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 <stddef.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 || __CYGWIN__
    #define CORO_WIN_TIB 1
  #endif

  asm (
       "\t.text\n"
       #if _WIN32 || __CYGWIN__
       "\t.globl _coro_transfer\n"
       "_coro_transfer:\n"
       #else
       "\t.globl coro_transfer\n"
       "coro_transfer:\n"
       #endif
       /* 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

         #if _WIN32 || __CYGWIN__
           #define NUM_SAVED 29
           "\tsubq $168, %rsp\t" /* one dummy qword to improve alignment */
           "\tmovaps %xmm6, (%rsp)\n"
           "\tmovaps %xmm7, 16(%rsp)\n"
           "\tmovaps %xmm8, 32(%rsp)\n"
           "\tmovaps %xmm9, 48(%rsp)\n"
           "\tmovaps %xmm10, 64(%rsp)\n"
           "\tmovaps %xmm11, 80(%rsp)\n"
           "\tmovaps %xmm12, 96(%rsp)\n"
           "\tmovaps %xmm13, 112(%rsp)\n"
           "\tmovaps %xmm14, 128(%rsp)\n"
           "\tmovaps %xmm15, 144(%rsp)\n"
           "\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"
           "\tmovaps (%rsp), %xmm6\n"
           "\tmovaps 16(%rsp), %xmm7\n"
           "\tmovaps 32(%rsp), %xmm8\n"
           "\tmovaps 48(%rsp), %xmm9\n"
           "\tmovaps 64(%rsp), %xmm10\n"
           "\tmovaps 80(%rsp), %xmm11\n"
           "\tmovaps 96(%rsp), %xmm12\n"
           "\tmovaps 112(%rsp), %xmm13\n"
           "\tmovaps 128(%rsp), %xmm14\n"
           "\tmovaps 144(%rsp), %xmm15\n"
           "\taddq $168, %rsp\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
         "\tpopq %rcx\n"
         "\tjmpq *%rcx\n"

       #elif __i386

         #define NUM_SAVED 4
         "\tpushl %ebp\n"
         "\tpushl %ebx\n"
         "\tpushl %esi\n"
         "\tpushl %edi\n"
         #if CORO_WIN_TIB
           #undef NUM_SAVED
           #define NUM_SAVED 7
           "\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"
         "\tpopl %ecx\n"
         "\tjmpl *%ecx\n"

       #else
         #error unsupported architecture
       #endif
  );

# endif

void
coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, size_t 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, size_t 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);*/
#elif __CYGWIN__
      /* POSIX, not here */
      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);
}

/*****************************************************************************/
/* fiber backend                                                             */
/*****************************************************************************/
#elif CORO_FIBER

#define WIN32_LEAN_AND_MEAN
#if _WIN32_WINNT < 0x0400
  #undef _WIN32_WINNT
  #define _WIN32_WINNT 0x0400
#endif
#include <windows.h>

VOID CALLBACK
coro_init (PVOID arg)
{
  coro_context *ctx = (coro_context *)arg;

  ctx->coro (ctx->arg);
}

void
coro_transfer (coro_context *prev, coro_context *next)
{
  if (!prev->fiber)
    {
      prev->fiber = GetCurrentFiber ();

      if (prev->fiber == 0 || prev->fiber == (void *)0x1e00)
        prev->fiber = ConvertThreadToFiber (0);
    }

  SwitchToFiber (next->fiber);
}

void
coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, size_t ssize)
{
  ctx->fiber = 0;
  ctx->coro  = coro;
  ctx->arg   = arg;

  if (!coro)
    return;

  ctx->fiber = CreateFiber (ssize, coro_init, ctx);
}

void
coro_destroy (coro_context *ctx)
{
  DeleteFiber (ctx->fiber);
}

#else
  #error unsupported backend
#endif

/*****************************************************************************/
/* stack management                                                          */
/*****************************************************************************/
#if CORO_STACKALLOC

