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Revision 1.13 by root, Sun Feb 19 22:30:58 2006 UTC vs.
Revision 1.60 by root, Fri Nov 18 06:22:05 2016 UTC

1/* 1/*
2 * Copyright (c) 2001-2005 Marc Alexander Lehmann <schmorp@schmorp.de> 2 * Copyright (c) 2001-2012,2015 Marc Alexander Lehmann <schmorp@schmorp.de>
3 * 3 *
4 * Redistribution and use in source and binary forms, with or without modifica- 4 * Redistribution and use in source and binary forms, with or without modifica-
5 * tion, are permitted provided that the following conditions are met: 5 * tion, are permitted provided that the following conditions are met:
6 * 6 *
7 * 1. Redistributions of source code must retain the above copyright notice, 7 * 1. Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer. 8 * this list of conditions and the following disclaimer.
9 * 9 *
10 * 2. Redistributions in binary form must reproduce the above copyright 10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the 11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution. 12 * documentation and/or other materials provided with the distribution.
13 * 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 14 * 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- 15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 16 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- 17 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 18 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
… …
23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 20 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- 21 * 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 22 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26 * OF THE POSSIBILITY OF SUCH DAMAGE. 23 * OF THE POSSIBILITY OF SUCH DAMAGE.
27 * 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 *
28 * This library is modelled strictly after Ralf S. Engelschalls article at 36 * 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 37 * http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
30 * go to Ralf S. Engelschall <rse@engelschall.com>. 38 * go to Ralf S. Engelschall <rse@engelschall.com>.
31 * 39 *
32 * This coroutine library is very much stripped down. You should either 40 * This coroutine library is very much stripped down. You should either
33 * build your own process abstraction using it or - better - just use GNU 41 * build your own process abstraction using it or - better - just use GNU
34 * Portable Threads, http://www.gnu.org/software/pth/. 42 * Portable Threads, http://www.gnu.org/software/pth/.
35 * 43 *
36 */ 44 */
37 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 * 2008-11-19 define coro_*jmp symbols for easier porting.
71 * 2009-06-23 tentative win32-backend support for mingw32 (Yasuhiro Matsumoto).
72 * 2010-12-03 tentative support for uclibc (which lacks all sorts of things).
73 * 2011-05-30 set initial callee-saved-registers to zero with CORO_ASM.
74 * use .cfi_undefined rip on linux-amd64 for better backtraces.
75 * 2011-06-08 maybe properly implement weird windows amd64 calling conventions.
76 * 2011-07-03 rely on __GCC_HAVE_DWARF2_CFI_ASM for cfi detection.
77 * 2011-08-08 cygwin trashes stacks, use pthreads with double stack on cygwin.
78 * 2012-12-04 reduce misprediction penalty for x86/amd64 assembly switcher.
79 * 2012-12-05 experimental fiber backend (allocates stack twice).
80 * 2012-12-07 API version 3 - add coro_stack_alloc/coro_stack_free.
81 * 2012-12-21 valgrind stack registering was broken.
82 * 2015-12-05 experimental asm be for arm7, based on a patch by Nick Zavaritsky.
83 * use __name__ for predefined symbols, as in libecb.
84 * enable guard pages on arm, aarch64 and mips.
85 * 2016-08-27 try to disable _FORTIFY_SOURCE with CORO_SJLJ, as it
86 * breaks setjmp/longjmp. Also disable CORO_ASM for asm by default,
87 * as it was reported to crash.
88 * 2016-11-18 disable cfi_undefined again - backtraces might be worse, but
89 * compile compatibility is improved.
90 */
91
38#ifndef CORO_H 92#ifndef CORO_H
39#define CORO_H 93#define CORO_H
40 94
41#define CORO_VERSION 2 95#if __cplusplus
42 96extern "C" {
43/* 97#endif
44 * Changes since API version 1:
45 * replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
46 */
47 98
48/* 99/*
49 * This library consists of only three files 100 * This library consists of only three files
50 * coro.h, coro.c and LICENSE (and optionally README) 101 * coro.h, coro.c and LICENSE (and optionally README)
51 * 102 *
52 * It implements what is known as coroutines, in a hopefully 103 * It implements what is known as coroutines, in a hopefully
53 * portable way. At the moment you have to define which kind 104 * portable way.
54 * of implementation flavour you want: 105 *
106 * All compiletime symbols must be defined both when including coro.h
107 * (using libcoro) as well as when compiling coro.c (the implementation).
108 *
109 * You can manually specify which flavour you want. If you don't define
110 * any of these, libcoro tries to choose a safe and fast default:
55 * 111 *
56 * -DCORO_UCONTEXT 112 * -DCORO_UCONTEXT
57 * 113 *
58 * This flavour uses SUSv2's get/set/swap/makecontext functions that 114 * This flavour uses SUSv2's get/set/swap/makecontext functions that
59 * unfortunately only newer unices support. 115 * unfortunately only some unices support, and is quite slow.
