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);

#ifdef __linux && __elf
  /* we blindly assume on any __linux with __elf we have a new enough gas with .cfi_undefined support */
  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

  asm (
       ".text\n"
       ".globl coro_transfer\n"
       ".type coro_transfer, @function\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
         #define NUM_SAVED 6
         "\tpush %rbp\n"
         "\tpush %rbx\n"
         "\tpush %r12\n"
         "\tpush %r13\n"
         "\tpush %r14\n"
         "\tpush %r15\n"
         #if CORO_WIN_TIB
           "\tpush %gs:0x0\n"
           "\tpush %gs:0x8\n"
           "\tpush %gs:0xc\n"
         #endif
         "\tmov  %rsp, (%rdi)\n"
         "\tmov  (%rsi), %rsp\n"
         #if CORO_WIN_TIB
           "\tpop  %gs:0xc\n"
           "\tpop  %gs:0x8\n"
           "\tpop  %gs:0x0\n"
         #endif
         "\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"
         #if CORO_WIN_TIB
           "\tpush %fs:0\n"
           "\tpush %fs:4\n"
           "\tpush %fs:8\n"
         #endif
         "\tmov  %esp, (%eax)\n"
         "\tmov  (%edx), %esp\n"
         #if CORO_WIN_TIB
           "\tpop  %fs:8\n"
           "\tpop  %fs:4\n"
           "\tpop  %fs:0\n"
         #endif
         "\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

  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:	1.56
Committed:	Mon May 30 02:32:06 2011 UTC (13 years ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.55:	+6 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.56	* Copyright (c) 2001-2011 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			static void
84			coro_init (void)
85			{
86			volatile coro_func func = coro_init_func;
87			volatile void *arg = coro_init_arg;
88
89	root	1.40	coro_transfer (new_coro, create_coro);
90	root	1.1
91	root	1.56	#ifdef __linux && __elf
92			/* we blindly assume on any __linux with __elf we have a new enough gas with .cfi_undefined support */
93			asm (".cfi_undefined rip");
94			#endif
95
96	root	1.3	func ((void *)arg);
97	root	1.1
98			/* the new coro returned. bad. just abort() for now */
99			abort ();
100			}
101
102			# if CORO_SJLJ
103
104	root	1.39	static volatile int trampoline_done;
105	root	1.1
106			/* trampoline signal handler */
107			static void
108	root	1.14	trampoline (int sig)
109	root	1.1	{
110	root	1.44	if (coro_setjmp (new_coro->env))
111			coro_init (); /* start it */
112	root	1.1	else
113	root	1.39	trampoline_done = 1;
114	root	1.1	}
115
116			# endif
117
118	root	1.39	# if CORO_ASM
119	root	1.38
120			asm (
121			".text\n"
122			".globl coro_transfer\n"
123			".type coro_transfer, @function\n"
124			"coro_transfer:\n"
125	root	1.52	/* windows, of course, gives a shit on the amd64 ABI and uses different registers */
126			/* http://blogs.msdn.com/freik/archive/2005/03/17/398200.aspx */
127	root	1.39	#if __amd64
128	root	1.50	#define NUM_SAVED 6
129	root	1.39	"\tpush %rbp\n"
130			"\tpush %rbx\n"
131			"\tpush %r12\n"
132			"\tpush %r13\n"
133			"\tpush %r14\n"
134			"\tpush %r15\n"
135	root	1.50	#if CORO_WIN_TIB
136	root	1.52	"\tpush %gs:0x0\n"
137			"\tpush %gs:0x8\n"
138			"\tpush %gs:0xc\n"
139	root	1.50	#endif
140	root	1.39	"\tmov %rsp, (%rdi)\n"
141			"\tmov (%rsi), %rsp\n"
142	root	1.50	#if CORO_WIN_TIB
143	root	1.52	"\tpop %gs:0xc\n"
144			"\tpop %gs:0x8\n"
145			"\tpop %gs:0x0\n"
146	root	1.50	#endif
147	root	1.39	"\tpop %r15\n"
148			"\tpop %r14\n"
149			"\tpop %r13\n"
150			"\tpop %r12\n"
151			"\tpop %rbx\n"
152			"\tpop %rbp\n"
153			#elif __i386
154	root	1.50	#define NUM_SAVED 4
155	root	1.39	"\tpush %ebp\n"
156			"\tpush %ebx\n"
157			"\tpush %esi\n"
158			"\tpush %edi\n"
159	root	1.50	#if CORO_WIN_TIB
160	root	1.51	"\tpush %fs:0\n"
161			"\tpush %fs:4\n"
162	root	1.50	"\tpush %fs:8\n"
163			#endif
164	root	1.39	"\tmov %esp, (%eax)\n"
165			"\tmov (%edx), %esp\n"
166	root	1.50	#if CORO_WIN_TIB
167	root	1.51	"\tpop %fs:8\n"
168			"\tpop %fs:4\n"
169	root	1.50	"\tpop %fs:0\n"
170			#endif
171	root	1.39	"\tpop %edi\n"
172			"\tpop %esi\n"
173			"\tpop %ebx\n"
174			"\tpop %ebp\n"
175			#else
176			#error unsupported architecture
177			#endif
178	root	1.38	"\tret\n"
179			);
