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root/radiance/ray/src/rt/persist.c
Revision: 2.19
Committed: Thu Sep 18 16:13:28 1997 UTC (26 years, 7 months ago) by gregl
Content type: text/plain
Branch: MAIN
Changes since 2.18: +1 -0 lines
Log Message:
added include of sys/select.h for AIX machines

File Contents

# Content
1 /* Copyright (c) 1996 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * Routines for persistent rtrace and rpict processes.
9 */
10
11 #include "standard.h"
12
13 #ifdef F_SETLKW
14 #include "paths.h"
15 #include <signal.h>
16 #include <sys/types.h>
17 #include <sys/select.h>
18 #include <sys/stat.h>
19 /* select call compatibility stuff */
20 #ifndef FD_SETSIZE
21 #include <sys/param.h>
22 #define FD_SETSIZE NOFILE /* maximum # select file descriptors */
23 #endif
24 #ifndef FD_SET
25 #ifndef NFDBITS
26 #define NFDBITS (8*sizeof(int)) /* number of bits per fd_mask */
27 #endif
28 #define FD_SET(n, p) ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
29 #define FD_CLR(n, p) ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
30 #define FD_ISSET(n, p) ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
31 #define FD_ZERO(p) bzero((char *)(p), sizeof(*(p)))
32 #endif
33
34 #ifndef TIMELIM
35 #define TIMELIM (8*3600) /* time limit for holding pattern */
36 #endif
37
38 extern char *strcpy(), *index();
39
40 extern int headismine; /* boolean true if header belongs to me */
41
42 extern char *progname; /* global program name */
43
44 extern char *errfile; /* global error file name */
45
46 static char *persistfname = NULL; /* persist file name */
47 static int persistfd = -1; /* persist file descriptor */
48
49 static char inpname[TEMPLEN+1], outpname[TEMPLEN+1], errname[TEMPLEN+1];
50
51
52 pfdetach() /* release persist (and header) resources */
53 {
54 if (persistfd >= 0)
55 close(persistfd);
56 persistfd = -1;
57 persistfname = NULL;
58 inpname[0] = '\0';
59 outpname[0] = '\0';
60 errname[0] = '\0';
61 headismine = 0;
62 }
63
64
65 pfclean() /* clean up persist files */
66 {
67 if (persistfd >= 0)
68 close(persistfd);
69 if (persistfname != NULL)
70 unlink(persistfname);
71 if (inpname[0])
72 unlink(inpname);
73 if (outpname[0])
74 unlink(outpname);
75 if (errname[0])
76 unlink(errname);
77 }
78
79
80 pflock(lf) /* place or release exclusive lock on file */
81 int lf;
82 {
83 struct flock fls;
84
85 fls.l_type = lf ? F_WRLCK : F_UNLCK;
86 fls.l_whence = 0;
87 fls.l_start = 0L;
88 fls.l_len = 0L;
89 if (fcntl(persistfd, F_SETLKW, &fls) < 0)
90 error(SYSTEM, "cannot (un)lock persist file");
91 }
92
93
94 persistfile(pfn) /* open persist file and lock it */
95 char *pfn;
96 {
97 persistfd = open(pfn, O_WRONLY|O_CREAT|O_EXCL, 0644);
98 if (persistfd >= 0) {
99 persistfname = pfn;
100 pflock(1);
101 return;
102 }
103 /* file exists -- switch to i/o process */
104 persistfd = open(pfn, O_RDWR);
105 if (persistfd < 0) {
106 sprintf(errmsg, "cannot open persist file \"%s\"", pfn);
107 error(SYSTEM, errmsg);
108 }
109 pflock(1);
110 io_process(); /* never returns */
111 }
112
113
114 static int got_io;
115
116 static int sig_io() { got_io++; }
117
118 static int sig_alrm() { quit(0); }
119
120
121 pfhold() /* holding pattern for idle rendering process */
122 {
123 int (*oldalrm)();
124 char buf[512];
125 register int n;
126 /* close input and output descriptors */
127 close(fileno(stdin));
128 close(fileno(stdout));
129 if (errfile == NULL)
130 close(fileno(stderr));
131 /* create named pipes for input and output */
132 if (mknod(mktemp(strcpy(inpname,TEMPLATE)), S_IFIFO|0600, 0) < 0)
133 goto createrr;
134 if (mknod(mktemp(strcpy(outpname,TEMPLATE)), S_IFIFO|0600, 0) < 0)
135 goto createrr;
136 if (errfile == NULL &&
137 mknod(mktemp(strcpy(errname,TEMPLATE)), S_IFIFO|0600, 0) < 0)
138 goto createrr;
139 sprintf(buf, "%s %d\n%s\n%s\n%s\n", progname, getpid(),
140 inpname, outpname, errname);
141 n = strlen(buf);
142 if (write(persistfd, buf, n) < n)
143 error(SYSTEM, "error writing persist file");
144 lseek(persistfd, 0L, 0);
145 /* wait TIMELIM for someone to signal us */
146 got_io = 0;
147 signal(SIGIO, sig_io);
148 oldalrm = (int (*)())signal(SIGALRM, sig_alrm);
149 alarm(TIMELIM);
150 pflock(0); /* unlock persist file for attach */
151 while (!got_io)
152 pause(); /* wait for attach */
153 alarm(0); /* turn off alarm */
154 signal(SIGALRM, oldalrm);
155 signal(SIGIO, SIG_DFL);
156 pflock(1); /* grab persist file back */
157 /* someone wants us; reopen stdin and stdout */