#include <stdlib.h>

#ifndef _WIN32
# include <unistd.h>
#endif

#if CORO_USE_VALGRIND
# include <valgrind/valgrind.h>
#endif

#if _POSIX_MAPPED_FILES
# include <sys/mman.h>
# define CORO_MMAP 1
# ifndef MAP_ANONYMOUS
#  ifdef MAP_ANON
#   define MAP_ANONYMOUS MAP_ANON
#  else
#   undef CORO_MMAP
#  endif
# endif
# include <limits.h>
#else
# undef CORO_MMAP
#endif

#if _POSIX_MEMORY_PROTECTION
# ifndef CORO_GUARDPAGES
#  define CORO_GUARDPAGES 4
# endif
#else
# undef CORO_GUARDPAGES
#endif

#if !CORO_MMAP
# undef CORO_GUARDPAGES
#endif

#if !__i386 && !__x86_64 && !__powerpc && !__m68k && !__alpha && !__mips && !__sparc64
# undef CORO_GUARDPAGES
#endif

#ifndef CORO_GUARDPAGES
# define CORO_GUARDPAGES 0
#endif

#if !PAGESIZE
  #if !CORO_MMAP
    #define PAGESIZE 4096
  #else
    static size_t
    coro_pagesize (void)
    {
      static size_t pagesize;

      if (!pagesize)
        pagesize = sysconf (_SC_PAGESIZE);

      return pagesize;
    }

    #define PAGESIZE coro_pagesize ()
  #endif
#endif

int
coro_stack_alloc (struct coro_stack *stack, unsigned int size)
{
  if (!size)
    size = 256 * 1024;

  stack->sptr = 0;
  stack->ssze = ((size_t)size * sizeof (void *) + PAGESIZE - 1) / PAGESIZE * PAGESIZE;

#if CORO_FIBER

  stack->sptr = (void *)stack;
  return 1;

#else

  size_t ssze = stack->ssze + CORO_GUARDPAGES * PAGESIZE;
  void *base;

  #if CORO_MMAP
    /* mmap supposedly does allocate-on-write for us */
    base = mmap (0, ssze, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

    if (base == (void *)-1)
      {
        /* some systems don't let us have executable heap */
        /* we assume they won't need executable stack in that case */
        base = mmap (0, ssze, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

        if (base == (void *)-1)
          return 0;
      }

    #if CORO_GUARDPAGES
      mprotect (base, CORO_GUARDPAGES * PAGESIZE, PROT_NONE);
    #endif

    base = (void*)((char *)base + CORO_GUARDPAGES * PAGESIZE);
  #else
    base = malloc (ssze);
    if (!base)
      return 0;
  #endif

  #if CORO_USE_VALGRIND
    stack->valgrind_id = VALGRIND_STACK_REGISTER ((char *)base, (char *)ssze - CORO_GUARDPAGES * PAGESIZE);
  #endif

  stack->sptr = base;
  return 1;

#endif
}

void
coro_stack_free (struct coro_stack *stack)
{
#if CORO_FIBER
  /* nop */
#else
  #if CORO_USE_VALGRIND
    VALGRIND_STACK_DEREGISTER (stack->valgrind_id);
  #endif

  #if CORO_MMAP
    if (stack->sptr)
      munmap ((void*)((char *)stack->sptr - CORO_GUARDPAGES * PAGESIZE),
              stack->ssze                 + CORO_GUARDPAGES * PAGESIZE);
  #else
    free (stack->sptr);
  #endif
#endif
}