60 * Use this for GNU/Linux + glibc-2.2.3 and possibly higher.
61 * 116 *
62 * -DCORO_SJLJ 117 * -DCORO_SJLJ
63 * 118 *
64 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to 119 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
65 * do it's job. Coroutine creation is much slower than UCONTEXT, but 120 * do it's job. Coroutine creation is much slower than UCONTEXT, but
66 * context switching is often a bit cheaper. It should work on almost 121 * context switching is a bit cheaper. It should work on almost all unices.
67 * all unices. Use this for GNU/Linux + glibc-2.2. glibc-2.1 and below
68 * do not work with any sane model (neither sigaltstack nor context
69 * functions are implemented)
70 * 122 *
71 * -DCORO_LINUX 123 * -DCORO_LINUX
72 * 124 *
125 * CORO_SJLJ variant.
73 * Old GNU/Linux systems (<= glibc-2.1) work with this implementation 126 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
74 * (it is very fast and therefore recommended over other methods). 127 * (it is very fast and therefore recommended over other methods, but
128 * doesn't work with anything newer).
75 * 129 *
76 * -DCORO_LOSER 130 * -DCORO_LOSER
77 * 131 *
132 * CORO_SJLJ variant.
78 * Microsoft's highly proprietary platform doesn't support sigaltstack, and 133 * Microsoft's highly proprietary platform doesn't support sigaltstack, and
79 * this automatically selects a suitable workaround for this platform. 134 * this selects a suitable workaround for this platform. It might not work
80 * (untested) 135 * with your compiler though - it has only been tested with MSVC 6.
136 *
137 * -DCORO_FIBER
138 *
139 * Slower, but probably more portable variant for the Microsoft operating
140 * system, using fibers. Ignores the passed stack and allocates it internally.
141 * Also, due to bugs in cygwin, this does not work with cygwin.
81 * 142 *
82 * -DCORO_IRIX 143 * -DCORO_IRIX
83 * 144 *
145 * CORO_SJLJ variant.
84 * SGI's version of Microsoft's NT ;) 146 * For SGI's version of Microsoft's NT ;)
147 *
148 * -DCORO_ASM
149 *
150 * Hand coded assembly, known to work only on a few architectures/ABI:
151 * GCC + arm7/x86/IA32/amd64/x86_64 + GNU/Linux and a few BSDs. Fastest
152 * choice, if it works.
153 *
154 * -DCORO_PTHREAD
155 *
156 * Use the pthread API. You have to provide <pthread.h> and -lpthread.
157 * This is likely the slowest backend, and it also does not support fork(),
158 * so avoid it at all costs.
85 * 159 *
86 * If you define neither of these symbols, coro.h will try to autodetect 160 * If you define neither of these symbols, coro.h will try to autodetect
87 * the model. This currently works for CORO_LOSER only. For the other 161 * the best/safest model. To help with the autodetection, you should check
88 * alternatives you should check (e.g. using autoconf) and define the 162 * (e.g. using autoconf) and define the following symbols: HAVE_UCONTEXT_H
89 * following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK. 163 * / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
164 */
165
166/*
167 * Changes when the API changes incompatibly.
168 * This is ONLY the API version - there is no ABI compatibility between releases.
90 */ 169 *
170 * Changes in API version 2:
171 * replaced bogus -DCORO_LOOSE with grammatically more correct -DCORO_LOSER
172 * Changes in API version 3:
173 * introduced stack management (CORO_STACKALLOC)
174 */
175#define CORO_VERSION 3
176
177#include <stddef.h>
91 178
92/* 179/*
93 * This is the type for the initialization function of a new coroutine. 180 * This is the type for the initialization function of a new coroutine.
94 */ 181 */
95typedef void (*coro_func)(void *); 182typedef void (*coro_func)(void *);
96 183
97/* 184/*
98 * A coroutine state is saved in the following structure. Treat it as a 185 * A coroutine state is saved in the following structure. Treat it as an
99 * opaque type. errno and sigmask might be saved, but don't rely on it, 186 * opaque type. errno and sigmask might be saved, but don't rely on it,
100 * implement your own switching primitive. 187 * implement your own switching primitive if you need that.
101 */ 188 */
102typedef struct coro_context coro_context; 189typedef struct coro_context coro_context;
103 190
104/* 191/*
105 * This function creates a new coroutine. Apart from a pointer to an 192 * This function creates a new coroutine. Apart from a pointer to an
106 * uninitialised coro_context, it expects a pointer to the entry function 193 * uninitialised coro_context, it expects a pointer to the entry function
107 * and the single pointer value that is given to it as argument. 194 * and the single pointer value that is given to it as argument.
