libcoro/coro.c

/*
 * Copyright (c) 2001-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
 * 
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, are permitted provided that the following conditions are met:
 * 
 *   1.  Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 * 
 *   2.  Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License ("GPL") version 2 or any later version,
 * in which case the provisions of the GPL are applicable instead of
 * the above. If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the BSD license, indicate your decision
 * by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL. If you do not delete the
 * provisions above, a recipient may use your version of this file under
 * either the BSD or the GPL.
 *
 * This library is modelled strictly after Ralf S. Engelschalls article at
 * http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
 * go to Ralf S. Engelschall <rse@engelschall.com>.
 */

#include "coro.h"

#if !defined(STACK_ADJUST_PTR)
/* IRIX is decidedly NON-unix */
# if __sgi
#  define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
#  define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
# elif (__i386__ && CORO_LINUX) || (_M_IX86 && CORO_LOSER)
#  define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
#  define STACK_ADJUST_SIZE(sp,ss) (ss)
# elif (__amd64__ && CORO_LINUX) || ((_M_AMD64 || _M_IA64) && CORO_LOSER)
#  define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
#  define STACK_ADJUST_SIZE(sp,ss) (ss)
# else
#  define STACK_ADJUST_PTR(sp,ss) (sp)
#  define STACK_ADJUST_SIZE(sp,ss) (ss)
# endif
#endif

#if CORO_UCONTEXT
# include <stddef.h>
#endif

#if CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM

#include <stdlib.h>

#if CORO_SJLJ
# include <stdio.h>
# include <signal.h>
# include <unistd.h>
#endif

static volatile coro_func coro_init_func;
static volatile void *coro_init_arg;
static volatile coro_context *new_coro, *create_coro;

/* what we really want to detect here is wether we use a new-enough version of GAS */
/* instead, check for gcc 3, ELF and GNU/Linux and hope for the best */
#if __GNUC__ >= 3 && __ELF__ && __linux__
# define HAVE_CFI 1
#endif

static void
coro_init (void)
{
  volatile coro_func func = coro_init_func;
  volatile void *arg = coro_init_arg;

  coro_transfer ((coro_context *)new_coro, (coro_context *)create_coro);

  func ((void *)arg);

  /* the new coro returned. bad. just abort() for now */
  abort ();
}

# if CORO_SJLJ

static volatile int trampoline_count;

/* trampoline signal handler */
static void
trampoline (int sig)
{
  if (setjmp (((coro_context *)new_coro)->env))
    {
#if HAVE_CFI
      asm (".cfi_startproc");
#endif
      coro_init (); /* start it */
#if HAVE_CFI
      asm (".cfi_endproc");
#endif
    }
  else
    trampoline_count++;
}

# endif

#endif

#if CORO_ASM
asm (
     ".text\n"
     ".globl coro_transfer\n"
     ".type coro_transfer, @function\n"
     "coro_transfer:\n"
#if __amd64
# define NUM_SAVED 6
     "\tpush %rbp\n"
     "\tpush %rbx\n"
     "\tpush %r12\n"
     "\tpush %r13\n"
     "\tpush %r14\n"
     "\tpush %r15\n"
     "\tmov  %rsp, (%rdi)\n"
     "\tmov  (%rsi), %rsp\n"
     "\tpop  %r15\n"
     "\tpop  %r14\n"
     "\tpop  %r13\n"
     "\tpop  %r12\n"
     "\tpop  %rbx\n"
     "\tpop  %rbp\n"
#elif __i386
# define NUM_SAVED 4
     "\tpush %ebp\n"
     "\tpush %ebx\n"
     "\tpush %esi\n"
     "\tpush %edi\n"
     "\tmov  %esp, (%eax)\n"
     "\tmov  (%edx), %esp\n"
     "\tpop  %edi\n"
     "\tpop  %esi\n"
     "\tpop  %ebx\n"
     "\tpop  %ebp\n"
#else
# error unsupported architecture
#endif
     "\tret\n"
);
#endif