158 if (freopen(inpname, "r", stdin) == NULL)
159 goto openerr;
160 if (freopen(outpname, "w", stdout) == NULL)
161 goto openerr;
162 if (errname[0]) {
163 if (freopen(errname, "w", stderr) == NULL)
164 goto openerr;
165 unlink(errname);
166 errname[0] = '\0';
167 }
168 unlink(inpname);
169 inpname[0] = '\0';
170 unlink(outpname);
171 outpname[0] = '\0';
172 return;
173 createrr:
174 error(SYSTEM, "cannot create named pipes in pfhold");
175 openerr:
176 error(SYSTEM, "cannot open named pipes in pfhold");
177 }
178
179
180 io_process() /* just act as go-between for actual process */
181 {
182 register char *cp;
183 register int nr, n;
184 char buf[BUFSIZ], *pfin, *pfout, *pferr;
185 int pid, nfds;
186 int fdin, fdout, fderr = -1;
187 fd_set readfds, writefds, excepfds;
188 /* load persist file */
189 n = 40;
190 while ((nr = read(persistfd, buf, sizeof(buf)-1)) == 0) {
191 if (!n--)
192 error(USER, "unattended persist file?");
193 pflock(0);
194 sleep(15); /* wait until ready */
195 pflock(1);
196 }
197 if (nr < 0)
198 error(SYSTEM, "error reading persist file");
199 ftruncate(persistfd, 0L); /* truncate persist file */
200 pfdetach(); /* close & release persist file */
201 buf[nr] = '\0'; /* parse what we got */
202 if ((cp = index(buf, ' ')) == NULL)
203 goto formerr;
204 *cp++ = '\0';
205 if ((pid = atoi(cp)) <= 0)
206 goto formerr;
207 if ((cp = index(cp, '\n')) == NULL)
208 goto formerr;
209 pfin = ++cp;
210 if ((cp = index(cp, '\n')) == NULL)
211 goto formerr;
212 *cp++ = '\0';
213 pfout = cp;
214 if ((cp = index(cp, '\n')) == NULL)
215 goto formerr;
216 *cp++ = '\0';
217 pferr = cp;
218 if ((cp = index(cp, '\n')) == NULL)
219 goto formerr;
220 *cp++ = '\0';
221 if (cp-buf != nr)
222 goto formerr;
223 if (strcmp(buf, progname)) {
224 sprintf(errmsg, "persist file for %s, not %s", buf, progname);
225 error(USER, errmsg);
226 }
227 /* wake up rendering process */
228 if (kill(pid, SIGIO) < 0)
229 error(SYSTEM, "cannot signal rendering process in io_process");
230 /* open named pipes, in order */
231 if ((fdin = open(pfin, O_WRONLY)) < 0)
232 error(SYSTEM, "cannot open input pipe in io_process");
233 if ((fdout = open(pfout, O_RDONLY)) < 0)
234 error(SYSTEM, "cannot open output pipe in io_process");
235 if (pferr[0] && (fderr = open(pferr, O_RDONLY)) < 0)
236 error(SYSTEM, "cannot open error pipe in io_process");
237 for ( ; ; ) { /* loop on select call */
238 FD_ZERO(&readfds);
239 FD_ZERO(&writefds);
240 FD_ZERO(&excepfds);
241 nfds = 0;
242 if (fdin >= 0) {
243 FD_SET(fdin, &writefds);
244 FD_SET(fdin, &excepfds);
245 nfds = fdin+1;
246 }
247 if (fdout >= 0) {
248 FD_SET(fdout, &readfds);
249 FD_SET(fdout, &excepfds);
250 nfds = fdout+1;
251 }
252 if (fderr >= 0) {
253 FD_SET(fderr, &readfds);
254 FD_SET(fderr, &excepfds);
255 nfds = fderr+1;
256 }
257 if (nfds == 0)
258 break; /* all done, exit */
259 if (select(nfds, &readfds, &writefds, &excepfds, NULL) < 0)
260 error(SYSTEM, "error in select call in io_process");
261 /* renderer stderr */
262 if (fderr >= 0 && (FD_ISSET(fderr, &readfds) ||
263 FD_ISSET(fderr, &excepfds))) {
264 nr = read(fderr, cp=buf, sizeof(buf));
265 if (nr < 0)
266 goto readerr;
267 if (nr == 0) {
268 close(fderr);
269 /* close(2); don't close stderr! */
270 fderr = -1;
271 } else
272 do { /* write it all */
273 if ((n = write(2, cp, nr)) <= 0)
274 goto writerr;
275 cp += n;
276 } while ((nr -= n) > 0);
277 }
278 /* renderer stdout */
279 if (fdout >= 0 && (FD_ISSET(fdout, &readfds) ||
280 FD_ISSET(fdout, &excepfds))) {
281 nr = read(fdout, cp=buf, sizeof(buf));
282 if (nr < 0)
283 goto readerr;
284 if (nr == 0) { /* EOF */
285 close(fdout);
286 close(1);
287 fdout = -1;
288 } else
289 do { /* write it all */
290 if ((n = write(1, cp, nr)) <= 0)
291 goto writerr;
292 cp += n;
293 } while ((nr -= n) > 0);
294 }
295 /* renderer stdin */
296 if (fdin >= 0 && (FD_ISSET(fdin, &writefds) ||
297 FD_ISSET(fdin, &excepfds))) {
298 nr = read(0, buf, 512); /* use minimal buffer */
299 if (nr < 0)
300 goto readerr;
301 if (nr == 0) {
302 close(0);
303 close(fdin);
304 fdin = -1;
305 } else if (write(fdin, buf, nr) < nr)
306 goto writerr; /* what else to do? */
307 }
308 }
309 _exit(0); /* we ought to return renderer error status! */
310 formerr:
311 error(USER, "format error in persist file");
312 readerr:
313 error(SYSTEM, "read error in io_process");
314 writerr:
315 error(SYSTEM, "write error in io_process");
316 }
317
318 #else
319
320 pfclean() {}
321
322 #endif