libcoro/coro.c

/*
 * Copyright (c) 2001-2011 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;

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

  coro_transfer (new_coro, create_coro);

#if __GCC_HAVE_DWARF2_CFI_ASM && __amd64
  asm (".cfi_undefined rip");
#endif

  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 (coro_setjmp (new_coro->env))
    coro_init (); /* start it */
  else
    trampoline_done = 1;
}

# endif

# if CORO_ASM

  #if _WIN32
    #define CORO_WIN_TIB 1
  #endif

  asm (
       "\t.text\n"
       "\t.globl coro_transfer\n"
       "coro_transfer:\n"
       /* windows, of course, gives a shit on the amd64 ABI and uses different registers */
       /* http://blogs.msdn.com/freik/archive/2005/03/17/398200.aspx */
       #if __amd64
         #ifdef WIN32
           /* TODO: xmm6..15 also would need to be saved. sigh. */
           #define NUM_SAVED 8
           "\tpushq %rsi\n"
           "\tpushq %rdi\n"
           "\tpushq %rbp\n"
           "\tpushq %rbx\n"
           "\tpushq %r12\n"
           "\tpushq %r13\n"
           "\tpushq %r14\n"
           "\tpushq %r15\n"
           #if CORO_WIN_TIB
             "\tpushq %fs:0x0\n"
             "\tpushq %fs:0x8\n"
             "\tpushq %fs:0xc\n"
           #endif
           "\tmovq %rsp, (%rcx)\n"
           "\tmovq (%rdx), %rsp\n"
           #if CORO_WIN_TIB
             "\tpopq %fs:0xc\n"
             "\tpopq %fs:0x8\n"
             "\tpopq %fs:0x0\n"
           #endif
           "\tpopq %r15\n"
           "\tpopq %r14\n"
           "\tpopq %r13\n"
           "\tpopq %r12\n"
           "\tpopq %rbx\n"
           "\tpopq %rbp\n"
           "\tpopq %rdi\n"
           "\tpopq %rsi\n"
         #else
           #define NUM_SAVED 6
           "\tpushq %rbp\n"
           "\tpushq %rbx\n"
           "\tpushq %r12\n"
           "\tpushq %r13\n"
           "\tpushq %r14\n"
           "\tpushq %r15\n"
           "\tmovq %rsp, (%rdi)\n"
           "\tmovq (%rsi), %rsp\n"
           "\tpopq %r15\n"
           "\tpopq %r14\n"
           "\tpopq %r13\n"
           "\tpopq %r12\n"
           "\tpopq %rbx\n"
           "\tpopq %rbp\n"
         #endif
       #elif __i386
         #define NUM_SAVED 4
         "\tpushl %ebp\n"
         "\tpushl %ebx\n"
         "\tpushl %esi\n"
         "\tpushl %edi\n"
         #if CORO_WIN_TIB
           "\tpushl %fs:0\n"
           "\tpushl %fs:4\n"
           "\tpushl %fs:8\n"
         #endif
         "\tmovl %esp, (%eax)\n"
         "\tmovl (%edx), %esp\n"
         #if CORO_WIN_TIB
           "\tpopl %fs:8\n"
           "\tpopl %fs:4\n"
           "\tpopl %fs:0\n"
         #endif
         "\tpopl %edi\n"
         "\tpopl %esi\n"
         "\tpopl %ebx\n"
         "\tpopl %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

  coro_setjmp (ctx->env);
  #if __CYGWIN__ && __i386
    ctx->env[8]                        = (long)    coro_init;
    ctx->env[7]                        = (long)    ((char *)sptr + ssize)         - sizeof (long);
  #elif __CYGWIN__ && __x86_64
    ctx->env[7]                        = (long)    coro_init;
    ctx->env[6]                        = (long)    ((char *)sptr + ssize)         - sizeof (long);
  #elif defined(__MINGW32__)
    ctx->env[5]                        = (long)    coro_init;
    ctx->env[4]                        = (long)    ((char *)sptr + ssize)         - sizeof (long);
  #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 (__int64);
  #elif defined(_M_IA64)
    ((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64) coro_init;
    ((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
  #else
    #error "microsoft libc or architecture not supported"
  #endif

# elif CORO_LINUX

  coro_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

  coro_setjmp (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;

  #if CORO_WIN_TIB
  *--ctx->sp = 0;                    /* ExceptionList */
  *--ctx->sp = (char *)sptr + ssize; /* StackBase */
  *--ctx->sp = sptr;                 /* StackLimit */
  #endif

  ctx->sp -= NUM_SAVED;
  memset (ctx->sp, 0, sizeof (*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);
#if __FreeBSD__ /* freebsd is of course broken and needs manual testcancel calls... yay... */
  pthread_testcancel ();
#endif
}

