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root/radiance/ray/src/rt/persist.c
Revision: 2.43
Committed: Fri Nov 8 18:08:07 2013 UTC (10 years, 5 months ago) by greg
Content type: text/plain
Branch: MAIN
CVS Tags: rad4R2P2, rad5R0, rad4R2, rad4R2P1
Changes since 2.42: +12 -12 lines
Log Message:
Minor fixes that should not affect operation

File Contents

# User Rev Content
1 greg 2.1 #ifndef lint
2 greg 2.43 static const char RCSid[] = "$Id: persist.c,v 2.42 2010/12/15 17:24:29 greg Exp $";
3 greg 2.1 #endif
4     /*
5     * Routines for persistent rtrace and rpict processes.
6 greg 2.26 *
7     * External symbols declared in ray.h
8     */
9    
10 greg 2.27 #include "copyright.h"
11 greg 2.1
12 schorsch 2.29 #include <string.h>
13     #include <signal.h>
14     #include <sys/stat.h>
15 schorsch 2.38 #include <sys/types.h>
16 schorsch 2.40
17     #include "platform.h"
18 schorsch 2.39 #ifndef NON_POSIX /* XXX need abstraction for process management */
19     #include <sys/wait.h>
20     #endif
21 schorsch 2.29
22 schorsch 2.30 #include "rtprocess.h" /* getpid() */
23 greg 2.1 #include "standard.h"
24 gregl 2.25 #include "random.h"
25 schorsch 2.34 #include "ray.h"
26 greg 2.6
27     #ifdef F_SETLKW
28 greg 2.1 #include "paths.h"
29 gregl 2.21 #include "selcall.h"
30 greg 2.1
31 greg 2.2 #ifndef TIMELIM
32     #define TIMELIM (8*3600) /* time limit for holding pattern */
33 greg 2.26 #endif
34    
35 greg 2.1 extern int headismine; /* boolean true if header belongs to me */
36 greg 2.12 extern char *progname; /* global program name */
37 greg 2.14 extern char *errfile; /* global error file name */
38 greg 2.1 static char *persistfname = NULL; /* persist file name */
39     static int persistfd = -1; /* persist file descriptor */
40 schorsch 2.34 static char inpname[TEMPLEN+1], outpname[TEMPLEN+1], errname[TEMPLEN+1];
41 greg 2.1
42 greg 2.42 typedef void (rsighandler_t)(int);
43     static rsighandler_t sig_io;
44     static rsighandler_t sig_alrm;
45 greg 2.1
46    
47 greg 2.43 void
48 schorsch 2.34 pfdetach(void) /* release persist (and header) resources */
49 greg 2.1 {
50     if (persistfd >= 0)
51     close(persistfd);
52     persistfd = -1;
53     persistfname = NULL;
54     inpname[0] = '\0';
55     outpname[0] = '\0';
56 greg 2.14 errname[0] = '\0';
57 greg 2.1 headismine = 0;
58     }
59    
60    
61 greg 2.43 void
62 schorsch 2.34 pfclean(void) /* clean up persist files */
63 greg 2.1 {
64     if (persistfd >= 0)
65     close(persistfd);
66     if (persistfname != NULL)
67     unlink(persistfname);
68     if (inpname[0])
69     unlink(inpname);
70     if (outpname[0])
71     unlink(outpname);
72 greg 2.14 if (errname[0])
73     unlink(errname);
74 greg 2.1 }
75    
76    
77 greg 2.43 void
78 schorsch 2.34 pflock( /* place or release exclusive lock on file */
79     int lf
80     )
81 greg 2.1 {
82     struct flock fls;
83    
84     fls.l_type = lf ? F_WRLCK : F_UNLCK;
85     fls.l_whence = 0;
