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/cvs/libcoro/coro.c
Revision: 1.29
Committed: Sun Mar 2 16:10:22 2008 UTC (16 years, 3 months ago) by root
Content type: text/plain
Branch: MAIN
CVS Tags: rel-4_45
Changes since 1.28: +12 -4 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 /*
2 * Copyright (c) 2001-2008 Marc Alexander Lehmann <schmorp@schmorp.de>
3 *
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 * 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 * This library is modelled strictly after Ralf S. Engelschalls article at
37 * http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
38 * go to Ralf S. Engelschall <rse@engelschall.com>.
39 */
40
41 #include "coro.h"
42
43 #if !defined(STACK_ADJUST_PTR)
44 /* IRIX is decidedly NON-unix */
45 # if __sgi
46 # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
47 # define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
48 # elif __i386__ && CORO_LINUX
49 # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
50 # define STACK_ADJUST_SIZE(sp,ss) (ss)
51 # elif __amd64__ && CORO_LINUX
52 # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
53 # define STACK_ADJUST_SIZE(sp,ss) (ss)
54 # else
55 # define STACK_ADJUST_PTR(sp,ss) (sp)
56 # define STACK_ADJUST_SIZE(sp,ss) (ss)
57 # endif
58 #endif
59
60 #if CORO_UCONTEXT
61 # include <stddef.h>
62 #endif
63
64 #if CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM
65
66 #include <stdlib.h>
67
68 #if CORO_SJLJ
69 # include <stdio.h>
70 # include <signal.h>
71 # include <unistd.h>
72 #endif
73
74 static volatile coro_func coro_init_func;
75 static volatile void *coro_init_arg;
76 static volatile coro_context *new_coro, *create_coro;
77
78 /* what we really want to detect here is wether we use a new-enough version of GAS */
79 /* instead, check for gcc 3, ELF and GNU/Linux and hope for the best */
80 #if __GNUC__ >= 3 && __ELF__ && __linux__
81 # define HAVE_CFI 1
82 #endif
83
84 static void
85 coro_init (void)
86 {
87 volatile coro_func func = coro_init_func;
88 volatile void *arg = coro_init_arg;
89
90 coro_transfer ((coro_context *)new_coro, (coro_context *)create_coro);
91
92 func ((void *)arg);
93
94 /* the new coro returned. bad. just abort() for now */
95 abort ();
96 }
97
98 # if CORO_SJLJ
99
100 static volatile int trampoline_count;
101
102 /* trampoline signal handler */
103 static void
104 trampoline (int sig)
105 {
106 if (setjmp (((coro_context *)new_coro)->env))
107 {
108 #if HAVE_CFI
109 asm (".cfi_startproc");
110 #endif
111 coro_init (); /* start it */
112 #if HAVE_CFI
113 asm (".cfi_endproc");
114 #endif
115 }
116 else
117 trampoline_count++;
118 }
119
120 # endif
121
122 #endif
123
124 #if CORO_ASM
125 void __attribute__((__noinline__, __fastcall__))
126 coro_transfer (struct coro_context *prev, struct coro_context *next)
127 {
128 asm volatile (
129 #if __amd64
130 # define NUM_CLOBBERED 5
131 "push %%rbx\n\t"
132 "push %%r12\n\t"
133 "push %%r13\n\t"
134 "push %%r14\n\t"
135 "push %%r15\n\t"
136 "mov %%rsp, %0\n\t"
137 "mov %1, %%rsp\n\t"
138 "pop %%r15\n\t"
139 "pop %%r14\n\t"
140 "pop %%r13\n\t"
141 "pop %%r12\n\t"
142 "pop %%rbx\n\t"
143 #elif __i386
144 # define NUM_CLOBBERED 4
145 "push %%ebx\n\t"
146 "push %%esi\n\t"
147 "push %%edi\n\t"
148 "push %%ebp\n\t"
149 "mov %%esp, %0\n\t"
150 "mov %1, %%esp\n\t"
151 "pop %%ebp\n\t"
152 "pop %%edi\n\t"
153 "pop %%esi\n\t"
154 "pop %%ebx\n\t"
155 #else
156 # error unsupported architecture
157 #endif
158 : "=m" (prev->sp)
159 : "m" (next->sp)
160 );
161 }
162 #endif
163
164 /* initialize a machine state */
165 void coro_create (coro_context *ctx,
166 coro_func coro, void *arg,
167 void *sptr, long ssize)
168 {
169 #if CORO_UCONTEXT
170
171 getcontext (&(ctx->uc));
172
173 ctx->uc.uc_link = 0;
174 ctx->uc.uc_stack.ss_sp = STACK_ADJUST_PTR (sptr,ssize);
175 ctx->uc.uc_stack.ss_size = (size_t) STACK_ADJUST_SIZE (sptr,ssize);
