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Revision: 1.51
Committed: Wed Dec 5 01:09:12 2012 UTC (11 years, 5 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.50: +31 -13 lines
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fiber

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# User Rev Content
1 root 1.1 /*
2 root 1.51 * Copyright (c) 2001-2012 Marc Alexander Lehmann <schmorp@schmorp.de>
3     *
4 root 1.1 * Redistribution and use in source and binary forms, with or without modifica-
5     * tion, are permitted provided that the following conditions are met:
6 root 1.51 *
7 root 1.1 * 1. Redistributions of source code must retain the above copyright notice,
8     * this list of conditions and the following disclaimer.
9 root 1.51 *
10 root 1.1 * 2. Redistributions in binary form must reproduce the above copyright
11     * notice, this list of conditions and the following disclaimer in the
12     * documentation and/or other materials provided with the distribution.
13 root 1.51 *
14 root 1.1 * 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-
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-
18     * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19     * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
20     * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
21     * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
22     * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
23     * OF THE POSSIBILITY OF SUCH DAMAGE.
24     *
25 root 1.24 * 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     *
36 root 1.1 * This library is modelled strictly after Ralf S. Engelschalls article at
37 root 1.24 * http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
38 root 1.1 * go to Ralf S. Engelschall <rse@engelschall.com>.
39     *
40     * This coroutine library is very much stripped down. You should either
41 pcg 1.7 * build your own process abstraction using it or - better - just use GNU
42 root 1.1 * Portable Threads, http://www.gnu.org/software/pth/.
43 root 1.4 *
44 root 1.1 */
45    
46 root 1.14 /*
47     * 2006-10-26 Include stddef.h on OS X to work around one of its bugs.
48     * Reported by Michael_G_Schwern.
49 root 1.17 * 2006-11-26 Use _setjmp instead of setjmp on GNU/Linux.
50 root 1.20 * 2007-04-27 Set unwind frame info if gcc 3+ and ELF is detected.
51 root 1.21 * Use _setjmp instead of setjmp on _XOPEN_SOURCE >= 600.
52 root 1.22 * 2007-05-02 Add assembly versions for x86 and amd64 (to avoid reliance
53     * on SIGUSR2 and sigaltstack in Crossfire).
54 root 1.23 * 2008-01-21 Disable CFI usage on anything but GNU/Linux.
55 root 1.24 * 2008-03-02 Switched to 2-clause BSD license with GPL exception.
56 root 1.25 * 2008-04-04 New (but highly unrecommended) pthreads backend.
57 root 1.26 * 2008-04-24 Reinstate CORO_LOSER (had wrong stack adjustments).
58 root 1.28 * 2008-10-30 Support assembly method on x86 with and without frame pointer.
59 root 1.29 * 2008-11-03 Use a global asm statement for CORO_ASM, idea by pippijn.
60 root 1.30 * 2008-11-05 Hopefully fix misaligned stacks with CORO_ASM/SETJMP.
61 root 1.31 * 2008-11-07 rbp wasn't saved in CORO_ASM on x86_64.
62 root 1.32 * 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 root 1.33 * do not rely on makecontext passing a void * correctly.
66     * try harder to get _setjmp/_longjmp.
67     * major code cleanup/restructuring.
68 root 1.37 * 2008-11-10 the .cfi hacks are no longer needed.
69 root 1.39 * 2008-11-16 work around a freebsd pthread bug.
70 root 1.40 * 2008-11-19 define coro_*jmp symbols for easier porting.
71 root 1.41 * 2009-06-23 tentative win32-backend support for mingw32 (Yasuhiro Matsumoto).
72 root 1.44 * 2010-12-03 tentative support for uclibc (which lacks all sorts of things).
73 root 1.45 * 2011-05-30 set initial callee-saved-registers to zero with CORO_ASM.
74 root 1.47 * use .cfi_undefined rip on linux-amd64 for better backtraces.
75 root 1.48 * 2011-06-08 maybe properly implement weird windows amd64 calling conventions.
76 root 1.49 * 2011-07-03 rely on __GCC_HAVE_DWARF2_CFI_ASM for cfi detection.
77 root 1.50 * 2011-08-08 cygwin trashes stacks, use pthreads with double stack on cygwin.
78 root 1.51 * 2012-12-04 reduce misprediction penalty for x86/amd64 assembly switcher.
79     * 2012-12-05 experimental fiber backend (allocates stack twice).
