ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libcoro/coro.h
(Generate patch)

Comparing libcoro/coro.h (file contents):
Revision 1.38 by root, Fri Nov 14 05:27:08 2008 UTC vs.
Revision 1.52 by root, Fri Dec 7 14:21:09 2012 UTC

1/* 1/*
2 * Copyright (c) 2001-2008 Marc Alexander Lehmann <schmorp@schmorp.de> 2 * Copyright (c) 2001-2012 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,
… …
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. 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.
69 */ 81 */
70 82
71#ifndef CORO_H 83#ifndef CORO_H
72#define CORO_H 84#define CORO_H
73 85
74#define CORO_VERSION 2 86#if __cplusplus
75 87extern "C" {
76/* 88#endif
77 * Changes since API version 1:
78 * replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
79 */
80 89
81/* 90/*
82 * This library consists of only three files 91 * This library consists of only three files
83 * coro.h, coro.c and LICENSE (and optionally README) 92 * coro.h, coro.c and LICENSE (and optionally README)
84 * 93 *
85 * It implements what is known as coroutines, in a hopefully 94 * It implements what is known as coroutines, in a hopefully
86 * portable way. At the moment you have to define which kind 95 * portable way.
87 * of implementation flavour you want: 96 *
97 * All compiletime symbols must be defined both when including coro.h
98 * (using libcoro) as well as when compiling coro.c (the implementation).
99 *
100 * You can manually specify which flavour you want. If you don't define
101 * any of these, libcoro tries to choose a safe and fast default:
88 * 102 *
89 * -DCORO_UCONTEXT 103 * -DCORO_UCONTEXT
90 * 104 *
91 * This flavour uses SUSv2's get/set/swap/makecontext functions that 105 * This flavour uses SUSv2's get/set/swap/makecontext functions that
92 * unfortunately only newer unices support. 106 * unfortunately only some unices support, and is quite slow.
93 * 107 *
94 * -DCORO_SJLJ 108 * -DCORO_SJLJ
95 * 109 *
96 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to 110 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
97 * do it's job. Coroutine creation is much slower than UCONTEXT, but 111 * do it's job. Coroutine creation is much slower than UCONTEXT, but
98 * context switching is often a bit cheaper. It should work on almost 112 * context switching is a bit cheaper. It should work on almost all unices.
99 * all unices.
100 * 113 *
101 * -DCORO_LINUX 114 * -DCORO_LINUX
102 * 115 *
116 * CORO_SJLJ variant.
103 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation 117 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
104 * (it is very fast and therefore recommended over other methods, but 118 * (it is very fast and therefore recommended over other methods, but
105 * doesn't work with anything newer). 119 * doesn't work with anything newer).
106 * 120 *
107 * -DCORO_LOSER 121 * -DCORO_LOSER
108 * 122 *
123 * CORO_SJLJ variant.
109 * Microsoft's highly proprietary platform doesn't support sigaltstack, and 124 * Microsoft's highly proprietary platform doesn't support sigaltstack, and
110 * this automatically selects a suitable workaround for this platform. 125 * this selects a suitable workaround for this platform. It might not work
111 * (untested) 126 * with your compiler though - it has only been tested with MSVC 6.
127 *
128 * -DCORO_FIBER
129 *
130 * Slower, but probably more portable variant for the Microsoft operating
131 * system, using fibers. Ignores the passed stack and allocates it internally.
132 * Also, due to bugs in cygwin, this does not work with cygwin.
112 * 133 *
113 * -DCORO_IRIX 134 * -DCORO_IRIX
114 * 135 *
136 * CORO_SJLJ variant.
115 * SGI's version of Microsoft's NT ;) 137 * For SGI's version of Microsoft's NT ;)
116 * 138 *
117 * -DCORO_ASM 139 * -DCORO_ASM
118 * 140 *
119 * Handcoded assembly, known to work only on a few architectures/ABI: 141 * Hand coded assembly, known to work only on a few architectures/ABI:
120 * ELF Linux x86 && amd64 when gcc is used and optimisation is turned on. 142 * GCC + x86/IA32 and amd64/x86_64 + GNU/Linux and a few BSDs. Fastest choice,
143 * if it works.