#if CORO_PTHREAD

struct coro_init_args {
  coro_func func;
  void *arg;
  coro_context *self, *main;
};

pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;

static void *
trampoline (void *args_)
{
  struct coro_init_args *args = (struct coro_init_args *)args_;
  coro_func func = args->func;
  void *arg = args->arg;

  pthread_mutex_lock (&coro_mutex);
  pthread_cond_destroy (&args->self->c);
  coro_transfer (args->self, args->main);
  func (arg);
  pthread_mutex_unlock (&coro_mutex);

  return 0;
}

asm("");

void coro_transfer(coro_context *prev, coro_context *next)
{
  pthread_cond_init (&prev->c, 0);
  pthread_cond_signal (&next->c);
  pthread_cond_wait (&prev->c, &coro_mutex);
  pthread_cond_destroy (&prev->c);
}

#endif

/* initialize a machine state */
void coro_create (coro_context *ctx,
                  coro_func coro, void *arg,
                  void *sptr, long ssize)
{
#if CORO_UCONTEXT

  getcontext (&(ctx->uc));

  ctx->uc.uc_link           =  0;
  ctx->uc.uc_stack.ss_sp    = STACK_ADJUST_PTR (sptr,ssize);
  ctx->uc.uc_stack.ss_size  = (size_t)STACK_ADJUST_SIZE (sptr,ssize);
  ctx->uc.uc_stack.ss_flags = 0;

  makecontext (&(ctx->uc), (void (*)()) coro, 1, arg);

#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM

# if CORO_SJLJ
  stack_t ostk, nstk;
  struct sigaction osa, nsa;
  sigset_t nsig, osig;
# endif
  coro_context nctx;

  coro_init_func = coro;
  coro_init_arg  = arg;

  new_coro    = ctx;
  create_coro = &nctx;

# if CORO_SJLJ
  /* we use SIGUSR2. first block it, then fiddle with it. */

  sigemptyset (&nsig);
  sigaddset (&nsig, SIGUSR2);
  sigprocmask (SIG_BLOCK, &nsig, &osig);

  nsa.sa_handler = trampoline;
  sigemptyset (&nsa.sa_mask);
  nsa.sa_flags = SA_ONSTACK;

  if (sigaction (SIGUSR2, &nsa, &osa))
    {
      perror ("sigaction");
      abort ();
    }

  /* set the new stack */
  nstk.ss_sp    = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
  nstk.ss_size  = STACK_ADJUST_SIZE (sptr,ssize);
  nstk.ss_flags = 0;

  if (sigaltstack (&nstk, &ostk) < 0)
    {
      perror ("sigaltstack");
      abort ();
    }

  trampoline_count = 0;
  kill (getpid (), SIGUSR2);
  sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);

  while (!trampoline_count)
    sigsuspend (&nsig);

  sigaltstack (0, &nstk);
  nstk.ss_flags = SS_DISABLE;
  if (sigaltstack (&nstk, 0) < 0)
    perror ("sigaltstack");

  sigaltstack (0, &nstk);
  if (~nstk.ss_flags & SS_DISABLE)
    abort ();

  if (~ostk.ss_flags & SS_DISABLE)
    sigaltstack (&ostk, 0);

  sigaction (SIGUSR2, &osa, 0);

  sigprocmask (SIG_SETMASK, &osig, 0);

# elif CORO_LOSER

  setjmp (ctx->env);
#if __CYGWIN__
  ctx->env[7] = (long)((char *)sptr + ssize) - sizeof (long);
  ctx->env[8] = (long)coro_init;
#elif defined(_M_IX86)
  ((_JUMP_BUFFER *)&ctx->env)->Eip   = (long)coro_init;
  ((_JUMP_BUFFER *)&ctx->env)->Esp   = (long)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
#elif defined(_M_AMD64)
  ((_JUMP_BUFFER *)&ctx->env)->Rip   = (__int64)coro_init;
  ((_JUMP_BUFFER *)&ctx->env)->Rsp   = (__int64)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
#elif defined(_M_IA64)
  ((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64)coro_init;
  ((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
#else
# error "microsoft libc or architecture not supported"
#endif

