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Comparing libcoro/coro.h (file contents):
Revision 1.47 by root, Mon May 30 02:46:52 2011 UTC vs.
Revision 1.52 by root, Fri Dec 7 14:21:09 2012 UTC

1/* 1/*
2 * Copyright (c) 2001-2009 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,
… …
70 * 2008-11-19 define coro_*jmp symbols for easier porting. 70 * 2008-11-19 define coro_*jmp symbols for easier porting.
71 * 2009-06-23 tentative win32-backend support for mingw32 (Yasuhiro Matsumoto). 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). 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. 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. 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.
75 */ 81 */
76 82
77#ifndef CORO_H 83#ifndef CORO_H
78#define CORO_H 84#define CORO_H
79 85
80#if __cplusplus 86#if __cplusplus
81extern "C" { 87extern "C" {
82#endif 88#endif
83 89
84#define CORO_VERSION 2
85
86/*
87 * Changes since API version 1:
88 * replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
89 */
90
91/* 90/*
92 * This library consists of only three files 91 * This library consists of only three files
93 * coro.h, coro.c and LICENSE (and optionally README) 92 * coro.h, coro.c and LICENSE (and optionally README)
94 * 93 *
95 * It implements what is known as coroutines, in a hopefully 94 * It implements what is known as coroutines, in a hopefully
96 * portable way. At the moment you have to define which kind 95 * portable way.
97 * 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:
98 * 102 *
99 * -DCORO_UCONTEXT 103 * -DCORO_UCONTEXT
100 * 104 *
101 * This flavour uses SUSv2's get/set/swap/makecontext functions that 105 * This flavour uses SUSv2's get/set/swap/makecontext functions that
102 * unfortunately only newer unices support. 106 * unfortunately only some unices support, and is quite slow.
103 * 107 *
104 * -DCORO_SJLJ 108 * -DCORO_SJLJ
105 * 109 *
106 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to 110 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
107 * 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
108 * 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.
109 * all unices.
110 * 113 *
111 * -DCORO_LINUX 114 * -DCORO_LINUX
112 * 115 *
116 * CORO_SJLJ variant.
113 * 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
114 * (it is very fast and therefore recommended over other methods, but 118 * (it is very fast and therefore recommended over other methods, but
115 * doesn't work with anything newer). 119 * doesn't work with anything newer).
116 * 120 *
117 * -DCORO_LOSER 121 * -DCORO_LOSER
118 * 122 *
123 * CORO_SJLJ variant.
119 * Microsoft's highly proprietary platform doesn't support sigaltstack, and 124 * Microsoft's highly proprietary platform doesn't support sigaltstack, and
120 * this automatically selects a suitable workaround for this platform. 125 * this selects a suitable workaround for this platform. It might not work
121 * (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.
122 * 133 *
123 * -DCORO_IRIX 134 * -DCORO_IRIX
124 * 135 *
136 * CORO_SJLJ variant.
125 * SGI's version of Microsoft's NT ;) 137 * For SGI's version of Microsoft's NT ;)
126 * 138 *
127 * -DCORO_ASM 139 * -DCORO_ASM
128 * 140 *
129 * Handcoded assembly, known to work only on a few architectures/ABI: 141 * Hand coded assembly, known to work only on a few architectures/ABI:
130 * GCC + x86/IA32 and amd64/x86_64 + GNU/Linux and a few BSDs. 142 * GCC + x86/IA32 and amd64/x86_64 + GNU/Linux and a few BSDs. Fastest choice,
143 * if it works.
131 * 144 *
132 * -DCORO_PTHREAD 145 * -DCORO_PTHREAD
133 * 146 *
134 * 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.
135 * This is likely the slowest backend, and it also does not support fork(), 148 * This is likely the slowest backend, and it also does not support fork(),
136 * so avoid it at all costs. 149 * so avoid it at all costs.
137 * 150 *
138 * 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
139 * 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
140 * alternatives you should check (e.g. using autoconf) and define the 153 * (e.g. using autoconf) and define the following symbols: HAVE_UCONTEXT_H
141 * 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.
142 */ 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>
143 169
144/* 170/*
145 * 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.
146 */ 172 */
147typedef void (*coro_func)(void *); 173typedef void (*coro_func)(void *);
… …
158 * uninitialised coro_context, it expects a pointer to the entry function 184 * uninitialised coro_context, it expects a pointer to the entry function
159 * 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.
160 * 186 *
161 * Allocating/deallocating the stack is your own responsibility. 187 * Allocating/deallocating the stack is your own responsibility.
162 * 188 *
163 * 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,
164 * then an "empty" coro_context will be created that is suitable 190 * then an "empty" coro_context will be created that is suitable
165 * as an initial source for coro_transfer. 191 * as an initial source for coro_transfer.
166 * 192 *
167 * This function is not reentrant, but putting a mutex around it 193 * This function is not reentrant, but putting a mutex around it
168 * will work. 194 * will work.
169 */ 195 */
170void coro_create (coro_context *ctx, /* an uninitialised coro_context */ 196void coro_create (coro_context *ctx, /* an uninitialised coro_context */
171 coro_func coro, /* the coroutine code to be executed */ 197 coro_func coro, /* the coroutine code to be executed */
172 void *arg, /* a single pointer passed to the coro */ 198 void *arg, /* a single pointer passed to the coro */
173 void *sptr, /* start of stack area */ 199 void *sptr, /* start of stack area */
174 long ssize); /* size of stack area */ 200 size_t ssze); /* size of stack area in bytes */
175 201
176/* 202/*
177 * The following prototype defines the coroutine switching function. It is 203 * The following prototype defines the coroutine switching function. It is
178 * usually implemented as a macro, so watch out. 204 * sometimes implemented as a macro, so watch out.
