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Comparing libcoro/coro.h (file contents):
Revision 1.32 by root, Fri Nov 7 20:12:26 2008 UTC vs.
Revision 1.57 by root, Sat Aug 27 12:50:11 2016 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,
… …
60 * 2008-11-05 Hopefully fix misaligned stacks with CORO_ASM/SETJMP. 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. 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. 62 * introduce coro_destroy, which is a nop except for pthreads.
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.
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.
65 */ 87 */
66 88
67#ifndef CORO_H 89#ifndef CORO_H
68#define CORO_H 90#define CORO_H
69 91
70#define CORO_VERSION 2 92#if __cplusplus
71 93extern "C" {
72/* 94#endif
73 * Changes since API version 1:
74 * replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
75 */
76 95
77/* 96/*
78 * This library consists of only three files 97 * This library consists of only three files
79 * coro.h, coro.c and LICENSE (and optionally README) 98 * coro.h, coro.c and LICENSE (and optionally README)
80 * 99 *
81 * It implements what is known as coroutines, in a hopefully 100 * It implements what is known as coroutines, in a hopefully
82 * portable way. At the moment you have to define which kind 101 * portable way.
83 * 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:
84 * 108 *
85 * -DCORO_UCONTEXT 109 * -DCORO_UCONTEXT
86 * 110 *
87 * This flavour uses SUSv2's get/set/swap/makecontext functions that 111 * This flavour uses SUSv2's get/set/swap/makecontext functions that
88 * unfortunately only newer unices support. 112 * unfortunately only some unices support, and is quite slow.
89 * 113 *
90 * -DCORO_SJLJ 114 * -DCORO_SJLJ
91 * 115 *
92 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to 116 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
93 * 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
94 * 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.
95 * all unices.
96 * 119 *
97 * -DCORO_LINUX 120 * -DCORO_LINUX
98 * 121 *
122 * CORO_SJLJ variant.
99 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation 123 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
100 * (it is very fast and therefore recommended over other methods, but 124 * (it is very fast and therefore recommended over other methods, but
101 * doesn't work with anything newer). 125 * doesn't work with anything newer).
102 * 126 *
103 * -DCORO_LOSER 127 * -DCORO_LOSER
104 * 128 *
129 * CORO_SJLJ variant.
105 * Microsoft's highly proprietary platform doesn't support sigaltstack, and 130 * Microsoft's highly proprietary platform doesn't support sigaltstack, and
106 * this automatically selects a suitable workaround for this platform. 131 * this selects a suitable workaround for this platform. It might not work
107 * (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.
108 * 139 *
109 * -DCORO_IRIX 140 * -DCORO_IRIX
110 * 141 *
142 * CORO_SJLJ variant.
111 * SGI's version of Microsoft's NT ;) 143 * For SGI's version of Microsoft's NT ;)
112 * 144 *
113 * -DCORO_ASM 145 * -DCORO_ASM
114 * 146 *
115 * Handcoded assembly, known to work only on a few architectures/ABI: 147 * Hand coded assembly, known to work only on a few architectures/ABI:
116 * ELF Linux x86 && amd64 when gcc is used and optimisation is turned on. 148 * GCC + arm7/x86/IA32/amd64/x86_64 + GNU/Linux and a few BSDs. Fastest
149 * choice, if it works.
117 * 150 *
118 * -DCORO_PTHREAD 151 * -DCORO_PTHREAD
119 * 152 *
120 * Use the pthread API. You have to provide <pthread.h> and -lpthread. 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.
121 * 156 *
122 * 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
123 * the model. This currently works for CORO_LOSER only. For the other 158 * the best/safest model. To help with the autodetection, you should check
124 * alternatives you should check (e.g. using autoconf) and define the 159 * (e.g. using autoconf) and define the following symbols: HAVE_UCONTEXT_H
125 * 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.
126 */ 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>
127 175
128/* 176/*
129 * 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.