121 * 144 *
122 * -DCORO_PTHREAD 145 * -DCORO_PTHREAD
123 * 146 *
124 * Use the pthread API. You have to provide <pthread.h> and -lpthread. 147 * Use the pthread API. You have to provide <pthread.h> and -lpthread.
148 * This is likely the slowest backend, and it also does not support fork(),
149 * so avoid it at all costs.
125 * 150 *
126 * If you define neither of these symbols, coro.h will try to autodetect 151 * If you define neither of these symbols, coro.h will try to autodetect
127 * the model. This currently works for CORO_LOSER only. For the other 152 * the best/safest model. To help with the autodetection, you should check
128 * alternatives you should check (e.g. using autoconf) and define the 153 * (e.g. using autoconf) and define the following symbols: HAVE_UCONTEXT_H
129 * following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK. 154 * / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
155 */
156
157/*
158 * Changes when the API changes incompatibly.
159 * This is ONLY the API version - there is no ABI compatibility between releases.
130 */ 160 *
161 * Changes in API version 2:
162 * replaced bogus -DCORO_LOOSE with grammatically more correct -DCORO_LOSER
163 * Changes in API version 3:
164 * introduced stack management (CORO_STACKALLOC)
165 */
166#define CORO_VERSION 3
167
168#include <stddef.h>
131 169
132/* 170/*
133 * This is the type for the initialization function of a new coroutine. 171 * This is the type for the initialization function of a new coroutine.
134 */ 172 */
135typedef void (*coro_func)(void *); 173typedef void (*coro_func)(void *);
… …
146 * uninitialised coro_context, it expects a pointer to the entry function 184 * uninitialised coro_context, it expects a pointer to the entry function
147 * and the single pointer value that is given to it as argument. 185 * and the single pointer value that is given to it as argument.
148 * 186 *
149 * Allocating/deallocating the stack is your own responsibility. 187 * Allocating/deallocating the stack is your own responsibility.
150 * 188 *
151 * As a special case, if coro, arg, sptr and ssize are all zero, 189 * As a special case, if coro, arg, sptr and ssze are all zero,
152 * then an "empty" coro_context will be created that is suitable 190 * then an "empty" coro_context will be created that is suitable
153 * as an initial source for coro_transfer. 191 * as an initial source for coro_transfer.
154 * 192 *
155 * This function is not reentrant, but putting a mutex around it 193 * This function is not reentrant, but putting a mutex around it
156 * will work. 194 * will work.
157 */ 195 */
158void coro_create (coro_context *ctx, /* an uninitialised coro_context */ 196void coro_create (coro_context *ctx, /* an uninitialised coro_context */
159 coro_func coro, /* the coroutine code to be executed */ 197 coro_func coro, /* the coroutine code to be executed */
160 void *arg, /* a single pointer passed to the coro */ 198 void *arg, /* a single pointer passed to the coro */
161 void *sptr, /* start of stack area */ 199 void *sptr, /* start of stack area */
162 long ssize); /* size of stack area */ 200 size_t ssze); /* size of stack area in bytes */
163 201
164/* 202/*
165 * The following prototype defines the coroutine switching function. It is 203 * The following prototype defines the coroutine switching function. It is
166 * usually implemented as a macro, so watch out. 204 * sometimes implemented as a macro, so watch out.
167 * 205 *
168 * This function is thread-safe and reentrant. 206 * This function is thread-safe and reentrant.
169 */ 207 */
170#if 0 208#if 0
171void coro_transfer (coro_context *prev, coro_context *next); 209void coro_transfer (coro_context *prev, coro_context *next);
172#endif 210#endif
173 211
174/* 212/*
175 * The following prototype defines the coroutine destroy function. It is 213 * The following prototype defines the coroutine destroy function. It
176 * usually implemented as a macro, so watch out. It also serves 214 * is sometimes implemented as a macro, so watch out. It also serves no
177 * no purpose unless you want to use the CORO_PTHREAD backend, 215 * purpose unless you want to use the CORO_PTHREAD backend, where it is
178 * where it is used to clean up the thread. You are responsible 216 * used to clean up the thread. You are responsible for freeing the stack
179 * for freeing the stack and the context itself. 217 * and the context itself.
180 * 218 *
181 * This function is thread-safe and reentrant. 219 * This function is thread-safe and reentrant.