# elif CORO_LINUX

  _setjmp (ctx->env);
#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
  ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
  ctx->env[0].__jmpbuf[JB_SP] = (long)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
#elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
  ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
  ctx->env[0].__jmpbuf[0].__sp = (int *)((char *)sptr + ssize) - sizeof (long);
#elif defined (__GNU_LIBRARY__) && defined (__i386__)
  ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
  ctx->env[0].__jmpbuf[0].__sp = (void *)((char *)sptr + ssize) - sizeof (long);
#elif defined (__GNU_LIBRARY__) && defined (__amd64__)
  ctx->env[0].__jmpbuf[JB_PC]  = (long)coro_init;
  ctx->env[0].__jmpbuf[0].__sp = (void *)((char *)sptr + ssize) - sizeof (long);
#else
# error "linux libc or architecture not supported"
#endif

# elif CORO_IRIX

  setjmp (ctx->env);
  ctx->env[JB_PC] = (__uint64_t)coro_init;
  ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);

# elif CORO_ASM

  ctx->sp = (volatile void **)(ssize + (char *)sptr);
  *--ctx->sp = (void *)abort; /* needed for alignment only */
  *--ctx->sp = (void *)coro_init;
  ctx->sp -= NUM_SAVED;

# endif

  coro_transfer ((coro_context *)create_coro, (coro_context *)new_coro);

# elif CORO_PTHREAD

  pthread_t id;
  pthread_attr_t attr;
  coro_context nctx;
  struct coro_init_args args;
  static int once;

  if (!once)
    {
      pthread_mutex_lock (&coro_mutex);
      once = 1;
    }

  args.func = coro;
  args.arg  = arg;
  args.self = ctx;
  args.main = &nctx;

  pthread_attr_init (&attr);
  pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
  pthread_attr_setstack (&attr, sptr, (size_t)ssize);
  pthread_create (&id, &attr, trampoline, &args);

  pthread_cond_init (&args.self->c, 0);
  coro_transfer (args.main, args.self);

