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"

#include <string.h>

/*****************************************************************************/
/* ucontext/setjmp/asm backends                                              */
/*****************************************************************************/
#if CORO_UCONTEXT || CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM

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

# if !defined(STACK_ADJUST_PTR)
#  if __sgi
/* IRIX is decidedly NON-unix */
#   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

# 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 */
/* with dwarf debug info. 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_done;

/* trampoline signal handler */
static void
trampoline (int sig)
{
  if (
    #if _XOPEN_UNIX > 0
      _setjmp (new_coro->env)
    #else
      setjmp (new_coro->env)
    #endif
  ) {
      #if HAVE_CFI
        asm (".cfi_startproc");
      #endif
      coro_init (); /* start it */
      #if HAVE_CFI
        asm (".cfi_endproc");
      #endif
    }
  else
    trampoline_done = 1;
}

# 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

void
coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, long ssize)
{
  coro_context nctx;
# if CORO_SJLJ
  stack_t ostk, nstk;
  struct sigaction osa, nsa;
  sigset_t nsig, osig;
# endif

  if (!coro)
    return;

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

  while (!trampoline_done)
    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;

# elif CORO_UCONTEXT

  getcontext (&(ctx->uc));

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

  makecontext (&(ctx->uc), (void (*)())coro_init, 0);

# endif

  coro_transfer (create_coro, new_coro);
}

#endif

/*****************************************************************************/
/* pthread backend                                                           */
/*****************************************************************************/

#if CORO_PTHREAD

/* this mutex will be locked by the running coroutine */
pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;

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

static pthread_t null_tid;

/* I'd so love to cast pthread_mutex_unlock to void (*)(void *)... */
static void
mutex_unlock_wrapper (void *arg)
{
  pthread_mutex_unlock ((pthread_mutex_t *)arg);
}

static void *
coro_init (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);

  /* we try to be good citizens and use deferred cancellation and cleanup handlers */
  pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
    coro_transfer (args->self, args->main);
    func (arg);
  pthread_cleanup_pop (1);

  return 0;
}

void
coro_transfer (coro_context *prev, coro_context *next)
{
  pthread_cond_signal (&next->cv);
  pthread_cond_wait (&prev->cv, &coro_mutex);
}

void
coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, long ssize)
{
  static coro_context nctx;
  static int once;

  if (!once)
    {
      once = 1;

      pthread_mutex_lock (&coro_mutex);
      pthread_cond_init (&nctx.cv, 0);
      null_tid = pthread_self ();
    }

  pthread_cond_init (&ctx->cv, 0);

  if (coro)
    {
      pthread_attr_t attr;
      struct coro_init_args args;

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

      pthread_attr_init (&attr);
      pthread_attr_setstack (&attr, sptr, (size_t)ssize);
      pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
      pthread_create (&ctx->id, &attr, coro_init, &args);

      coro_transfer (args.main, args.self);
    }
  else
    ctx->id = null_tid;
}

void
coro_destroy (coro_context *ctx)
{
  if (!pthread_equal (ctx->id, null_tid))
    {
      pthread_cancel (ctx->id);
      pthread_mutex_unlock (&coro_mutex);
      pthread_join (ctx->id, 0);
      pthread_mutex_lock (&coro_mutex);
    }