182 */ 220 */
183#if 0 221#if 0
184void coro_destroy (coro_context *ctx); 222void coro_destroy (coro_context *ctx);
185#endif 223#endif
186 224
187/*
188 * That was it. No other user-visible functions are implemented here.
189 */
190
191/*****************************************************************************/ 225/*****************************************************************************/
226/* optional stack management */
227/*****************************************************************************/
228/*
229 * You can disable all of the stack management functions by
230 * defining CORO_STACKALLOC to 0. Otherwise, they are enabled by default.
231 *
232 * If stack management is enabled, you can influence the implementation via these
233 * symbols:
234 *
235 * -DCORO_USE_VALGRIND
236 *
237 * If defined, then libcoro will include valgrind/valgrind.h and register
238 * and unregister stacks with valgrind.
239 *
240 * -DCORO_GUARDPAGES=n
241 *
242 * libcoro will try to use the specified number of guard pages to protect against
243 * stack overflow. If n is 0, then the feature will be disabled. If it isn't
244 * defined, then libcoro will choose a suitable default. If guardpages are not
245 * supported on the platform, then the feature will be silently disabled.
246 */
247#ifndef CORO_STACKALLOC
248# define CORO_STACKALLOC 1
249#endif
192 250
251#if CORO_STACKALLOC
252
253/*
254 * The only allowed operations on these struct members is to read the
255 * "sptr" and "ssze" members to pass it to coro_create, to read the "sptr"
256 * member to see if it is false, in which case the stack isn't allocated,
257 * and to set the "sptr" member to 0, to indicate to coro_stack_free to
258 * not actually do anything.
259 */
260
261struct coro_stack
262{
263 void *sptr;
264 size_t ssze;
265#if CORO_USE_VALGRIND
266 int valgrind_id;
267#endif
268};
269
270/*
271 * Try to allocate a stack of at least the given size and return true if
272 * successful, or false otherwise.
273 *
274 * The size is *NOT* specified in bytes, but in units of sizeof (void *),
275 * i.e. the stack is typically 4(8) times larger on 32 bit(64 bit) platforms
276 * then the size passed in.
277 *
278 * If size is 0, then a "suitable" stack size is chosen (usually 1-2MB).
279 */
280int coro_stack_alloc (struct coro_stack *stack, unsigned int size);
281
282/*
283 * Free the stack allocated by coro_stack_alloc again. It is safe to
284 * call this function on the coro_stack structure even if coro_stack_alloc
285 * failed.
286 */
287void coro_stack_free (struct coro_stack *stack);
288
289#endif
290
291/*
292 * That was it. No other user-serviceable parts below here.
293 */
294
295/*****************************************************************************/
296
193#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \ 297#if !defined CORO_LOSER && !defined CORO_UCONTEXT \
194 && !defined(CORO_SJLJ) && !defined(CORO_LINUX) \ 298 && !defined CORO_SJLJ && !defined CORO_LINUX \
195 && !defined(CORO_IRIX) && !defined(CORO_ASM) \ 299 && !defined CORO_IRIX && !defined CORO_ASM \
196 && !defined(CORO_PTHREAD) 300 && !defined CORO_PTHREAD && !defined CORO_FIBER
197# if defined(WINDOWS) 301# if defined WINDOWS && (defined __x86 || defined __amd64 || defined _M_IX86 || defined _M_AMD64)
302# define CORO_ASM 1
303# elif defined WINDOWS || defined _WIN32
198# define CORO_LOSER 1 /* you don't win with windoze */ 304# define CORO_LOSER 1 /* you don't win with windoze */
199# elif defined(__linux) && (defined(__x86) || defined (__amd64)) 305# elif defined __linux && (defined __x86 || defined __amd64)
200# define CORO_ASM 1 306# define CORO_ASM 1
201# elif defined(HAVE_UCONTEXT_H) 307# elif defined HAVE_UCONTEXT_H
202# define CORO_UCONTEXT 1 308# define CORO_UCONTEXT 1
203# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) 309# elif defined HAVE_SETJMP_H && defined HAVE_SIGALTSTACK