130 */ 178 */
131typedef void (*coro_func)(void *); 179typedef void (*coro_func)(void *);
… …
142 * uninitialised coro_context, it expects a pointer to the entry function 190 * uninitialised coro_context, it expects a pointer to the entry function
143 * 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.
144 * 192 *
145 * Allocating/deallocating the stack is your own responsibility. 193 * Allocating/deallocating the stack is your own responsibility.
146 * 194 *
147 * As a special case, if coro, arg, sptr and ssize are all zero, 195 * As a special case, if coro, arg, sptr and ssze are all zero,
148 * then an "empty" coro_contetx will be created that is suitable 196 * then an "empty" coro_context will be created that is suitable
149 * as an initial source for coro_transfer. 197 * as an initial source for coro_transfer.
150 * 198 *
151 * This function is not reentrant, but putting a mutex around it 199 * This function is not reentrant, but putting a mutex around it
152 * will work. 200 * will work.
153 */ 201 */
154void coro_create (coro_context *ctx, /* an uninitialised coro_context */ 202void coro_create (coro_context *ctx, /* an uninitialised coro_context */
155 coro_func coro, /* the coroutine code to be executed */ 203 coro_func coro, /* the coroutine code to be executed */
156 void *arg, /* a single pointer passed to the coro */ 204 void *arg, /* a single pointer passed to the coro */
157 void *sptr, /* start of stack area */ 205 void *sptr, /* start of stack area */
158 long ssize); /* size of stack area */ 206 size_t ssze); /* size of stack area in bytes */
159 207
160/* 208/*
161 * The following prototype defines the coroutine switching function. It is 209 * The following prototype defines the coroutine switching function. It is
162 * usually implemented as a macro, so watch out. 210 * sometimes implemented as a macro, so watch out.
163 * 211 *
164 * This function is thread-safe and reentrant. 212 * This function is thread-safe and reentrant.
165 */ 213 */
166#if 0 214#if 0
167void coro_transfer (coro_context *prev, coro_context *next); 215void coro_transfer (coro_context *prev, coro_context *next);
168#endif 216#endif
169 217
170/* 218/*
171 * The following prototype defines the coroutine destroy function. It is 219 * The following prototype defines the coroutine destroy function. It
172 * usually implemented as a macro, so watch out. It also serves 220 * is sometimes implemented as a macro, so watch out. It also serves no
173 * no purpose unless you want to use the CORO_PTHREAD backend. 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.
174 * 224 *
175 * This function is thread-safe and reentrant. 225 * This function is thread-safe and reentrant.
176 */ 226 */
177#if 0 227#if 0
178void coro_destroy (coro_context *ctx); 228void coro_destroy (coro_context *ctx);
179#endif 229#endif
180 230
181/*
182 * That was it. No other user-visible functions are implemented here.