#endif

Revision:	1.66
Committed:	Fri Dec 7 14:21:09 2012 UTC (11 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-6_23
Changes since 1.65:	+154 -5 lines
Log Message:	libecoro, erhm, stack management
#	User	Rev	Content
1	root	1.1	/*
2	root	1.56	* Copyright (c) 2001-2011 Marc Alexander Lehmann <schmorp@schmorp.de>
3	root	1.63	*
4	root	1.1	* Redistribution and use in source and binary forms, with or without modifica-
5			* tion, are permitted provided that the following conditions are met:
6	root	1.63	*
7	root	1.1	* 1. Redistributions of source code must retain the above copyright notice,
8			* this list of conditions and the following disclaimer.
9	root	1.63	*
10	root	1.1	* 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	root	1.63	*
14	root	1.1	* 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	1.66	#include <stddef.h>
44	root	1.38	#include <string.h>
45
46	root	1.39	/*****************************************************************************/
47			/* ucontext/setjmp/asm backends */
48			/*****************************************************************************/
49			#if CORO_UCONTEXT \|\| CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX \|\| CORO_ASM
50
51			# if CORO_UCONTEXT
52			# include <stddef.h>
53			# endif
54
55			# if !defined(STACK_ADJUST_PTR)
56			# if __sgi
57	root	1.5	/* IRIX is decidedly NON-unix */
58	root	1.39	# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
59			# define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
60			# elif (__i386__ && CORO_LINUX) \|\| (_M_IX86 && CORO_LOSER)
61			# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
62			# define STACK_ADJUST_SIZE(sp,ss) (ss)
63			# elif (__amd64__ && CORO_LINUX) \|\| ((_M_AMD64 \|\| _M_IA64) && CORO_LOSER)
64			# define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
65			# define STACK_ADJUST_SIZE(sp,ss) (ss)
66			# else
67			# define STACK_ADJUST_PTR(sp,ss) (sp)
68			# define STACK_ADJUST_SIZE(sp,ss) (ss)
69			# endif
70	root	1.8	# endif
71	root	1.1
72	root	1.38	# include <stdlib.h>
73	root	1.17
74	root	1.38	# if CORO_SJLJ
75			# include <stdio.h>
76			# include <signal.h>
77			# include <unistd.h>
78			# endif
79	root	1.1
80	root	1.40	static coro_func coro_init_func;
81			static void *coro_init_arg;
82			static coro_context new_coro, create_coro;
83	root	1.1
84			static void
85			coro_init (void)
86			{
87			volatile coro_func func = coro_init_func;
88			volatile void *arg = coro_init_arg;
89
90	root	1.40	coro_transfer (new_coro, create_coro);
91	root	1.1
92	root	1.61	#if __GCC_HAVE_DWARF2_CFI_ASM && __amd64
93	root	1.56	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	root	1.63	#if _WIN32 \|\| __CYGWIN__
121	root	1.60	#define CORO_WIN_TIB 1
122			#endif
123
124	root	1.38	asm (
125	root	1.60	"\t.text\n"
126	root	1.63	#if _WIN32 \|\| __CYGWIN__
127			"\t.globl _coro_transfer\n"
128			"_coro_transfer:\n"
129			#else
130	root	1.60	"\t.globl coro_transfer\n"
131	root	1.38	"coro_transfer:\n"
132	root	1.63	#endif
133	root	1.52	/* windows, of course, gives a shit on the amd64 ABI and uses different registers */
134			/* http://blogs.msdn.com/freik/archive/2005/03/17/398200.aspx */
135	root	1.39	#if __amd64
136	root	1.63
137			#if _WIN32 \|\| __CYGWIN__