204# define CORO_SJLJ 1 310# define CORO_SJLJ 1
205# else 311# else
206error unknown or unsupported architecture 312error unknown or unsupported architecture
207# endif 313# endif
208#endif 314#endif
… …
211 317
212#if CORO_UCONTEXT 318#if CORO_UCONTEXT
213 319
214# include <ucontext.h> 320# include <ucontext.h>
215 321
216struct coro_context { 322struct coro_context
323{
217 ucontext_t uc; 324 ucontext_t uc;
218}; 325};
219 326
220# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc)) 327# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
221# define coro_destroy(ctx) (void *)(ctx) 328# define coro_destroy(ctx) (void *)(ctx)
222 329
223#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX 330#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
224 331
225# if defined(CORO_LINUX) && !defined(_GNU_SOURCE) 332# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
226# define _GNU_SOURCE /* for linux libc */ 333# define _GNU_SOURCE /* for glibc */
227# endif 334# endif
228 335
229# if !CORO_LOSER 336# if !CORO_LOSER
230# include <unistd.h> 337# include <unistd.h>
231# endif 338# endif
… …
236# define _XOPEN_UNIX 1 343# define _XOPEN_UNIX 1
237# endif 344# endif
238 345
239# include <setjmp.h> 346# include <setjmp.h>
240 347
241struct coro_context { 348# if _XOPEN_UNIX > 0 || defined (_setjmp)
242#if _XOPEN_UNIX > 0 || CORO_LOSER 349# define coro_jmp_buf jmp_buf
243 jmp_buf env; 350# define coro_setjmp(env) _setjmp (env)
244#else 351# define coro_longjmp(env) _longjmp ((env), 1)
245 sigjmp_buf env;
246#endif
247};
248
249# if _XOPEN_UNIX > 0
250# define coro_transfer(p,n) do { if (! _setjmp ((p)->env )) _longjmp ((n)->env, 1); } while (0)
251# elif CORO_LOSER 352# elif CORO_LOSER
252# define coro_transfer(p,n) do { if (! setjmp ((p)->env )) longjmp ((n)->env, 1); } while (0) 353# define coro_jmp_buf jmp_buf
354# define coro_setjmp(env) setjmp (env)
355# define coro_longjmp(env) longjmp ((env), 1)
253# else 356# else
254# define coro_transfer(p,n) do { if (!sigsetjmp ((p)->env, 0)) siglongjmp ((n)->env, 1); } while (0) 357# define coro_jmp_buf sigjmp_buf
358# define coro_setjmp(env) sigsetjmp (env, 0)
359# define coro_longjmp(env) siglongjmp ((env), 1)
255# endif 360# endif
256 361
362struct coro_context
363{
364 coro_jmp_buf env;
365};
366
367# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
257# define coro_destroy(ctx) (void *)(ctx) 368# define coro_destroy(ctx) (void *)(ctx)
258 369
259#elif CORO_ASM 370#elif CORO_ASM
260 371
261struct coro_context { 372struct coro_context
373{
262 void **sp; /* must be at offset 0 */ 374 void **sp; /* must be at offset 0 */
263}; 375};
264 376
265void __attribute__ ((__noinline__, __regparm__(2))) 377void __attribute__ ((__noinline__, __regparm__(2)))
266coro_transfer (coro_context *prev, coro_context *next); 378coro_transfer (coro_context *prev, coro_context *next);
… …
271 383
272# include <pthread.h> 384# include <pthread.h>
273 385
274extern pthread_mutex_t coro_mutex; 386extern pthread_mutex_t coro_mutex;
275 387
276struct coro_context { 388struct coro_context
389{
277 pthread_cond_t cv; 390 pthread_cond_t cv;
278 pthread_t id; 391 pthread_t id;
279}; 392};
280 393
281void coro_transfer (coro_context *prev, coro_context *next); 394void coro_transfer (coro_context *prev, coro_context *next);
282void coro_destroy (coro_context *ctx); 395void coro_destroy (coro_context *ctx);
283 396
284#endif 397#elif CORO_FIBER
285 398
286#endif 399struct coro_context
400{
401 void *fiber;
402 /* only used for initialisation */
403 coro_func coro;
404 void *arg;
405};
287 406
407void coro_transfer (coro_context *prev, coro_context *next);
408void coro_destroy (coro_context *ctx);
409
410#endif
411
412#if __cplusplus
413}
414#endif
415
416#endif
417

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines