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/cvs/libcoro/coro.c
Revision: 1.25
Committed: Fri Apr 27 19:26:18 2007 UTC (17 years, 1 month ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.24: +12 -0 lines
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File Contents

# Content
1 /*
2 * Copyright (c) 2001-2006 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 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26 * OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * This library is modelled strictly after Ralf S. Engelschalls article at
29 * http://www.gnu.org/software/pth/rse-pmt.ps. So most of the credit must
30 * go to Ralf S. Engelschall <rse@engelschall.com>.
31 */
32
33 #include "coro.h"
34
35 #if !defined(STACK_ADJUST_PTR)
36 /* IRIX is decidedly NON-unix */
37 # if __sgi
38 # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
39 # define STACK_ADJUST_SIZE(sp,ss) ((ss) - 8)
40 # elif __i386__ && CORO_LINUX
41 # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss))
42 # define STACK_ADJUST_SIZE(sp,ss) (ss)
43 # elif __amd64__ && CORO_LINUX
44 # define STACK_ADJUST_PTR(sp,ss) ((char *)(sp) + (ss) - 8)
45 # define STACK_ADJUST_SIZE(sp,ss) (ss)
46 # else
47 # define STACK_ADJUST_PTR(sp,ss) (sp)
48 # define STACK_ADJUST_SIZE(sp,ss) (ss)
49 # endif
50 #endif
51
52 #if CORO_UCONTEXT
53 # include <stddef.h>
54 #endif
55
56 #if CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
57
58 #include <stdlib.h>
59
60 #if CORO_SJLJ
61 # include <stdio.h>
62 # include <signal.h>
63 # include <unistd.h>
64 #endif
65
66 static volatile coro_func coro_init_func;
67 static volatile void *coro_init_arg;
68 static volatile coro_context *new_coro, *create_coro;
69
70 /* what we really want to detect here is wether we use a new-enough version of GAS */
71 /* instead, check for gcc 3 and ELF and hope for the best */
72 #if __GNUC__ >= 3 && __ELF__
73 # define HAVE_CFI 1
74 #endif
75
76 static void
77 coro_init (void)
78 {
79 volatile coro_func func = coro_init_func;
80 volatile void *arg = coro_init_arg;
81
82 coro_transfer ((coro_context *)new_coro, (coro_context *)create_coro);
83
84 #if HAVE_CFI
85 asm (".cfi_startproc");
86 #endif
87 func ((void *)arg);
88 #if HAVE_CFI
89 asm (".cfi_endproc");
90 #endif
91
92 /* the new coro returned. bad. just abort() for now */
93 abort ();
94 }
95
96 # if CORO_SJLJ
97
98 static volatile int trampoline_count;
99
100 /* trampoline signal handler */
101 static void
102 trampoline (int sig)
103 {
104 if (setjmp (((coro_context *)new_coro)->env))
105 coro_init (); /* start it */
106 else
107 trampoline_count++;
108 }
109
110 # endif
111
112 #endif
113
114 /* initialize a machine state */
115 void coro_create (coro_context *ctx,
116 coro_func coro, void *arg,
117 void *sptr, long ssize)
118 {
119 #if CORO_UCONTEXT
120
121 getcontext (&(ctx->uc));
122
123 ctx->uc.uc_link = 0;
124 ctx->uc.uc_stack.ss_sp = STACK_ADJUST_PTR (sptr,ssize);
125 ctx->uc.uc_stack.ss_size = (size_t) STACK_ADJUST_SIZE (sptr,ssize);
126 ctx->uc.uc_stack.ss_flags = 0;
127
128 makecontext (&(ctx->uc), (void (*)()) coro, 1, arg);
129
130 #elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
131
132 # if CORO_SJLJ
133 stack_t ostk, nstk;
134 struct sigaction osa, nsa;
135 sigset_t nsig, osig;
136 # endif
137 coro_context nctx;
138