138			#define NUM_SAVED 29
139			"\tsubq $168, %rsp\t" /* one dummy qword to improve alignment */
140			"\tmovaps %xmm6, (%rsp)\n"
141			"\tmovaps %xmm7, 16(%rsp)\n"
142			"\tmovaps %xmm8, 32(%rsp)\n"
143			"\tmovaps %xmm9, 48(%rsp)\n"
144			"\tmovaps %xmm10, 64(%rsp)\n"
145			"\tmovaps %xmm11, 80(%rsp)\n"
146			"\tmovaps %xmm12, 96(%rsp)\n"
147			"\tmovaps %xmm13, 112(%rsp)\n"
148			"\tmovaps %xmm14, 128(%rsp)\n"
149			"\tmovaps %xmm15, 144(%rsp)\n"
150	root	1.59	"\tpushq %rsi\n"
151			"\tpushq %rdi\n"
152			"\tpushq %rbp\n"
153			"\tpushq %rbx\n"
154			"\tpushq %r12\n"
155			"\tpushq %r13\n"
156			"\tpushq %r14\n"
157			"\tpushq %r15\n"
158	root	1.60	#if CORO_WIN_TIB
159			"\tpushq %fs:0x0\n"
160			"\tpushq %fs:0x8\n"
161			"\tpushq %fs:0xc\n"
162			#endif
163	root	1.59	"\tmovq %rsp, (%rcx)\n"
164			"\tmovq (%rdx), %rsp\n"
165	root	1.60	#if CORO_WIN_TIB
166			"\tpopq %fs:0xc\n"
167			"\tpopq %fs:0x8\n"
168			"\tpopq %fs:0x0\n"
169			#endif
170	root	1.59	"\tpopq %r15\n"
171			"\tpopq %r14\n"
172			"\tpopq %r13\n"
173			"\tpopq %r12\n"
174			"\tpopq %rbx\n"
175			"\tpopq %rbp\n"
176			"\tpopq %rdi\n"
177			"\tpopq %rsi\n"
178	root	1.63	"\tmovaps (%rsp), %xmm6\n"
179			"\tmovaps 16(%rsp), %xmm7\n"
180			"\tmovaps 32(%rsp), %xmm8\n"
181			"\tmovaps 48(%rsp), %xmm9\n"
182			"\tmovaps 64(%rsp), %xmm10\n"
183			"\tmovaps 80(%rsp), %xmm11\n"
184			"\tmovaps 96(%rsp), %xmm12\n"
185			"\tmovaps 112(%rsp), %xmm13\n"
186			"\tmovaps 128(%rsp), %xmm14\n"
187			"\tmovaps 144(%rsp), %xmm15\n"
188			"\taddq $168, %rsp\n"
189	root	1.58	#else
190			#define NUM_SAVED 6
191	root	1.59	"\tpushq %rbp\n"
192			"\tpushq %rbx\n"
193			"\tpushq %r12\n"
194			"\tpushq %r13\n"
195			"\tpushq %r14\n"
196			"\tpushq %r15\n"
197			"\tmovq %rsp, (%rdi)\n"
198			"\tmovq (%rsi), %rsp\n"
199			"\tpopq %r15\n"
200			"\tpopq %r14\n"
201			"\tpopq %r13\n"
202			"\tpopq %r12\n"
203			"\tpopq %rbx\n"
204			"\tpopq %rbp\n"
205	root	1.50	#endif
206	root	1.63	"\tpopq %rcx\n"
207			"\tjmpq *%rcx\n"
208
209	root	1.39	#elif __i386
210	root	1.63
211	root	1.50	#define NUM_SAVED 4
212	root	1.59	"\tpushl %ebp\n"
213			"\tpushl %ebx\n"
214			"\tpushl %esi\n"
215			"\tpushl %edi\n"
216	root	1.50	#if CORO_WIN_TIB
217	root	1.63	#undef NUM_SAVED
218			#define NUM_SAVED 7
219	root	1.59	"\tpushl %fs:0\n"
220			"\tpushl %fs:4\n"
221			"\tpushl %fs:8\n"
222	root	1.50	#endif
223	root	1.59	"\tmovl %esp, (%eax)\n"
224			"\tmovl (%edx), %esp\n"
225	root	1.50	#if CORO_WIN_TIB
226	root	1.59	"\tpopl %fs:8\n"
227			"\tpopl %fs:4\n"
228			"\tpopl %fs:0\n"
229	root	1.50	#endif
230	root	1.59	"\tpopl %edi\n"
231			"\tpopl %esi\n"
232			"\tpopl %ebx\n"
233			"\tpopl %ebp\n"
234	root	1.63	"\tpopl %ecx\n"
235			"\tjmpl *%ecx\n"
236
237	root	1.39	#else
238			#error unsupported architecture
239			#endif
240	root	1.38	);
241
242	root	1.39	# endif
243	root	1.38
244			void
245	root	1.66	coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, size_t ssize)
246	root	1.1	{
247	root	1.39	coro_context nctx;
248	root	1.1	# if CORO_SJLJ
249			stack_t ostk, nstk;
250			struct sigaction osa, nsa;
251			sigset_t nsig, osig;
252			# endif
253
254	root	1.38	if (!coro)
255			return;
256
257	root	1.1	coro_init_func = coro;
258			coro_init_arg = arg;