86     fls.l_start = 0L;
87     fls.l_len = 0L;
88     if (fcntl(persistfd, F_SETLKW, &fls) < 0)
89     error(SYSTEM, "cannot (un)lock persist file");
90     }
91    
92    
93 greg 2.43 void
94 schorsch 2.34 persistfile( /* open persist file and lock it */
95     char *pfn
96     )
97 greg 2.1 {
98 greg 2.13 persistfd = open(pfn, O_WRONLY|O_CREAT|O_EXCL, 0644);
99 greg 2.1 if (persistfd >= 0) {
100     persistfname = pfn;
101     pflock(1);
102     return;
103     }
104     /* file exists -- switch to i/o process */
105     persistfd = open(pfn, O_RDWR);
106     if (persistfd < 0) {
107     sprintf(errmsg, "cannot open persist file \"%s\"", pfn);
108     error(SYSTEM, errmsg);
109     }
110     pflock(1);
111     io_process(); /* never returns */
112     }
113    
114    
115 greg 2.13 static int got_io;
116 greg 2.1
117 schorsch 2.34 static void sig_io(int i) { got_io++; }
118 greg 2.1
119 schorsch 2.34 static void sig_alrm(int i) { quit(0); }
120 greg 2.13
121    
122 greg 2.43 void
123 schorsch 2.34 pfhold(void) /* holding pattern for idle rendering process */
124 greg 2.1 {
125 greg 2.42 rsighandler_t *oldalrm;
126 greg 2.12 char buf[512];
127 greg 2.43 int n;
128 greg 2.1 /* close input and output descriptors */
129 greg 2.37 close(0);
130     close(1);
131 greg 2.16 if (errfile == NULL)
132 greg 2.37 close(2);
133 greg 2.1 /* create named pipes for input and output */
134 greg 2.26 if (mkfifo(mktemp(strcpy(inpname,TEMPLATE)), 0600) < 0)
135 greg 2.1 goto createrr;
136 greg 2.26 if (mkfifo(mktemp(strcpy(outpname,TEMPLATE)), 0600) < 0)
137 greg 2.1 goto createrr;
138 greg 2.14 if (errfile == NULL &&
139 greg 2.26 mkfifo(mktemp(strcpy(errname,TEMPLATE)), 0600) < 0)
140 greg 2.14 goto createrr;
141     sprintf(buf, "%s %d\n%s\n%s\n%s\n", progname, getpid(),
142     inpname, outpname, errname);
143 greg 2.1 n = strlen(buf);
144     if (write(persistfd, buf, n) < n)
145 greg 2.10 error(SYSTEM, "error writing persist file");
146 greg 2.32 lseek(persistfd, (off_t)0, SEEK_SET);
147 greg 2.2 /* wait TIMELIM for someone to signal us */
148 greg 2.13 got_io = 0;
149     signal(SIGIO, sig_io);
150 schorsch 2.34 oldalrm = signal(SIGALRM, sig_alrm);
151 greg 2.2 alarm(TIMELIM);
152 greg 2.15 pflock(0); /* unlock persist file for attach */
153 greg 2.13 while (!got_io)
154 greg 2.15 pause(); /* wait for attach */
155     alarm(0); /* turn off alarm */
156 greg 2.13 signal(SIGALRM, oldalrm);
157 greg 2.2 signal(SIGIO, SIG_DFL);
158 greg 2.17 pflock(1); /* grab persist file back */
159 greg 2.1 /* someone wants us; reopen stdin and stdout */
160 greg 2.26 close(0);
161     if (open(inpname, O_RDONLY) != 0)
162     error(INTERNAL, "unexpected stdin file number");
163     clearerr(stdin);
164     close(1);
165     if (open(outpname, O_WRONLY) != 1)
166     error(INTERNAL, "unexpected stdout file number");
167 gregl 2.22 sleep(3); /* give them a chance to open their pipes */
168 greg 2.14 if (errname[0]) {
169 greg 2.26 close(2);
