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/cvs/libcoro/coro.c
Revision: 1.44
Committed: Wed Nov 19 02:56:16 2008 UTC (15 years, 6 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: rel-5_1, rel-5_0, rel-6_13, rel-5_11, rel-5_12, rel-5_132, rel-5_131
Changes since 1.43: +5 -12 lines
Log Message:
*** empty log message ***

File Contents

# User Rev Content
1 root 1.1 /*
2 root 1.28 * Copyright (c) 2001-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
3 root 1.1 *
4     * Redistribution and use in source and binary forms, with or without modifica-
5     * tion, are permitted provided that the following conditions are met:
6     *
7     * 1. Redistributions of source code must retain the above copyright notice,
8     * this list of conditions and the following disclaimer.
9     *
10     * 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     *
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-
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 1.29 * 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 1.29 * 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    
41     #include "coro.h"
42    
43 root 1.38 #include <string.h>
44    
45 root 1.39 /*****************************************************************************/
46     /* ucontext/setjmp/asm backends */
47     /*****************************************************************************/
48     #if CORO_UCONTEXT || CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM
49    
50     # if CORO_UCONTEXT
51     # include <stddef.h>
52     # endif
53    
54     # if !defined(STACK_ADJUST_PTR)
55     # if __sgi
56 root 1.5 /* IRIX is decidedly NON-unix */
57 root 1.39 # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
58     # define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
59     # elif (__i386__ && CORO_LINUX) || (_M_IX86 && CORO_LOSER)
60     # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
61     # define STACK_ADJUST_SIZE(sp,ss) (ss)
62     # elif (__amd64__ && CORO_LINUX) || ((_M_AMD64 || _M_IA64) && CORO_LOSER)
63     # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
64     # define STACK_ADJUST_SIZE(sp,ss) (ss)
65     # else
66     # define STACK_ADJUST_PTR(sp,ss) (sp)
67     # define STACK_ADJUST_SIZE(sp,ss) (ss)
68     # endif
69 root 1.8 # endif
70 root 1.1
71 root 1.38 # include <stdlib.h>
72 root 1.17
73 root 1.38 # if CORO_SJLJ
74     # include <stdio.h>
75     # include <signal.h>
76     # include <unistd.h>
77     # endif
78 root 1.1
79 root 1.40 static coro_func coro_init_func;
80     static void *coro_init_arg;
81     static coro_context *new_coro, *create_coro;
82 root 1.1
83     static void
84     coro_init (void)
85     {
86     volatile coro_func func = coro_init_func;
87     volatile void *arg = coro_init_arg;
88    
89 root 1.40 coro_transfer (new_coro, create_coro);
90 root 1.1
91 root 1.3 func ((void *)arg);
92 root 1.1
93     /* the new coro returned. bad. just abort() for now */
94     abort ();
95     }
96    
97     # if CORO_SJLJ
98    
99 root 1.39 static volatile int trampoline_done;
100 root 1.1
101     /* trampoline signal handler */
102     static void
103 root 1.14 trampoline (int sig)
104 root 1.1 {
105 root 1.44 if (coro_setjmp (new_coro->env))
106     coro_init (); /* start it */
107 root 1.1 else
108 root 1.39 trampoline_done = 1;
109 root 1.1 }
110    
111     # endif
112    
113 root 1.39 # if CORO_ASM
114 root 1.38
115     asm (
116     ".text\n"
117     ".globl coro_transfer\n"
118     ".type coro_transfer, @function\n"
119     "coro_transfer:\n"
120 root 1.39 #if __amd64
121     #define NUM_SAVED 6
122     "\tpush %rbp\n"
123     "\tpush %rbx\n"
124     "\tpush %r12\n"
125     "\tpush %r13\n"
126     "\tpush %r14\n"
127     "\tpush %r15\n"
128     "\tmov %rsp, (%rdi)\n"
129     "\tmov (%rsi), %rsp\n"
130     "\tpop %r15\n"
131     "\tpop %r14\n"
132     "\tpop %r13\n"
133     "\tpop %r12\n"
134     "\tpop %rbx\n"
135     "\tpop %rbp\n"
136     #elif __i386
137     #define NUM_SAVED 4
138     "\tpush %ebp\n"
139     "\tpush %ebx\n"
140     "\tpush %esi\n"
141     "\tpush %edi\n"