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);
#if __UCLIBC__
      /* exists, but is borked */
      /*pthread_attr_setstacksize (&attr, (size_t)ssize);*/
#else
      pthread_attr_setstack (&attr, sptr, (size_t)ssize);
#endif
      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:	1.61
Committed:	Sun Jul 3 10:51:42 2011 UTC (12 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-6_05, rel-6_04, rel-6_03, rel-6_02, rel-6_01
Changes since 1.60:	+1 -2 lines
Log Message:	6.01
#	Content
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 <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 coro_func coro_init_func;
80	static void *coro_init_arg;
81	static coro_context new_coro, create_coro;
82
83	static void
84	coro_init (void)
85	{
86	volatile coro_func func = coro_init_func;
87	volatile void *arg = coro_init_arg;
88
89	coro_transfer (new_coro, create_coro);
90
91	#if __GCC_HAVE_DWARF2_CFI_ASM && __amd64
92	asm (".cfi_undefined rip");
93	#endif
94
95	func ((void *)arg);
96
97	/* the new coro returned. bad. just abort() for now */
98	abort ();
99	}
100
101	# if CORO_SJLJ
102
103	static volatile int trampoline_done;
104
105	/* trampoline signal handler */
106	static void
107	trampoline (int sig)
108	{
109	if (coro_setjmp (new_coro->env))
110	coro_init (); /* start it */
111	else
112	trampoline_done = 1;
113	}
114
115	# endif
116
117	# if CORO_ASM
118
119	#if _WIN32
120	#define CORO_WIN_TIB 1
121	#endif
122
123	asm (
124	"\t.text\n"
125	"\t.globl coro_transfer\n"
126	"coro_transfer:\n"
127	/* windows, of course, gives a shit on the amd64 ABI and uses different registers */
128	/* http://blogs.msdn.com/freik/archive/2005/03/17/398200.aspx */
129	#if __amd64
130	#ifdef WIN32
131	/* TODO: xmm6..15 also would need to be saved. sigh. */
132	#define NUM_SAVED 8
133	"\tpushq %rsi\n"
134	"\tpushq %rdi\n"
135	"\tpushq %rbp\n"
136	"\tpushq %rbx\n"
137	"\tpushq %r12\n"
138	"\tpushq %r13\n"
139	"\tpushq %r14\n"
140	"\tpushq %r15\n"
141	#if CORO_WIN_TIB
142	"\tpushq %fs:0x0\n"
143	"\tpushq %fs:0x8\n"
144	"\tpushq %fs:0xc\n"
145	#endif
146	"\tmovq %rsp, (%rcx)\n"
147	"\tmovq (%rdx), %rsp\n"
148	#if CORO_WIN_TIB
149	"\tpopq %fs:0xc\n"
150	"\tpopq %fs:0x8\n"
151	"\tpopq %fs:0x0\n"
152	#endif
153	"\tpopq %r15\n"
154	"\tpopq %r14\n"
155	"\tpopq %r13\n"
156	"\tpopq %r12\n"
157	"\tpopq %rbx\n"
158	"\tpopq %rbp\n"
159	"\tpopq %rdi\n"
160	"\tpopq %rsi\n"
161	#else
162	#define NUM_SAVED 6
163	"\tpushq %rbp\n"
164	"\tpushq %rbx\n"
165	"\tpushq %r12\n"
166	"\tpushq %r13\n"
167	"\tpushq %r14\n"
168	"\tpushq %r15\n"
169	"\tmovq %rsp, (%rdi)\n"
170	"\tmovq (%rsi), %rsp\n"
171	"\tpopq %r15\n"
172	"\tpopq %r14\n"
173	"\tpopq %r13\n"
174	"\tpopq %r12\n"
175	"\tpopq %rbx\n"
176	"\tpopq %rbp\n"
177	#endif
178	#elif __i386
179	#define NUM_SAVED 4
180	"\tpushl %ebp\n"
181	"\tpushl %ebx\n"
182	"\tpushl %esi\n"
183	"\tpushl %edi\n"
184	#if CORO_WIN_TIB
185	"\tpushl %fs:0\n"
186	"\tpushl %fs:4\n"
187	"\tpushl %fs:8\n"
188	#endif
189	"\tmovl %esp, (%eax)\n"
190	"\tmovl (%edx), %esp\n"
191	#if CORO_WIN_TIB
192	"\tpopl %fs:8\n"
193	"\tpopl %fs:4\n"
194	"\tpopl %fs:0\n"
195	#endif
196	"\tpopl %edi\n"
197	"\tpopl %esi\n"
198	"\tpopl %ebx\n"
199	"\tpopl %ebp\n"
200	#else
201	#error unsupported architecture
202	#endif
203	"\tret\n"
204	);
205
206	# endif
207
208	void
209	coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, long ssize)
210	{
211	coro_context nctx;
212	# if CORO_SJLJ
213	stack_t ostk, nstk;
214	struct sigaction osa, nsa;
215	sigset_t nsig, osig;
216	# endif