#else
# error unsupported backend
#endif
}

Revision:	1.37
Committed:	Fri Nov 7 16:39:35 2008 UTC (15 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.36:	+6 -6 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* Copyright (c) 2001-2008 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	#if !defined(STACK_ADJUST_PTR)
44	/* IRIX is decidedly NON-unix */
45	# if __sgi
46	# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
47	# define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
48	# elif (__i386__ && CORO_LINUX) \|\| (_M_IX86 && CORO_LOSER)
49	# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
50	# define STACK_ADJUST_SIZE(sp,ss) (ss)
51	# elif (__amd64__ && CORO_LINUX) \|\| ((_M_AMD64 \|\| _M_IA64) && CORO_LOSER)
52	# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
53	# define STACK_ADJUST_SIZE(sp,ss) (ss)
54	# else
55	# define STACK_ADJUST_PTR(sp,ss) (sp)
56	# define STACK_ADJUST_SIZE(sp,ss) (ss)
57	# endif
58	#endif
59
60	#if CORO_UCONTEXT
61	# include <stddef.h>
62	#endif
63
64	#if CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX \|\| CORO_ASM
65
66	#include <stdlib.h>
67
68	#if CORO_SJLJ
69	# include <stdio.h>
70	# include <signal.h>
71	# include <unistd.h>
72	#endif
73
74	static volatile coro_func coro_init_func;
75	static volatile void *coro_init_arg;
76	static volatile coro_context new_coro, create_coro;
77
78	/* what we really want to detect here is wether we use a new-enough version of GAS */
79	/* instead, check for gcc 3, ELF and GNU/Linux and hope for the best */
80	#if __GNUC__ >= 3 && __ELF__ && __linux__
81	# define HAVE_CFI 1
82	#endif
83
84	static void
85	coro_init (void)
86	{
87	volatile coro_func func = coro_init_func;
88	volatile void *arg = coro_init_arg;
89
90	coro_transfer ((coro_context )new_coro, (coro_context )create_coro);
91
92	func ((void *)arg);
93
94	/* the new coro returned. bad. just abort() for now */
95	abort ();
96	}
97
98	# if CORO_SJLJ
99
100	static volatile int trampoline_count;
101
102	/* trampoline signal handler */
103	static void
104	trampoline (int sig)
105	{
106	if (setjmp (((coro_context *)new_coro)->env))
107	{
108	#if HAVE_CFI
109	asm (".cfi_startproc");
110	#endif
111	coro_init (); /* start it */
112	#if HAVE_CFI
113	asm (".cfi_endproc");
114	#endif
115	}
116	else
117	trampoline_count++;
118	}
119
120	# endif
121
122	#endif
123
124	#if CORO_ASM
125	asm (
126	".text\n"
127	".globl coro_transfer\n"
128	".type coro_transfer, @function\n"
129	"coro_transfer:\n"
130	#if __amd64
131	# define NUM_SAVED 6
132	"\tpush %rbp\n"
133	"\tpush %rbx\n"
134	"\tpush %r12\n"
135	"\tpush %r13\n"
136	"\tpush %r14\n"
137	"\tpush %r15\n"
138	"\tmov %rsp, (%rdi)\n"
139	"\tmov (%rsi), %rsp\n"
140	"\tpop %r15\n"
141	"\tpop %r14\n"
142	"\tpop %r13\n"
143	"\tpop %r12\n"
144	"\tpop %rbx\n"
145	"\tpop %rbp\n"
146	#elif __i386
147	# define NUM_SAVED 4
148	"\tpush %ebp\n"
149	"\tpush %ebx\n"
150	"\tpush %esi\n"
151	"\tpush %edi\n"
152	"\tmov %esp, (%eax)\n"
153	"\tmov (%edx), %esp\n"
154	"\tpop %edi\n"
155	"\tpop %esi\n"
156	"\tpop %ebx\n"
157	"\tpop %ebp\n"
158	#else
159	# error unsupported architecture
160	#endif
161	"\tret\n"
162	);
163	#endif
164
165	#if CORO_PTHREAD
166
167	struct coro_init_args {
168	coro_func func;
169	void *arg;
170	coro_context self, main;
171	};
172
173	pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
174
175	static void *
176	trampoline (void *args_)
177	{
178	struct coro_init_args args = (struct coro_init_args )args_;
179	coro_func func = args->func;
180	void *arg = args->arg;
181
182	pthread_mutex_lock (&coro_mutex);
183	pthread_cond_destroy (&args->self->c);
184	coro_transfer (args->self, args->main);
185	func (arg);
186	pthread_mutex_unlock (&coro_mutex);
187
188	return 0;
189	}
190
191	asm("");
192
193	void coro_transfer(coro_context prev, coro_context next)
194	{
195	pthread_cond_init (&prev->c, 0);
196	pthread_cond_signal (&next->c);
197	pthread_cond_wait (&prev->c, &coro_mutex);
198	pthread_cond_destroy (&prev->c);
199	}
200
201	#endif
202
203	/* initialize a machine state */
204	void coro_create (coro_context *ctx,
205	coro_func coro, void *arg,
206	void *sptr, long ssize)
207	{
208	#if CORO_UCONTEXT
209
210	getcontext (&(ctx->uc));
211
212	ctx->uc.uc_link = 0;
213	ctx->uc.uc_stack.ss_sp = STACK_ADJUST_PTR (sptr,ssize);
214	ctx->uc.uc_stack.ss_size = (size_t)STACK_ADJUST_SIZE (sptr,ssize);
215	ctx->uc.uc_stack.ss_flags = 0;
216