108 * 195 *
109 * Allocating/deallocating the stack is your own responsibility, so there is 196 * Allocating/deallocating the stack is your own responsibility.
110 * no coro_destroy function.
111 */ 197 *
112void coro_create (coro_context *ctx, 198 * As a special case, if coro, arg, sptr and ssze are all zero,
113 coro_func coro, void *arg, 199 * then an "empty" coro_context will be created that is suitable
114 void *sptr, long ssize); 200 * as an initial source for coro_transfer.
201 *
202 * This function is not reentrant, but putting a mutex around it
203 * will work.
204 */
205void coro_create (coro_context *ctx, /* an uninitialised coro_context */
206 coro_func coro, /* the coroutine code to be executed */
207 void *arg, /* a single pointer passed to the coro */
208 void *sptr, /* start of stack area */
209 size_t ssze); /* size of stack area in bytes */
115 210
116/* 211/*
117 * The following prototype defines the coroutine switching function. It is 212 * The following prototype defines the coroutine switching function. It is
118 * usually implemented as a macro, so watch out. 213 * sometimes implemented as a macro, so watch out.
214 *
215 * This function is thread-safe and reentrant.
119 * 216 */
217#if 0
120void coro_transfer(coro_context *prev, coro_context *next); 218void coro_transfer (coro_context *prev, coro_context *next);
219#endif
220
221/*
222 * The following prototype defines the coroutine destroy function. It
223 * is sometimes implemented as a macro, so watch out. It also serves no
224 * purpose unless you want to use the CORO_PTHREAD backend, where it is
225 * used to clean up the thread. You are responsible for freeing the stack
226 * and the context itself.
121 */ 227 *
122 228 * This function is thread-safe and reentrant.
123/*
124 * That was it. No other user-visible functions are implemented here.
125 */ 229 */
230#if 0
231void coro_destroy (coro_context *ctx);
232#endif
126 233
127/*****************************************************************************/ 234/*****************************************************************************/
235/* optional stack management */
236/*****************************************************************************/
237/*
238 * You can disable all of the stack management functions by
239 * defining CORO_STACKALLOC to 0. Otherwise, they are enabled by default.
240 *
241 * If stack management is enabled, you can influence the implementation via these
242 * symbols:
243 *
244 * -DCORO_USE_VALGRIND
245 *
246 * If defined, then libcoro will include valgrind/valgrind.h and register
247 * and unregister stacks with valgrind.
248 *
249 * -DCORO_GUARDPAGES=n
250 *
251 * libcoro will try to use the specified number of guard pages to protect against
252 * stack overflow. If n is 0, then the feature will be disabled. If it isn't
253 * defined, then libcoro will choose a suitable default. If guardpages are not
254 * supported on the platform, then the feature will be silently disabled.
255 */
256#ifndef CORO_STACKALLOC
257# define CORO_STACKALLOC 1
258#endif
128 259
260#if CORO_STACKALLOC
261
262/*
263 * The only allowed operations on these struct members is to read the
264 * "sptr" and "ssze" members to pass it to coro_create, to read the "sptr"
265 * member to see if it is false, in which case the stack isn't allocated,
266 * and to set the "sptr" member to 0, to indicate to coro_stack_free to
267 * not actually do anything.
268 */
269
270struct coro_stack
271{
272 void *sptr;
273 size_t ssze;
274#if CORO_USE_VALGRIND
275 int valgrind_id;
276#endif
277};
278
279/*
280 * Try to allocate a stack of at least the given size and return true if
281 * successful, or false otherwise.
282 *
283 * The size is *NOT* specified in bytes, but in units of sizeof (void *),
284 * i.e. the stack is typically 4(8) times larger on 32 bit(64 bit) platforms
285 * then the size passed in.
286 *
287 * If size is 0, then a "suitable" stack size is chosen (usually 1-2MB).
288 */
289int coro_stack_alloc (struct coro_stack *stack, unsigned int size);
290
291/*
292 * Free the stack allocated by coro_stack_alloc again. It is safe to
293 * call this function on the coro_stack structure even if coro_stack_alloc
294 * failed.
295 */
296void coro_stack_free (struct coro_stack *stack);
297
298#endif
299
300/*
301 * That was it. No other user-serviceable parts below here.