139 coro_init_func = coro;
140 coro_init_arg = arg;
141
142 new_coro = ctx;
143 create_coro = &nctx;
144
145 # if CORO_SJLJ
146 /* we use SIGUSR2. first block it, then fiddle with it. */
147
148 sigemptyset (&nsig);
149 sigaddset (&nsig, SIGUSR2);
150 sigprocmask (SIG_BLOCK, &nsig, &osig);
151
152 nsa.sa_handler = trampoline;
153 sigemptyset (&nsa.sa_mask);
154 nsa.sa_flags = SA_ONSTACK;
155
156 if (sigaction (SIGUSR2, &nsa, &osa))
157 {
158 perror ("sigaction");
159 abort ();
160 }
161
162 /* set the new stack */
163 nstk.ss_sp = STACK_ADJUST_PTR (sptr,ssize); /* yes, some platforms (IRIX) get this wrong. */
164 nstk.ss_size = STACK_ADJUST_SIZE (sptr,ssize);
165 nstk.ss_flags = 0;
166
167 if (sigaltstack (&nstk, &ostk) < 0)
168 {
169 perror ("sigaltstack");
170 abort ();
171 }
172
173 trampoline_count = 0;
174 kill (getpid (), SIGUSR2);
175 sigfillset (&nsig); sigdelset (&nsig, SIGUSR2);
176
177 while (!trampoline_count)
178 sigsuspend (&nsig);
179
180 sigaltstack (0, &nstk);
181 nstk.ss_flags = SS_DISABLE;
182 if (sigaltstack (&nstk, 0) < 0)
183 perror ("sigaltstack");
184
185 sigaltstack (0, &nstk);
186 if (~nstk.ss_flags & SS_DISABLE)
187 abort ();
188
189 if (~ostk.ss_flags & SS_DISABLE)
190 sigaltstack (&ostk, 0);
191
192 sigaction (SIGUSR2, &osa, 0);
193
194 sigprocmask (SIG_SETMASK, &osig, 0);
195
196 # elif CORO_LOSER
197
198 setjmp (ctx->env);
199 #if __CYGWIN__
200 ctx->env[7] = (long)((char *)sptr + ssize);
201 ctx->env[8] = (long)coro_init;
202 #elif defined(_M_IX86)
203 ((_JUMP_BUFFER *)&ctx->env)->Eip = (long)coro_init;
204 ((_JUMP_BUFFER *)&ctx->env)->Esp = (long)STACK_ADJUST_PTR (sptr,ssize);
205 #elif defined(_M_AMD64)
206 ((_JUMP_BUFFER *)&ctx->env)->Rip = (__int64)coro_init;
207 ((_JUMP_BUFFER *)&ctx->env)->Rsp = (__int64)STACK_ADJUST_PTR (sptr,ssize);
208 #elif defined(_M_IA64)
209 ((_JUMP_BUFFER *)&ctx->env)->StIIP = (__int64)coro_init;
210 ((_JUMP_BUFFER *)&ctx->env)->IntSp = (__int64)STACK_ADJUST_PTR (sptr,ssize);
211 #else
212 #error "microsoft libc or architecture not supported"
213 #endif
214
215 # elif CORO_LINUX
216
217 _setjmp (ctx->env);
218 #if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (JB_PC) && defined (JB_SP)
219 ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
220 ctx->env[0].__jmpbuf[JB_SP] = (long)STACK_ADJUST_PTR (sptr, ssize);
221 #elif __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 0 && defined (__mc68000__)
222 ctx->env[0].__jmpbuf[0].__aregs[0] = (long int)coro_init;
223 ctx->env[0].__jmpbuf[0].__sp = (int *)((char *)sptr + ssize);
224 #elif defined (__GNU_LIBRARY__) && defined (__i386__)
225 ctx->env[0].__jmpbuf[0].__pc = (char *)coro_init;
226 ctx->env[0].__jmpbuf[0].__sp = (void *)((char *)sptr + ssize);
227 #elif defined (__GNU_LIBRARY__) && defined (__amd64__)
228 ctx->env[0].__jmpbuf[JB_PC] = (long)coro_init;
229 ctx->env[0].__jmpbuf[JB_RSP] = (long)STACK_ADJUST_PTR (sptr, ssize);
230 #else
231 #error "linux libc or architecture not supported"
232 #endif
233
234 # elif CORO_IRIX
235
236 setjmp (ctx->env);
237 ctx->env[JB_PC] = (__uint64_t)coro_init;
238 ctx->env[JB_SP] = (__uint64_t)STACK_ADJUST_PTR (sptr, ssize);
239
240 # endif
241
242 coro_transfer ((coro_context *)create_coro, (coro_context *)new_coro);
243
244 #else
245 error unsupported architecture
246 #endif
247 }
248