src/rt/persist.c

#ifndef lint
static const char       RCSid[] = "$Id$";
#endif
/*
 * Routines for persistent rtrace and rpict processes.
 *
 *  External symbols declared in ray.h
 */

#include "copyright.h"

#include "standard.h"
#include "random.h"

#ifdef F_SETLKW
#include "paths.h"
#include "selcall.h"
#include <signal.h>
#include <sys/stat.h>

#ifndef TIMELIM
#define TIMELIM         (8*3600)        /* time limit for holding pattern */
#endif

#ifndef freebsd
#define mkfifo(fn,md)   mknod(fn, S_IFIFO|(md), 0)
#endif

extern void     io_process();

extern int      headismine;     /* boolean true if header belongs to me */

extern char     *progname;      /* global program name */

extern char     *errfile;       /* global error file name */

static char     *persistfname = NULL;   /* persist file name */
static int      persistfd = -1;         /* persist file descriptor */

static char     inpname[TEMPLEN+1], outpname[TEMPLEN+1], errname[TEMPLEN+1];


void
pfdetach()              /* release persist (and header) resources */
{
        if (persistfd >= 0)
                close(persistfd);
        persistfd = -1;
        persistfname = NULL;
        inpname[0] = '\0';
        outpname[0] = '\0';
        errname[0] = '\0';
        headismine = 0;
}


void
pfclean()               /* clean up persist files */
{
        if (persistfd >= 0)
                close(persistfd);
        if (persistfname != NULL)
                unlink(persistfname);
        if (inpname[0])
                unlink(inpname);
        if (outpname[0])
                unlink(outpname);
        if (errname[0])
                unlink(errname);
}


void
pflock(lf)              /* place or release exclusive lock on file */
int     lf;
{
        struct flock    fls;

        fls.l_type = lf ? F_WRLCK : F_UNLCK;
        fls.l_whence = 0;
        fls.l_start = 0L;
        fls.l_len = 0L;
        if (fcntl(persistfd, F_SETLKW, &fls) < 0)
                error(SYSTEM, "cannot (un)lock persist file");
}


persistfile(pfn)        /* open persist file and lock it */
char    *pfn;
{
        persistfd = open(pfn, O_WRONLY|O_CREAT|O_EXCL, 0644);
        if (persistfd >= 0) {
                persistfname = pfn;
                pflock(1);
                return;
        }
                                /* file exists -- switch to i/o process */
        persistfd = open(pfn, O_RDWR);
        if (persistfd < 0) {
                sprintf(errmsg, "cannot open persist file \"%s\"", pfn);
                error(SYSTEM, errmsg);
        }
        pflock(1);
        io_process();   /* never returns */
}


static int      got_io;

static void sig_io() { got_io++; }

static void sig_alrm() { quit(0); }


void
pfhold()                /* holding pattern for idle rendering process */
{
        void    (*oldalrm)();
        char    buf[512];
        register int    n;
                                /* close input and output descriptors */
        close(fileno(stdin));
        close(fileno(stdout));
        if (errfile == NULL)
                close(fileno(stderr));
                                /* create named pipes for input and output */
        if (mkfifo(mktemp(strcpy(inpname,TEMPLATE)), 0600) < 0)
                goto createrr;
        if (mkfifo(mktemp(strcpy(outpname,TEMPLATE)), 0600) < 0)
                goto createrr;
        if (errfile == NULL &&
                mkfifo(mktemp(strcpy(errname,TEMPLATE)), 0600) < 0)
                goto createrr;
        sprintf(buf, "%s %d\n%s\n%s\n%s\n", progname, getpid(),
                        inpname, outpname, errname);
        n = strlen(buf);
        if (write(persistfd, buf, n) < n)
                error(SYSTEM, "error writing persist file");
        lseek(persistfd, (off_t)0L, 0);
                                /* wait TIMELIM for someone to signal us */
        got_io = 0;
        signal(SIGIO, sig_io);
        oldalrm = (void (*)())signal(SIGALRM, sig_alrm);
        alarm(TIMELIM);
        pflock(0);                      /* unlock persist file for attach */
        while (!got_io)
                pause();                /* wait for attach */
        alarm(0);                       /* turn off alarm */
        signal(SIGALRM, oldalrm);
        signal(SIGIO, SIG_DFL);
        pflock(1);                      /* grab persist file back */
                                /* someone wants us; reopen stdin and stdout */
        /*
        if (freopen(inpname, "r", stdin) == NULL)
                goto openerr;
        if (freopen(outpname, "w", stdout) == NULL)
                goto openerr;
        */
        close(0);
        if (open(inpname, O_RDONLY) != 0)
                error(INTERNAL, "unexpected stdin file number");
        clearerr(stdin);
        close(1);
        if (open(outpname, O_WRONLY) != 1)
                error(INTERNAL, "unexpected stdout file number");
        sleep(3);               /* give them a chance to open their pipes */
        if (errname[0]) {
                close(2);
                if (open(errname, O_WRONLY) != 2)
                        error(INTERNAL, "unexpected stderr file number");
                unlink(errname);
                errname[0] = '\0';
        }
        unlink(inpname);
        inpname[0] = '\0';
        unlink(outpname);
        outpname[0] = '\0';
        return;
createrr:
        error(SYSTEM, "cannot create named pipes in pfhold");
openerr:
        error(SYSTEM, "cannot open named pipes in pfhold");
}


