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Comparing libcoro/coro.h (file contents):
Revision 1.34 by root, Sat Nov 8 04:52:01 2008 UTC vs.
Revision 1.61 by root, Tue Aug 14 15:46:04 2018 UTC

1/* 1/*
2 * Copyright (c) 2001-2008 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 * 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
15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- 15 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
16 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 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- 17 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
18 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 18 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
… …
63 * speed up CORO_PTHREAD. Do no longer leak threads either. 63 * speed up CORO_PTHREAD. Do no longer leak threads either.
64 * coro_create now allows one to create source coro_contexts. 64 * coro_create now allows one to create source coro_contexts.
65 * do not rely on makecontext passing a void * correctly. 65 * do not rely on makecontext passing a void * correctly.
66 * try harder to get _setjmp/_longjmp. 66 * try harder to get _setjmp/_longjmp.
67 * major code cleanup/restructuring. 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 * 2018-08-14 use a completely different pthread strategy that should allow
91 * sharing of coroutines among different threads. this would
92 * undefined behaviour before as mutexes would be unlocked on
93 * a different thread. overall, this might be slower than
94 * using a pipe for synchronisation, but pipes eat fd's...
68 */ 95 */
69 96
70#ifndef CORO_H 97#ifndef CORO_H
71#define CORO_H 98#define CORO_H
72 99
73#define CORO_VERSION 2 100#if __cplusplus
74 101extern "C" {
75/* 102#endif
76 * Changes since API version 1:
77 * replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
78 */
79 103
80/* 104/*
81 * This library consists of only three files 105 * This library consists of only three files
82 * coro.h, coro.c and LICENSE (and optionally README) 106 * coro.h, coro.c and LICENSE (and optionally README)
83 * 107 *
84 * It implements what is known as coroutines, in a hopefully 108 * It implements what is known as coroutines, in a hopefully
85 * portable way. At the moment you have to define which kind 109 * portable way.
86 * of implementation flavour you want: 110 *
111 * All compiletime symbols must be defined both when including coro.h
112 * (using libcoro) as well as when compiling coro.c (the implementation).
113 *
114 * You can manually specify which flavour you want. If you don't define
115 * any of these, libcoro tries to choose a safe and fast default:
87 * 116 *
88 * -DCORO_UCONTEXT 117 * -DCORO_UCONTEXT
89 * 118 *
90 * This flavour uses SUSv2's get/set/swap/makecontext functions that 119 * This flavour uses SUSv2's get/set/swap/makecontext functions that
91 * unfortunately only newer unices support. 120 * unfortunately only some unices support, and is quite slow.
92 * 121 *
93 * -DCORO_SJLJ 122 * -DCORO_SJLJ
94 * 123 *
95 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to 124 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
96 * do it's job. Coroutine creation is much slower than UCONTEXT, but 125 * do it's job. Coroutine creation is much slower than UCONTEXT, but
97 * context switching is often a bit cheaper. It should work on almost 126 * context switching is a bit cheaper. It should work on almost all unices.
98 * all unices.
99 * 127 *
100 * -DCORO_LINUX 128 * -DCORO_LINUX
101 * 129 *
130 * CORO_SJLJ variant.
102 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation 131 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
103 * (it is very fast and therefore recommended over other methods, but 132 * (it is very fast and therefore recommended over other methods, but
104 * doesn't work with anything newer). 133 * doesn't work with anything newer).
105 * 134 *
106 * -DCORO_LOSER 135 * -DCORO_LOSER
107 * 136 *
137 * CORO_SJLJ variant.
108 * Microsoft's highly proprietary platform doesn't support sigaltstack, and 138 * Microsoft's highly proprietary platform doesn't support sigaltstack, and
109 * this automatically selects a suitable workaround for this platform. 139 * this selects a suitable workaround for this platform. It might not work
110 * (untested) 140 * with your compiler though - it has only been tested with MSVC 6.
141 *
142 * -DCORO_FIBER
143 *
144 * Slower, but probably more portable variant for the Microsoft operating
145 * system, using fibers. Ignores the passed stack and allocates it internally.
146 * Also, due to bugs in cygwin, this does not work with cygwin.
111 * 147 *
112 * -DCORO_IRIX 148 * -DCORO_IRIX
113 * 149 *
150 * CORO_SJLJ variant.