170     if (open(errname, O_WRONLY) != 2)
171     error(INTERNAL, "unexpected stderr file number");
172 greg 2.14 unlink(errname);
173     errname[0] = '\0';
174     }
175 greg 2.1 unlink(inpname);
176     inpname[0] = '\0';
177     unlink(outpname);
178     outpname[0] = '\0';
179     return;
180     createrr:
181     error(SYSTEM, "cannot create named pipes in pfhold");
182     }
183    
184    
185 greg 2.43 void
186 schorsch 2.34 io_process(void) /* just act as go-between for actual process */
187 greg 2.1 {
188 greg 2.43 char *cp;
189     int nr, n;
190 greg 2.16 char buf[BUFSIZ], *pfin, *pfout, *pferr;
191     int pid, nfds;
192 gregl 2.22 int fdout, fderr = -1;
193 gregl 2.23 int status = 0;
194 gregl 2.22 fd_set readfds, excepfds;
195 greg 2.15 /* load persist file */
196 greg 2.17 n = 40;
197 greg 2.15 while ((nr = read(persistfd, buf, sizeof(buf)-1)) == 0) {
198 greg 2.17 if (!n--)
199     error(USER, "unattended persist file?");
200 greg 2.15 pflock(0);
201 gregl 2.25 sleep(3+(3*getpid()+random())%13); /* wait until ready */
202 greg 2.15 pflock(1);
203     }
204     if (nr < 0)
205 greg 2.14 error(SYSTEM, "error reading persist file");
206 schorsch 2.28 #ifndef _WIN32 /* XXX we need a replacement for that one */
207 greg 2.26 ftruncate(persistfd, (off_t)0L); /* truncate persist file */
208 schorsch 2.28 #endif
209 greg 2.17 pfdetach(); /* close & release persist file */
210     buf[nr] = '\0'; /* parse what we got */
211 schorsch 2.29 if ((cp = strchr(buf, ' ')) == NULL)
212 greg 2.1 goto formerr;
213     *cp++ = '\0';
214 greg 2.12 if ((pid = atoi(cp)) <= 0)
215 greg 2.1 goto formerr;
216 schorsch 2.29 if ((cp = strchr(cp, '\n')) == NULL)
217 greg 2.1 goto formerr;
218 greg 2.12 pfin = ++cp;
219 schorsch 2.29 if ((cp = strchr(cp, '\n')) == NULL)
220 greg 2.12 goto formerr;
221 greg 2.1 *cp++ = '\0';
222     pfout = cp;
223 schorsch 2.29 if ((cp = strchr(cp, '\n')) == NULL)
224 greg 2.1 goto formerr;
225     *cp++ = '\0';
226 greg 2.14 pferr = cp;
227 schorsch 2.29 if ((cp = strchr(cp, '\n')) == NULL)
228 greg 2.14 goto formerr;
229     *cp++ = '\0';
230 greg 2.1 if (cp-buf != nr)
231     goto formerr;
232 greg 2.12 if (strcmp(buf, progname)) {
233     sprintf(errmsg, "persist file for %s, not %s", buf, progname);
234     error(USER, errmsg);
235     }
236 greg 2.16 /* wake up rendering process */
237 greg 2.2 if (kill(pid, SIGIO) < 0)
238 greg 2.1 error(SYSTEM, "cannot signal rendering process in io_process");
239 gregl 2.22 /* fork child feeder process */
240     pid = fork();
241     if (pid < 0)
242     error(SYSTEM, "fork failed in io_process");
243     if (pid == 0) { /* feeder loop */
244     int fdin;
245     close(1); /* open input pipe */
246     if ((fdin = open(pfin, O_WRONLY)) < 0)
247     error(SYSTEM, "cannot open feed pipe in io_process");
248     /* renderer stdin */
249     while ((nr = read(0, cp=buf, sizeof(buf))) > 0) {
250     do {
251     if ((n = write(fdin, cp, nr)) <= 0)
252     goto writerr;
253     cp += n;
