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Revision 1.6 by root, Sun Sep 16 01:34:36 2001 UTC vs.
Revision 1.57 by root, Sat Aug 27 12:50:11 2016 UTC

1/* 1/*
2 * Copyright (c) 2001 Marc Alexander Lehmann <pcg@goof.com> 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 avstraction 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 * VERSION: 0.1 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 * 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.
37 */ 87 */
38 88
39#ifndef CORO_H 89#ifndef CORO_H
40#define CORO_H 90#define CORO_H
41 91
92#if __cplusplus
93extern "C" {
94#endif
95
42/* 96/*
43 * This library consists of only three files 97 * This library consists of only three files
44 * coro.h, coro.c and LICENSE 98 * coro.h, coro.c and LICENSE (and optionally README)
45 * 99 *
46 * It implements what is known as coroutines, in a hopefully 100 * It implements what is known as coroutines, in a hopefully
47 * portable way. At the moment you have to define which kind 101 * portable way.
48 * of implementation flavour you want: 102 *
103 * All compiletime symbols must be defined both when including coro.h
104 * (using libcoro) as well as when compiling coro.c (the implementation).
105 *
106 * You can manually specify which flavour you want. If you don't define
107 * any of these, libcoro tries to choose a safe and fast default:
49 * 108 *
50 * -DCORO_UCONTEXT 109 * -DCORO_UCONTEXT
51 * 110 *
52 * This flavour uses SUSv2's get/set/swap/makecontext functions that 111 * This flavour uses SUSv2's get/set/swap/makecontext functions that
53 * unfortunately only newer unices support. 112 * unfortunately only some unices support, and is quite slow.
54 * Use this for GNU/Linux + glibc-2.2.3.
55 * 113 *
56 * -DCORO_SJLJ 114 * -DCORO_SJLJ
57 * 115 *
58 * This flavour uses SUSv'2 setjmp/longjmp and sigaltstack functions to 116 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
59 * do it's job. Coroutine creation is much slower than UCONTEXT, but 117 * do it's job. Coroutine creation is much slower than UCONTEXT, but
60 * context switching is often a bit cheaper. It should work on almost 118 * context switching is a bit cheaper. It should work on almost all unices.
61 * all unices. Use this for GNU/Linux + glibc-2.2. glibc-2.1 and below
62 * do not work with any sane model (neither sigaltstack nor context
63 * functions are implemented)
64 * 119 *
65 * -DCORO_LINUX 120 * -DCORO_LINUX
66 * 121 *
122 * CORO_SJLJ variant.
67 * Old GNU/Linux systems (<= glibc-2.1) work with this implementation 123 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
68 * (very fast). 124 * (it is very fast and therefore recommended over other methods, but
125 * doesn't work with anything newer).
69 * 126 *
70 * -DCORO_LOOSE 127 * -DCORO_LOSER
71 * 128 *
129 * CORO_SJLJ variant.
72 * Microsoft's highly proprietary platform doesn't support sigaltstack, and 130 * Microsoft's highly proprietary platform doesn't support sigaltstack, and
73 * this automatically selects a suitable workaround for this platform. 131 * this selects a suitable workaround for this platform. It might not work
74 * (untested) 132 * with your compiler though - it has only been tested with MSVC 6.
133 *
134 * -DCORO_FIBER
135 *
136 * Slower, but probably more portable variant for the Microsoft operating
137 * system, using fibers. Ignores the passed stack and allocates it internally.
138 * Also, due to bugs in cygwin, this does not work with cygwin.
75 * 139 *
76 * -DCORO_IRIX 140 * -DCORO_IRIX
77 * 141 *
142 * CORO_SJLJ variant.
78 * SGI's version of Microsoft's NT ;) 143 * For SGI's version of Microsoft's NT ;)
144 *
145 * -DCORO_ASM
146 *
147 * Hand coded assembly, known to work only on a few architectures/ABI:
148 * GCC + arm7/x86/IA32/amd64/x86_64 + GNU/Linux and a few BSDs. Fastest
149 * choice, if it works.