176 ctx->uc.uc_stack.ss_flags = 0;
177
178 makecontext (&(ctx->uc), (void (*)()) coro, 1, arg);
179
180 #elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM
181
182 # if CORO_SJLJ
183 stack_t ostk, nstk;
184 struct sigaction osa, nsa;
185 sigset_t nsig, osig;
186 # endif
187 coro_context nctx;
188
189 coro_init_func = coro;
190 coro_init_arg = arg;
191
192 new_coro = ctx;
193 create_coro = &nctx;
194
195 # if CORO_SJLJ
196 /* we use SIGUSR2. first block it, then fiddle with it. */
197
198 sigemptyset (&nsig);
199 sigaddset (&nsig, SIGUSR2);
200 sigprocmask (SIG_BLOCK, &nsig, &osig);
201
202 nsa.sa_handler = trampoline;
203 sigemptyset (&nsa.sa_mask);
204 nsa.sa_flags = SA_ONSTACK;
205
206 if (sigaction (SIGUSR2, &nsa, &osa))
207 {
208 perror ("sigaction");
209 abort ();
210 }
211
212 /* set the new stack */
213 nstk.ss_sp = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
214 nstk.ss_size = STACK_ADJUST_SIZE (sptr,ssize);
215 nstk.ss_flags = 0;
216
217 if (sigaltstack (&nstk, &ostk) < 0)
218 {
219 perror ("sigaltstack");
220 abort ();
221 }
222
223 trampoline_count = 0;
224 kill (getpid (), SIGUSR2);
225 sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
226
227 while (!trampoline_count)
228 sigsuspend (&nsig);
229
230 sigaltstack (0, &nstk);
231 nstk.ss_flags = SS_DISABLE;
232 if (sigaltstack (&nstk, 0) < 0)
233 perror ("sigaltstack");
234
235 sigaltstack (0, &nstk);
236 if (~nstk.ss_flags & SS_DISABLE)
237 abort ();
238
239 if (~ostk.ss_flags & SS_DISABLE)
240 sigaltstack (&ostk, 0);
241
242 sigaction (SIGUSR2, &osa, 0);
243
244 sigprocmask (SIG_SETMASK, &osig, 0);
245
246 # elif CORO_LOSER
247
248 setjmp (ctx->env);
249 #if __CYGWIN__
250 ctx->env[7] = (long)((char *)sptr + ssize);
251 ctx->env[8] = (long)coro_init;
252 #elif defined(_M_IX86)
253 ((_JUMP_BUFFER *)&ctx->env)->Eip = (long)coro_init;
254 ((_JUMP_BUFFER *)&ctx->env)->Esp = (long)STACK_ADJUST_PTR (sptr,ssize);
255 #elif defined(_M_AMD64)
256 ((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64)coro_init;
257 ((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64)STACK_ADJUST_PTR (sptr,ssize);
258 #elif defined(_M_IA64)
259 ((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64)coro_init;
260 ((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64)STACK_ADJUST_PTR (sptr,ssize);
261 #else
262 #error "microsoft libc or architecture not supported"
263 #endif
264
265 # elif CORO_LINUX
266
267 _setjmp (ctx->env);
268 #if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
269 ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
270 ctx->env[0].__jmpbuf[JB_SP] = (long)STACK_ADJUST_PTR (sptr, ssize);
271 #elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
272 ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
273 ctx->env[0].__jmpbuf[0].__sp = (int *)((char *)sptr + ssize);
274 #elif defined (__GNU_LIBRARY__) && defined (__i386__)
275 ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
276 ctx->env[0].__jmpbuf[0].__sp = (void *)((char *)sptr + ssize);
277 #elif defined (__GNU_LIBRARY__) && defined (__amd64__)
278 ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
279 ctx->env[0].__jmpbuf[JB_RSP] = (long)STACK_ADJUST_PTR (sptr, ssize);
280 #else
281 # error "linux libc or architecture not supported"
282 #endif
283
284 # elif CORO_IRIX
285
286 setjmp (ctx->env);
287 ctx->env[JB_PC] = (__uint64_t)coro_init;
288 ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize);
289
290 # elif CORO_ASM
291
292 ctx->sp = (volatile void **)(ssize + (char *)sptr);
293 *--ctx->sp = (void *)coro_init;
294 *--ctx->sp = (void *)coro_init; // this is needed when the prologue saves ebp
295 ctx->sp -= NUM_CLOBBERED;
296
297 # endif
298
299 coro_transfer ((coro_context *)create_coro, (coro_context *)new_coro);
300
301 #else
302 # error unsupported architecture
303 #endif
304 }
305