  pthread_cond_destroy (&ctx->cv);
}

#endif

Revision:	1.39
Committed:	Sat Nov 8 04:31:28 2008 UTC (15 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.38:	+188 -185 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	#include <string.h>
44
45	/*****************************************************************************/
46	/* ucontext/setjmp/asm backends */
47	/*****************************************************************************/
48	#if CORO_UCONTEXT \|\| CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX \|\| CORO_ASM
49
50	# if CORO_UCONTEXT
51	# include <stddef.h>
52	# endif
53
54	# if !defined(STACK_ADJUST_PTR)
55	# if __sgi
56	/* IRIX is decidedly NON-unix */
57	# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
58	# define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
59	# elif (__i386__ && CORO_LINUX) \|\| (_M_IX86 && CORO_LOSER)
60	# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
61	# define STACK_ADJUST_SIZE(sp,ss) (ss)
62	# elif (__amd64__ && CORO_LINUX) \|\| ((_M_AMD64 \|\| _M_IA64) && CORO_LOSER)
63	# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
64	# define STACK_ADJUST_SIZE(sp,ss) (ss)
65	# else
66	# define STACK_ADJUST_PTR(sp,ss) (sp)
67	# define STACK_ADJUST_SIZE(sp,ss) (ss)
68	# endif
69	# endif
70
71	# include <stdlib.h>
72
73	# if CORO_SJLJ
74	# include <stdio.h>
75	# include <signal.h>
76	# include <unistd.h>
77	# endif
78
79	static volatile coro_func coro_init_func;
80	static volatile void *coro_init_arg;
81	static volatile coro_context new_coro, create_coro;
82
83	/* what we really want to detect here is wether we use a new-enough version of GAS */
84	/* with dwarf debug info. instead, check for gcc 3, ELF and GNU/Linux and hope for the best */
85	# if __GNUC__ >= 3 && __ELF__ && __linux__
86	# define HAVE_CFI 1
87	# endif
88
89	static void
90	coro_init (void)
91	{
92	volatile coro_func func = coro_init_func;
93	volatile void *arg = coro_init_arg;
94
95	coro_transfer ((coro_context )new_coro, (coro_context )create_coro);
96
97	func ((void *)arg);
98
99	/* the new coro returned. bad. just abort() for now */
100	abort ();
101	}
102
103	# if CORO_SJLJ
104
105	static volatile int trampoline_done;
106
107	/* trampoline signal handler */
108	static void
109	trampoline (int sig)
110	{
111	if (
112	#if _XOPEN_UNIX > 0
113	_setjmp (new_coro->env)
114	#else
115	setjmp (new_coro->env)
116	#endif
117	) {
118	#if HAVE_CFI
119	asm (".cfi_startproc");
120	#endif
121	coro_init (); /* start it */
122	#if HAVE_CFI
123	asm (".cfi_endproc");
124	#endif
125	}
126	else
127	trampoline_done = 1;
128	}
129
130	# endif
131
132	# if CORO_ASM
133
134	asm (
135	".text\n"
136	".globl coro_transfer\n"
137	".type coro_transfer, @function\n"
138	"coro_transfer:\n"
139	#if __amd64
140	#define NUM_SAVED 6
141	"\tpush %rbp\n"
142	"\tpush %rbx\n"
143	"\tpush %r12\n"
144	"\tpush %r13\n"
145	"\tpush %r14\n"
146	"\tpush %r15\n"
147	"\tmov %rsp, (%rdi)\n"
148	"\tmov (%rsi), %rsp\n"
149	"\tpop %r15\n"
150	"\tpop %r14\n"
151	"\tpop %r13\n"
152	"\tpop %r12\n"
153	"\tpop %rbx\n"
154	"\tpop %rbp\n"
155	#elif __i386
156	#define NUM_SAVED 4
157	"\tpush %ebp\n"
158	"\tpush %ebx\n"
159	"\tpush %esi\n"
160	"\tpush %edi\n"
161	"\tmov %esp, (%eax)\n"
162	"\tmov (%edx), %esp\n"
163	"\tpop %edi\n"
164	"\tpop %esi\n"
165	"\tpop %ebx\n"
166	"\tpop %ebp\n"
167	#else
168	#error unsupported architecture
169	#endif
170	"\tret\n"
171	);
172
173	# endif
174
175	void
176	coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, long ssize)
177	{
178	coro_context nctx;
179	# if CORO_SJLJ
180	stack_t ostk, nstk;
181	struct sigaction osa, nsa;
182	sigset_t nsig, osig;
183	# endif
184
185	if (!coro)
186	return;
187
188	coro_init_func = coro;
189	coro_init_arg = arg;
190
191	new_coro = ctx;
192	create_coro = &nctx;
193
194	# if CORO_SJLJ
195	/* we use SIGUSR2. first block it, then fiddle with it. */
196
197	sigemptyset (&nsig);
198	sigaddset (&nsig, SIGUSR2);
199	sigprocmask (SIG_BLOCK, &nsig, &osig);
200
201	nsa.sa_handler = trampoline;
202	sigemptyset (&nsa.sa_mask);
203	nsa.sa_flags = SA_ONSTACK;
204
205	if (sigaction (SIGUSR2, &nsa, &osa))
206	{
207	perror ("sigaction");
208	abort ();
209	}
210
211	/* set the new stack */
212	nstk.ss_sp = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
213	nstk.ss_size = STACK_ADJUST_SIZE (sptr,ssize);
214	nstk.ss_flags = 0;
215
216	if (sigaltstack (&nstk, &ostk) < 0)
217	{
218	perror ("sigaltstack");
219	abort ();
220	}
221
222	trampoline_done = 0;
223	kill (getpid (), SIGUSR2);
224	sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
225
226	while (!trampoline_done)
227	sigsuspend (&nsig);
228
229	sigaltstack (0, &nstk);
230	nstk.ss_flags = SS_DISABLE;
231	if (sigaltstack (&nstk, 0) < 0)
232	perror ("sigaltstack");
233
234	sigaltstack (0, &nstk);
235	if (~nstk.ss_flags & SS_DISABLE)
236	abort ();
237
238	if (~ostk.ss_flags & SS_DISABLE)
239	sigaltstack (&ostk, 0);
240
