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.
 * 
 *   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.
 * 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.
 */

#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 ;)
 *
 * -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:	1.23
Committed:	Sun Jan 20 17:30:24 2008 UTC (16 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-4_4
Changes since 1.22:	+2 -1 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			* 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	1.20	* 2007-04-27 Set unwind frame info if gcc 3+ and ELF is detected.
43	root	1.21	* Use _setjmp instead of setjmp on _XOPEN_SOURCE >= 600.
44	root	1.22	* 2007-05-02 Add assembly versions for x86 and amd64 (to avoid reliance
45			* on SIGUSR2 and sigaltstack in Crossfire).
46	root	1.23	* 2008-01-21 Disable CFI usage on anything but GNU/Linux.
47	root	1.14	*/
48
49	root	1.1	#ifndef CORO_H
50			#define CORO_H
51
52	root	1.11	#define CORO_VERSION 2
53
54			/*
55			* Changes since API version 1:
56	root	1.12	* replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
57	root	1.11	*/
58	root	1.9
59	root	1.2	/*
60			* This library consists of only three files
61	root	1.9	* coro.h, coro.c and LICENSE (and optionally README)
62	root	1.2	*
63			* It implements what is known as coroutines, in a hopefully
64			* portable way. At the moment you have to define which kind
65			* of implementation flavour you want:
66			*
67			* -DCORO_UCONTEXT
68			*
69			* This flavour uses SUSv2's get/set/swap/makecontext functions that
70			* unfortunately only newer unices support.
71	root	1.13	* Use this for GNU/Linux + glibc-2.2.3 and possibly higher.
72	root	1.2	*
73			* -DCORO_SJLJ
74			*
75	root	1.13	* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
76	root	1.2	* do it's job. Coroutine creation is much slower than UCONTEXT, but
77			* context switching is often a bit cheaper. It should work on almost
78			* all unices. Use this for GNU/Linux + glibc-2.2. glibc-2.1 and below
79	root	1.3	* do not work with any sane model (neither sigaltstack nor context
80			* functions are implemented)
81			*
82			* -DCORO_LINUX
83			*
84			* Old GNU/Linux systems (<= glibc-2.1) work with this implementation
85	root	1.13	* (it is very fast and therefore recommended over other methods).
86	root	1.2	*
87	root	1.11	* -DCORO_LOSER
88	root	1.2	*
89			* Microsoft's highly proprietary platform doesn't support sigaltstack, and
90			* this automatically selects a suitable workaround for this platform.
91			* (untested)
92			*
93	root	1.5	* -DCORO_IRIX
94			*
95			* SGI's version of Microsoft's NT ;)
96			*
97	root	1.22	* -DCORO_ASM
98			*
99			* Handcoded assembly, known to work only on a few architectures/ABI:
100			* ELF Linux x86 && amd64 when gcc is used and optimisation is turned on.
101			*
102	root	1.2	* If you define neither of these symbols, coro.h will try to autodetect
103	root	1.11	* the model. This currently works for CORO_LOSER only. For the other
104	root	1.2	* alternatives you should check (e.g. using autoconf) and define the
105			* following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
106			*/
107
108			/*
109	root	1.6	* This is the type for the initialization function of a new coroutine.
110	root	1.2	*/
111	root	1.1	typedef void (coro_func)(void );
112	root	1.2
113			/*
114	root	1.19	* A coroutine state is saved in the following structure. Treat it as an
115	root	1.2	* opaque type. errno and sigmask might be saved, but don't rely on it,
116	root	1.19	* implement your own switching primitive if you need that.
117	root	1.2	*/
118			typedef struct coro_context coro_context;
119
120			/*
121			* This function creates a new coroutine. Apart from a pointer to an
122	root	1.13	* uninitialised coro_context, it expects a pointer to the entry function
123	root	1.2	* and the single pointer value that is given to it as argument.
124			*
125			* Allocating/deallocating the stack is your own responsibility, so there is
126			* no coro_destroy function.
127			*/
128	root	1.19	void coro_create (coro_context ctx, / an uninitialised coro_context */
129			coro_func coro, /* the coroutine code to be executed */
130			void arg, / a single pointer passed to the coro */
131			void sptr, / start of stack area */
132			long ssize); /* size of stack area */
133	root	1.2
134			/*
135			* The following prototype defines the coroutine switching function. It is
136			* usually implemented as a macro, so watch out.
137			*
138			void coro_transfer(coro_context prev, coro_context next);
139			*/
140
141			/*
142			* That was it. No other user-visible functions are implemented here.
143			*/
144
145	root	1.5	/*****************************************************************************/
146
147	root	1.11	#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \
148	root	1.5	&& !defined(CORO_SJLJ) && !defined(CORO_LINUX) \
149	root	1.22	&& !defined(CORO_IRIX) && !defined(CORO_ASM)
150	root	1.2	# if defined(WINDOWS)
151	root	1.11	# define CORO_LOSER 1 /* you don't win with windoze */
152	root	1.22	# elif defined(__linux) && (defined(__x86) \|\| defined (__amd64))
153			# define CORO_ASM 1
154	root	1.2	# elif defined(HAVE_UCONTEXT_H)
155			# define CORO_UCONTEXT 1
156			# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK)
157			# define CORO_SJLJ 1
158			# else
159	root	1.1	error unknown or unsupported architecture
160	root	1.2	# endif
161	root	1.1	#endif
162
163	root	1.5	/*****************************************************************************/
164
165	root	1.1	#if CORO_UCONTEXT
166
167	root	1.22	# include <ucontext.h>
168	root	1.1
169	root	1.2	struct coro_context {
170	root	1.1	ucontext_t uc;
171	root	1.2	};
172	root	1.1
173	root	1.22	# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
174	root	1.1
175	root	1.11	#elif CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX
176	root	1.1
177	root	1.22	# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
178			# define _GNU_SOURCE /* for linux libc */
179			# endif
180	root	1.8
181	root	1.22	# include <setjmp.h>
182	root	1.1
183	root	1.2	struct coro_context {
184	root	1.1	jmp_buf env;
185	root	1.2	};
186	root	1.1
187	root	1.22	# if CORO_LINUX \|\| (_XOPEN_SOURCE >= 600)
188			# define coro_transfer(p,n) do { if (!_setjmp ((p)->env)) _longjmp ((n)->env, 1); } while (0)
189			# else
190			# define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while (0)
191			# endif
192
193			#elif CORO_ASM
194
195			struct coro_context {
196			volatile void **sp;
197			};
198
199			void __attribute__ ((__noinline__, __fastcall__))
200			coro_transfer(coro_context prev, coro_context next);
201	root	1.1
202			#endif
203
204			#endif
205