1 |
/* Copyright (c) 1997 Silicon Graphics, Inc. */ |
2 |
|
3 |
#ifndef lint |
4 |
static char SCCSid[] = "$SunId$ SGI"; |
5 |
#endif |
6 |
|
7 |
/* |
8 |
* Routines for persistent rtrace and rpict processes. |
9 |
*/ |
10 |
|
11 |
#include "standard.h" |
12 |
#include "random.h" |
13 |
|
14 |
#ifdef F_SETLKW |
15 |
#include "paths.h" |
16 |
#include "selcall.h" |
17 |
#include <signal.h> |
18 |
#include <sys/stat.h> |
19 |
|
20 |
#ifndef TIMELIM |
21 |
#define TIMELIM (8*3600) /* time limit for holding pattern */ |
22 |
#endif |
23 |
|
24 |
extern char *strcpy(), *index(); |
25 |
|
26 |
extern int headismine; /* boolean true if header belongs to me */ |
27 |
|
28 |
extern char *progname; /* global program name */ |
29 |
|
30 |
extern char *errfile; /* global error file name */ |
31 |
|
32 |
static char *persistfname = NULL; /* persist file name */ |
33 |
static int persistfd = -1; /* persist file descriptor */ |
34 |
|
35 |
static char inpname[TEMPLEN+1], outpname[TEMPLEN+1], errname[TEMPLEN+1]; |
36 |
|
37 |
|
38 |
pfdetach() /* release persist (and header) resources */ |
39 |
{ |
40 |
if (persistfd >= 0) |
41 |
close(persistfd); |
42 |
persistfd = -1; |
43 |
persistfname = NULL; |
44 |
inpname[0] = '\0'; |
45 |
outpname[0] = '\0'; |
46 |
errname[0] = '\0'; |
47 |
headismine = 0; |
48 |
} |
49 |
|
50 |
|
51 |
pfclean() /* clean up persist files */ |
52 |
{ |
53 |
if (persistfd >= 0) |
54 |
close(persistfd); |
55 |
if (persistfname != NULL) |
56 |
unlink(persistfname); |
57 |
if (inpname[0]) |
58 |
unlink(inpname); |
59 |
if (outpname[0]) |
60 |
unlink(outpname); |
61 |
if (errname[0]) |
62 |
unlink(errname); |
63 |
} |
64 |
|
65 |
|
66 |
pflock(lf) /* place or release exclusive lock on file */ |
67 |
int lf; |
68 |
{ |
69 |
struct flock fls; |
70 |
|
71 |
fls.l_type = lf ? F_WRLCK : F_UNLCK; |
72 |
fls.l_whence = 0; |
73 |
fls.l_start = 0L; |
74 |
fls.l_len = 0L; |
75 |
if (fcntl(persistfd, F_SETLKW, &fls) < 0) |
76 |
error(SYSTEM, "cannot (un)lock persist file"); |
77 |
} |
78 |
|
79 |
|
80 |
persistfile(pfn) /* open persist file and lock it */ |
81 |
char *pfn; |
82 |
{ |
83 |
persistfd = open(pfn, O_WRONLY|O_CREAT|O_EXCL, 0644); |
84 |
if (persistfd >= 0) { |
85 |
persistfname = pfn; |
86 |
pflock(1); |
87 |
return; |
88 |
} |
89 |
/* file exists -- switch to i/o process */ |
90 |
persistfd = open(pfn, O_RDWR); |
91 |
if (persistfd < 0) { |
92 |
sprintf(errmsg, "cannot open persist file \"%s\"", pfn); |
93 |
error(SYSTEM, errmsg); |
94 |
} |
95 |
pflock(1); |
96 |
io_process(); /* never returns */ |
97 |
} |
98 |
|
99 |
|
100 |
static int got_io; |
101 |
|
102 |
static int sig_io() { got_io++; } |
103 |
|
104 |
static int sig_alrm() { quit(0); } |
105 |
|
106 |
|
107 |
pfhold() /* holding pattern for idle rendering process */ |
108 |
{ |
109 |
int (*oldalrm)(); |
110 |
char buf[512]; |
111 |
register int n; |
112 |
/* close input and output descriptors */ |
113 |
close(fileno(stdin)); |
114 |
close(fileno(stdout)); |
115 |
if (errfile == NULL) |
116 |
close(fileno(stderr)); |
117 |
/* create named pipes for input and output */ |
118 |
if (mknod(mktemp(strcpy(inpname,TEMPLATE)), S_IFIFO|0600, 0) < 0) |
119 |
goto createrr; |
120 |
if (mknod(mktemp(strcpy(outpname,TEMPLATE)), S_IFIFO|0600, 0) < 0) |
121 |