void
io_process()            /* just act as go-between for actual process */
{
        register char   *cp;
        register int    nr, n;
        char    buf[BUFSIZ], *pfin, *pfout, *pferr;
        int     pid, nfds;
        int     fdout, fderr = -1;
        int     status = 0;
        fd_set  readfds, excepfds;
                                        /* load persist file */
        n = 40;
        while ((nr = read(persistfd, buf, sizeof(buf)-1)) == 0) {
                if (!n--)
                        error(USER, "unattended persist file?");
                pflock(0);
                sleep(3+(3*getpid()+random())%13);      /* wait until ready */
                pflock(1);
        }
        if (nr < 0)
                error(SYSTEM, "error reading persist file");
        ftruncate(persistfd, (off_t)0L);        /* truncate persist file */
        pfdetach();                     /* close & release persist file */
        buf[nr] = '\0';                 /* parse what we got */
        if ((cp = index(buf, ' ')) == NULL)
                goto formerr;
        *cp++ = '\0';
        if ((pid = atoi(cp)) <= 0)
                goto formerr;
        if ((cp = index(cp, '\n')) == NULL)
                goto formerr;
        pfin = ++cp;
        if ((cp = index(cp, '\n')) == NULL)
                goto formerr;
        *cp++ = '\0';
        pfout = cp;
        if ((cp = index(cp, '\n')) == NULL)
                goto formerr;
        *cp++ = '\0';
        pferr = cp;
        if ((cp = index(cp, '\n')) == NULL)
                goto formerr;
        *cp++ = '\0';
        if (cp-buf != nr)
                goto formerr;
        if (strcmp(buf, progname)) {
                sprintf(errmsg, "persist file for %s, not %s", buf, progname);
                error(USER, errmsg);
        }
                                        /* wake up rendering process */
        if (kill(pid, SIGIO) < 0)
                error(SYSTEM, "cannot signal rendering process in io_process");
                                        /* fork child feeder process */
        pid = fork();
        if (pid < 0)
                error(SYSTEM, "fork failed in io_process");
        if (pid == 0) {                 /* feeder loop */
                int     fdin;
                close(1);               /* open input pipe */
                if ((fdin = open(pfin, O_WRONLY)) < 0)
                        error(SYSTEM, "cannot open feed pipe in io_process");
                                                /* renderer stdin */
                while ((nr = read(0, cp=buf, sizeof(buf))) > 0) {
                        do {
                                if ((n = write(fdin, cp, nr)) <= 0)
                                        goto writerr;
                                cp += n;
                        } while ((nr -= n) > 0);
                }
                if (nr < 0)
                        goto readerr;
                _exit(0);
        }
        close(0);
                                        /* open output pipes, in order */
        if ((fdout = open(pfout, O_RDONLY)) < 0)
                error(SYSTEM, "cannot open output pipe in io_process");
        if (pferr[0] && (fderr = open(pferr, O_RDONLY)) < 0)
                error(SYSTEM, "cannot open error pipe in io_process");
        for ( ; ; ) {                   /* eater loop */
                FD_ZERO(&readfds);
                FD_ZERO(&excepfds);
                nfds = 0;
                if (fdout >= 0) {
                        FD_SET(fdout, &readfds);
                        FD_SET(fdout, &excepfds);
                        nfds = fdout+1;
                }
                if (fderr >= 0) {
                        FD_SET(fderr, &readfds);
                        FD_SET(fderr, &excepfds);
                        nfds = fderr+1;
                }
                if (nfds == 0)
                        break;                  /* all done, exit */
                if (select(nfds, &readfds, NULL, &excepfds, NULL) < 0)
                        error(SYSTEM, "error in select call in io_process");
                                                /* renderer stderr */
                if (fderr >= 0 && (FD_ISSET(fderr, &readfds) ||
                                FD_ISSET(fderr, &excepfds))) {
                        nr = read(fderr, cp=buf, sizeof(buf));
                        if (nr < 0)
                                goto readerr;
                        if (nr == 0) {
                                close(fderr);
                                /* close(2);    don't close stderr! */
                                fderr = -1;
                        } else {
                                cp[nr] = '\0';  /* deduce status if we can */
                                n = strlen(progname);
                                if (!strncmp(cp, progname, n) &&
                                                cp[n++] == ':' &&
                                                cp[n++] == ' ') {
                                        register struct erract  *ep;
                                        for (ep = erract; ep < erract+NERRS;
                                                        ep++)
                                                if (ep->pre[0] &&
                                                        !strncmp(cp+n, ep->pre,
                                                            strlen(ep->pre))) {
                                                        status = ep->ec;
                                                        break;
                                                }
                                }
                                do {            /* write message */
                                        if ((n = write(2, cp, nr)) <= 0)
                                                goto writerr;
                                        cp += n;
                                } while ((nr -= n) > 0);
                        }
                }
                                                /* renderer stdout */
                if (fdout >= 0 && (FD_ISSET(fdout, &readfds) ||
                                FD_ISSET(fdout, &excepfds))) {
                        nr = read(fdout, cp=buf, sizeof(buf));
                        if (nr < 0)
                                goto readerr;
                        if (nr == 0) {          /* EOF */
                                close(fdout);
                                close(1);
                                fdout = -1;
                        } else
                                do {            /* write it all */
                                        if ((n = write(1, cp, nr)) <= 0)
                                                goto writerr;
                                        cp += n;
                                } while ((nr -= n) > 0);
                }
        }
        wait(0);                /* wait for feeder process */
        _exit(status);
formerr:
        error(USER, "format error in persist file");
readerr:
        error(SYSTEM, "read error in io_process");
writerr:
        error(SYSTEM, "write error in io_process");
}