183 */
184
185/*****************************************************************************/ 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
186 256
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
187#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \ 303#if !defined CORO_LOSER && !defined CORO_UCONTEXT \
188 && !defined(CORO_SJLJ) && !defined(CORO_LINUX) \ 304 && !defined CORO_SJLJ && !defined CORO_LINUX \
189 && !defined(CORO_IRIX) && !defined(CORO_ASM) \ 305 && !defined CORO_IRIX && !defined CORO_ASM \
190 && !defined(CORO_PTHREAD) 306 && !defined CORO_PTHREAD && !defined CORO_FIBER
191# if defined(WINDOWS) 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
192# define CORO_LOSER 1 /* you don't win with windoze */ 310# define CORO_LOSER 1 /* you don't win with windoze */
193# elif defined(__linux) && (defined(__x86) || defined (__amd64)) 311# elif __linux && (__i386__ || (__x86_64__ && !__ILP32__) || (__arm__ && __ARM_ARCH == 7))
194# define CORO_ASM 1 312# define CORO_ASM 1
195# elif defined(HAVE_UCONTEXT_H) 313# elif defined HAVE_UCONTEXT_H
196# define CORO_UCONTEXT 1 314# define CORO_UCONTEXT 1
197# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) 315# elif defined HAVE_SETJMP_H && defined HAVE_SIGALTSTACK
198# define CORO_SJLJ 1 316# define CORO_SJLJ 1
199# else 317# else
200error unknown or unsupported architecture 318error unknown or unsupported architecture
201# endif 319# endif
202#endif 320#endif
… …
205 323
206#if CORO_UCONTEXT 324#if CORO_UCONTEXT
207 325
208# include <ucontext.h> 326# include <ucontext.h>
209 327
210struct coro_context { 328struct coro_context
329{
211 ucontext_t uc; 330 ucontext_t uc;
212}; 331};
213 332
214# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc)) 333# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
215# define coro_destroy(ctx) (void *)(ctx) 334# define coro_destroy(ctx) (void *)(ctx)
216 335
217#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX 336#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
218 337
219# if defined(CORO_LINUX) && !defined(_GNU_SOURCE) 338# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
220# define _GNU_SOURCE /* for linux libc */ 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
221# endif 356# endif
222 357
223# include <setjmp.h> 358# include <setjmp.h>
224 359
225struct coro_context { 360# if _XOPEN_UNIX > 0 || defined (_setjmp)
226 jmp_buf env; 361# define coro_jmp_buf jmp_buf
227}; 362# define coro_setjmp(env) _setjmp (env)
228 363# define coro_longjmp(env) _longjmp ((env), 1)
229# if CORO_LINUX || (_XOPEN_SOURCE >= 600) 364# elif CORO_LOSER
230# define coro_transfer(p,n) do { if (!_setjmp ((p)->env)) _longjmp ((n)->env, 1); } while (0) 365# define coro_jmp_buf jmp_buf
366# define coro_setjmp(env) setjmp (env)
367# define coro_longjmp(env) longjmp ((env), 1)
231# else 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
374struct coro_context
375{
376 coro_jmp_buf env;
377};
378
232# define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while (0) 379# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
233# endif
234
235# define coro_destroy(ctx) (void *)(ctx) 380# define coro_destroy(ctx) (void *)(ctx)
236 381
237#elif CORO_ASM 382#elif CORO_ASM
238 383
239struct coro_context { 384struct coro_context
385{
240 volatile void **sp; /* must be at offset 0 */ 386 void **sp; /* must be at offset 0 */
241}; 387};
242 388
389#if __i386__ || __x86_64__
243void __attribute__ ((__noinline__, __regparm__(2))) 390void __attribute__ ((__noinline__, __regparm__(2)))
391#else
392void __attribute__ ((__noinline__))
393#endif
244coro_transfer (coro_context *prev, coro_context *next); 394coro_transfer (coro_context *prev, coro_context *next);
245 395
246# define coro_destroy(ctx) (void *)(ctx) 396# define coro_destroy(ctx) (void *)(ctx)
247 397
248#elif CORO_PTHREAD 398#elif CORO_PTHREAD
249 399
250# include <pthread.h> 400# include <pthread.h>
251 401
252extern pthread_mutex_t coro_mutex; 402extern pthread_mutex_t coro_mutex;
253 403
254struct coro_context { 404struct coro_context
405{
255 pthread_cond_t cv; 406 pthread_cond_t cv;
256 pthread_t id; 407 pthread_t id;
257}; 408};
258 409
259void coro_transfer (coro_context *prev, coro_context *next); 410void coro_transfer (coro_context *prev, coro_context *next);
260void coro_destroy (coro_context *ctx); 411void coro_destroy (coro_context *ctx);
261 412
262#endif 413#elif CORO_FIBER
263 414
264#endif 415struct coro_context
416{
417 void *fiber;
418 /* only used for initialisation */
419 coro_func coro;
420 void *arg;
421};
265 422
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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