217
218	if (!coro)
219	return;
220
221	coro_init_func = coro;
222	coro_init_arg = arg;
223
224	new_coro = ctx;
225	create_coro = &nctx;
226
227	# if CORO_SJLJ
228	/* we use SIGUSR2. first block it, then fiddle with it. */
229
230	sigemptyset (&nsig);
231	sigaddset (&nsig, SIGUSR2);
232	sigprocmask (SIG_BLOCK, &nsig, &osig);
233
234	nsa.sa_handler = trampoline;
235	sigemptyset (&nsa.sa_mask);
236	nsa.sa_flags = SA_ONSTACK;
237
238	if (sigaction (SIGUSR2, &nsa, &osa))
239	{
240	perror ("sigaction");
241	abort ();
242	}
243
244	/* set the new stack */
245	nstk.ss_sp = STACK_ADJUST_PTR (sptr, ssize); /* yes, some platforms (IRIX) get this wrong. */
246	nstk.ss_size = STACK_ADJUST_SIZE (sptr, ssize);
247	nstk.ss_flags = 0;
248
249	if (sigaltstack (&nstk, &ostk) < 0)
250	{
251	perror ("sigaltstack");
252	abort ();
253	}
254
255	trampoline_done = 0;
256	kill (getpid (), SIGUSR2);
257	sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
258
259	while (!trampoline_done)
260	sigsuspend (&nsig);
261
262	sigaltstack (0, &nstk);
263	nstk.ss_flags = SS_DISABLE;
264	if (sigaltstack (&nstk, 0) < 0)
265	perror ("sigaltstack");
266
267	sigaltstack (0, &nstk);
268	if (~nstk.ss_flags & SS_DISABLE)
269	abort ();
270
271	if (~ostk.ss_flags & SS_DISABLE)
272	sigaltstack (&ostk, 0);
273
274	sigaction (SIGUSR2, &osa, 0);
275	sigprocmask (SIG_SETMASK, &osig, 0);
276
277	# elif CORO_LOSER
278
279	coro_setjmp (ctx->env);
280	#if __CYGWIN__ && __i386
281	ctx->env[8] = (long) coro_init;
282	ctx->env[7] = (long) ((char *)sptr + ssize) - sizeof (long);
283	#elif __CYGWIN__ && __x86_64
284	ctx->env[7] = (long) coro_init;
285	ctx->env[6] = (long) ((char *)sptr + ssize) - sizeof (long);
286	#elif defined(__MINGW32__)
287	ctx->env[5] = (long) coro_init;
288	ctx->env[4] = (long) ((char *)sptr + ssize) - sizeof (long);
289	#elif defined(_M_IX86)
290	((_JUMP_BUFFER *)&ctx->env)->Eip = (long) coro_init;
291	((_JUMP_BUFFER *)&ctx->env)->Esp = (long) STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
292	#elif defined(_M_AMD64)
293	((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64) coro_init;
294	((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
295	#elif defined(_M_IA64)
296	((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64) coro_init;
297	((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
298	#else
299	#error "microsoft libc or architecture not supported"
300	#endif
301
302	# elif CORO_LINUX
303
304	coro_setjmp (ctx->env);
305	#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
306	ctx->env[0].__jmpbuf[JB_PC] = (long) coro_init;
307	ctx->env[0].__jmpbuf[JB_SP] = (long) STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
308	#elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
309	ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
310	ctx->env[0].__jmpbuf[0].__sp = (int ) ((char )sptr + ssize) - sizeof (long);
311	#elif defined (__GNU_LIBRARY__) && defined (__i386__)
312	ctx->env[0].__jmpbuf[0].__pc = (char *) coro_init;
313	ctx->env[0].__jmpbuf[0].__sp = (void ) ((char )sptr + ssize) - sizeof (long);
314	#elif defined (__GNU_LIBRARY__) && defined (__amd64__)
315	ctx->env[0].__jmpbuf[JB_PC] = (long) coro_init;
316	ctx->env[0].__jmpbuf[0].__sp = (void ) ((char )sptr + ssize) - sizeof (long);
317	#else
318	#error "linux libc or architecture not supported"
319	#endif
320
321	# elif CORO_IRIX
322
323	coro_setjmp (ctx->env, 0);
324	ctx->env[JB_PC] = (__uint64_t)coro_init;
325	ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
326
