/* * Copyright (c) 2001-2008 Marc Alexander Lehmann * * 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 . * * 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. * 2007-05-02 Add assembly versions for x86 and amd64 (to avoid reliance * on SIGUSR2 and sigaltstack in Crossfire). * 2008-01-21 Disable CFI usage on anything but GNU/Linux. * 2008-03-02 Switched to 2-clause BSD license with GPL exception. * 2008-04-04 New (but highly unrecommended) pthreads backend. * 2008-04-24 Reinstate CORO_LOSER (had wrong stack adjustments). */ #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. * * -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. * * -DCORO_LINUX * * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation * (it is very fast and therefore recommended over other methods, but * doesn't work with anything newer). * * -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 ;) * * -DCORO_ASM * * Handcoded assembly, known to work only on a few architectures/ABI: * ELF Linux x86 && amd64 when gcc is used and optimisation is turned on. * * -DCORO_PTHREAD * * Use the pthread API. You have to provide and -lpthread. * * 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) && !defined(CORO_ASM) \ && !defined(CORO_PTHREAD) # if defined(WINDOWS) # define CORO_LOSER 1 /* you don't win with windoze */ # elif defined(__linux) && (defined(__x86) || defined (__amd64)) # define CORO_ASM 1 # 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 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 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 #elif CORO_ASM struct coro_context { volatile void **sp; }; void __attribute__ ((__noinline__, __fastcall__)) coro_transfer (coro_context *prev, coro_context *next); #elif CORO_PTHREAD #include extern pthread_mutex_t coro_mutex; struct coro_context { pthread_cond_t c; }; void coro_transfer (coro_context *prev, coro_context *next); #endif #endif