180
181	root	1.39	# endif
182	root	1.38
183			void
184			coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, long ssize)
185	root	1.1	{
186	root	1.39	coro_context nctx;
187	root	1.1	# if CORO_SJLJ
188			stack_t ostk, nstk;
189			struct sigaction osa, nsa;
190			sigset_t nsig, osig;
191			# endif
192
193	root	1.38	if (!coro)
194			return;
195
196	root	1.1	coro_init_func = coro;
197			coro_init_arg = arg;
198
199			new_coro = ctx;
200			create_coro = &nctx;
201
202			# if CORO_SJLJ
203			/* we use SIGUSR2. first block it, then fiddle with it. */
204
205			sigemptyset (&nsig);
206			sigaddset (&nsig, SIGUSR2);
207			sigprocmask (SIG_BLOCK, &nsig, &osig);
208
209			nsa.sa_handler = trampoline;
210			sigemptyset (&nsa.sa_mask);
211			nsa.sa_flags = SA_ONSTACK;
212
213			if (sigaction (SIGUSR2, &nsa, &osa))
214	root	1.23	{
215			perror ("sigaction");
216			abort ();
217			}
218	root	1.1
219			/* set the new stack */
220	root	1.54	nstk.ss_sp = STACK_ADJUST_PTR (sptr, ssize); /* yes, some platforms (IRIX) get this wrong. */
221			nstk.ss_size = STACK_ADJUST_SIZE (sptr, ssize);
222	root	1.1	nstk.ss_flags = 0;
223
224			if (sigaltstack (&nstk, &ostk) < 0)
225	root	1.23	{
226			perror ("sigaltstack");
227			abort ();
228			}
229	root	1.1
230	root	1.39	trampoline_done = 0;
231	root	1.1	kill (getpid (), SIGUSR2);
232			sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
233
234	root	1.39	while (!trampoline_done)
235	root	1.1	sigsuspend (&nsig);
236
237			sigaltstack (0, &nstk);
238			nstk.ss_flags = SS_DISABLE;
239			if (sigaltstack (&nstk, 0) < 0)
240			perror ("sigaltstack");
241
242			sigaltstack (0, &nstk);
243			if (~nstk.ss_flags & SS_DISABLE)
244			abort ();
245
246			if (~ostk.ss_flags & SS_DISABLE)
247			sigaltstack (&ostk, 0);
248
249	root	1.19	sigaction (SIGUSR2, &osa, 0);
250	root	1.1	sigprocmask (SIG_SETMASK, &osig, 0);
251
252	root	1.16	# elif CORO_LOSER
253	root	1.1
254	root	1.44	coro_setjmp (ctx->env);
255	root	1.48	#if __CYGWIN__ && __i386
256	root	1.47	ctx->env[8] = (long) coro_init;
257			ctx->env[7] = (long) ((char *)sptr + ssize) - sizeof (long);
258	root	1.48	#elif __CYGWIN__ && __x86_64
259			ctx->env[7] = (long) coro_init;
260			ctx->env[6] = (long) ((char *)sptr + ssize) - sizeof (long);
261	root	1.45	#elif defined(__MINGW32__)
262	root	1.47	ctx->env[5] = (long) coro_init;
263			ctx->env[4] = (long) ((char *)sptr + ssize) - sizeof (long);
264	root	1.39	#elif defined(_M_IX86)
265	root	1.47	((_JUMP_BUFFER *)&ctx->env)->Eip = (long) coro_init;
266			((_JUMP_BUFFER *)&ctx->env)->Esp = (long) STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
267	root	1.39	#elif defined(_M_AMD64)
268	root	1.47	((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64) coro_init;
269	root	1.48	((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
270	root	1.39	#elif defined(_M_IA64)
271	root	1.47	((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64) coro_init;
272	root	1.48	((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
273	root	1.39	#else
274			#error "microsoft libc or architecture not supported"
275			#endif
276	root	1.4
277			# elif CORO_LINUX
278
279	root	1.44	coro_setjmp (ctx->env);
280	root	1.39	#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
281	root	1.47	ctx->env[0].__jmpbuf[JB_PC] = (long) coro_init;
282			ctx->env[0].__jmpbuf[JB_SP] = (long) STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
283	root	1.39	#elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
284			ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
285	root	1.47	ctx->env[0].__jmpbuf[0].__sp = (int ) ((char )sptr + ssize) - sizeof (long);
286	root	1.39	#elif defined (__GNU_LIBRARY__) && defined (__i386__)
287	root	1.47	ctx->env[0].__jmpbuf[0].__pc = (char *) coro_init;
288			ctx->env[0].__jmpbuf[0].__sp = (void ) ((char )sptr + ssize) - sizeof (long);
289	root	1.39	#elif defined (__GNU_LIBRARY__) && defined (__amd64__)
290	root	1.47	ctx->env[0].__jmpbuf[JB_PC] = (long) coro_init;
291			ctx->env[0].__jmpbuf[0].__sp = (void ) ((char )sptr + ssize) - sizeof (long);
292	root	1.39	#else
293			#error "linux libc or architecture not supported"
294			#endif
295	root	1.5
296			# elif CORO_IRIX
297
298	root	1.44	coro_setjmp (ctx->env, 0);