142     "\tmov %esp, (%eax)\n"
143     "\tmov (%edx), %esp\n"
144     "\tpop %edi\n"
145     "\tpop %esi\n"
146     "\tpop %ebx\n"
147     "\tpop %ebp\n"
148     #else
149     #error unsupported architecture
150     #endif
151 root 1.38 "\tret\n"
152     );
153    
154 root 1.39 # endif
155 root 1.38
156     void
157     coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, long ssize)
158 root 1.1 {
159 root 1.39 coro_context nctx;
160 root 1.1 # if CORO_SJLJ
161     stack_t ostk, nstk;
162     struct sigaction osa, nsa;
163     sigset_t nsig, osig;
164     # endif
165    
166 root 1.38 if (!coro)
167     return;
168    
169 root 1.1 coro_init_func = coro;
170     coro_init_arg = arg;
171    
172     new_coro = ctx;
173     create_coro = &nctx;
174    
175     # if CORO_SJLJ
176     /* we use SIGUSR2. first block it, then fiddle with it. */
177    
178     sigemptyset (&nsig);
179     sigaddset (&nsig, SIGUSR2);
180     sigprocmask (SIG_BLOCK, &nsig, &osig);
181    
182     nsa.sa_handler = trampoline;
183     sigemptyset (&nsa.sa_mask);
184     nsa.sa_flags = SA_ONSTACK;
185    
186     if (sigaction (SIGUSR2, &nsa, &osa))
187 root 1.23 {
188     perror ("sigaction");
189     abort ();
190     }
191 root 1.1
192     /* set the new stack */
193 root 1.9 nstk.ss_sp = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
194 root 1.8 nstk.ss_size = STACK_ADJUST_SIZE (sptr,ssize);
195 root 1.1 nstk.ss_flags = 0;
196    
197     if (sigaltstack (&nstk, &ostk) < 0)
198 root 1.23 {
199     perror ("sigaltstack");
200     abort ();
201     }
202 root 1.1
203 root 1.39 trampoline_done = 0;
204 root 1.1 kill (getpid (), SIGUSR2);
205     sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
206    
207 root 1.39 while (!trampoline_done)
208 root 1.1 sigsuspend (&nsig);
209    
210     sigaltstack (0, &nstk);
211     nstk.ss_flags = SS_DISABLE;
212     if (sigaltstack (&nstk, 0) < 0)
213     perror ("sigaltstack");
214    
215     sigaltstack (0, &nstk);
216     if (~nstk.ss_flags & SS_DISABLE)
217     abort ();
218    
219     if (~ostk.ss_flags & SS_DISABLE)
220     sigaltstack (&ostk, 0);
221    
222 root 1.19 sigaction (SIGUSR2, &osa, 0);
223 root 1.1 sigprocmask (SIG_SETMASK, &osig, 0);
224    
225 root 1.16 # elif CORO_LOSER
226 root 1.1
227 root 1.44 coro_setjmp (ctx->env);
228 root 1.39 #if __CYGWIN__
229     ctx->env[7] = (long)((char *)sptr + ssize) - sizeof (long);
230     ctx->env[8] = (long)coro_init;
231     #elif defined(_M_IX86)
232     ((_JUMP_BUFFER *)&ctx->env)->Eip = (long)coro_init;
233     ((_JUMP_BUFFER *)&ctx->env)->Esp = (long)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
234     #elif defined(_M_AMD64)
235     ((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64)coro_init;
236     ((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
237     #elif defined(_M_IA64)
238     ((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64)coro_init;
239     ((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
240     #else
241     #error "microsoft libc or architecture not supported"
242     #endif
243 root 1.4
244     # elif CORO_LINUX
245    
246 root 1.44 coro_setjmp (ctx->env);
247 root 1.39 #if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
248     ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
249     ctx->env[0].__jmpbuf[JB_SP] = (long)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
250     #elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
251     ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
252     ctx->env[0].__jmpbuf[0].__sp = (int *)((char *)sptr + ssize) - sizeof (long);
253     #elif defined (__GNU_LIBRARY__) && defined (__i386__)
254     ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
255     ctx->env[0].__jmpbuf[0].__sp = (void *)((char *)sptr + ssize) - sizeof (long);
256     #elif defined (__GNU_LIBRARY__) && defined (__amd64__)
257     ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
258     ctx->env[0].__jmpbuf[0].__sp = (void *)((char *)sptr + ssize) - sizeof (long);
259     #else
260     #error "linux libc or architecture not supported"
261     #endif