goto createrr; |
122 |
if (errfile == NULL && |
123 |
mknod(mktemp(strcpy(errname,TEMPLATE)), S_IFIFO|0600, 0) < 0) |
124 |
goto createrr; |
125 |
sprintf(buf, "%s %d\n%s\n%s\n%s\n", progname, getpid(), |
126 |
inpname, outpname, errname); |
127 |
n = strlen(buf); |
128 |
if (write(persistfd, buf, n) < n) |
129 |
error(SYSTEM, "error writing persist file"); |
130 |
lseek(persistfd, 0L, 0); |
131 |
/* wait TIMELIM for someone to signal us */ |
132 |
got_io = 0; |
133 |
signal(SIGIO, sig_io); |
134 |
oldalrm = (int (*)())signal(SIGALRM, sig_alrm); |
135 |
alarm(TIMELIM); |
136 |
pflock(0); /* unlock persist file for attach */ |
137 |
while (!got_io) |
138 |
pause(); /* wait for attach */ |
139 |
alarm(0); /* turn off alarm */ |
140 |
signal(SIGALRM, oldalrm); |
141 |
signal(SIGIO, SIG_DFL); |
142 |
pflock(1); /* grab persist file back */ |
143 |
/* someone wants us; reopen stdin and stdout */ |
144 |
if (freopen(inpname, "r", stdin) == NULL) |
145 |
goto openerr; |
146 |
if (freopen(outpname, "w", stdout) == NULL) |
147 |
goto openerr; |
148 |
sleep(3); /* give them a chance to open their pipes */ |
149 |
if (errname[0]) { |
150 |
if (freopen(errname, "w", stderr) == NULL) |
151 |
goto openerr; |
152 |
unlink(errname); |
153 |
errname[0] = '\0'; |
154 |
} |
155 |
unlink(inpname); |
156 |
inpname[0] = '\0'; |
157 |
unlink(outpname); |
158 |
outpname[0] = '\0'; |
159 |
return; |
160 |
createrr: |
161 |
error(SYSTEM, "cannot create named pipes in pfhold"); |
162 |
openerr: |
163 |
error(SYSTEM, "cannot open named pipes in pfhold"); |
164 |
} |
165 |
|
166 |
|
167 |
io_process() /* just act as go-between for actual process */ |
168 |
{ |
169 |
register char *cp; |
170 |
register int nr, n; |
171 |
char buf[BUFSIZ], *pfin, *pfout, *pferr; |
172 |
int pid, nfds; |
173 |
int fdout, fderr = -1; |
174 |
int status = 0; |
175 |
fd_set readfds, excepfds; |
176 |
/* load persist file */ |
177 |
n = 40; |
178 |
while ((nr = read(persistfd, buf, sizeof(buf)-1)) == 0) { |
179 |
if (!n--) |
180 |
error(USER, "unattended persist file?"); |
181 |
pflock(0); |
182 |
sleep(3+(3*getpid()+random())%13); /* wait until ready */ |
183 |
pflock(1); |
184 |
} |
185 |
if (nr < 0) |
186 |
error(SYSTEM, "error reading persist file"); |
187 |
ftruncate(persistfd, 0L); /* truncate persist file */ |
188 |
pfdetach(); /* close & release persist file */ |
189 |
buf[nr] = '\0'; /* parse what we got */ |
190 |
if ((cp = index(buf, ' ')) == NULL) |
191 |
goto formerr; |
192 |
*cp++ = '\0'; |
193 |
if ((pid = atoi(cp)) <= 0) |
194 |
goto formerr; |
195 |
if ((cp = index(cp, '\n')) == NULL) |
196 |
goto formerr; |
197 |
pfin = ++cp; |
198 |
if ((cp = index(cp, '\n')) == NULL) |
199 |
goto formerr; |
200 |
*cp++ = '\0'; |
201 |
pfout = cp; |
202 |
if ((cp = index(cp, '\n')) == NULL) |
203 |
goto formerr; |
204 |
*cp++ = '\0'; |
205 |
pferr = cp; |
206 |
if ((cp = index(cp, '\n')) == NULL) |
207 |
goto formerr; |
208 |
*cp++ = '\0'; |
209 |
if (cp-buf != nr) |
210 |
goto formerr; |
211 |
if (strcmp(buf, progname)) { |
212 |
sprintf(errmsg, "persist file for %s, not %s", buf, progname); |
213 |
error(USER, errmsg); |
214 |
} |
215 |
/* wake up rendering process */ |
216 |
if (kill(pid, SIGIO) < 0) |
217 |
error(SYSTEM, "cannot signal rendering process in io_process"); |