#else

void pfclean() {}

#endif
Revision:	2.27
Committed:	Tue Feb 25 02:47:23 2003 UTC (21 years, 8 months ago) by greg
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rad3R5
Changes since 2.26:	+1 -56 lines
Log Message:	Replaced inline copyright notice with #include "copyright.h"
#	User	Rev	Content
1	greg	2.1	#ifndef lint
2	greg	2.26	static const char RCSid[] = "$Id$";
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			#include "standard.h"
13	gregl	2.25	#include "random.h"
14	greg	2.6
15			#ifdef F_SETLKW
16	greg	2.1	#include "paths.h"
17	gregl	2.21	#include "selcall.h"
18	greg	2.1	#include <signal.h>
19			#include <sys/stat.h>
20
21	greg	2.2	#ifndef TIMELIM
22			#define TIMELIM (83600) / time limit for holding pattern */
23			#endif
24
25	greg	2.26	#ifndef freebsd
26			#define mkfifo(fn,md) mknod(fn, S_IFIFO\|(md), 0)
27			#endif
28
29			extern void io_process();
30	greg	2.1
31			extern int headismine; /* boolean true if header belongs to me */
32
33	greg	2.12	extern char progname; / global program name */
34
35	greg	2.14	extern char errfile; / global error file name */
36
37	greg	2.1	static char persistfname = NULL; / persist file name */
38			static int persistfd = -1; /* persist file descriptor */
39
40	greg	2.14	static char inpname[TEMPLEN+1], outpname[TEMPLEN+1], errname[TEMPLEN+1];
41	greg	2.1
42
43	greg	2.26	void
44	greg	2.1	pfdetach() /* release persist (and header) resources */
45			{
46			if (persistfd >= 0)
47			close(persistfd);
48			persistfd = -1;
49			persistfname = NULL;
50			inpname[0] = '\0';
51			outpname[0] = '\0';
52	greg	2.14	errname[0] = '\0';
53	greg	2.1	headismine = 0;
54			}
55
56
57	greg	2.26	void
58	greg	2.1	pfclean() /* clean up persist files */
59			{
60			if (persistfd >= 0)
61			close(persistfd);
62			if (persistfname != NULL)
63			unlink(persistfname);
64			if (inpname[0])
65			unlink(inpname);
66			if (outpname[0])
67			unlink(outpname);
68	greg	2.14	if (errname[0])
69			unlink(errname);
70	greg	2.1	}
71
72
73	greg	2.26	void
74	greg	2.1	pflock(lf) /* place or release exclusive lock on file */
75			int lf;
76			{
77			struct flock fls;
78
79			fls.l_type = lf ? F_WRLCK : F_UNLCK;
80			fls.l_whence = 0;
81			fls.l_start = 0L;
82			fls.l_len = 0L;
83			if (fcntl(persistfd, F_SETLKW, &fls) < 0)
84			error(SYSTEM, "cannot (un)lock persist file");
85			}
86
87
88			persistfile(pfn) /* open persist file and lock it */
89			char *pfn;
90			{
91	greg	2.13	persistfd = open(pfn, O_WRONLY\|O_CREAT\|O_EXCL, 0644);
92	greg	2.1	if (persistfd >= 0) {
93			persistfname = pfn;
94			pflock(1);
95			return;
96			}
97			/* file exists -- switch to i/o process */
98			persistfd = open(pfn, O_RDWR);
99			if (persistfd < 0) {
100			sprintf(errmsg, "cannot open persist file \"%s\"", pfn);
101			error(SYSTEM, errmsg);