150 *
151 * -DCORO_PTHREAD
152 *
153 * Use the pthread API. You have to provide <pthread.h> and -lpthread.
154 * This is likely the slowest backend, and it also does not support fork(),
155 * so avoid it at all costs.
79 * 156 *
80 * If you define neither of these symbols, coro.h will try to autodetect 157 * If you define neither of these symbols, coro.h will try to autodetect
81 * the model. This currently works for CORO_LOOSE only. For the other 158 * the best/safest model. To help with the autodetection, you should check
82 * alternatives you should check (e.g. using autoconf) and define the 159 * (e.g. using autoconf) and define the following symbols: HAVE_UCONTEXT_H
83 * following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK. 160 * / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
161 */
162
163/*
164 * Changes when the API changes incompatibly.
165 * This is ONLY the API version - there is no ABI compatibility between releases.
84 */ 166 *
167 * Changes in API version 2:
168 * replaced bogus -DCORO_LOOSE with grammatically more correct -DCORO_LOSER
169 * Changes in API version 3:
170 * introduced stack management (CORO_STACKALLOC)
171 */
172#define CORO_VERSION 3
173
174#include <stddef.h>
85 175
86/* 176/*
87 * This is the type for the initialization function of a new coroutine. 177 * This is the type for the initialization function of a new coroutine.
88 */ 178 */
89typedef void (*coro_func)(void *); 179typedef void (*coro_func)(void *);
90 180
91/* 181/*
92 * A coroutine state is saved in the following structure. Treat it as a 182 * A coroutine state is saved in the following structure. Treat it as an
93 * opaque type. errno and sigmask might be saved, but don't rely on it, 183 * opaque type. errno and sigmask might be saved, but don't rely on it,
94 * implement your own switching primitive. 184 * implement your own switching primitive if you need that.
95 */ 185 */
96typedef struct coro_context coro_context; 186typedef struct coro_context coro_context;
97 187
98/* 188/*
99 * This function creates a new coroutine. Apart from a pointer to an 189 * This function creates a new coroutine. Apart from a pointer to an
100 * uninitialized coro_context, it expects a pointer to the entry function 190 * uninitialised coro_context, it expects a pointer to the entry function
101 * and the single pointer value that is given to it as argument. 191 * and the single pointer value that is given to it as argument.
102 * 192 *
103 * Allocating/deallocating the stack is your own responsibility, so there is 193 * Allocating/deallocating the stack is your own responsibility.
104 * no coro_destroy function.
105 */ 194 *
106void coro_create(coro_context *ctx, 195 * As a special case, if coro, arg, sptr and ssze are all zero,
107 coro_func coro, void *arg, 196 * then an "empty" coro_context will be created that is suitable
108 void *sptr, long ssize); 197 * as an initial source for coro_transfer.
198 *
199 * This function is not reentrant, but putting a mutex around it
200 * will work.
201 */
202void coro_create (coro_context *ctx, /* an uninitialised coro_context */
203 coro_func coro, /* the coroutine code to be executed */
204 void *arg, /* a single pointer passed to the coro */
205 void *sptr, /* start of stack area */
206 size_t ssze); /* size of stack area in bytes */
109 207
110/* 208/*
111 * The following prototype defines the coroutine switching function. It is 209 * The following prototype defines the coroutine switching function. It is
112 * usually implemented as a macro, so watch out. 210 * sometimes implemented as a macro, so watch out.
211 *
212 * This function is thread-safe and reentrant.
113 * 213 */
214#if 0
114void coro_transfer(coro_context *prev, coro_context *next); 215void coro_transfer (coro_context *prev, coro_context *next);
216#endif
217
218/*
219 * The following prototype defines the coroutine destroy function. It
220 * is sometimes implemented as a macro, so watch out. It also serves no
221 * purpose unless you want to use the CORO_PTHREAD backend, where it is
222 * used to clean up the thread. You are responsible for freeing the stack
223 * and the context itself.