259
260			new_coro = ctx;
261			create_coro = &nctx;
262
263			# if CORO_SJLJ
264			/* we use SIGUSR2. first block it, then fiddle with it. */
265
266			sigemptyset (&nsig);
267			sigaddset (&nsig, SIGUSR2);
268			sigprocmask (SIG_BLOCK, &nsig, &osig);
269
270			nsa.sa_handler = trampoline;
271			sigemptyset (&nsa.sa_mask);
272			nsa.sa_flags = SA_ONSTACK;
273
274			if (sigaction (SIGUSR2, &nsa, &osa))
275	root	1.23	{
276			perror ("sigaction");
277			abort ();
278			}
279	root	1.1
280			/* set the new stack */
281	root	1.54	nstk.ss_sp = STACK_ADJUST_PTR (sptr, ssize); /* yes, some platforms (IRIX) get this wrong. */
282			nstk.ss_size = STACK_ADJUST_SIZE (sptr, ssize);
283	root	1.1	nstk.ss_flags = 0;
284
285			if (sigaltstack (&nstk, &ostk) < 0)
286	root	1.23	{
287			perror ("sigaltstack");
288			abort ();
289			}
290	root	1.1
291	root	1.39	trampoline_done = 0;
292	root	1.1	kill (getpid (), SIGUSR2);
293			sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
294
295	root	1.39	while (!trampoline_done)
296	root	1.1	sigsuspend (&nsig);
297
298			sigaltstack (0, &nstk);
299			nstk.ss_flags = SS_DISABLE;
300			if (sigaltstack (&nstk, 0) < 0)
301			perror ("sigaltstack");
302
303			sigaltstack (0, &nstk);
304			if (~nstk.ss_flags & SS_DISABLE)
305			abort ();
306
307			if (~ostk.ss_flags & SS_DISABLE)
308			sigaltstack (&ostk, 0);
309
310	root	1.19	sigaction (SIGUSR2, &osa, 0);
311	root	1.1	sigprocmask (SIG_SETMASK, &osig, 0);
312
313	root	1.16	# elif CORO_LOSER
314	root	1.1
315	root	1.44	coro_setjmp (ctx->env);
316	root	1.48	#if __CYGWIN__ && __i386
317	root	1.47	ctx->env[8] = (long) coro_init;
318			ctx->env[7] = (long) ((char *)sptr + ssize) - sizeof (long);
319	root	1.48	#elif __CYGWIN__ && __x86_64
320			ctx->env[7] = (long) coro_init;
321			ctx->env[6] = (long) ((char *)sptr + ssize) - sizeof (long);
322	root	1.63	#elif defined __MINGW32__
323	root	1.47	ctx->env[5] = (long) coro_init;
324			ctx->env[4] = (long) ((char *)sptr + ssize) - sizeof (long);
325	root	1.63	#elif defined _M_IX86
326	root	1.47	((_JUMP_BUFFER *)&ctx->env)->Eip = (long) coro_init;
327			((_JUMP_BUFFER *)&ctx->env)->Esp = (long) STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
328	root	1.63	#elif defined _M_AMD64
329	root	1.47	((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64) coro_init;
330	root	1.48	((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
331	root	1.63	#elif defined _M_IA64
332	root	1.47	((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64) coro_init;
333	root	1.48	((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64) STACK_ADJUST_PTR (sptr, ssize) - sizeof (__int64);
334	root	1.39	#else
335			#error "microsoft libc or architecture not supported"
336			#endif
337	root	1.4
338			# elif CORO_LINUX
339
340	root	1.44	coro_setjmp (ctx->env);
341	root	1.39	#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
342	root	1.47	ctx->env[0].__jmpbuf[JB_PC] = (long) coro_init;
343			ctx->env[0].__jmpbuf[JB_SP] = (long) STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
344	root	1.39	#elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
345			ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
346	root	1.47	ctx->env[0].__jmpbuf[0].__sp = (int ) ((char )sptr + ssize) - sizeof (long);