254     } while ((nr -= n) > 0);
255     }
256     if (nr < 0)
257     goto readerr;
258     _exit(0);
259     }
260     close(0);
261     /* open output pipes, in order */
262 greg 2.16 if ((fdout = open(pfout, O_RDONLY)) < 0)
263     error(SYSTEM, "cannot open output pipe in io_process");
264     if (pferr[0] && (fderr = open(pferr, O_RDONLY)) < 0)
265     error(SYSTEM, "cannot open error pipe in io_process");
266 gregl 2.22 for ( ; ; ) { /* eater loop */
267 greg 2.16 FD_ZERO(&readfds);
268     FD_ZERO(&excepfds);
269     nfds = 0;
270     if (fdout >= 0) {
271     FD_SET(fdout, &readfds);
272     FD_SET(fdout, &excepfds);
273     nfds = fdout+1;
274 greg 2.14 }
275 greg 2.16 if (fderr >= 0) {
276     FD_SET(fderr, &readfds);
277     FD_SET(fderr, &excepfds);
278     nfds = fderr+1;
279     }
280     if (nfds == 0)
281     break; /* all done, exit */
282 gregl 2.22 if (select(nfds, &readfds, NULL, &excepfds, NULL) < 0)
283 greg 2.16 error(SYSTEM, "error in select call in io_process");
284     /* renderer stderr */
285     if (fderr >= 0 && (FD_ISSET(fderr, &readfds) ||
286     FD_ISSET(fderr, &excepfds))) {
287     nr = read(fderr, cp=buf, sizeof(buf));
288     if (nr < 0)
289     goto readerr;
290     if (nr == 0) {
291     close(fderr);
292 greg 2.18 /* close(2); don't close stderr! */
293 greg 2.16 fderr = -1;
294 gregl 2.24 } else {
295 gregl 2.23 cp[nr] = '\0'; /* deduce status if we can */
296     n = strlen(progname);
297     if (!strncmp(cp, progname, n) &&
298     cp[n++] == ':' &&
299     cp[n++] == ' ') {
300 greg 2.43 struct erract *ep;
301 gregl 2.23 for (ep = erract; ep < erract+NERRS;
302     ep++)
303     if (ep->pre[0] &&
304     !strncmp(cp+n, ep->pre,
305     strlen(ep->pre))) {
306     status = ep->ec;
307     break;
308     }
309     }
310     do { /* write message */
311 greg 2.16 if ((n = write(2, cp, nr)) <= 0)
312     goto writerr;
313     cp += n;
314     } while ((nr -= n) > 0);
315 gregl 2.24 }
316 greg 2.16 }
317     /* renderer stdout */
318     if (fdout >= 0 && (FD_ISSET(fdout, &readfds) ||
319     FD_ISSET(fdout, &excepfds))) {
320     nr = read(fdout, cp=buf, sizeof(buf));
321     if (nr < 0)
322     goto readerr;
323     if (nr == 0) { /* EOF */
324     close(fdout);
325     close(1);
326     fdout = -1;
327     } else
328     do { /* write it all */
329     if ((n = write(1, cp, nr)) <= 0)
330     goto writerr;
331     cp += n;
332     } while ((nr -= n) > 0);
333     }
334 greg 2.1 }
335 greg 2.36 kill(pid, SIGTERM); /* no more process to feed, so... */
336 greg 2.35 waitpid(pid, 0, 0); /* wait for feeder process */
337 gregl 2.23 _exit(status);
338 greg 2.1 formerr:
339     error(USER, "format error in persist file");
340 greg 2.16 readerr:
341     error(SYSTEM, "read error in io_process");
342     writerr:
343     error(SYSTEM, "write error in io_process");
344 greg 2.1 }
345 greg 2.6
346 greg 2.8 #else
347    
348 greg 2.43 void pfclean(void) {}
349 greg 2.8
350 greg 2.6 #endif