115 */ 224 *
116 225 * This function is thread-safe and reentrant.
117/*
118 * That was it. No other user-visible functions are implemented here.
119 */ 226 */
227#if 0
228void coro_destroy (coro_context *ctx);
229#endif
120 230
121/*****************************************************************************/ 231/*****************************************************************************/
232/* optional stack management */
233/*****************************************************************************/
234/*
235 * You can disable all of the stack management functions by
236 * defining CORO_STACKALLOC to 0. Otherwise, they are enabled by default.
237 *
238 * If stack management is enabled, you can influence the implementation via these
239 * symbols:
240 *
241 * -DCORO_USE_VALGRIND
242 *
243 * If defined, then libcoro will include valgrind/valgrind.h and register
244 * and unregister stacks with valgrind.
245 *
246 * -DCORO_GUARDPAGES=n
247 *
248 * libcoro will try to use the specified number of guard pages to protect against
249 * stack overflow. If n is 0, then the feature will be disabled. If it isn't
250 * defined, then libcoro will choose a suitable default. If guardpages are not
251 * supported on the platform, then the feature will be silently disabled.
252 */
253#ifndef CORO_STACKALLOC
254# define CORO_STACKALLOC 1
255#endif
122 256
257#if CORO_STACKALLOC
258
259/*
260 * The only allowed operations on these struct members is to read the
261 * "sptr" and "ssze" members to pass it to coro_create, to read the "sptr"
262 * member to see if it is false, in which case the stack isn't allocated,
263 * and to set the "sptr" member to 0, to indicate to coro_stack_free to
264 * not actually do anything.
265 */
266
267struct coro_stack
268{
269 void *sptr;
270 size_t ssze;
271#if CORO_USE_VALGRIND
272 int valgrind_id;
273#endif
274};
275
276/*
277 * Try to allocate a stack of at least the given size and return true if
278 * successful, or false otherwise.
279 *
280 * The size is *NOT* specified in bytes, but in units of sizeof (void *),
281 * i.e. the stack is typically 4(8) times larger on 32 bit(64 bit) platforms
282 * then the size passed in.
283 *
284 * If size is 0, then a "suitable" stack size is chosen (usually 1-2MB).
285 */
286int coro_stack_alloc (struct coro_stack *stack, unsigned int size);
287
288/*
289 * Free the stack allocated by coro_stack_alloc again. It is safe to
290 * call this function on the coro_stack structure even if coro_stack_alloc
291 * failed.
292 */
293void coro_stack_free (struct coro_stack *stack);
294
295#endif
296
297/*
298 * That was it. No other user-serviceable parts below here.
299 */
300
301/*****************************************************************************/
302
123#if !defined(CORO_LOOSE) && !defined(CORO_UCONTEXT) \ 303#if !defined CORO_LOSER && !defined CORO_UCONTEXT \
124 && !defined(CORO_SJLJ) && !defined(CORO_LINUX) \ 304 && !defined CORO_SJLJ && !defined CORO_LINUX \
125 && !defined(CORO_IRIX) 305 && !defined CORO_IRIX && !defined CORO_ASM \
126# if defined(WINDOWS) 306 && !defined CORO_PTHREAD && !defined CORO_FIBER
307# if defined WINDOWS && (defined __i386__ || (__x86_64__ || defined _M_IX86 || defined _M_AMD64)
308# define CORO_ASM 1
309# elif defined WINDOWS || defined _WIN32
127# define CORO_LOOSE 1 /* you don't win with windoze */ 310# define CORO_LOSER 1 /* you don't win with windoze */
128# elif defined(__linux) && defined(__x86) 311# elif __linux && (__i386__ || (__x86_64__ && !__ILP32__) || (__arm__ && __ARM_ARCH == 7))
312# define CORO_ASM 1