347	root	1.39	#elif defined (__GNU_LIBRARY__) && defined (__i386__)
348	root	1.47	ctx->env[0].__jmpbuf[0].__pc = (char *) coro_init;
349			ctx->env[0].__jmpbuf[0].__sp = (void ) ((char )sptr + ssize) - sizeof (long);
350	root	1.39	#elif defined (__GNU_LIBRARY__) && defined (__amd64__)
351	root	1.47	ctx->env[0].__jmpbuf[JB_PC] = (long) coro_init;
352			ctx->env[0].__jmpbuf[0].__sp = (void ) ((char )sptr + ssize) - sizeof (long);
353	root	1.39	#else
354			#error "linux libc or architecture not supported"
355			#endif
356	root	1.5
357			# elif CORO_IRIX
358
359	root	1.44	coro_setjmp (ctx->env, 0);
360	root	1.47	ctx->env[JB_PC] = (__uint64_t)coro_init;
361			ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
362	root	1.1
363	root	1.27	# elif CORO_ASM
364
365	root	1.41	ctx->sp = (void *)(ssize + (char )sptr);
366	root	1.37	--ctx->sp = (void )abort; /* needed for alignment only */
367	root	1.27	--ctx->sp = (void )coro_init;
368
369	root	1.50	#if CORO_WIN_TIB
370	root	1.51	--ctx->sp = 0; / ExceptionList */
371			--ctx->sp = (char )sptr + ssize; /* StackBase */
372	root	1.50	--ctx->sp = sptr; / StackLimit */
373			#endif
374
375	root	1.51	ctx->sp -= NUM_SAVED;
376	root	1.55	memset (ctx->sp, 0, sizeof (ctx->sp) NUM_SAVED);
377	root	1.51
378	root	1.39	# elif CORO_UCONTEXT
379
380			getcontext (&(ctx->uc));
381
382			ctx->uc.uc_link = 0;
383			ctx->uc.uc_stack.ss_sp = sptr;
384			ctx->uc.uc_stack.ss_size = (size_t)ssize;
385			ctx->uc.uc_stack.ss_flags = 0;
386
387			makecontext (&(ctx->uc), (void (*)())coro_init, 0);
388
389	root	1.1	# endif
390
391	root	1.39	coro_transfer (create_coro, new_coro);
392			}
393
394			/*****************************************************************************/
395			/* pthread backend */
396			/*****************************************************************************/
397	root	1.40	#elif CORO_PTHREAD
398	root	1.1
399	root	1.39	/* this mutex will be locked by the running coroutine */
400			pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
401	root	1.30
402	root	1.39	struct coro_init_args
403			{
404			coro_func func;
405			void *arg;
406			coro_context self, main;
407			};
408
409			static pthread_t null_tid;
410
411			/* I'd so love to cast pthread_mutex_unlock to void ()(void )... */
412			static void
413			mutex_unlock_wrapper (void *arg)
414			{
415			pthread_mutex_unlock ((pthread_mutex_t *)arg);
416			}
417
418			static void *
419			coro_init (void *args_)
420			{
421			struct coro_init_args args = (struct coro_init_args )args_;
422			coro_func func = args->func;
423			void *arg = args->arg;
424
425			pthread_mutex_lock (&coro_mutex);
426
427			/* we try to be good citizens and use deferred cancellation and cleanup handlers */
428			pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
429			coro_transfer (args->self, args->main);
430			func (arg);
431			pthread_cleanup_pop (1);
432
433			return 0;
434			}
435
436			void
437			coro_transfer (coro_context prev, coro_context next)
438			{
439			pthread_cond_signal (&next->cv);
440			pthread_cond_wait (&prev->cv, &coro_mutex);
441	root	1.43	#if __FreeBSD__ /* freebsd is of course broken and needs manual testcancel calls... yay... */
442			pthread_testcancel ();