302 */
303
304/*****************************************************************************/
305
129#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \ 306#if !defined CORO_LOSER && !defined CORO_UCONTEXT \
130 && !defined(CORO_SJLJ) && !defined(CORO_LINUX) \ 307 && !defined CORO_SJLJ && !defined CORO_LINUX \
131 && !defined(CORO_IRIX) 308 && !defined CORO_IRIX && !defined CORO_ASM \
132# if defined(WINDOWS) 309 && !defined CORO_PTHREAD && !defined CORO_FIBER
310# if defined WINDOWS && (defined __i386__ || (__x86_64__ || defined _M_IX86 || defined _M_AMD64)
311# define CORO_ASM 1
312# elif defined WINDOWS || defined _WIN32
133# define CORO_LOSER 1 /* you don't win with windoze */ 313# define CORO_LOSER 1 /* you don't win with windoze */
134# elif defined(__linux) && defined(__x86) 314# elif __linux && (__i386__ || (__x86_64__ && !__ILP32__) /*|| (__arm__ && __ARM_ARCH == 7)), not working */
315# define CORO_ASM 1
135# elif defined(HAVE_UCONTEXT_H) 316# elif defined HAVE_UCONTEXT_H
136# define CORO_UCONTEXT 1 317# define CORO_UCONTEXT 1
137# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) 318# elif defined HAVE_SETJMP_H && defined HAVE_SIGALTSTACK
138# define CORO_SJLJ 1 319# define CORO_SJLJ 1
139# else 320# else
140error unknown or unsupported architecture 321error unknown or unsupported architecture
141# endif 322# endif
142#endif 323#endif
143 324
144/*****************************************************************************/ 325/*****************************************************************************/
145 326
146#if CORO_UCONTEXT 327#if CORO_UCONTEXT
147 328
148#include <ucontext.h> 329# include <ucontext.h>
149 330
150struct coro_context { 331struct coro_context
332{
151 ucontext_t uc; 333 ucontext_t uc;
152}; 334};
153 335
154#define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc)) 336# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
337# define coro_destroy(ctx) (void *)(ctx)
155 338
156#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX 339#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
157 340
158#if defined(CORO_LINUX) && !defined(_GNU_SOURCE) 341# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
159# define _GNU_SOURCE // for linux libc 342# define _GNU_SOURCE /* for glibc */
160#endif 343# endif
161 344
345/* try to disable well-meant but buggy checks in some libcs */
346# ifdef _FORTIFY_SOURCE
347# undef _FORTIFY_SOURCE
348# undef __USE_FORTIFY_LEVEL /* helps some more when too much has been included already */
349# endif
350
351# if !CORO_LOSER
352# include <unistd.h>
353# endif
354
355/* solaris is hopelessly borked, it expands _XOPEN_UNIX to nothing */
356# if __sun
357# undef _XOPEN_UNIX
358# define _XOPEN_UNIX 1
359# endif
360
162#include <setjmp.h> 361# include <setjmp.h>
163 362
363# if _XOPEN_UNIX > 0 || defined (_setjmp)
364# define coro_jmp_buf jmp_buf
365# define coro_setjmp(env) _setjmp (env)
366# define coro_longjmp(env) _longjmp ((env), 1)
367# elif CORO_LOSER
368# define coro_jmp_buf jmp_buf
369# define coro_setjmp(env) setjmp (env)
370# define coro_longjmp(env) longjmp ((env), 1)
371# else
372# define coro_jmp_buf sigjmp_buf
373# define coro_setjmp(env) sigsetjmp (env, 0)
374# define coro_longjmp(env) siglongjmp ((env), 1)
375# endif
376
164struct coro_context { 377struct coro_context
378{
165 jmp_buf env; 379 coro_jmp_buf env;
166}; 380};
167 381
168#define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while(0) 382# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
383# define coro_destroy(ctx) (void *)(ctx)
169 384
170#endif 385#elif CORO_ASM
171 386
172#endif 387struct coro_context
388{
389 void **sp; /* must be at offset 0 */
390};
173 391
392#if __i386__ || __x86_64__
393void __attribute__ ((__noinline__, __regparm__(2)))
394#else
395void __attribute__ ((__noinline__))
396#endif
397coro_transfer (coro_context *prev, coro_context *next);
398
399# define coro_destroy(ctx) (void *)(ctx)
400
401#elif CORO_PTHREAD
402
403# include <pthread.h>
404
405extern pthread_mutex_t coro_mutex;
406
407struct coro_context
408{
409 pthread_cond_t cv;
410 pthread_t id;
411};
412
413void coro_transfer (coro_context *prev, coro_context *next);
414void coro_destroy (coro_context *ctx);
415
416#elif CORO_FIBER
417
418struct coro_context
419{
420 void *fiber;
421 /* only used for initialisation */
422 coro_func coro;
423 void *arg;
424};
425
426void coro_transfer (coro_context *prev, coro_context *next);
427void coro_destroy (coro_context *ctx);
428
429#endif
430
431#if __cplusplus
432}
433#endif
434
435#endif
436

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