327	# elif CORO_ASM
328
329	ctx->sp = (void *)(ssize + (char )sptr);
330	--ctx->sp = (void )abort; /* needed for alignment only */
331	--ctx->sp = (void )coro_init;
332
333	#if CORO_WIN_TIB
334	--ctx->sp = 0; / ExceptionList */
335	--ctx->sp = (char )sptr + ssize; /* StackBase */
336	--ctx->sp = sptr; / StackLimit */
337	#endif
338
339	ctx->sp -= NUM_SAVED;
340	memset (ctx->sp, 0, sizeof (ctx->sp) NUM_SAVED);
341
342	# elif CORO_UCONTEXT
343
344	getcontext (&(ctx->uc));
345
346	ctx->uc.uc_link = 0;
347	ctx->uc.uc_stack.ss_sp = sptr;
348	ctx->uc.uc_stack.ss_size = (size_t)ssize;
349	ctx->uc.uc_stack.ss_flags = 0;
350
351	makecontext (&(ctx->uc), (void (*)())coro_init, 0);
352
353	# endif
354
355	coro_transfer (create_coro, new_coro);
356	}
357
358	/*****************************************************************************/
359	/* pthread backend */
360	/*****************************************************************************/
361	#elif CORO_PTHREAD
362
363	/* this mutex will be locked by the running coroutine */
364	pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
365
366	struct coro_init_args
367	{
368	coro_func func;
369	void *arg;
370	coro_context self, main;
371	};
372
373	static pthread_t null_tid;
374
375	/* I'd so love to cast pthread_mutex_unlock to void ()(void )... */
376	static void
377	mutex_unlock_wrapper (void *arg)
378	{
379	pthread_mutex_unlock ((pthread_mutex_t *)arg);
380	}
381
382	static void *
383	coro_init (void *args_)
384	{
385	struct coro_init_args args = (struct coro_init_args )args_;
386	coro_func func = args->func;
387	void *arg = args->arg;
388
389	pthread_mutex_lock (&coro_mutex);
390
391	/* we try to be good citizens and use deferred cancellation and cleanup handlers */
392	pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
393	coro_transfer (args->self, args->main);
394	func (arg);
395	pthread_cleanup_pop (1);
396
397	return 0;
398	}
399
400	void
401	coro_transfer (coro_context prev, coro_context next)
402	{
403	pthread_cond_signal (&next->cv);
404	pthread_cond_wait (&prev->cv, &coro_mutex);
405	#if __FreeBSD__ /* freebsd is of course broken and needs manual testcancel calls... yay... */
406	pthread_testcancel ();
407	#endif
408	}
409
410	void
411	coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, long ssize)
412	{
413	static coro_context nctx;
414	static int once;
415
416	if (!once)
417	{
418	once = 1;
419
420	pthread_mutex_lock (&coro_mutex);
421	pthread_cond_init (&nctx.cv, 0);
422	null_tid = pthread_self ();
423	}
424
425	pthread_cond_init (&ctx->cv, 0);
426
427	if (coro)
428	{
429	pthread_attr_t attr;
430	struct coro_init_args args;
431
432	args.func = coro;
433	args.arg = arg;
434	args.self = ctx;
435	args.main = &nctx;
436
437	pthread_attr_init (&attr);
438	#if __UCLIBC__
439	/* exists, but is borked */
440	/pthread_attr_setstacksize (&attr, (size_t)ssize);/
441	#else
442	pthread_attr_setstack (&attr, sptr, (size_t)ssize);
443	#endif
444	pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
445	pthread_create (&ctx->id, &attr, coro_init, &args);
446
447	coro_transfer (args.main, args.self);
448	}
449	else
450	ctx->id = null_tid;
451	}
452
453	void
454	coro_destroy (coro_context *ctx)
455	{
456	if (!pthread_equal (ctx->id, null_tid))
457	{
458	pthread_cancel (ctx->id);
459	pthread_mutex_unlock (&coro_mutex);
460	pthread_join (ctx->id, 0);
461	pthread_mutex_lock (&coro_mutex);
462	}
463
464	pthread_cond_destroy (&ctx->cv);
465	}
466
467	#else
468	# error unsupported backend
469	#endif
470