241	sigaction (SIGUSR2, &osa, 0);
242	sigprocmask (SIG_SETMASK, &osig, 0);
243
244	# elif CORO_LOSER
245
246	setjmp (ctx->env);
247	#if __CYGWIN__
248	ctx->env[7] = (long)((char *)sptr + ssize) - sizeof (long);
249	ctx->env[8] = (long)coro_init;
250	#elif defined(_M_IX86)
251	((_JUMP_BUFFER *)&ctx->env)->Eip = (long)coro_init;
252	((_JUMP_BUFFER *)&ctx->env)->Esp = (long)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
253	#elif defined(_M_AMD64)
254	((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64)coro_init;
255	((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
256	#elif defined(_M_IA64)
257	((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64)coro_init;
258	((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
259	#else
260	#error "microsoft libc or architecture not supported"
261	#endif
262
263	# elif CORO_LINUX
264
265	_setjmp (ctx->env);
266	#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
267	ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
268	ctx->env[0].__jmpbuf[JB_SP] = (long)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
269	#elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
270	ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
271	ctx->env[0].__jmpbuf[0].__sp = (int )((char )sptr + ssize) - sizeof (long);
272	#elif defined (__GNU_LIBRARY__) && defined (__i386__)
273	ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
274	ctx->env[0].__jmpbuf[0].__sp = (void )((char )sptr + ssize) - sizeof (long);
275	#elif defined (__GNU_LIBRARY__) && defined (__amd64__)
276	ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
277	ctx->env[0].__jmpbuf[0].__sp = (void )((char )sptr + ssize) - sizeof (long);
278	#else
279	#error "linux libc or architecture not supported"
280	#endif
281
282	# elif CORO_IRIX
283
284	setjmp (ctx->env);
285	ctx->env[JB_PC] = (__uint64_t)coro_init;
286	ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
287
288	# elif CORO_ASM
289
290	ctx->sp = (volatile void *)(ssize + (char )sptr);
291	--ctx->sp = (void )abort; /* needed for alignment only */
292	--ctx->sp = (void )coro_init;
293	ctx->sp -= NUM_SAVED;
294
295	# elif CORO_UCONTEXT
296
297	getcontext (&(ctx->uc));
298
299	ctx->uc.uc_link = 0;
300	ctx->uc.uc_stack.ss_sp = sptr;
301	ctx->uc.uc_stack.ss_size = (size_t)ssize;
302	ctx->uc.uc_stack.ss_flags = 0;
303
304	makecontext (&(ctx->uc), (void (*)())coro_init, 0);
305
306	# endif
307
308	coro_transfer (create_coro, new_coro);
309	}
310
311	#endif
312
313	/*****************************************************************************/
314	/* pthread backend */
315	/*****************************************************************************/
316
317	#if CORO_PTHREAD
318
319	/* this mutex will be locked by the running coroutine */
320	pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
321
322	struct coro_init_args
323	{
324	coro_func func;
325	void *arg;
326	coro_context self, main;
327	};
328
329	static pthread_t null_tid;
330
331	/* I'd so love to cast pthread_mutex_unlock to void ()(void )... */
332	static void
333	mutex_unlock_wrapper (void *arg)
334	{
335	pthread_mutex_unlock ((pthread_mutex_t *)arg);
336	}
337
338	static void *
339	coro_init (void *args_)
340	{
341	struct coro_init_args args = (struct coro_init_args )args_;
342	coro_func func = args->func;
343	void *arg = args->arg;
344
345	pthread_mutex_lock (&coro_mutex);
346
347	/* we try to be good citizens and use deferred cancellation and cleanup handlers */
348	pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
349	coro_transfer (args->self, args->main);
350	func (arg);
351	pthread_cleanup_pop (1);
352
353	return 0;
354	}
355
356	void
357	coro_transfer (coro_context prev, coro_context next)
358	{
359	pthread_cond_signal (&next->cv);
360	pthread_cond_wait (&prev->cv, &coro_mutex);
361	}
362
363	void
364	coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, long ssize)
365	{
366	static coro_context nctx;
367	static int once;
368
369	if (!once)
370	{
371	once = 1;
372
373	pthread_mutex_lock (&coro_mutex);
374	pthread_cond_init (&nctx.cv, 0);
375	null_tid = pthread_self ();
376	}
377
378	pthread_cond_init (&ctx->cv, 0);
379
380	if (coro)
381	{
382	pthread_attr_t attr;
383	struct coro_init_args args;
384
385	args.func = coro;
386	args.arg = arg;
387	args.self = ctx;
388	args.main = &nctx;
389
390	pthread_attr_init (&attr);
391	pthread_attr_setstack (&attr, sptr, (size_t)ssize);
392	pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
393	pthread_create (&ctx->id, &attr, coro_init, &args);
394
395	coro_transfer (args.main, args.self);
396	}
397	else
398	ctx->id = null_tid;
399	}
400
401	void
402	coro_destroy (coro_context *ctx)
403	{
404	if (!pthread_equal (ctx->id, null_tid))
405	{
406	pthread_cancel (ctx->id);
407	pthread_mutex_unlock (&coro_mutex);
408	pthread_join (ctx->id, 0);
409	pthread_mutex_lock (&coro_mutex);
410	}
411
412	pthread_cond_destroy (&ctx->cv);
413	}
414
415	#endif
416