libcoro/coro.h

/*
 * Copyright (c) 2001-2009 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>.
 *
 * 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).
 * 2008-10-30 Support assembly method on x86 with and without frame pointer.
 * 2008-11-03 Use a global asm statement for CORO_ASM, idea by pippijn.
 * 2008-11-05 Hopefully fix misaligned stacks with CORO_ASM/SETJMP.
 * 2008-11-07 rbp wasn't saved in CORO_ASM on x86_64.
 *            introduce coro_destroy, which is a nop except for pthreads.
 *            speed up CORO_PTHREAD. Do no longer leak threads either.
 *            coro_create now allows one to create source coro_contexts.
 *            do not rely on makecontext passing a void * correctly.
 *            try harder to get _setjmp/_longjmp.
 *            major code cleanup/restructuring.
 * 2008-11-10 the .cfi hacks are no longer needed.
 * 2008-11-16 work around a freebsd pthread bug.
 * 2008-11-19 define coro_*jmp symbols for easier porting.
 * 2009-06-23 tentative win32-backend support for mingw32 (Yasuhiro Matsumoto).
 * 2010-12-03 tentative support for uclibc (which lacks all sorts of things).
 * 2011-05-30 set initial callee-saved-registers to zero with CORO_ASM.
 *            use .cfi_undefined rip on linux-amd64 for better backtraces.
 */

#ifndef CORO_H
#define CORO_H

#if __cplusplus
extern "C" {
#endif

#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:
 *    GCC + x86/IA32 and amd64/x86_64 + GNU/Linux and a few BSDs.
 *
 * -DCORO_PTHREAD
 *
 *    Use the pthread API. You have to provide <pthread.h> and -lpthread.
 *    This is likely the slowest backend, and it also does not support fork(),
 *    so avoid it at all costs.
 *
 * 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.
 *
 * As a special case, if coro, arg, sptr and ssize are all zero,
 * then an "empty" coro_context will be created that is suitable
 * as an initial source for coro_transfer.
 *
 * This function is not reentrant, but putting a mutex around it
 * will work.
 */
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.
 *
 * This function is thread-safe and reentrant.
 */
#if 0
void coro_transfer (coro_context *prev, coro_context *next);
#endif

/*
 * The following prototype defines the coroutine destroy function. It is
 * usually implemented as a macro, so watch out. It also serves
 * no purpose unless you want to use the CORO_PTHREAD backend,
 * where it is used to clean up the thread. You are responsible
 * for freeing the stack and the context itself.
 *
 * This function is thread-safe and reentrant.
 */
#if 0
void coro_destroy (coro_context *ctx);
#endif

/*
 * 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 <ucontext.h>

struct coro_context {
  ucontext_t uc;
};

# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
# define coro_destroy(ctx) (void *)(ctx)

#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX

# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
#  define _GNU_SOURCE /* for linux libc */
# endif

# if !CORO_LOSER
#  include <unistd.h>
# endif

/* solaris is hopelessly borked, it expands _XOPEN_UNIX to nothing */
# if __sun
#  undef _XOPEN_UNIX
#  define _XOPEN_UNIX 1
# endif

# include <setjmp.h>

# if _XOPEN_UNIX > 0 || defined (_setjmp)
#  define coro_jmp_buf      jmp_buf
#  define coro_setjmp(env)  _setjmp (env)
#  define coro_longjmp(env) _longjmp ((env), 1)
# elif CORO_LOSER
#  define coro_jmp_buf      jmp_buf
#  define coro_setjmp(env)  setjmp (env)
#  define coro_longjmp(env) longjmp ((env), 1)
# else
#  define coro_jmp_buf      sigjmp_buf
#  define coro_setjmp(env)  sigsetjmp (env, 0)
#  define coro_longjmp(env) siglongjmp ((env), 1)
# endif

struct coro_context {
  coro_jmp_buf env;
};

# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
# define coro_destroy(ctx) (void *)(ctx)

#elif CORO_ASM

struct coro_context {
  void **sp; /* must be at offset 0 */
};

void __attribute__ ((__noinline__, __regparm__(2)))
coro_transfer (coro_context *prev, coro_context *next);

# define coro_destroy(ctx) (void *)(ctx)

#elif CORO_PTHREAD

# include <pthread.h>

extern pthread_mutex_t coro_mutex;

struct coro_context {
  pthread_cond_t cv;
  pthread_t id;
};

void coro_transfer (coro_context *prev, coro_context *next);
void coro_destroy (coro_context *ctx);

#endif

#if __cplusplus
}
#endif

#endif

Revision:	1.47
Committed:	Mon May 30 02:46:52 2011 UTC (13 years ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.46:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.42	* Copyright (c) 2001-2009 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	1.24	* 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	1.24	* 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			* This coroutine library is very much stripped down. You should either
41	pcg	1.7	* build your own process abstraction using it or - better - just use GNU
42	root	1.1	* Portable Threads, http://www.gnu.org/software/pth/.
43	root	1.4	*
44	root	1.1	*/
45
46	root	1.14	/*
47			* 2006-10-26 Include stddef.h on OS X to work around one of its bugs.
48			* Reported by Michael_G_Schwern.
49	root	1.17	* 2006-11-26 Use _setjmp instead of setjmp on GNU/Linux.
50	root	1.20	* 2007-04-27 Set unwind frame info if gcc 3+ and ELF is detected.
51	root	1.21	* Use _setjmp instead of setjmp on _XOPEN_SOURCE >= 600.
52	root	1.22	* 2007-05-02 Add assembly versions for x86 and amd64 (to avoid reliance
53			* on SIGUSR2 and sigaltstack in Crossfire).
54	root	1.23	* 2008-01-21 Disable CFI usage on anything but GNU/Linux.
55	root	1.24	* 2008-03-02 Switched to 2-clause BSD license with GPL exception.
56	root	1.25	* 2008-04-04 New (but highly unrecommended) pthreads backend.
57	root	1.26	* 2008-04-24 Reinstate CORO_LOSER (had wrong stack adjustments).
58	root	1.28	* 2008-10-30 Support assembly method on x86 with and without frame pointer.
59	root	1.29	* 2008-11-03 Use a global asm statement for CORO_ASM, idea by pippijn.
60	root	1.30	* 2008-11-05 Hopefully fix misaligned stacks with CORO_ASM/SETJMP.
61	root	1.31	* 2008-11-07 rbp wasn't saved in CORO_ASM on x86_64.
62	root	1.32	* introduce coro_destroy, which is a nop except for pthreads.
63			* speed up CORO_PTHREAD. Do no longer leak threads either.
64			* coro_create now allows one to create source coro_contexts.
65	root	1.33	* do not rely on makecontext passing a void * correctly.
66			* try harder to get _setjmp/_longjmp.
67			* major code cleanup/restructuring.
68	root	1.37	* 2008-11-10 the .cfi hacks are no longer needed.
69	root	1.39	* 2008-11-16 work around a freebsd pthread bug.
70	root	1.40	* 2008-11-19 define coro_*jmp symbols for easier porting.
71	root	1.41	* 2009-06-23 tentative win32-backend support for mingw32 (Yasuhiro Matsumoto).
72	root	1.44	* 2010-12-03 tentative support for uclibc (which lacks all sorts of things).
73	root	1.45	* 2011-05-30 set initial callee-saved-registers to zero with CORO_ASM.
74	root	1.47	* use .cfi_undefined rip on linux-amd64 for better backtraces.
75	root	1.14	*/
76
77	root	1.1	#ifndef CORO_H
78			#define CORO_H
79
80	root	1.43	#if __cplusplus
81			extern "C" {
82			#endif
83
84	root	1.11	#define CORO_VERSION 2
85
86			/*
87			* Changes since API version 1:
88	root	1.12	* replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
89	root	1.11	*/
90	root	1.9
91	root	1.2	/*
92			* This library consists of only three files
93	root	1.9	* coro.h, coro.c and LICENSE (and optionally README)
94	root	1.2	*
95			* It implements what is known as coroutines, in a hopefully
96			* portable way. At the moment you have to define which kind
97			* of implementation flavour you want:
98			*
99			* -DCORO_UCONTEXT
100			*
101			* This flavour uses SUSv2's get/set/swap/makecontext functions that
102			* unfortunately only newer unices support.
103			*
104			* -DCORO_SJLJ
105			*
106	root	1.13	* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
107	root	1.2	* do it's job. Coroutine creation is much slower than UCONTEXT, but
108			* context switching is often a bit cheaper. It should work on almost
109	root	1.24	* all unices.
110	root	1.3	*
111			* -DCORO_LINUX
112			*
113	root	1.24	* Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
114			* (it is very fast and therefore recommended over other methods, but
115			* doesn't work with anything newer).
116	root	1.2	*
117	root	1.11	* -DCORO_LOSER
118	root	1.2	*
119			* Microsoft's highly proprietary platform doesn't support sigaltstack, and
120			* this automatically selects a suitable workaround for this platform.
121			* (untested)
122			*
123	root	1.5	* -DCORO_IRIX
124			*
125			* SGI's version of Microsoft's NT ;)
126			*
127	root	1.22	* -DCORO_ASM
128			*
129			* Handcoded assembly, known to work only on a few architectures/ABI:
130	root	1.39	* GCC + x86/IA32 and amd64/x86_64 + GNU/Linux and a few BSDs.
131	root	1.22	*
132	root	1.25	* -DCORO_PTHREAD
133			*
134			* Use the pthread API. You have to provide <pthread.h> and -lpthread.
135	root	1.39	* This is likely the slowest backend, and it also does not support fork(),
136			* so avoid it at all costs.
137	root	1.25	*
138	root	1.2	* If you define neither of these symbols, coro.h will try to autodetect
139	root	1.24	* the model. This currently works for CORO_LOSER only. For the other
140	root	1.2	* alternatives you should check (e.g. using autoconf) and define the
141			* following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
142			*/
143
144			/*
145	root	1.6	* This is the type for the initialization function of a new coroutine.
146	root	1.2	*/
147	root	1.1	typedef void (coro_func)(void );
148	root	1.2
149			/*
150	root	1.19	* A coroutine state is saved in the following structure. Treat it as an
151	root	1.2	* opaque type. errno and sigmask might be saved, but don't rely on it,
152	root	1.19	* implement your own switching primitive if you need that.
153	root	1.2	*/
154			typedef struct coro_context coro_context;
155
156			/*
157			* This function creates a new coroutine. Apart from a pointer to an
158	root	1.13	* uninitialised coro_context, it expects a pointer to the entry function
159	root	1.2	* and the single pointer value that is given to it as argument.
160			*
161	root	1.32	* Allocating/deallocating the stack is your own responsibility.
162			*
163			* As a special case, if coro, arg, sptr and ssize are all zero,
164	root	1.38	* then an "empty" coro_context will be created that is suitable
165	root	1.32	* as an initial source for coro_transfer.
166			*
167			* This function is not reentrant, but putting a mutex around it
168			* will work.
169	root	1.2	*/
170	root	1.19	void coro_create (coro_context ctx, / an uninitialised coro_context */
171			coro_func coro, /* the coroutine code to be executed */
172			void arg, / a single pointer passed to the coro */
173			void sptr, / start of stack area */
174			long ssize); /* size of stack area */
175	root	1.2
176			/*
177			* The following prototype defines the coroutine switching function. It is
178			* usually implemented as a macro, so watch out.
179			*
180	root	1.32	* This function is thread-safe and reentrant.
181	root	1.2	*/
182	root	1.32	#if 0
183			void coro_transfer (coro_context prev, coro_context next);
184			#endif
185
186			/*
187			* The following prototype defines the coroutine destroy function. It is
188			* usually implemented as a macro, so watch out. It also serves
189	root	1.38	* no purpose unless you want to use the CORO_PTHREAD backend,