80 root 1.14 */
81    
82 root 1.1 #ifndef CORO_H
83     #define CORO_H
84    
85 root 1.43 #if __cplusplus
86     extern "C" {
87     #endif
88    
89 root 1.11 #define CORO_VERSION 2
90    
91     /*
92     * Changes since API version 1:
93 root 1.12 * replaced bogus -DCORO_LOOSE with gramatically more correct -DCORO_LOSER
94 root 1.11 */
95 root 1.9
96 root 1.2 /*
97     * This library consists of only three files
98 root 1.9 * coro.h, coro.c and LICENSE (and optionally README)
99 root 1.2 *
100     * It implements what is known as coroutines, in a hopefully
101     * portable way. At the moment you have to define which kind
102     * of implementation flavour you want:
103     *
104     * -DCORO_UCONTEXT
105     *
106     * This flavour uses SUSv2's get/set/swap/makecontext functions that
107     * unfortunately only newer unices support.
108     *
109     * -DCORO_SJLJ
110     *
111 root 1.13 * This flavour uses SUSv2's setjmp/longjmp and sigaltstack functions to
112 root 1.2 * do it's job. Coroutine creation is much slower than UCONTEXT, but
113     * context switching is often a bit cheaper. It should work on almost
114 root 1.24 * all unices.
115 root 1.3 *
116     * -DCORO_LINUX
117     *
118 root 1.24 * Old GNU/Linux systems (<= glibc-2.1) only work with this implementation
119     * (it is very fast and therefore recommended over other methods, but
120     * doesn't work with anything newer).
121 root 1.2 *
122 root 1.11 * -DCORO_LOSER
123 root 1.2 *
124     * Microsoft's highly proprietary platform doesn't support sigaltstack, and
125     * this automatically selects a suitable workaround for this platform.
126     * (untested)
127     *
128 root 1.51 * -DCORO_FIBER
129     *
130     * slower, but probably more portable variant for the Microsoft operating
131     * system, using fibers. ignores your stack.
132     *
133 root 1.5 * -DCORO_IRIX
134     *
135     * SGI's version of Microsoft's NT ;)
136     *
137 root 1.22 * -DCORO_ASM
138     *
139     * Handcoded assembly, known to work only on a few architectures/ABI:
140 root 1.39 * GCC + x86/IA32 and amd64/x86_64 + GNU/Linux and a few BSDs.
141 root 1.22 *
142 root 1.25 * -DCORO_PTHREAD
143     *
144     * Use the pthread API. You have to provide <pthread.h> and -lpthread.
145 root 1.39 * This is likely the slowest backend, and it also does not support fork(),
146     * so avoid it at all costs.
147 root 1.25 *
148 root 1.2 * If you define neither of these symbols, coro.h will try to autodetect
149 root 1.24 * the model. This currently works for CORO_LOSER only. For the other
150 root 1.2 * alternatives you should check (e.g. using autoconf) and define the
151     * following symbols: HAVE_UCONTEXT_H / HAVE_SETJMP_H / HAVE_SIGALTSTACK.
152     */
153    
154     /*
155 root 1.6 * This is the type for the initialization function of a new coroutine.
156 root 1.2 */
157 root 1.1 typedef void (*coro_func)(void *);
158 root 1.2
159     /*
160 root 1.19 * A coroutine state is saved in the following structure. Treat it as an
161 root 1.2 * opaque type. errno and sigmask might be saved, but don't rely on it,
162 root 1.19 * implement your own switching primitive if you need that.
163 root 1.2 */
164     typedef struct coro_context coro_context;
165    
166     /*
167     * This function creates a new coroutine. Apart from a pointer to an
168 root 1.13 * uninitialised coro_context, it expects a pointer to the entry function
169 root 1.2 * and the single pointer value that is given to it as argument.
170     *
171 root 1.32 * Allocating/deallocating the stack is your own responsibility.
172     *
173     * As a special case, if coro, arg, sptr and ssize are all zero,
174 root 1.38 * then an "empty" coro_context will be created that is suitable
175 root 1.32 * as an initial source for coro_transfer.
176     *
177     * This function is not reentrant, but putting a mutex around it
178     * will work.
179 root 1.2 */
180 root 1.19 void coro_create (coro_context *ctx, /* an uninitialised coro_context */
181     coro_func coro, /* the coroutine code to be executed */
182     void *arg, /* a single pointer passed to the coro */
183     void *sptr, /* start of stack area */
184     long ssize); /* size of stack area */
185 root 1.2
186     /*
187     * The following prototype defines the coroutine switching function. It is
188     * usually implemented as a macro, so watch out.
189     *
190 root 1.32 * This function is thread-safe and reentrant.
191 root 1.2 */
192 root 1.32 #if 0
193     void coro_transfer (coro_context *prev, coro_context *next);
194     #endif
195    
196     /*
197     * The following prototype defines the coroutine destroy function. It is
198     * usually implemented as a macro, so watch out. It also serves
199 root 1.38 * no purpose unless you want to use the CORO_PTHREAD backend,
200     * where it is used to clean up the thread. You are responsible
201     * for freeing the stack and the context itself.
202 root 1.32 *
203     * This function is thread-safe and reentrant.