179 * 205 *
180 * This function is thread-safe and reentrant. 206 * This function is thread-safe and reentrant.
181 */ 207 */
182#if 0 208#if 0
183void coro_transfer (coro_context *prev, coro_context *next); 209void coro_transfer (coro_context *prev, coro_context *next);
184#endif 210#endif
185 211
186/* 212/*
187 * The following prototype defines the coroutine destroy function. It is 213 * The following prototype defines the coroutine destroy function. It
188 * 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
189 * 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
190 * 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
191 * for freeing the stack and the context itself. 217 * and the context itself.
192 * 218 *
193 * This function is thread-safe and reentrant. 219 * This function is thread-safe and reentrant.
194 */ 220 */
195#if 0 221#if 0
196void coro_destroy (coro_context *ctx); 222void coro_destroy (coro_context *ctx);
197#endif 223#endif
198 224
199/*
200 * That was it. No other user-visible functions are implemented here.
201 */
202
203/*****************************************************************************/ 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
204 250
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
205#if !defined(CORO_LOSER) && !defined(CORO_UCONTEXT) \ 297#if !defined CORO_LOSER && !defined CORO_UCONTEXT \
206 && !defined(CORO_SJLJ) && !defined(CORO_LINUX) \ 298 && !defined CORO_SJLJ && !defined CORO_LINUX \
207 && !defined(CORO_IRIX) && !defined(CORO_ASM) \ 299 && !defined CORO_IRIX && !defined CORO_ASM \
208 && !defined(CORO_PTHREAD) 300 && !defined CORO_PTHREAD && !defined CORO_FIBER
209# 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
210# define CORO_LOSER 1 /* you don't win with windoze */ 304# define CORO_LOSER 1 /* you don't win with windoze */
211# elif defined(__linux) && (defined(__x86) || defined (__amd64)) 305# elif defined __linux && (defined __x86 || defined __amd64)
212# define CORO_ASM 1 306# define CORO_ASM 1
213# elif defined(HAVE_UCONTEXT_H) 307# elif defined HAVE_UCONTEXT_H
214# define CORO_UCONTEXT 1 308# define CORO_UCONTEXT 1
215# elif defined(HAVE_SETJMP_H) && defined(HAVE_SIGALTSTACK) 309# elif defined HAVE_SETJMP_H && defined HAVE_SIGALTSTACK
216# define CORO_SJLJ 1 310# define CORO_SJLJ 1
217# else 311# else
218error unknown or unsupported architecture 312error unknown or unsupported architecture
219# endif 313# endif
220#endif 314#endif
… …
223 317
224#if CORO_UCONTEXT 318#if CORO_UCONTEXT
225 319
226# include <ucontext.h> 320# include <ucontext.h>
227 321
228struct coro_context { 322struct coro_context
323{
229 ucontext_t uc; 324 ucontext_t uc;
230}; 325};
231 326
232# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc)) 327# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
233# define coro_destroy(ctx) (void *)(ctx) 328# define coro_destroy(ctx) (void *)(ctx)
234 329
235#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX 330#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
236 331
237# if defined(CORO_LINUX) && !defined(_GNU_SOURCE) 332# if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
238# define _GNU_SOURCE /* for linux libc */ 333# define _GNU_SOURCE /* for glibc */
239# endif 334# endif
240 335
241# if !CORO_LOSER 336# if !CORO_LOSER
242# include <unistd.h> 337# include <unistd.h>
243# endif 338# endif
… …
262# define coro_jmp_buf sigjmp_buf 357# define coro_jmp_buf sigjmp_buf
263# define coro_setjmp(env) sigsetjmp (env, 0) 358# define coro_setjmp(env) sigsetjmp (env, 0)
264# define coro_longjmp(env) siglongjmp ((env), 1) 359# define coro_longjmp(env) siglongjmp ((env), 1)
265# endif 360# endif
266 361
267struct coro_context { 362struct coro_context
363{
268 coro_jmp_buf env; 364 coro_jmp_buf env;
269}; 365};
270 366
271# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0) 367# define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
272# define coro_destroy(ctx) (void *)(ctx) 368# define coro_destroy(ctx) (void *)(ctx)
273 369
274#elif CORO_ASM 370#elif CORO_ASM
275 371
276struct coro_context { 372struct coro_context
373{
277 void **sp; /* must be at offset 0 */ 374 void **sp; /* must be at offset 0 */
278}; 375};
279 376
280void __attribute__ ((__noinline__, __regparm__(2))) 377void __attribute__ ((__noinline__, __regparm__(2)))
281coro_transfer (coro_context *prev, coro_context *next); 378coro_transfer (coro_context *prev, coro_context *next);
… …
286 383
287# include <pthread.h> 384# include <pthread.h>
288 385
289extern pthread_mutex_t coro_mutex; 386extern pthread_mutex_t coro_mutex;
290 387
291struct coro_context { 388struct coro_context
389{
292 pthread_cond_t cv; 390 pthread_cond_t cv;
293 pthread_t id; 391 pthread_t id;
294}; 392};
295 393
296void coro_transfer (coro_context *prev, coro_context *next); 394void coro_transfer (coro_context *prev, coro_context *next);
297void coro_destroy (coro_context *ctx); 395void coro_destroy (coro_context *ctx);
298 396
397#elif CORO_FIBER
398
399struct coro_context
400{
401 void *fiber;
402 /* only used for initialisation */
403 coro_func coro;
404 void *arg;
405};
406
407void coro_transfer (coro_context *prev, coro_context *next);
408void coro_destroy (coro_context *ctx);
409
299#endif 410#endif
300 411
301#if __cplusplus 412#if __cplusplus
302} 413}
303#endif 414#endif

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