190			* where it is used to clean up the thread. You are responsible
191			* for freeing the stack and the context itself.
192	root	1.32	*
193			* This function is thread-safe and reentrant.
194			*/
195			#if 0
196			void coro_destroy (coro_context *ctx);
197			#endif
198	root	1.2
199			/*
200			* That was it. No other user-visible functions are implemented here.
201			*/
202
203	root	1.5	/*****************************************************************************/
204
205	root	1.11	#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \
206	root	1.5	&& !defined(CORO_SJLJ) && !defined(CORO_LINUX) \
207	root	1.25	&& !defined(CORO_IRIX) && !defined(CORO_ASM) \
208			&& !defined(CORO_PTHREAD)
209	root	1.2	# if defined(WINDOWS)
210	root	1.11	# define CORO_LOSER 1 /* you don't win with windoze */
211	root	1.22	# elif defined(__linux) && (defined(__x86) \|\| defined (__amd64))
212			# define CORO_ASM 1
213	root	1.2	# elif defined(HAVE_UCONTEXT_H)
214			# define CORO_UCONTEXT 1
215			# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK)
216			# define CORO_SJLJ 1
217			# else
218	root	1.1	error unknown or unsupported architecture
219	root	1.2	# endif
220	root	1.1	#endif
221
222	root	1.5	/*****************************************************************************/
223
224	root	1.1	#if CORO_UCONTEXT
225
226	root	1.22	# include <ucontext.h>
227	root	1.1
228	root	1.2	struct coro_context {
229	root	1.1	ucontext_t uc;
230	root	1.2	};
231	root	1.1
232	root	1.22	# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
233	root	1.32	# define coro_destroy(ctx) (void *)(ctx)
234	root	1.1
235	root	1.11	#elif CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX
236	root	1.1
237	root	1.22	# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
238			# define _GNU_SOURCE /* for linux libc */
239			# endif
240	root	1.8
241	root	1.33	# if !CORO_LOSER
242			# include <unistd.h>
243			# endif
244
245	root	1.36	/* solaris is hopelessly borked, it expands _XOPEN_UNIX to nothing */
246			# if __sun
247			# undef _XOPEN_UNIX
248			# define _XOPEN_UNIX 1
249			# endif
250
251	root	1.22	# include <setjmp.h>
252	root	1.1
253	root	1.40	# if _XOPEN_UNIX > 0 \|\| defined (_setjmp)
254			# define coro_jmp_buf jmp_buf
255			# define coro_setjmp(env) _setjmp (env)
256			# define coro_longjmp(env) _longjmp ((env), 1)
257	root	1.34	# elif CORO_LOSER
258	root	1.40	# define coro_jmp_buf jmp_buf
259			# define coro_setjmp(env) setjmp (env)
260			# define coro_longjmp(env) longjmp ((env), 1)
261	root	1.22	# else
262	root	1.40	# define coro_jmp_buf sigjmp_buf
263			# define coro_setjmp(env) sigsetjmp (env, 0)
264			# define coro_longjmp(env) siglongjmp ((env), 1)
265	root	1.22	# endif
266
267	root	1.40	struct coro_context {
268			coro_jmp_buf env;
269			};
270
271			# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
272	root	1.32	# define coro_destroy(ctx) (void *)(ctx)
273
274	root	1.22	#elif CORO_ASM
275
276			struct coro_context {
277	root	1.34	void *sp; / must be at offset 0 */
278	root	1.22	};
279
280	root	1.27	void __attribute__ ((__noinline__, __regparm__(2)))
281	root	1.29	coro_transfer (coro_context prev, coro_context next);
282	root	1.25
283	root	1.32	# define coro_destroy(ctx) (void *)(ctx)
284
285	root	1.25	#elif CORO_PTHREAD
286
287	root	1.32	# include <pthread.h>
288	root	1.25
289			extern pthread_mutex_t coro_mutex;
290
291			struct coro_context {
292	root	1.32	pthread_cond_t cv;
293			pthread_t id;
294	root	1.25	};
295
296			void coro_transfer (coro_context prev, coro_context next);
297	root	1.32	void coro_destroy (coro_context *ctx);
298	root	1.1
299			#endif
300
301	root	1.43	#if __cplusplus
302			}
303			#endif
304
305	root	1.1	#endif
306