443			#endif
444	root	1.39	}
445
446			void
447	root	1.66	coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, size_t ssize)
448	root	1.39	{
449	root	1.38	static coro_context nctx;
450	root	1.30	static int once;
451
452			if (!once)
453			{
454	root	1.38	once = 1;
455
456	root	1.30	pthread_mutex_lock (&coro_mutex);
457	root	1.38	pthread_cond_init (&nctx.cv, 0);
458			null_tid = pthread_self ();
459	root	1.30	}
460
461	root	1.38	pthread_cond_init (&ctx->cv, 0);
462	root	1.30
463	root	1.38	if (coro)
464			{
465			pthread_attr_t attr;
466			struct coro_init_args args;
467
468			args.func = coro;
469			args.arg = arg;
470			args.self = ctx;
471			args.main = &nctx;
472
473			pthread_attr_init (&attr);
474	root	1.53	#if __UCLIBC__
475	root	1.54	/* exists, but is borked */
476			/pthread_attr_setstacksize (&attr, (size_t)ssize);/
477	root	1.62	#elif __CYGWIN__
478			/* POSIX, not here */
479			pthread_attr_setstacksize (&attr, (size_t)ssize);
480	root	1.53	#else
481	root	1.38	pthread_attr_setstack (&attr, sptr, (size_t)ssize);
482	root	1.53	#endif
483	root	1.38	pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
484	root	1.39	pthread_create (&ctx->id, &attr, coro_init, &args);
485	root	1.38
486			coro_transfer (args.main, args.self);
487			}
488			else
489			ctx->id = null_tid;
490	root	1.39	}
491
492			void
493			coro_destroy (coro_context *ctx)
494			{
495			if (!pthread_equal (ctx->id, null_tid))
496			{
497			pthread_cancel (ctx->id);
498			pthread_mutex_unlock (&coro_mutex);
499			pthread_join (ctx->id, 0);
500			pthread_mutex_lock (&coro_mutex);
501			}
502
503			pthread_cond_destroy (&ctx->cv);
504			}
505	root	1.30
506	root	1.63	/*****************************************************************************/
507			/* fiber backend */
508			/*****************************************************************************/
509			#elif CORO_FIBER
510
511			#define WIN32_LEAN_AND_MEAN
512	root	1.66	#if _WIN32_WINNT < 0x0400
513			#undef _WIN32_WINNT
514			#define _WIN32_WINNT 0x0400
515			#endif
516	root	1.63	#include <windows.h>
517
518			VOID CALLBACK
519			coro_init (PVOID arg)
520			{
521			coro_context ctx = (coro_context )arg;
522
523			ctx->coro (ctx->arg);
524			}
525
526			void
527			coro_transfer (coro_context prev, coro_context next)
528			{
529			if (!prev->fiber)
530			{
531			prev->fiber = GetCurrentFiber ();
532
533			if (prev->fiber == 0 \|\| prev->fiber == (void *)0x1e00)
534			prev->fiber = ConvertThreadToFiber (0);
535			}
536
537			SwitchToFiber (next->fiber);
538			}
539
540			void
541	root	1.66	coro_create (coro_context ctx, coro_func coro, void arg, void *sptr, size_t ssize)
542	root	1.63	{
543			ctx->fiber = 0;
544			ctx->coro = coro;
545			ctx->arg = arg;
546
547			if (!coro)
548			return;
549
550			ctx->fiber = CreateFiber (ssize, coro_init, ctx);
551			}
552
553			void
554			coro_destroy (coro_context *ctx)
555			{
556			DeleteFiber (ctx->fiber);
557			}
558
559	root	1.40	#else
560	root	1.66	#error unsupported backend
561			#endif
562
563			/*****************************************************************************/
564			/* stack management */
565			/*****************************************************************************/
