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 coro_func coro_init_func;
static void *coro_init_arg;
static 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 (new_coro, 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
      sigsetjmp (new_coro->env, 0)
    #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

  sigsetjmp (ctx->env, 0);
  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 = (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);
}

/*****************************************************************************/
/* pthread backend                                                           */
/*****************************************************************************/
#elif 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);
}

#else
# error unsupported backend
#endif

Revision:	1.41
Committed:	Sat Nov 8 13:32:18 2008 UTC (15 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-4_9
Changes since 1.40:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.28	* Copyright (c) 2001-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
3	root	1.1	*
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	root	1.29	* 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	root	1.1	* This library is modelled strictly after Ralf S. Engelschalls article at
37	root	1.29	* http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
38	root	1.1	* go to Ralf S. Engelschall <rse@engelschall.com>.
39			*/
40
41			#include "coro.h"
42
43	root	1.38	#include <string.h>
44
45	root	1.39	/*****************************************************************************/
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	root	1.5	/* IRIX is decidedly NON-unix */
57	root	1.39	# 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	root	1.8	# endif
70	root	1.1
71	root	1.38	# include <stdlib.h>
72	root	1.17
73	root	1.38	# if CORO_SJLJ
74			# include <stdio.h>
75			# include <signal.h>
76			# include <unistd.h>
77			# endif
78	root	1.1
79	root	1.40	static coro_func coro_init_func;
80			static void *coro_init_arg;
81			static coro_context new_coro, create_coro;
82	root	1.1
83	root	1.25	/* what we really want to detect here is wether we use a new-enough version of GAS */
84	root	1.39	/* with dwarf debug info. instead, check for gcc 3, ELF and GNU/Linux and hope for the best */
85	root	1.38	# if __GNUC__ >= 3 && __ELF__ && __linux__
86			# define HAVE_CFI 1
87			# endif
88	root	1.25
89	root	1.1	static void
90			coro_init (void)
91			{
92			volatile coro_func func = coro_init_func;
93			volatile void *arg = coro_init_arg;
94
95	root	1.40	coro_transfer (new_coro, create_coro);
96	root	1.1
97	root	1.3	func ((void *)arg);
98	root	1.1
99			/* the new coro returned. bad. just abort() for now */
100			abort ();
101			}
102
103			# if CORO_SJLJ
104
105	root	1.39	static volatile int trampoline_done;
106	root	1.1
107			/* trampoline signal handler */
108			static void
109	root	1.14	trampoline (int sig)
110	root	1.1	{
111	root	1.39	if (
112			#if _XOPEN_UNIX > 0
113			_setjmp (new_coro->env)
114			#else
115	root	1.40	sigsetjmp (new_coro->env, 0)
116	root	1.39	#endif
117			) {
118			#if HAVE_CFI
119			asm (".cfi_startproc");
120			#endif
121	root	1.26	coro_init (); /* start it */
122	root	1.39	#if HAVE_CFI
123			asm (".cfi_endproc");
124			#endif
125	root	1.26	}
126	root	1.1	else
127	root	1.39	trampoline_done = 1;
128	root	1.1	}
129
130			# endif
131
132	root	1.39	# if CORO_ASM
133	root	1.38
134			asm (
135			".text\n"
136			".globl coro_transfer\n"
137			".type coro_transfer, @function\n"
138			"coro_transfer:\n"
139	root	1.39	#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	root	1.38	"\tret\n"
171			);
172
173	root	1.39	# endif
174	root	1.38
175			void
176			coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, long ssize)
177	root	1.1	{
178	root	1.39	coro_context nctx;
179	root	1.1	# if CORO_SJLJ
180			stack_t ostk, nstk;
181			struct sigaction osa, nsa;
182			sigset_t nsig, osig;
183			# endif
184
185	root	1.38	if (!coro)
186			return;
187
188	root	1.1	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	root	1.23	{
207			perror ("sigaction");
208			abort ();
209			}
210	root	1.1
211			/* set the new stack */
212	root	1.9	nstk.ss_sp = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