217	makecontext (&(ctx->uc), (void (*)()) coro, 1, arg);
218
219	#elif CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX \|\| CORO_ASM
220
221	# if CORO_SJLJ
222	stack_t ostk, nstk;
223	struct sigaction osa, nsa;
224	sigset_t nsig, osig;
225	# endif
226	coro_context nctx;
227
228	coro_init_func = coro;
229	coro_init_arg = arg;
230
231	new_coro = ctx;
232	create_coro = &nctx;
233
234	# if CORO_SJLJ
235	/* we use SIGUSR2. first block it, then fiddle with it. */
236
237	sigemptyset (&nsig);
238	sigaddset (&nsig, SIGUSR2);
239	sigprocmask (SIG_BLOCK, &nsig, &osig);
240
241	nsa.sa_handler = trampoline;
242	sigemptyset (&nsa.sa_mask);
243	nsa.sa_flags = SA_ONSTACK;
244
245	if (sigaction (SIGUSR2, &nsa, &osa))
246	{
247	perror ("sigaction");
248	abort ();
249	}
250
251	/* set the new stack */
252	nstk.ss_sp = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
253	nstk.ss_size = STACK_ADJUST_SIZE (sptr,ssize);
254	nstk.ss_flags = 0;
255
256	if (sigaltstack (&nstk, &ostk) < 0)
257	{
258	perror ("sigaltstack");
259	abort ();
260	}
261
262	trampoline_count = 0;
263	kill (getpid (), SIGUSR2);
264	sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
265
266	while (!trampoline_count)
267	sigsuspend (&nsig);
268
269	sigaltstack (0, &nstk);
270	nstk.ss_flags = SS_DISABLE;
271	if (sigaltstack (&nstk, 0) < 0)
272	perror ("sigaltstack");
273
274	sigaltstack (0, &nstk);
275	if (~nstk.ss_flags & SS_DISABLE)
276	abort ();
277
278	if (~ostk.ss_flags & SS_DISABLE)
279	sigaltstack (&ostk, 0);
280
281	sigaction (SIGUSR2, &osa, 0);
282
283	sigprocmask (SIG_SETMASK, &osig, 0);
284
285	# elif CORO_LOSER
286
287	setjmp (ctx->env);
288	#if __CYGWIN__
289	ctx->env[7] = (long)((char *)sptr + ssize) - sizeof (long);
290	ctx->env[8] = (long)coro_init;
291	#elif defined(_M_IX86)
292	((_JUMP_BUFFER *)&ctx->env)->Eip = (long)coro_init;
293	((_JUMP_BUFFER *)&ctx->env)->Esp = (long)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
294	#elif defined(_M_AMD64)
295	((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64)coro_init;
296	((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
297	#elif defined(_M_IA64)
298	((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64)coro_init;
299	((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
300	#else
301	# error "microsoft libc or architecture not supported"
302	#endif
303
304	# elif CORO_LINUX
305
306	_setjmp (ctx->env);
307	#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
308	ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
309	ctx->env[0].__jmpbuf[JB_SP] = (long)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
310	#elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
311	ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
312	ctx->env[0].__jmpbuf[0].__sp = (int )((char )sptr + ssize) - sizeof (long);
313	#elif defined (__GNU_LIBRARY__) && defined (__i386__)
314	ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
315	ctx->env[0].__jmpbuf[0].__sp = (void )((char )sptr + ssize) - sizeof (long);
316	#elif defined (__GNU_LIBRARY__) && defined (__amd64__)
317	ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
318	ctx->env[0].__jmpbuf[0].__sp = (void )((char )sptr + ssize) - sizeof (long);
319	#else
320	# error "linux libc or architecture not supported"
321	#endif
322
323	# elif CORO_IRIX
324
325	setjmp (ctx->env);
326	ctx->env[JB_PC] = (__uint64_t)coro_init;
327	ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
328
329	# elif CORO_ASM
330
331	ctx->sp = (volatile void *)(ssize + (char )sptr);
332	--ctx->sp = (void )abort; /* needed for alignment only */
333	--ctx->sp = (void )coro_init;
334	ctx->sp -= NUM_SAVED;
335
336	# endif
337
338	coro_transfer ((coro_context )create_coro, (coro_context )new_coro);
339
340	# elif CORO_PTHREAD
341
342	pthread_t id;
343	pthread_attr_t attr;
344	coro_context nctx;
345	struct coro_init_args args;
346	static int once;
347
348	if (!once)
349	{
350	pthread_mutex_lock (&coro_mutex);
351	once = 1;
352	}
353
354	args.func = coro;
355	args.arg = arg;
356	args.self = ctx;
357	args.main = &nctx;
358
359	pthread_attr_init (&attr);
360	pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
361	pthread_attr_setstack (&attr, sptr, (size_t)ssize);
362	pthread_create (&id, &attr, trampoline, &args);
363
364	pthread_cond_init (&args.self->c, 0);
365	coro_transfer (args.main, args.self);
366
367	#else
368	# error unsupported backend
369	#endif
370	}
371