114 * SGI's version of Microsoft's NT ;) 151 * For SGI's version of Microsoft's NT ;)
115 * 152 *
116 * -DCORO_ASM 153 * -DCORO_ASM
117 * 154 *
118 * Handcoded assembly, known to work only on a few architectures/ABI: 155 * Hand coded assembly, known to work only on a few architectures/ABI:
119 * ELF Linux x86 && amd64 when gcc is used and optimisation is turned on. 156 * GCC + arm7/x86/IA32/amd64/x86_64 + GNU/Linux and a few BSDs. Fastest
157 * choice, if it works.
120 * 158 *
121 * -DCORO_PTHREAD 159 * -DCORO_PTHREAD
122 * 160 *
123 * Use the pthread API. You have to provide <pthread.h> and -lpthread. 161 * Use the pthread API. You have to provide <pthread.h> and -lpthread.
162 * This is likely the slowest backend, and it also does not support fork(),
163 * so avoid it at all costs.
124 * 164 *
125 * If you define neither of these symbols, coro.h will try to autodetect 165 * If you define neither of these symbols, coro.h will try to autodetect
126 * the model. This currently works for CORO_LOSER only. For the other 166 * the best/safest model. To help with the autodetection, you should check
127 * alternatives you should check (e.g. using autoconf) and define the 167 * (e.g. using autoconf) and define the following symbols: HAVE_UCONTEXT_H
128 * following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK. 168 * / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
169 */
170
171/*
172 * Changes when the API changes incompatibly.
173 * This is ONLY the API version - there is no ABI compatibility between releases.
129 */ 174 *
175 * Changes in API version 2:
176 * replaced bogus -DCORO_LOOSE with grammatically more correct -DCORO_LOSER
177 * Changes in API version 3:
178 * introduced stack management (CORO_STACKALLOC)
179 */
180#define CORO_VERSION 3
181
182#include <stddef.h>
130 183
131/* 184/*
132 * This is the type for the initialization function of a new coroutine. 185 * This is the type for the initialization function of a new coroutine.
133 */ 186 */
134typedef void (*coro_func)(void *); 187typedef void (*coro_func)(void *);
… …
145 * uninitialised coro_context, it expects a pointer to the entry function 198 * uninitialised coro_context, it expects a pointer to the entry function
146 * and the single pointer value that is given to it as argument. 199 * and the single pointer value that is given to it as argument.
147 * 200 *
148 * Allocating/deallocating the stack is your own responsibility. 201 * Allocating/deallocating the stack is your own responsibility.
149 * 202 *
150 * As a special case, if coro, arg, sptr and ssize are all zero, 203 * As a special case, if coro, arg, sptr and ssze are all zero,
151 * then an "empty" coro_contetx will be created that is suitable 204 * then an "empty" coro_context will be created that is suitable
152 * as an initial source for coro_transfer. 205 * as an initial source for coro_transfer.
153 * 206 *
154 * This function is not reentrant, but putting a mutex around it 207 * This function is not reentrant, but putting a mutex around it
155 * will work. 208 * will work.
156 */ 209 */
157void coro_create (coro_context *ctx, /* an uninitialised coro_context */ 210void coro_create (coro_context *ctx, /* an uninitialised coro_context */
158 coro_func coro, /* the coroutine code to be executed */ 211 coro_func coro, /* the coroutine code to be executed */
159 void *arg, /* a single pointer passed to the coro */ 212 void *arg, /* a single pointer passed to the coro */
160 void *sptr, /* start of stack area */ 213 void *sptr, /* start of stack area */
161 long ssize); /* size of stack area */ 214 size_t ssze); /* size of stack area in bytes */
162 215
163/* 216/*
164 * The following prototype defines the coroutine switching function. It is 217 * The following prototype defines the coroutine switching function. It is
165 * usually implemented as a macro, so watch out. 218 * sometimes implemented as a macro, so watch out.
166 * 219 *
167 * This function is thread-safe and reentrant. 220 * This function is thread-safe and reentrant.
168 */ 221 */
169#if 0 222#if 0
170void coro_transfer (coro_context *prev, coro_context *next); 223void coro_transfer (coro_context *prev, coro_context *next);
171#endif 224#endif
172 225
173/* 226/*
174 * The following prototype defines the coroutine destroy function. It is 227 * The following prototype defines the coroutine destroy function. It
175 * usually implemented as a macro, so watch out. It also serves 228 * is sometimes implemented as a macro, so watch out. It also serves no
176 * no purpose unless you want to use the CORO_PTHREAD backend. 229 * purpose unless you want to use the CORO_PTHREAD backend, where it is
230 * used to clean up the thread. You are responsible for freeing the stack
231 * and the context itself.
177 * 232 *
178 * This function is thread-safe and reentrant. 233 * This function is thread-safe and reentrant.