566			#if CORO_STACKALLOC
567
568			#include <stdlib.h>
569
570			#ifndef _WIN32
571			# include <unistd.h>
572			#endif
573
574			#if CORO_USE_VALGRIND
575			# include <valgrind/valgrind.h>
576			#endif
577
578			#if _POSIX_MAPPED_FILES
579			# include <sys/mman.h>
580			# define CORO_MMAP 1
581			# ifndef MAP_ANONYMOUS
582			# ifdef MAP_ANON
583			# define MAP_ANONYMOUS MAP_ANON
584			# else
585			# undef CORO_MMAP
586			# endif
587			# endif
588			# include <limits.h>
589			#else
590			# undef CORO_MMAP
591			#endif
592
593			#if _POSIX_MEMORY_PROTECTION
594			# ifndef CORO_GUARDPAGES
595			# define CORO_GUARDPAGES 4
596			# endif
597			#else
598			# undef CORO_GUARDPAGES
599			#endif
600
601			#if !CORO_MMAP
602			# undef CORO_GUARDPAGES
603			#endif
604
605			#if !__i386 && !__x86_64 && !__powerpc && !__m68k && !__alpha && !__mips && !__sparc64
606			# undef CORO_GUARDPAGES
607			#endif
608
609			#ifndef CORO_GUARDPAGES
610			# define CORO_GUARDPAGES 0
611			#endif
612
613			#if !PAGESIZE
614			#if !CORO_MMAP
615			#define PAGESIZE 4096
616			#else
617			static size_t
618			coro_pagesize (void)
619			{
620			static size_t pagesize;
621
622			if (!pagesize)
623			pagesize = sysconf (_SC_PAGESIZE);
624
625			return pagesize;
626			}
627
628			#define PAGESIZE coro_pagesize ()
629			#endif
630			#endif
631
632			int
633			coro_stack_alloc (struct coro_stack *stack, unsigned int size)
634			{
635			if (!size)
636			size = 256 * 1024;
637
638			stack->sptr = 0;
639			stack->ssze = ((size_t)size * sizeof (void ) + PAGESIZE - 1) / PAGESIZE PAGESIZE;
640
641			#if CORO_FIBER
642
643			stack->sptr = (void *)stack;
644			return 1;
645
646			#else
647
648			size_t ssze = stack->ssze + CORO_GUARDPAGES * PAGESIZE;
649			void *base;
650
651			#if CORO_MMAP
652			/* mmap supposedly does allocate-on-write for us */
653			base = mmap (0, ssze, PROT_READ \| PROT_WRITE \| PROT_EXEC, MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
654
655			if (base == (void *)-1)
656			{
657			/* some systems don't let us have executable heap */
658			/* we assume they won't need executable stack in that case */
659			base = mmap (0, ssze, PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
660
661			if (base == (void *)-1)
662			return 0;
663			}
664
665			#if CORO_GUARDPAGES
666			mprotect (base, CORO_GUARDPAGES * PAGESIZE, PROT_NONE);
667			#endif
668
669			base = (void)((char )base + CORO_GUARDPAGES * PAGESIZE);
670			#else
671			base = malloc (ssze);
672			if (!base)
673			return 0;
674			#endif
675
676			#if CORO_USE_VALGRIND
677			stack->valgrind_id = VALGRIND_STACK_REGISTER ((char )base, (char )ssze - CORO_GUARDPAGES * PAGESIZE);
678			#endif
679
680			stack->sptr = base;
681			return 1;
682
683			#endif
684			}
685
686			void
687			coro_stack_free (struct coro_stack *stack)
688			{
689			#if CORO_FIBER
690			/* nop */
691			#else
692			#if CORO_USE_VALGRIND
693			VALGRIND_STACK_DEREGISTER (stack->valgrind_id);
694			#endif
695
696			#if CORO_MMAP
697			if (stack->sptr)
698			munmap ((void)((char )stack->sptr - CORO_GUARDPAGES * PAGESIZE),
699			stack->ssze + CORO_GUARDPAGES * PAGESIZE);
700			#else
701			free (stack->sptr);
702			#endif
703			#endif
704			}
705
706	root	1.1	#endif
707