299	root	1.47	ctx->env[JB_PC] = (__uint64_t)coro_init;
300			ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
301	root	1.1
302	root	1.27	# elif CORO_ASM
303
304	root	1.41	ctx->sp = (void *)(ssize + (char )sptr);
305	root	1.37	--ctx->sp = (void )abort; /* needed for alignment only */
306	root	1.27	--ctx->sp = (void )coro_init;
307
308	root	1.50	#if CORO_WIN_TIB
309	root	1.51	--ctx->sp = 0; / ExceptionList */
310			--ctx->sp = (char )sptr + ssize; /* StackBase */
311	root	1.50	--ctx->sp = sptr; / StackLimit */
312			#endif
313
314	root	1.51	ctx->sp -= NUM_SAVED;
315	root	1.55	memset (ctx->sp, 0, sizeof (ctx->sp) NUM_SAVED);
316	root	1.51
317	root	1.39	# elif CORO_UCONTEXT
318
319			getcontext (&(ctx->uc));
320
321			ctx->uc.uc_link = 0;
322			ctx->uc.uc_stack.ss_sp = sptr;
323			ctx->uc.uc_stack.ss_size = (size_t)ssize;
324			ctx->uc.uc_stack.ss_flags = 0;
325
326			makecontext (&(ctx->uc), (void (*)())coro_init, 0);
327
328	root	1.1	# endif
329
330	root	1.39	coro_transfer (create_coro, new_coro);
331			}
332
333			/*****************************************************************************/
334			/* pthread backend */
335			/*****************************************************************************/
336	root	1.40	#elif CORO_PTHREAD
337	root	1.1
338	root	1.39	/* this mutex will be locked by the running coroutine */
339			pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
340	root	1.30
341	root	1.39	struct coro_init_args
342			{
343			coro_func func;
344			void *arg;
345			coro_context self, main;
346			};
347
348			static pthread_t null_tid;
349
350			/* I'd so love to cast pthread_mutex_unlock to void ()(void )... */
351			static void
352			mutex_unlock_wrapper (void *arg)
353			{
354			pthread_mutex_unlock ((pthread_mutex_t *)arg);
355			}
356
357			static void *
358			coro_init (void *args_)
359			{
360			struct coro_init_args args = (struct coro_init_args )args_;
361			coro_func func = args->func;
362			void *arg = args->arg;
363
364			pthread_mutex_lock (&coro_mutex);
365
366			/* we try to be good citizens and use deferred cancellation and cleanup handlers */
367			pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
368			coro_transfer (args->self, args->main);
369			func (arg);
370			pthread_cleanup_pop (1);
371
372			return 0;
373			}
374
375			void
376			coro_transfer (coro_context prev, coro_context next)
377			{
378			pthread_cond_signal (&next->cv);
379			pthread_cond_wait (&prev->cv, &coro_mutex);
380	root	1.43	#if __FreeBSD__ /* freebsd is of course broken and needs manual testcancel calls... yay... */
381			pthread_testcancel ();
382			#endif
383	root	1.39	}
384
385			void
386			coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, long ssize)
387			{
388	root	1.38	static coro_context nctx;
389	root	1.30	static int once;
390
391			if (!once)
392			{
393	root	1.38	once = 1;
394
395	root	1.30	pthread_mutex_lock (&coro_mutex);
396	root	1.38	pthread_cond_init (&nctx.cv, 0);
397			null_tid = pthread_self ();
398	root	1.30	}
399
400	root	1.38	pthread_cond_init (&ctx->cv, 0);
401	root	1.30
402	root	1.38	if (coro)
403			{
404			pthread_attr_t attr;
405			struct coro_init_args args;
406
407			args.func = coro;
408			args.arg = arg;
409			args.self = ctx;
410			args.main = &nctx;
411
412			pthread_attr_init (&attr);
413	root	1.53	#if __UCLIBC__
414	root	1.54	/* exists, but is borked */
415			/pthread_attr_setstacksize (&attr, (size_t)ssize);/
416	root	1.53	#else
417	root	1.38	pthread_attr_setstack (&attr, sptr, (size_t)ssize);
418	root	1.53	#endif
419	root	1.38	pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
420	root	1.39	pthread_create (&ctx->id, &attr, coro_init, &args);
421	root	1.38
422			coro_transfer (args.main, args.self);
423			}
424			else
425			ctx->id = null_tid;
426	root	1.39	}
427
428			void
429			coro_destroy (coro_context *ctx)
430			{
431			if (!pthread_equal (ctx->id, null_tid))
432			{
433			pthread_cancel (ctx->id);
434			pthread_mutex_unlock (&coro_mutex);
435			pthread_join (ctx->id, 0);
436			pthread_mutex_lock (&coro_mutex);
437			}
438
439			pthread_cond_destroy (&ctx->cv);
440			}
441	root	1.30
442	root	1.40	#else
443			# error unsupported backend
444	root	1.1	#endif
445