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.
 * 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.
 */

#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:
 *    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>

struct coro_context {
#if _XOPEN_UNIX > 0 || CORO_LOSER
  jmp_buf env;
#else
  sigjmp_buf env;
#endif
};

# if _XOPEN_UNIX > 0
#  define coro_transfer(p,n) do { if (!  _setjmp ((p)->env   ))   _longjmp ((n)->env, 1); } while (0)
# elif CORO_LOSER
#  define coro_transfer(p,n) do { if (!   setjmp ((p)->env   ))    longjmp ((n)->env, 1); } while (0)
# else
#  define coro_transfer(p,n) do { if (!sigsetjmp ((p)->env, 0)) siglongjmp ((n)->env, 1); } while (0)
# endif

# 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

#endif

Revision:	1.39
Committed:	Sun Nov 16 00:55:41 2008 UTC (15 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.38:	+4 -1 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	* 2008-11-03 Use a global asm statement for CORO_ASM, idea by pippijn.
60	* 2008-11-05 Hopefully fix misaligned stacks with CORO_ASM/SETJMP.
61	* 2008-11-07 rbp wasn't saved in CORO_ASM on x86_64.
62	* 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	* do not rely on makecontext passing a void * correctly.
66	* try harder to get _setjmp/_longjmp.
67	* major code cleanup/restructuring.
68	* 2008-11-10 the .cfi hacks are no longer needed.
69	* 2008-11-16 work around a freebsd pthread bug.
70	*/
71
72	#ifndef CORO_H
73	#define CORO_H
74
75	#define CORO_VERSION 2
76
77	/*
78	* Changes since API version 1:
79	* replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
80	*/
81
82	/*
83	* This library consists of only three files
84	* coro.h, coro.c and LICENSE (and optionally README)
85	*
86	* It implements what is known as coroutines, in a hopefully
87	* portable way. At the moment you have to define which kind
88	* of implementation flavour you want:
89	*
90	* -DCORO_UCONTEXT
91	*
92	* This flavour uses SUSv2's get/set/swap/makecontext functions that
93	* unfortunately only newer unices support.
94	*
95	* -DCORO_SJLJ
96	*
97	* This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
98	* do it's job. Coroutine creation is much slower than UCONTEXT, but
99	* context switching is often a bit cheaper. It should work on almost
100	* all unices.
101	*
102	* -DCORO_LINUX
103	*
104	* Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
105	* (it is very fast and therefore recommended over other methods, but
106	* doesn't work with anything newer).
107	*
108	* -DCORO_LOSER
109	*
110	* Microsoft's highly proprietary platform doesn't support sigaltstack, and
111	* this automatically selects a suitable workaround for this platform.
112	* (untested)
113	*
114	* -DCORO_IRIX
115	*
116	* SGI's version of Microsoft's NT ;)
117	*
118	* -DCORO_ASM
119	*
120	* Handcoded assembly, known to work only on a few architectures/ABI:
121	* GCC + x86/IA32 and amd64/x86_64 + GNU/Linux and a few BSDs.
122	*
123	* -DCORO_PTHREAD
124	*
125	* Use the pthread API. You have to provide <pthread.h> and -lpthread.
126	* This is likely the slowest backend, and it also does not support fork(),
127	* so avoid it at all costs.
128	*
129	* If you define neither of these symbols, coro.h will try to autodetect
130	* the model. This currently works for CORO_LOSER only. For the other
131	* alternatives you should check (e.g. using autoconf) and define the
132	* following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
133	*/
134
135	/*
136	* This is the type for the initialization function of a new coroutine.
137	*/
138	typedef void (coro_func)(void );
139
140	/*
141	* A coroutine state is saved in the following structure. Treat it as an
142	* opaque type. errno and sigmask might be saved, but don't rely on it,
143	* implement your own switching primitive if you need that.
144	*/
145	typedef struct coro_context coro_context;
146
147	/*
148	* This function creates a new coroutine. Apart from a pointer to an
149	* uninitialised coro_context, it expects a pointer to the entry function
150	* and the single pointer value that is given to it as argument.
