libcoro/coro.h

/*
 * 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.
 */

#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 a
 * opaque type. errno and sigmask might be saved, but don't rely on it,
 * implement your own switching primitive if you need it.
 */
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,
                  coro_func coro, void *arg,
                  void *sptr, long ssize);

/*
 * 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
# 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

Revision:	1.17
Committed:	Sun Nov 26 03:18:51 2006 UTC (19 years, 9 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.16:	+6 -2 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.14	* Copyright (c) 2001-2006 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			* 3. The name of the author may not be used to endorse or promote products
15			* derived from this software without specific prior written permission.
16			*
17			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26			* OF THE POSSIBILITY OF SUCH DAMAGE.
27			*
28			* This library is modelled strictly after Ralf S. Engelschalls article at
29			* http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
30			* go to Ralf S. Engelschall <rse@engelschall.com>.
31			*
32			* This coroutine library is very much stripped down. You should either
33	pcg	1.7	* build your own process abstraction using it or - better - just use GNU
34	root	1.1	* Portable Threads, http://www.gnu.org/software/pth/.
35	root	1.4	*
36	root	1.1	*/
37
38	root	1.14	/*
39			* 2006-10-26 Include stddef.h on OS X to work around one of its bugs.
40			* Reported by Michael_G_Schwern.
41	root	1.17	* 2006-11-26 Use _setjmp instead of setjmp on GNU/Linux.
42	root	1.14	*/
43
44	root	1.1	#ifndef CORO_H
45			#define CORO_H
46
47	root	1.11	#define CORO_VERSION 2
48
49			/*
50			* Changes since API version 1:
51	root	1.12	* replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
52	root	1.11	*/
53	root	1.9
54	root	1.2	/*
55			* This library consists of only three files
56	root	1.9	* coro.h, coro.c and LICENSE (and optionally README)
57	root	1.2	*
58			* It implements what is known as coroutines, in a hopefully
59			* portable way. At the moment you have to define which kind
60			* of implementation flavour you want:
61			*
62			* -DCORO_UCONTEXT
63			*
64			* This flavour uses SUSv2's get/set/swap/makecontext functions that
65			* unfortunately only newer unices support.
66	root	1.13	* Use this for GNU/Linux + glibc-2.2.3 and possibly higher.
67	root	1.2	*
68			* -DCORO_SJLJ
69			*
70	root	1.13	* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
71	root	1.2	* do it's job. Coroutine creation is much slower than UCONTEXT, but
72			* context switching is often a bit cheaper. It should work on almost
73			* all unices. Use this for GNU/Linux + glibc-2.2. glibc-2.1 and below
74	root	1.3	* do not work with any sane model (neither sigaltstack nor context
75			* functions are implemented)
76			*
77			* -DCORO_LINUX
78			*
79			* Old GNU/Linux systems (<= glibc-2.1) work with this implementation
80	root	1.13	* (it is very fast and therefore recommended over other methods).
81	root	1.2	*
82	root	1.11	* -DCORO_LOSER
83	root	1.2	*
84			* Microsoft's highly proprietary platform doesn't support sigaltstack, and
85			* this automatically selects a suitable workaround for this platform.
86			* (untested)
87			*
88	root	1.5	* -DCORO_IRIX
89			*
90			* SGI's version of Microsoft's NT ;)
91			*
92	root	1.2	* If you define neither of these symbols, coro.h will try to autodetect
93	root	1.11	* the model. This currently works for CORO_LOSER only. For the other
94	root	1.2	* alternatives you should check (e.g. using autoconf) and define the
95			* following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
96			*/
97
98			/*
99	root	1.6	* This is the type for the initialization function of a new coroutine.
100	root	1.2	*/
101	root	1.1	typedef void (coro_func)(void );
102	root	1.2
103			/*
104			* A coroutine state is saved in the following structure. Treat it as a
105			* opaque type. errno and sigmask might be saved, but don't rely on it,
106	root	1.15	* implement your own switching primitive if you need it.
107	root	1.2	*/
108			typedef struct coro_context coro_context;
109
110			/*
111			* This function creates a new coroutine. Apart from a pointer to an
112	root	1.13	* uninitialised coro_context, it expects a pointer to the entry function
113	root	1.2	* and the single pointer value that is given to it as argument.
114			*
115			* Allocating/deallocating the stack is your own responsibility, so there is
116			* no coro_destroy function.
117			*/
118	pcg	1.7	void coro_create (coro_context *ctx,
119			coro_func coro, void *arg,
120			void *sptr, long ssize);
121	root	1.2
122			/*
123			* The following prototype defines the coroutine switching function. It is
124			* usually implemented as a macro, so watch out.
125			*
126			void coro_transfer(coro_context prev, coro_context next);
127			*/
128
129			/*
130			* That was it. No other user-visible functions are implemented here.
131			*/
132
133	root	1.5	/*****************************************************************************/
134
135	root	1.11	#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \
136	root	1.5	&& !defined(CORO_SJLJ) && !defined(CORO_LINUX) \
137			&& !defined(CORO_IRIX)
138	root	1.2	# if defined(WINDOWS)
139	root	1.11	# define CORO_LOSER 1 /* you don't win with windoze */
140	root	1.3	# elif defined(__linux) && defined(__x86)
141	root	1.2	# elif defined(HAVE_UCONTEXT_H)
142			# define CORO_UCONTEXT 1
143			# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK)
144			# define CORO_SJLJ 1
145			# else
146	root	1.1	error unknown or unsupported architecture
147	root	1.2	# endif
148	root	1.1	#endif
149
150	root	1.5	/*****************************************************************************/
151
152	root	1.1	#if CORO_UCONTEXT
153
154			#include <ucontext.h>
155
156	root	1.2	struct coro_context {
157	root	1.1	ucontext_t uc;
158	root	1.2	};
159	root	1.1
160	pcg	1.7	#define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
161	root	1.1
162	root	1.11	#elif CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX
163	root	1.1
164	root	1.10	#if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
165	root	1.8	# define _GNU_SOURCE // for linux libc
166			#endif
167
168	root	1.1	#include <setjmp.h>
169
170	root	1.2	struct coro_context {
171	root	1.1	jmp_buf env;
172	root	1.2	};
173	root	1.1
174	root	1.17	#if CORO_LINUX
175			# define coro_transfer(p,n) do { if (!_setjmp ((p)->env)) _longjmp ((n)->env, 1); } while(0)
176			#else
177			# define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while(0)
178			#endif
179	root	1.1
180			#endif
181
182			#endif
183