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/*
* Copyright (c) 2001-2006 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.
*
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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.
*
* 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>.
*
* This coroutine library is very much stripped down. You should either
* build your own process abstraction using it or - better - just use GNU
* Portable Threads, http://www.gnu.org/software/pth/.
*
*/
/*
* 2006-10-26 Include stddef.h on OS X to work around one of its bugs.
* Reported by Michael_G_Schwern.
* 2006-11-26 Use _setjmp instead of setjmp on GNU/Linux.
* 2007-04-27 Set unwind frame info if gcc 3+ and ELF is detected.
* Use _setjmp instead of setjmp on _XOPEN_SOURCE >= 600.
*/
#ifndef CORO_H
#define CORO_H
#define CORO_VERSION 2
/*
* Changes since API version 1:
* replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
*/
/*
* This library consists of only three files
* coro.h, coro.c and LICENSE (and optionally README)
*
* It implements what is known as coroutines, in a hopefully
* portable way. At the moment you have to define which kind
* of implementation flavour you want:
*
* -DCORO_UCONTEXT
*
* This flavour uses SUSv2's get/set/swap/makecontext functions that
* unfortunately only newer unices support.
* Use this for GNU/Linux + glibc-2.2.3 and possibly higher.
*
* -DCORO_SJLJ
*
* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
* do it's job. Coroutine creation is much slower than UCONTEXT, but
* context switching is often a bit cheaper. It should work on almost
* all unices. Use this for GNU/Linux + glibc-2.2. glibc-2.1 and below
* do not work with any sane model (neither sigaltstack nor context
* functions are implemented)
*
* -DCORO_LINUX
*
* Old GNU/Linux systems (<= glibc-2.1) work with this implementation
* (it is very fast and therefore recommended over other methods).
*
* -DCORO_LOSER
*
* Microsoft's highly proprietary platform doesn't support sigaltstack, and
* this automatically selects a suitable workaround for this platform.
* (untested)
*
* -DCORO_IRIX
*
* SGI's version of Microsoft's NT ;)
*
* If you define neither of these symbols, coro.h will try to autodetect
* the model. This currently works for CORO_LOSER only. For the other
* alternatives you should check (e.g. using autoconf) and define the
* following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
*/
/*
* This is the type for the initialization function of a new coroutine.
*/
typedef void (*coro_func)(void *);
/*
* A coroutine state is saved in the following structure. Treat it as an
* opaque type. errno and sigmask might be saved, but don't rely on it,
* implement your own switching primitive if you need that.
*/
typedef struct coro_context coro_context;
/*
* This function creates a new coroutine. Apart from a pointer to an
* uninitialised coro_context, it expects a pointer to the entry function
* and the single pointer value that is given to it as argument.
*
* Allocating/deallocating the stack is your own responsibility, so there is
* no coro_destroy function.
*/
void coro_create (coro_context *ctx, /* an uninitialised coro_context */
coro_func coro, /* the coroutine code to be executed */
void *arg, /* a single pointer passed to the coro */
void *sptr, /* start of stack area */
long ssize); /* size of stack area */
/*
* The following prototype defines the coroutine switching function. It is
* usually implemented as a macro, so watch out.
*
void coro_transfer(coro_context *prev, coro_context *next);
*/
/*
* That was it. No other user-visible functions are implemented here.
*/
/*****************************************************************************/
#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \
&& !defined(CORO_SJLJ) && !defined(CORO_LINUX) \
&& !defined(CORO_IRIX)
# if defined(WINDOWS)
# define CORO_LOSER 1 /* you don't win with windoze */
# elif defined(__linux) && defined(__x86)
# elif defined(HAVE_UCONTEXT_H)
# define CORO_UCONTEXT 1
# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK)
# define CORO_SJLJ 1
# else
error unknown or unsupported architecture
# endif
#endif
/*****************************************************************************/
#if CORO_UCONTEXT
#include <ucontext.h>
struct coro_context {
ucontext_t uc;
};
#define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
#if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
# define _GNU_SOURCE /* for linux libc */
#endif
#include <setjmp.h>
struct coro_context {
jmp_buf env;
};
#if CORO_LINUX || (_XOPEN_SOURCE >= 600)
# define coro_transfer(p,n) do { if (!_setjmp ((p)->env)) _longjmp ((n)->env, 1); } while (0)
#else
# define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while (0)
#endif
#endif
#endif
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