libcoro/coro.h

/*
 * Copyright (c) 2001-2008 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.
 */

#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 <pthread.h> 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 <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

#elif CORO_ASM

struct coro_context {
  volatile void **sp;
};

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

#elif CORO_PTHREAD

#include <pthread.h>

extern pthread_mutex_t coro_mutex;

struct coro_context {
  pthread_cond_t c;
};

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

#endif

#endif

Revision:	1.28
Committed:	Thu Oct 30 09:44:31 2008 UTC (15 years, 7 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-4_802
Changes since 1.27:	+1 -0 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* Copyright (c) 2001-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
3	*
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	* 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	* This library is modelled strictly after Ralf S. Engelschalls article at
37	* http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
38	* go to Ralf S. Engelschall <rse@engelschall.com>.
39	*
40	* This coroutine library is very much stripped down. You should either
41	* build your own process abstraction using it or - better - just use GNU
42	* Portable Threads, http://www.gnu.org/software/pth/.
43	*
44	*/
45
46	/*
47	* 2006-10-26 Include stddef.h on OS X to work around one of its bugs.
48	* Reported by Michael_G_Schwern.
49	* 2006-11-26 Use _setjmp instead of setjmp on GNU/Linux.
50	* 2007-04-27 Set unwind frame info if gcc 3+ and ELF is detected.
51	* Use _setjmp instead of setjmp on _XOPEN_SOURCE >= 600.
52	* 2007-05-02 Add assembly versions for x86 and amd64 (to avoid reliance
53	* on SIGUSR2 and sigaltstack in Crossfire).
54	* 2008-01-21 Disable CFI usage on anything but GNU/Linux.
55	* 2008-03-02 Switched to 2-clause BSD license with GPL exception.
56	* 2008-04-04 New (but highly unrecommended) pthreads backend.
57	* 2008-04-24 Reinstate CORO_LOSER (had wrong stack adjustments).
58	* 2008-10-30 Support assembly method on x86 with and without frame pointer.
59	*/
60
61	#ifndef CORO_H
62	#define CORO_H
63
64	#define CORO_VERSION 2
65
66	/*
67	* Changes since API version 1:
68	* replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
69	*/
70
71	/*
72	* This library consists of only three files
73	* coro.h, coro.c and LICENSE (and optionally README)
74	*
75	* It implements what is known as coroutines, in a hopefully
76	* portable way. At the moment you have to define which kind
77	* of implementation flavour you want:
78	*
79	* -DCORO_UCONTEXT
80	*
81	* This flavour uses SUSv2's get/set/swap/makecontext functions that
82	* unfortunately only newer unices support.
83	*
84	* -DCORO_SJLJ
85	*
86	* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
87	* do it's job. Coroutine creation is much slower than UCONTEXT, but
88	* context switching is often a bit cheaper. It should work on almost
89	* all unices.
90	*
91	* -DCORO_LINUX
92	*
93	* Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
94	* (it is very fast and therefore recommended over other methods, but
95	* doesn't work with anything newer).
96	*
97	* -DCORO_LOSER
98	*
99	* Microsoft's highly proprietary platform doesn't support sigaltstack, and
100	* this automatically selects a suitable workaround for this platform.
101	* (untested)
102	*
103	* -DCORO_IRIX
104	*
105	* SGI's version of Microsoft's NT ;)
106	*
107	* -DCORO_ASM
108	*
109	* Handcoded assembly, known to work only on a few architectures/ABI:
110	* ELF Linux x86 && amd64 when gcc is used and optimisation is turned on.
111	*
112	* -DCORO_PTHREAD
113	*
114	* Use the pthread API. You have to provide <pthread.h> and -lpthread.
115	*
116	* If you define neither of these symbols, coro.h will try to autodetect
117	* the model. This currently works for CORO_LOSER only. For the other
118	* alternatives you should check (e.g. using autoconf) and define the
119	* following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
120	*/
121
122	/*
123	* This is the type for the initialization function of a new coroutine.
124	*/
125	typedef void (coro_func)(void );
126
127	/*
128	* A coroutine state is saved in the following structure. Treat it as an
129	* opaque type. errno and sigmask might be saved, but don't rely on it,
130	* implement your own switching primitive if you need that.
131	*/
132	typedef struct coro_context coro_context;
133
134	/*
135	* This function creates a new coroutine. Apart from a pointer to an
136	* uninitialised coro_context, it expects a pointer to the entry function
137	* and the single pointer value that is given to it as argument.
138	*
139	* Allocating/deallocating the stack is your own responsibility, so there is
140	* no coro_destroy function.
141	*/
142	void coro_create (coro_context ctx, / an uninitialised coro_context */
143	coro_func coro, /* the coroutine code to be executed */
144	void arg, / a single pointer passed to the coro */
145	void sptr, / start of stack area */
146	long ssize); /* size of stack area */
147
148	/*
149	* The following prototype defines the coroutine switching function. It is
150	* usually implemented as a macro, so watch out.
151	*
152	void coro_transfer(coro_context prev, coro_context next);
153	*/
154
155	/*
156	* That was it. No other user-visible functions are implemented here.
157	*/
158
159	/*****************************************************************************/
160
161	#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \
162	&& !defined(CORO_SJLJ) && !defined(CORO_LINUX) \
163	&& !defined(CORO_IRIX) && !defined(CORO_ASM) \
164	&& !defined(CORO_PTHREAD)
165	# if defined(WINDOWS)
166	# define CORO_LOSER 1 /* you don't win with windoze */
167	# elif defined(__linux) && (defined(__x86) \|\| defined (__amd64))
168	# define CORO_ASM 1
169	# elif defined(HAVE_UCONTEXT_H)
170	# define CORO_UCONTEXT 1
171	# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK)
172	# define CORO_SJLJ 1
173	# else
174	error unknown or unsupported architecture
175	# endif
176	#endif
177
178	/*****************************************************************************/
179
180	#if CORO_UCONTEXT
181
182	# include <ucontext.h>
183
184	struct coro_context {
185	ucontext_t uc;
186	};
187
188	# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
189
190	#elif CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX
191
192	# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
193	# define _GNU_SOURCE /* for linux libc */
194	# endif
195
196	# include <setjmp.h>
197
198	struct coro_context {
199	jmp_buf env;
200	};
201
202	# if CORO_LINUX \|\| (_XOPEN_SOURCE >= 600)
203	# define coro_transfer(p,n) do { if (!_setjmp ((p)->env)) _longjmp ((n)->env, 1); } while (0)
204	# else
205	# define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while (0)
206	# endif
207
208	#elif CORO_ASM
209
210	struct coro_context {
211	volatile void **sp;
212	};
213
214	void __attribute__ ((__noinline__, __regparm__(2)))
215	coro_transfer (coro_context prev, coro_context next);
216
217	#elif CORO_PTHREAD
218
219	#include <pthread.h>
220
221	extern pthread_mutex_t coro_mutex;
222
223	struct coro_context {
224	pthread_cond_t c;
225	};
226
227	void coro_transfer (coro_context prev, coro_context next);
228
229	#endif
230
231	#endif
232