218 |
/* fork child feeder process */ |
219 |
pid = fork(); |
220 |
if (pid < 0) |
221 |
error(SYSTEM, "fork failed in io_process"); |
222 |
if (pid == 0) { /* feeder loop */ |
223 |
int fdin; |
224 |
close(1); /* open input pipe */ |
225 |
if ((fdin = open(pfin, O_WRONLY)) < 0) |
226 |
error(SYSTEM, "cannot open feed pipe in io_process"); |
227 |
/* renderer stdin */ |
228 |
while ((nr = read(0, cp=buf, sizeof(buf))) > 0) { |
229 |
do { |
230 |
if ((n = write(fdin, cp, nr)) <= 0) |
231 |
goto writerr; |
232 |
cp += n; |
233 |
} while ((nr -= n) > 0); |
234 |
} |
235 |
if (nr < 0) |
236 |
goto readerr; |
237 |
_exit(0); |
238 |
} |
239 |
close(0); |
240 |
/* open output pipes, in order */ |
241 |
if ((fdout = open(pfout, O_RDONLY)) < 0) |
242 |
error(SYSTEM, "cannot open output pipe in io_process"); |
243 |
if (pferr[0] && (fderr = open(pferr, O_RDONLY)) < 0) |
244 |
error(SYSTEM, "cannot open error pipe in io_process"); |
245 |
for ( ; ; ) { /* eater loop */ |
246 |
FD_ZERO(&readfds); |
247 |
FD_ZERO(&excepfds); |
248 |
nfds = 0; |
249 |
if (fdout >= 0) { |
250 |
FD_SET(fdout, &readfds); |
251 |
FD_SET(fdout, &excepfds); |
252 |
nfds = fdout+1; |
253 |
} |
254 |
if (fderr >= 0) { |
255 |
FD_SET(fderr, &readfds); |
256 |
FD_SET(fderr, &excepfds); |
257 |
nfds = fderr+1; |
258 |
} |
259 |
if (nfds == 0) |
260 |
break; /* all done, exit */ |
261 |
if (select(nfds, &readfds, NULL, &excepfds, NULL) < 0) |
262 |
error(SYSTEM, "error in select call in io_process"); |
263 |
/* renderer stderr */ |
264 |
if (fderr >= 0 && (FD_ISSET(fderr, &readfds) || |
265 |
FD_ISSET(fderr, &excepfds))) { |
266 |
nr = read(fderr, cp=buf, sizeof(buf)); |
267 |
if (nr < 0) |
268 |
goto readerr; |
269 |
if (nr == 0) { |
270 |
close(fderr); |
271 |
/* close(2); don't close stderr! */ |
272 |
fderr = -1; |
273 |
} else { |
274 |
cp[nr] = '\0'; /* deduce status if we can */ |
275 |
n = strlen(progname); |
276 |
if (!strncmp(cp, progname, n) && |
277 |
cp[n++] == ':' && |
278 |
cp[n++] == ' ') { |
279 |
register struct erract *ep; |
280 |
for (ep = erract; ep < erract+NERRS; |
281 |
ep++) |
282 |
if (ep->pre[0] && |
283 |
!strncmp(cp+n, ep->pre, |
284 |
strlen(ep->pre))) { |
285 |
status = ep->ec; |
286 |
break; |
287 |
} |
288 |
} |
289 |
do { /* write message */ |
290 |
if ((n = write(2, cp, nr)) <= 0) |
291 |
goto writerr; |
292 |
cp += n; |
293 |
} while ((nr -= n) > 0); |
294 |
} |
295 |
} |
296 |
/* renderer stdout */ |
297 |
if (fdout >= 0 && (FD_ISSET(fdout, &readfds) || |
298 |
FD_ISSET(fdout, &excepfds))) { |
299 |
nr = read(fdout, cp=buf, sizeof(buf)); |
300 |
if (nr < 0) |
301 |
goto readerr; |
302 |
if (nr == 0) { /* EOF */ |
303 |
close(fdout); |
304 |
close(1); |
305 |
fdout = -1; |
306 |
} else |
307 |
do { /* write it all */ |
308 |
if ((n = write(1, cp, nr)) <= 0) |
309 |
goto writerr; |
310 |
cp += n; |
311 |
} while ((nr -= n) > 0); |
312 |
} |
313 |
} |
314 |
wait(0); /* wait for feeder process */ |
315 |
_exit(status); |
316 |
formerr: |
317 |
error(USER, "format error in persist file"); |
318 |
readerr: |
319 |
error(SYSTEM, "read error in io_process"); |
320 |
writerr: |
321 |
error(SYSTEM, "write error in io_process"); |
322 |
} |
323 |
|
324 |
#else |
325 |
|
326 |
pfclean() {} |
327 |
|
328 |
#endif |