213	root	1.8	nstk.ss_size = STACK_ADJUST_SIZE (sptr,ssize);
214	root	1.1	nstk.ss_flags = 0;
215
216			if (sigaltstack (&nstk, &ostk) < 0)
217	root	1.23	{
218			perror ("sigaltstack");
219			abort ();
220			}
221	root	1.1
222	root	1.39	trampoline_done = 0;
223	root	1.1	kill (getpid (), SIGUSR2);
224			sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
225
226	root	1.39	while (!trampoline_done)
227	root	1.1	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	root	1.19	sigaction (SIGUSR2, &osa, 0);
242	root	1.1	sigprocmask (SIG_SETMASK, &osig, 0);
243
244	root	1.16	# elif CORO_LOSER
245	root	1.1
246	root	1.4	setjmp (ctx->env);
247	root	1.39	#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	root	1.4
263			# elif CORO_LINUX
264
265	root	1.22	_setjmp (ctx->env);
266	root	1.39	#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	root	1.5
282			# elif CORO_IRIX
283
284	root	1.40	sigsetjmp (ctx->env, 0);
285	root	1.6	ctx->env[JB_PC] = (__uint64_t)coro_init;
286	root	1.36	ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
287	root	1.1
288	root	1.27	# elif CORO_ASM
289
290	root	1.41	ctx->sp = (void *)(ssize + (char )sptr);
291	root	1.37	--ctx->sp = (void )abort; /* needed for alignment only */
292	root	1.27	--ctx->sp = (void )coro_init;
293	root	1.36	ctx->sp -= NUM_SAVED;
294	root	1.27
295	root	1.39	# 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	root	1.1	# endif
307
308	root	1.39	coro_transfer (create_coro, new_coro);
309			}
310
311			/*****************************************************************************/
312			/* pthread backend */
313			/*****************************************************************************/
314	root	1.40	#elif CORO_PTHREAD
315	root	1.1
316	root	1.39	/* this mutex will be locked by the running coroutine */
317			pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
318	root	1.30
319	root	1.39	struct coro_init_args
320			{
321			coro_func func;
322			void *arg;
323			coro_context self, main;
324			};
325
326			static pthread_t null_tid;
327
328			/* I'd so love to cast pthread_mutex_unlock to void ()(void )... */
329			static void
330			mutex_unlock_wrapper (void *arg)
331			{
332			pthread_mutex_unlock ((pthread_mutex_t *)arg);
333			}
334
335			static void *
336			coro_init (void *args_)
337			{
338			struct coro_init_args args = (struct coro_init_args )args_;
339			coro_func func = args->func;
340			void *arg = args->arg;
341
342			pthread_mutex_lock (&coro_mutex);
343
344			/* we try to be good citizens and use deferred cancellation and cleanup handlers */
345			pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
346			coro_transfer (args->self, args->main);
347			func (arg);
348			pthread_cleanup_pop (1);
349
350			return 0;
351			}
352
353			void
354			coro_transfer (coro_context prev, coro_context next)
355			{
356			pthread_cond_signal (&next->cv);
357			pthread_cond_wait (&prev->cv, &coro_mutex);
358			}
359
360			void
361			coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, long ssize)
362			{
363	root	1.38	static coro_context nctx;
364	root	1.30	static int once;
365
366			if (!once)
367			{
368	root	1.38	once = 1;
369
370	root	1.30	pthread_mutex_lock (&coro_mutex);
371	root	1.38	pthread_cond_init (&nctx.cv, 0);
372			null_tid = pthread_self ();
373	root	1.30	}
374
375	root	1.38	pthread_cond_init (&ctx->cv, 0);
376	root	1.30
377	root	1.38	if (coro)
378			{
379			pthread_attr_t attr;
380			struct coro_init_args args;
381
382			args.func = coro;
383			args.arg = arg;
384			args.self = ctx;
385			args.main = &nctx;
386
387			pthread_attr_init (&attr);
388			pthread_attr_setstack (&attr, sptr, (size_t)ssize);
389			pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
390	root	1.39	pthread_create (&ctx->id, &attr, coro_init, &args);
391	root	1.38
392			coro_transfer (args.main, args.self);
393			}
394			else
395			ctx->id = null_tid;
396	root	1.39	}
397
398			void
399			coro_destroy (coro_context *ctx)
400			{
401			if (!pthread_equal (ctx->id, null_tid))
402			{
403			pthread_cancel (ctx->id);
404			pthread_mutex_unlock (&coro_mutex);
405			pthread_join (ctx->id, 0);
406			pthread_mutex_lock (&coro_mutex);
407			}
408
409			pthread_cond_destroy (&ctx->cv);
410			}
411	root	1.30
412	root	1.40	#else
413			# error unsupported backend
414	root	1.1	#endif
415