentFiber ();
628
629 if (prev->fiber == 0 || prev->fiber == (void *)0x1e00)
630 prev->fiber = ConvertThreadToFiber (0);
631 }
632
633 SwitchToFiber (next->fiber);
634}
635
636void
637coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, size_t ssize)
638{
639 ctx->fiber = 0;
640 ctx->coro = coro;
641 ctx->arg = arg;
642
643 if (!coro)
644 return;
645
646 ctx->fiber = CreateFiber (ssize, coro_init, ctx);
647}
648
649void
650coro_destroy (coro_context *ctx)
651{
652 DeleteFiber (ctx->fiber);
653}
654
655#else
656 #error unsupported backend
657#endif
658
659/*****************************************************************************/
660/* stack management */
661/*****************************************************************************/
662#if CORO_STACKALLOC
663
664#include <stdlib.h>
665
666#ifndef _WIN32
667# include <unistd.h>
668#endif
669
670#if CORO_USE_VALGRIND
671# include <valgrind/valgrind.h>
672#endif
673
674#if _POSIX_MAPPED_FILES
675# include <sys/mman.h>
676# define CORO_MMAP 1
677# ifndef MAP_ANONYMOUS
678# ifdef MAP_ANON
679# define MAP_ANONYMOUS MAP_ANON
680# else
681# undef CORO_MMAP
682# endif
683# endif
684# include <limits.h>
685#else
686# undef CORO_MMAP
687#endif
688
689#if _POSIX_MEMORY_PROTECTION
690# ifndef CORO_GUARDPAGES
691# define CORO_GUARDPAGES 4
692# endif
693#else
694# undef CORO_GUARDPAGES
695#endif
696
697#if !CORO_MMAP
698# undef CORO_GUARDPAGES
699#endif
700
701#if !__i386__ && !__x86_64__ && !__powerpc__ && !__arm__ && !__aarch64__ && !__m68k__ && !__alpha__ && !__mips__ && !__sparc64__
702# undef CORO_GUARDPAGES
703#endif
704
705#ifndef CORO_GUARDPAGES
706# define CORO_GUARDPAGES 0
707#endif
708
709#if !PAGESIZE
710 #if !CORO_MMAP
711 #define PAGESIZE 4096
712 #else
713 static size_t
714 coro_pagesize (void)
715 {
716 static size_t pagesize;
717
718 if (!pagesize)
719 pagesize = sysconf (_SC_PAGESIZE);
720
721 return pagesize;
722 }
723
724 #define PAGESIZE coro_pagesize ()
725 #endif
726#endif
727
728int
729coro_stack_alloc (struct coro_stack *stack, unsigned int size)
730{
731 if (!size)
732 size = 256 * 1024;
733
734 stack->sptr = 0;
735 stack->ssze = ((size_t)size * sizeof (void *) + PAGESIZE - 1) / PAGESIZE * PAGESIZE;
736
737#if CORO_FIBER
738
739 stack->sptr = (void *)stack;
740 return 1;
741
742#else
743
744 size_t ssze = stack->ssze + CORO_GUARDPAGES * PAGESIZE;
745 void *base;
746
747 #if CORO_MMAP
748 /* mmap supposedly does allocate-on-write for us */
749 base = mmap (0, ssze, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
750
751 if (base == (void *)-1)
752 {
753 /* some systems don't let us have executable heap */
754 /* we assume they won't need executable stack in that case */
755 base = mmap (0, ssze, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
756
757 if (base == (void *)-1)
758 return 0;
759 }
760
761 #if CORO_GUARDPAGES
762 mprotect (base, CORO_GUARDPAGES * PAGESIZE, PROT_NONE);
763 #endif
764
765 base = (void*)((char *)base + CORO_GUARDPAGES * PAGESIZE);
766 #else
767 base = malloc (ssze);
768 if (!base)
769 return 0;
770 #endif
771
772 #if CORO_USE_VALGRIND
773 stack->valgrind_id = VALGRIND_STACK_REGISTER ((char *)base, ((char *)base) + ssze - CORO_GUARDPAGES * PAGESIZE);
774 #endif
775
776 stack->sptr = base;
777 return 1;
778
779#endif
780}
781
782void
783coro_stack_free (struct coro_stack *stack)
784{
785#if CORO_FIBER
786 /* nop */
787#else
788 #if CORO_USE_VALGRIND
789 VALGRIND_STACK_DEREGISTER (stack->valgrind_id);
790 #endif
791
792 #if CORO_MMAP
793 if (stack->sptr)
794 munmap ((void*)((char *)stack->sptr - CORO_GUARDPAGES * PAGESIZE),
795 stack->ssze + CORO_GUARDPAGES * PAGESIZE);
796 #else
797 free (stack->sptr);
798 #endif
799#endif
800}
801
802#endif
803
804