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.
 */

#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.
 *
 * 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)
# 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__, __fastcall__))
     coro_transfer(coro_context *prev, coro_context *next);

#endif

#endif

Revision:	1.24
Committed:	Sun Mar 2 16:10:22 2008 UTC (16 years, 3 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-4_45
Changes since 1.23:	+18 -11 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.23	* Copyright (c) 2001-2008 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	1.14	*/
57
58	root	1.1	#ifndef CORO_H
59			#define CORO_H
60
61	root	1.11	#define CORO_VERSION 2
62
63			/*
64			* Changes since API version 1:
65	root	1.12	* replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
66	root	1.11	*/
67	root	1.9
68	root	1.2	/*
69			* This library consists of only three files
70	root	1.9	* coro.h, coro.c and LICENSE (and optionally README)
71	root	1.2	*
72			* It implements what is known as coroutines, in a hopefully
73			* portable way. At the moment you have to define which kind
74			* of implementation flavour you want:
75			*
76			* -DCORO_UCONTEXT
77			*
78			* This flavour uses SUSv2's get/set/swap/makecontext functions that
79			* unfortunately only newer unices support.
80			*
81			* -DCORO_SJLJ
82			*
83	root	1.13	* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
84	root	1.2	* do it's job. Coroutine creation is much slower than UCONTEXT, but
85			* context switching is often a bit cheaper. It should work on almost
86	root	1.24	* all unices.
87	root	1.3	*
88			* -DCORO_LINUX
89			*
90	root	1.24	* Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
91			* (it is very fast and therefore recommended over other methods, but
92			* doesn't work with anything newer).
93	root	1.2	*
94	root	1.11	* -DCORO_LOSER
95	root	1.2	*
96			* Microsoft's highly proprietary platform doesn't support sigaltstack, and
97			* this automatically selects a suitable workaround for this platform.
98			* (untested)
99			*
100	root	1.5	* -DCORO_IRIX
101			*
102			* SGI's version of Microsoft's NT ;)
103			*
104	root	1.22	* -DCORO_ASM
105			*
106			* Handcoded assembly, known to work only on a few architectures/ABI:
107			* ELF Linux x86 && amd64 when gcc is used and optimisation is turned on.
108			*
109	root	1.2	* If you define neither of these symbols, coro.h will try to autodetect
110	root	1.24	* the model. This currently works for CORO_LOSER only. For the other
111	root	1.2	* alternatives you should check (e.g. using autoconf) and define the
112			* following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
113			*/
114
115			/*
116	root	1.6	* This is the type for the initialization function of a new coroutine.
117	root	1.2	*/
118	root	1.1	typedef void (coro_func)(void );
119	root	1.2
120			/*
121	root	1.19	* A coroutine state is saved in the following structure. Treat it as an
122	root	1.2	* opaque type. errno and sigmask might be saved, but don't rely on it,
123	root	1.19	* implement your own switching primitive if you need that.
124	root	1.2	*/
125			typedef struct coro_context coro_context;
126
127			/*
128			* This function creates a new coroutine. Apart from a pointer to an
129	root	1.13	* uninitialised coro_context, it expects a pointer to the entry function
130	root	1.2	* and the single pointer value that is given to it as argument.
131			*
132			* Allocating/deallocating the stack is your own responsibility, so there is
133			* no coro_destroy function.
134			*/
135	root	1.19	void coro_create (coro_context ctx, / an uninitialised coro_context */
136			coro_func coro, /* the coroutine code to be executed */
137			void arg, / a single pointer passed to the coro */
138			void sptr, / start of stack area */
139			long ssize); /* size of stack area */
140	root	1.2
141			/*
142			* The following prototype defines the coroutine switching function. It is
143			* usually implemented as a macro, so watch out.
144			*
145			void coro_transfer(coro_context prev, coro_context next);
146			*/
147
148			/*
149			* That was it. No other user-visible functions are implemented here.
150			*/
151
152	root	1.5	/*****************************************************************************/
153
154	root	1.11	#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \
155	root	1.5	&& !defined(CORO_SJLJ) && !defined(CORO_LINUX) \
156	root	1.22	&& !defined(CORO_IRIX) && !defined(CORO_ASM)
157	root	1.2	# if defined(WINDOWS)
158	root	1.11	# define CORO_LOSER 1 /* you don't win with windoze */
159	root	1.22	# elif defined(__linux) && (defined(__x86) \|\| defined (__amd64))
160			# define CORO_ASM 1
161	root	1.2	# elif defined(HAVE_UCONTEXT_H)
162			# define CORO_UCONTEXT 1
163			# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK)
164			# define CORO_SJLJ 1
165			# else
166	root	1.1	error unknown or unsupported architecture
167	root	1.2	# endif
168	root	1.1	#endif
169
170	root	1.5	/*****************************************************************************/
171
172	root	1.1	#if CORO_UCONTEXT
173
174	root	1.22	# include <ucontext.h>
175	root	1.1
176	root	1.2	struct coro_context {
177	root	1.1	ucontext_t uc;
178	root	1.2	};
179	root	1.1
180	root	1.22	# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
181	root	1.1
182	root	1.11	#elif CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX
183	root	1.1
184	root	1.22	# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
185			# define _GNU_SOURCE /* for linux libc */
186			# endif
187	root	1.8
188	root	1.22	# include <setjmp.h>
189	root	1.1
190	root	1.2	struct coro_context {
191	root	1.1	jmp_buf env;
192	root	1.2	};
193	root	1.1
194	root	1.22	# if CORO_LINUX \|\| (_XOPEN_SOURCE >= 600)
195			# define coro_transfer(p,n) do { if (!_setjmp ((p)->env)) _longjmp ((n)->env, 1); } while (0)
196			# else
197			# define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while (0)
198			# endif
199
200			#elif CORO_ASM
201
202			struct coro_context {
203			volatile void **sp;
204			};
205
206			void __attribute__ ((__noinline__, __fastcall__))
207			coro_transfer(coro_context prev, coro_context next);
208	root	1.1
209			#endif
210
211			#endif
212