204     */
205     #if 0
206     void coro_destroy (coro_context *ctx);
207     #endif
208 root 1.2
209     /*
210     * That was it. No other user-visible functions are implemented here.
211     */
212    
213 root 1.5 /*****************************************************************************/
214    
215 root 1.51 #if !defined CORO_LOSER && !defined CORO_UCONTEXT \
216     && !defined CORO_SJLJ && !defined CORO_LINUX \
217     && !defined CORO_IRIX && !defined CORO_ASM \
218     && !defined CORO_PTHREAD && !defined CORO_FIBER
219     # if defined WINDOWS && (defined __x86 || defined __amd64 || defined _M_IX86 || defined _M_AMD64)
220     # define CORO_ASM 1
221     # elif defined WINDOWS || defined _WIN32
222 root 1.11 # define CORO_LOSER 1 /* you don't win with windoze */
223 root 1.51 # elif defined __linux && (defined __x86 || defined __amd64)
224 root 1.22 # define CORO_ASM 1
225 root 1.51 # elif defined HAVE_UCONTEXT_H
226 root 1.2 # define CORO_UCONTEXT 1
227 root 1.51 # elif defined HAVE_SETJMP_H && defined HAVE_SIGALTSTACK
228 root 1.2 # define CORO_SJLJ 1
229     # else
230 root 1.1 error unknown or unsupported architecture
231 root 1.2 # endif
232 root 1.1 #endif
233    
234 root 1.5 /*****************************************************************************/
235    
236 root 1.1 #if CORO_UCONTEXT
237    
238 root 1.22 # include <ucontext.h>
239 root 1.1
240 root 1.2 struct coro_context {
241 root 1.1 ucontext_t uc;
242 root 1.2 };
243 root 1.1
244 root 1.22 # define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
245 root 1.32 # define coro_destroy(ctx) (void *)(ctx)
246 root 1.1
247 root 1.11 #elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
248 root 1.1
249 root 1.22 # if defined(CORO_LINUX) && !defined(_GNU_SOURCE)
250     # define _GNU_SOURCE /* for linux libc */
251     # endif
252 root 1.8
253 root 1.33 # if !CORO_LOSER
254     # include <unistd.h>
255     # endif
256    
257 root 1.36 /* solaris is hopelessly borked, it expands _XOPEN_UNIX to nothing */
258     # if __sun
259     # undef _XOPEN_UNIX
260     # define _XOPEN_UNIX 1
261     # endif
262    
263 root 1.22 # include <setjmp.h>
264 root 1.1
265 root 1.40 # if _XOPEN_UNIX > 0 || defined (_setjmp)
266     # define coro_jmp_buf jmp_buf
267     # define coro_setjmp(env) _setjmp (env)
268     # define coro_longjmp(env) _longjmp ((env), 1)
269 root 1.34 # elif CORO_LOSER
270 root 1.40 # define coro_jmp_buf jmp_buf
271     # define coro_setjmp(env) setjmp (env)
272     # define coro_longjmp(env) longjmp ((env), 1)
273 root 1.22 # else
274 root 1.40 # define coro_jmp_buf sigjmp_buf
275     # define coro_setjmp(env) sigsetjmp (env, 0)
276     # define coro_longjmp(env) siglongjmp ((env), 1)
277 root 1.22 # endif
278    
279 root 1.40 struct coro_context {
280     coro_jmp_buf env;
281     };
282    
283     # define coro_transfer(p,n) do { if (!coro_setjmp ((p)->env)) coro_longjmp ((n)->env); } while (0)
284 root 1.32 # define coro_destroy(ctx) (void *)(ctx)
285    
286 root 1.22 #elif CORO_ASM
287    
288     struct coro_context {
289 root 1.34 void **sp; /* must be at offset 0 */
290 root 1.22 };
291    
292 root 1.27 void __attribute__ ((__noinline__, __regparm__(2)))
293 root 1.29 coro_transfer (coro_context *prev, coro_context *next);
294 root 1.25
295 root 1.32 # define coro_destroy(ctx) (void *)(ctx)
296    
297 root 1.25 #elif CORO_PTHREAD
298    
299 root 1.32 # include <pthread.h>
300 root 1.25
301     extern pthread_mutex_t coro_mutex;
302    
303     struct coro_context {
304 root 1.32 pthread_cond_t cv;
305     pthread_t id;
306 root 1.25 };
307    
308     void coro_transfer (coro_context *prev, coro_context *next);
309 root 1.32 void coro_destroy (coro_context *ctx);
310 root 1.1
311 root 1.51 #elif CORO_FIBER
312    
313     struct coro_context {
314     void *fiber;
315     /* only used for initialisation */
316     coro_func coro;
317     void *arg;
318     };
319    
320 root 1.1 #endif
321    
322 root 1.43 #if __cplusplus
323     }
324     #endif
325    
326 root 1.1 #endif
327