151	*
152	* Allocating/deallocating the stack is your own responsibility.
153	*
154	* As a special case, if coro, arg, sptr and ssize are all zero,
155	* then an "empty" coro_context will be created that is suitable
156	* as an initial source for coro_transfer.
157	*
158	* This function is not reentrant, but putting a mutex around it
159	* will work.
160	*/
161	void coro_create (coro_context ctx, / an uninitialised coro_context */
162	coro_func coro, /* the coroutine code to be executed */
163	void arg, / a single pointer passed to the coro */
164	void sptr, / start of stack area */
165	long ssize); /* size of stack area */
166
167	/*
168	* The following prototype defines the coroutine switching function. It is
169	* usually implemented as a macro, so watch out.
170	*
171	* This function is thread-safe and reentrant.
172	*/
173	#if 0
174	void coro_transfer (coro_context prev, coro_context next);
175	#endif
176
177	/*
178	* The following prototype defines the coroutine destroy function. It is
179	* usually implemented as a macro, so watch out. It also serves
180	* no purpose unless you want to use the CORO_PTHREAD backend,
181	* where it is used to clean up the thread. You are responsible
182	* for freeing the stack and the context itself.
183	*
184	* This function is thread-safe and reentrant.
185	*/
186	#if 0
187	void coro_destroy (coro_context *ctx);
188	#endif
189
190	/*
191	* That was it. No other user-visible functions are implemented here.
192	*/
193
194	/*****************************************************************************/
195
196	#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \
197	&& !defined(CORO_SJLJ) && !defined(CORO_LINUX) \
198	&& !defined(CORO_IRIX) && !defined(CORO_ASM) \
199	&& !defined(CORO_PTHREAD)
200	# if defined(WINDOWS)
201	# define CORO_LOSER 1 /* you don't win with windoze */
202	# elif defined(__linux) && (defined(__x86) \|\| defined (__amd64))
203	# define CORO_ASM 1
204	# elif defined(HAVE_UCONTEXT_H)
205	# define CORO_UCONTEXT 1
206	# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK)
207	# define CORO_SJLJ 1
208	# else
209	error unknown or unsupported architecture
210	# endif
211	#endif
212
213	/*****************************************************************************/
214
215	#if CORO_UCONTEXT
216
217	# include <ucontext.h>
218
219	struct coro_context {
220	ucontext_t uc;
221	};
222
223	# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
224	# define coro_destroy(ctx) (void *)(ctx)
225
226	#elif CORO_SJLJ \|\| CORO_LOSER \|\| CORO_LINUX \|\| CORO_IRIX
227
228	# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
229	# define _GNU_SOURCE /* for linux libc */
230	# endif
231
232	# if !CORO_LOSER
233	# include <unistd.h>
234	# endif
235
236	/* solaris is hopelessly borked, it expands _XOPEN_UNIX to nothing */
237	# if __sun
238	# undef _XOPEN_UNIX
239	# define _XOPEN_UNIX 1
240	# endif
241
242	# include <setjmp.h>
243
244	struct coro_context {
245	#if _XOPEN_UNIX > 0 \|\| CORO_LOSER
246	jmp_buf env;
247	#else
248	sigjmp_buf env;
249	#endif
250	};
251
252	# if _XOPEN_UNIX > 0
253	# define coro_transfer(p,n) do { if (! _setjmp ((p)->env )) _longjmp ((n)->env, 1); } while (0)
254	# elif CORO_LOSER
255	# define coro_transfer(p,n) do { if (! setjmp ((p)->env )) longjmp ((n)->env, 1); } while (0)
256	# else
257	# define coro_transfer(p,n) do { if (!sigsetjmp ((p)->env, 0)) siglongjmp ((n)->env, 1); } while (0)
258	# endif
259
260	# define coro_destroy(ctx) (void *)(ctx)
261
262	#elif CORO_ASM
263
264	struct coro_context {
265	void *sp; / must be at offset 0 */
266	};
267
268	void __attribute__ ((__noinline__, __regparm__(2)))
269	coro_transfer (coro_context prev, coro_context next);
270
271	# define coro_destroy(ctx) (void *)(ctx)
272
273	#elif CORO_PTHREAD
274
275	# include <pthread.h>
276
277	extern pthread_mutex_t coro_mutex;
278
279	struct coro_context {
280	pthread_cond_t cv;
281	pthread_t id;
282	};
283
284	void coro_transfer (coro_context prev, coro_context next);
285	void coro_destroy (coro_context *ctx);
286
287	#endif
288
289	#endif
290