262 root 1.5
263     # elif CORO_IRIX
264    
265 root 1.44 coro_setjmp (ctx->env, 0);
266 root 1.6 ctx->env[JB_PC] = (__uint64_t)coro_init;
267 root 1.36 ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize) - sizeof (long);
268 root 1.1
269 root 1.27 # elif CORO_ASM
270    
271 root 1.41 ctx->sp = (void **)(ssize + (char *)sptr);
272 root 1.37 *--ctx->sp = (void *)abort; /* needed for alignment only */
273 root 1.27 *--ctx->sp = (void *)coro_init;
274 root 1.36 ctx->sp -= NUM_SAVED;
275 root 1.27
276 root 1.39 # elif CORO_UCONTEXT
277    
278     getcontext (&(ctx->uc));
279    
280     ctx->uc.uc_link = 0;
281     ctx->uc.uc_stack.ss_sp = sptr;
282     ctx->uc.uc_stack.ss_size = (size_t)ssize;
283     ctx->uc.uc_stack.ss_flags = 0;
284    
285     makecontext (&(ctx->uc), (void (*)())coro_init, 0);
286    
287 root 1.1 # endif
288    
289 root 1.39 coro_transfer (create_coro, new_coro);
290     }
291    
292     /*****************************************************************************/
293     /* pthread backend */
294     /*****************************************************************************/
295 root 1.40 #elif CORO_PTHREAD
296 root 1.1
297 root 1.39 /* this mutex will be locked by the running coroutine */
298     pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
299 root 1.30
300 root 1.39 struct coro_init_args
301     {
302     coro_func func;
303     void *arg;
304     coro_context *self, *main;
305     };
306    
307     static pthread_t null_tid;
308    
309     /* I'd so love to cast pthread_mutex_unlock to void (*)(void *)... */
310     static void
311     mutex_unlock_wrapper (void *arg)
312     {
313     pthread_mutex_unlock ((pthread_mutex_t *)arg);
314     }
315    
316     static void *
317     coro_init (void *args_)
318     {
319     struct coro_init_args *args = (struct coro_init_args *)args_;
320     coro_func func = args->func;
321     void *arg = args->arg;
322    
323     pthread_mutex_lock (&coro_mutex);
324    
325     /* we try to be good citizens and use deferred cancellation and cleanup handlers */
326     pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
327     coro_transfer (args->self, args->main);
328     func (arg);
329     pthread_cleanup_pop (1);
330    
331     return 0;
332     }
333    
334     void
335     coro_transfer (coro_context *prev, coro_context *next)
336     {
337     pthread_cond_signal (&next->cv);
338     pthread_cond_wait (&prev->cv, &coro_mutex);
339 root 1.43 #if __FreeBSD__ /* freebsd is of course broken and needs manual testcancel calls... yay... */
340     pthread_testcancel ();
341     #endif
342 root 1.39 }
343    
344     void
345     coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, long ssize)
346     {
347 root 1.38 static coro_context nctx;
348 root 1.30 static int once;
349    
350     if (!once)
351     {
352 root 1.38 once = 1;
353    
354 root 1.30 pthread_mutex_lock (&coro_mutex);
355 root 1.38 pthread_cond_init (&nctx.cv, 0);
356     null_tid = pthread_self ();
357 root 1.30 }
358    
359 root 1.38 pthread_cond_init (&ctx->cv, 0);
360 root 1.30
361 root 1.38 if (coro)
362     {
363     pthread_attr_t attr;
364     struct coro_init_args args;
365    
366     args.func = coro;
367     args.arg = arg;
368     args.self = ctx;
369     args.main = &nctx;
370    
371     pthread_attr_init (&attr);
372     pthread_attr_setstack (&attr, sptr, (size_t)ssize);
373     pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
374 root 1.39 pthread_create (&ctx->id, &attr, coro_init, &args);
375 root 1.38
376     coro_transfer (args.main, args.self);
377     }
378     else
379     ctx->id = null_tid;
380 root 1.39 }
381    
382     void
383     coro_destroy (coro_context *ctx)
384     {
385     if (!pthread_equal (ctx->id, null_tid))
386     {
387     pthread_cancel (ctx->id);
388     pthread_mutex_unlock (&coro_mutex);
389     pthread_join (ctx->id, 0);
390     pthread_mutex_lock (&coro_mutex);
391     }
392    
393     pthread_cond_destroy (&ctx->cv);
394     }
395 root 1.30
396 root 1.40 #else
397     # error unsupported backend
398 root 1.1 #endif
399