129# elif defined(HAVE_UCONTEXT_H) 313# elif defined HAVE_UCONTEXT_H
130# define CORO_UCONTEXT 1 314# define CORO_UCONTEXT 1
131# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) 315# elif defined HAVE_SETJMP_H && defined HAVE_SIGALTSTACK
132# define CORO_SJLJ 1 316# define CORO_SJLJ 1
133# else 317# else
134error unknown or unsupported architecture 318error unknown or unsupported architecture
135# endif 319# endif
136#endif 320#endif
137 321
138/*****************************************************************************/ 322/*****************************************************************************/
139 323
140#if CORO_UCONTEXT 324#if CORO_UCONTEXT
141 325
142#include <ucontext.h> 326# include <ucontext.h>
143 327
144struct coro_context { 328struct coro_context
329{
145 ucontext_t uc; 330 ucontext_t uc;
146}; 331};
147 332
148#define coro_transfer(p,n) swapcontext(&((p)->uc), &((n)->uc)) 333# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
334# define coro_destroy(ctx) (void *)(ctx)
149 335
150#elif CORO_SJLJ || CORO_LOOSE || CORO_LINUX || CORO_IRIX 336#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
151 337
338# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
339# define _GNU_SOURCE /* for glibc */
340# endif
341
342/* try to disable well-meant but buggy checks in some libcs */
343# ifdef _FORTIFY_SOURCE
344# undef _FORTIFY_SOURCE
345# undef __USE_FORTIFY_LEVEL /* helps some more when too much has been included already */
346# endif
347
348# if !CORO_LOSER
349# include <unistd.h>
350# endif
351
352/* solaris is hopelessly borked, it expands _XOPEN_UNIX to nothing */
353# if __sun
354# undef _XOPEN_UNIX
355# define _XOPEN_UNIX 1
356# endif
357
152#include <setjmp.h> 358# include <setjmp.h>
153 359
360# if _XOPEN_UNIX > 0 || defined (_setjmp)
361# define coro_jmp_buf jmp_buf
362# define coro_setjmp(env) _setjmp (env)
363# define coro_longjmp(env) _longjmp ((env), 1)
364# elif CORO_LOSER
365# define coro_jmp_buf jmp_buf
366# define coro_setjmp(env) setjmp (env)
367# define coro_longjmp(env) longjmp ((env), 1)
368# else
369# define coro_jmp_buf sigjmp_buf
370# define coro_setjmp(env) sigsetjmp (env, 0)
371# define coro_longjmp(env) siglongjmp ((env), 1)
372# endif
373
154struct coro_context { 374struct coro_context
375{
155 jmp_buf env; 376 coro_jmp_buf env;
156}; 377};
157 378
158#define coro_transfer(p,n) if (!setjmp ((p)->env)) longjmp ((n)->env, 1) 379# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
380# define coro_destroy(ctx) (void *)(ctx)
159 381
160#endif 382#elif CORO_ASM
161 383
162#endif 384struct coro_context
385{
386 void **sp; /* must be at offset 0 */
387};
163 388
389#if __i386__ || __x86_64__
390void __attribute__ ((__noinline__, __regparm__(2)))
391#else
392void __attribute__ ((__noinline__))
393#endif
394coro_transfer (coro_context *prev, coro_context *next);
395
396# define coro_destroy(ctx) (void *)(ctx)
397
398#elif CORO_PTHREAD
399
400# include <pthread.h>
401
402extern pthread_mutex_t coro_mutex;
403
404struct coro_context
405{
406 pthread_cond_t cv;
407 pthread_t id;
408};
409
410void coro_transfer (coro_context *prev, coro_context *next);
411void coro_destroy (coro_context *ctx);
412
413#elif CORO_FIBER
414
415struct coro_context
416{
417 void *fiber;
418 /* only used for initialisation */
419 coro_func coro;
420 void *arg;
421};
422
423void coro_transfer (coro_context *prev, coro_context *next);
424void coro_destroy (coro_context *ctx);
425
426#endif
427
428#if __cplusplus
429}
430#endif
431
432#endif
433

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