179 */ 234 */
180#if 0 235#if 0
181void coro_destroy (coro_context *ctx); 236void coro_destroy (coro_context *ctx);
182#endif 237#endif
183 238
184/*
185 * That was it. No other user-visible functions are implemented here.
186 */
187
188/*****************************************************************************/ 239/*****************************************************************************/
240/* optional stack management */
241/*****************************************************************************/
242/*
243 * You can disable all of the stack management functions by
244 * defining CORO_STACKALLOC to 0. Otherwise, they are enabled by default.
245 *
246 * If stack management is enabled, you can influence the implementation via these
247 * symbols:
248 *
249 * -DCORO_USE_VALGRIND
250 *
251 * If defined, then libcoro will include valgrind/valgrind.h and register
252 * and unregister stacks with valgrind.
253 *
254 * -DCORO_GUARDPAGES=n
255 *
256 * libcoro will try to use the specified number of guard pages to protect against
257 * stack overflow. If n is 0, then the feature will be disabled. If it isn't
258 * defined, then libcoro will choose a suitable default. If guardpages are not
259 * supported on the platform, then the feature will be silently disabled.
260 */
261#ifndef CORO_STACKALLOC
262# define CORO_STACKALLOC 1
263#endif
189 264
265#if CORO_STACKALLOC
266
267/*
268 * The only allowed operations on these struct members is to read the
269 * "sptr" and "ssze" members to pass it to coro_create, to read the "sptr"
270 * member to see if it is false, in which case the stack isn't allocated,
271 * and to set the "sptr" member to 0, to indicate to coro_stack_free to
272 * not actually do anything.
273 */
274
275struct coro_stack
276{
277 void *sptr;
278 size_t ssze;
279#if CORO_USE_VALGRIND
280 int valgrind_id;
281#endif
282};
283
284/*
285 * Try to allocate a stack of at least the given size and return true if
286 * successful, or false otherwise.
287 *
288 * The size is *NOT* specified in bytes, but in units of sizeof (void *),
289 * i.e. the stack is typically 4(8) times larger on 32 bit(64 bit) platforms
290 * then the size passed in.
291 *
292 * If size is 0, then a "suitable" stack size is chosen (usually 1-2MB).
293 */
294int coro_stack_alloc (struct coro_stack *stack, unsigned int size);
295
296/*
297 * Free the stack allocated by coro_stack_alloc again. It is safe to
298 * call this function on the coro_stack structure even if coro_stack_alloc
299 * failed.
300 */
301void coro_stack_free (struct coro_stack *stack);
302
303#endif
304
305/*
306 * That was it. No other user-serviceable parts below here.
307 */
308
309/*****************************************************************************/
310
190#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \ 311#if !defined CORO_LOSER && !defined CORO_UCONTEXT \
191 && !defined(CORO_SJLJ) && !defined(CORO_LINUX) \ 312 && !defined CORO_SJLJ && !defined CORO_LINUX \
192 && !defined(CORO_IRIX) && !defined(CORO_ASM) \ 313 && !defined CORO_IRIX && !defined CORO_ASM \
193 && !defined(CORO_PTHREAD) 314 && !defined CORO_PTHREAD && !defined CORO_FIBER
194# if defined(WINDOWS) 315# if defined WINDOWS && (defined __i386__ || (__x86_64__ || defined _M_IX86 || defined _M_AMD64)
316# define CORO_ASM 1
317# elif defined WINDOWS || defined _WIN32
195# define CORO_LOSER 1 /* you don't win with windoze */ 318# define CORO_LOSER 1 /* you don't win with windoze */
196# elif defined(__linux) && (defined(__x86) || defined (__amd64)) 319# elif __linux && (__i386__ || (__x86_64__ && !__ILP32__) /*|| (__arm__ && __ARM_ARCH == 7)), not working */
197# define CORO_ASM 1 320# define CORO_ASM 1
198# elif defined(HAVE_UCONTEXT_H) 321# elif defined HAVE_UCONTEXT_H
199# define CORO_UCONTEXT 1 322# define CORO_UCONTEXT 1
200# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) 323# elif defined HAVE_SETJMP_H && defined HAVE_SIGALTSTACK
201# define CORO_SJLJ 1 324# define CORO_SJLJ 1
202# else 325# else
203error unknown or unsupported architecture 326error unknown or unsupported architecture
204# endif 327# endif
205#endif 328#endif
… …
208 331
209#if CORO_UCONTEXT 332#if CORO_UCONTEXT
210 333
211# include <ucontext.h> 334# include <ucontext.h>
212 335
213struct coro_context { 336struct coro_context
337{
214 ucontext_t uc; 338 ucontext_t uc;
215}; 339};
216 340
217# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc)) 341# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
218# define coro_destroy(ctx) (void *)(ctx) 342# define coro_destroy(ctx) (void *)(ctx)
219 343
220#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX 344#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
221 345
222# if defined(CORO_LINUX) && !defined(_GNU_SOURCE) 346# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
223# define _GNU_SOURCE /* for linux libc */ 347# define _GNU_SOURCE /* for glibc */
348# endif
349
350/* try to disable well-meant but buggy checks in some libcs */
351# ifdef _FORTIFY_SOURCE
352# undef _FORTIFY_SOURCE
353# undef __USE_FORTIFY_LEVEL /* helps some more when too much has been included already */
224# endif 354# endif
225 355
226# if !CORO_LOSER 356# if !CORO_LOSER
227# include <unistd.h> 357# include <unistd.h>
228# endif 358# endif
229 359
360/* solaris is hopelessly borked, it expands _XOPEN_UNIX to nothing */
361# if __sun
362# undef _XOPEN_UNIX
363# define _XOPEN_UNIX 1
364# endif
365
230# include <setjmp.h> 366# include <setjmp.h>
231 367
232struct coro_context { 368# if _XOPEN_UNIX > 0 || defined (_setjmp)
233 jmp_buf env; 369# define coro_jmp_buf jmp_buf
234}; 370# define coro_setjmp(env) _setjmp (env)
235 371# define coro_longjmp(env) _longjmp ((env), 1)
236# if _XOPEN_UNIX > 0
237# define coro_transfer(p,n) do { if (! _setjmp ((p)->env )) _longjmp ((n)->env, 1); } while (0)
238# elif CORO_LOSER 372# elif CORO_LOSER
239# define coro_transfer(p,n) do { if (! setjmp ((p)->env )) longjmp ((n)->env, 1); } while (0) 373# define coro_jmp_buf jmp_buf
374# define coro_setjmp(env) setjmp (env)
375# define coro_longjmp(env) longjmp ((env), 1)
240# else 376# else
377# define coro_jmp_buf sigjmp_buf
378# define coro_setjmp(env) sigsetjmp (env, 0)
379# define coro_longjmp(env) siglongjmp ((env), 1)
380# endif
381
382struct coro_context
383{
384 coro_jmp_buf env;
385};
386
241# define coro_transfer(p,n) do { if (!sigsetjmp ((p)->env, 0)) siglongjmp ((n)->env, 1); } while (0) 387# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
242# endif
243
244# define coro_destroy(ctx) (void *)(ctx) 388# define coro_destroy(ctx) (void *)(ctx)
245 389
246#elif CORO_ASM 390#elif CORO_ASM
247 391
248struct coro_context { 392struct coro_context
393{
249 void **sp; /* must be at offset 0 */ 394 void **sp; /* must be at offset 0 */
250}; 395};
251 396
397#if __i386__ || __x86_64__
252void __attribute__ ((__noinline__, __regparm__(2))) 398void __attribute__ ((__noinline__, __regparm__(2)))
399#else
400void __attribute__ ((__noinline__))
401#endif
253coro_transfer (coro_context *prev, coro_context *next); 402coro_transfer (coro_context *prev, coro_context *next);
254 403
255# define coro_destroy(ctx) (void *)(ctx) 404# define coro_destroy(ctx) (void *)(ctx)
256 405
257#elif CORO_PTHREAD 406#elif CORO_PTHREAD
258 407
259# include <pthread.h> 408# include <pthread.h>
260 409
261extern pthread_mutex_t coro_mutex; 410extern pthread_mutex_t coro_mutex;
262 411
263struct coro_context { 412struct coro_context
413{
414 int flags;
264 pthread_cond_t cv; 415 pthread_cond_t cv;
265 pthread_t id;
266}; 416};
267 417
268void coro_transfer (coro_context *prev, coro_context *next); 418void coro_transfer (coro_context *prev, coro_context *next);
269void coro_destroy (coro_context *ctx); 419void coro_destroy (coro_context *ctx);
270 420
271#endif 421#elif CORO_FIBER
272 422
273#endif 423struct coro_context
424{
425 void *fiber;
426 /* only used for initialisation */
427 coro_func coro;
428 void *arg;
429};
274 430
431void coro_transfer (coro_context *prev, coro_context *next);
432void coro_destroy (coro_context *ctx);
433
434#endif
435
436#if __cplusplus
437}
438#endif
439
440#endif
441

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