102			}
103			pflock(1);
104			io_process(); /* never returns */
105			}
106
107
108	greg	2.13	static int got_io;
109	greg	2.1
110	greg	2.26	static void sig_io() { got_io++; }
111	greg	2.1
112	greg	2.26	static void sig_alrm() { quit(0); }
113	greg	2.13
114
115	greg	2.26	void
116	greg	2.1	pfhold() /* holding pattern for idle rendering process */
117			{
118	greg	2.26	void (*oldalrm)();
119	greg	2.12	char buf[512];
120	greg	2.1	register int n;
121			/* close input and output descriptors */
122			close(fileno(stdin));
123			close(fileno(stdout));
124	greg	2.16	if (errfile == NULL)
125			close(fileno(stderr));
126	greg	2.1	/* create named pipes for input and output */
127	greg	2.26	if (mkfifo(mktemp(strcpy(inpname,TEMPLATE)), 0600) < 0)
128	greg	2.1	goto createrr;
129	greg	2.26	if (mkfifo(mktemp(strcpy(outpname,TEMPLATE)), 0600) < 0)
130	greg	2.1	goto createrr;
131	greg	2.14	if (errfile == NULL &&
132	greg	2.26	mkfifo(mktemp(strcpy(errname,TEMPLATE)), 0600) < 0)
133	greg	2.14	goto createrr;
134			sprintf(buf, "%s %d\n%s\n%s\n%s\n", progname, getpid(),
135			inpname, outpname, errname);
136	greg	2.1	n = strlen(buf);
137			if (write(persistfd, buf, n) < n)
138	greg	2.10	error(SYSTEM, "error writing persist file");
139	greg	2.26	lseek(persistfd, (off_t)0L, 0);
140	greg	2.2	/* wait TIMELIM for someone to signal us */
141	greg	2.13	got_io = 0;
142			signal(SIGIO, sig_io);
143	greg	2.26	oldalrm = (void (*)())signal(SIGALRM, sig_alrm);
144	greg	2.2	alarm(TIMELIM);
145	greg	2.15	pflock(0); /* unlock persist file for attach */
146	greg	2.13	while (!got_io)
147	greg	2.15	pause(); /* wait for attach */
148			alarm(0); /* turn off alarm */
149	greg	2.13	signal(SIGALRM, oldalrm);
150	greg	2.2	signal(SIGIO, SIG_DFL);
151	greg	2.17	pflock(1); /* grab persist file back */
152	greg	2.1	/* someone wants us; reopen stdin and stdout */
153	greg	2.26	/*
154	greg	2.1	if (freopen(inpname, "r", stdin) == NULL)
155			goto openerr;
156			if (freopen(outpname, "w", stdout) == NULL)
157			goto openerr;
158	greg	2.26	*/
159			close(0);
160			if (open(inpname, O_RDONLY) != 0)
161			error(INTERNAL, "unexpected stdin file number");
162			clearerr(stdin);
163			close(1);
164			if (open(outpname, O_WRONLY) != 1)
165			error(INTERNAL, "unexpected stdout file number");
166	gregl	2.22	sleep(3); /* give them a chance to open their pipes */
167	greg	2.14	if (errname[0]) {
168	greg	2.26	close(2);
169			if (open(errname, O_WRONLY) != 2)
170			error(INTERNAL, "unexpected stderr file number");
171	greg	2.14	unlink(errname);
172			errname[0] = '\0';
173			}
174	greg	2.1	unlink(inpname);
175			inpname[0] = '\0';
176			unlink(outpname);
177			outpname[0] = '\0';
178			return;
179			createrr:
180			error(SYSTEM, "cannot create named pipes in pfhold");
181			openerr:
182			error(SYSTEM, "cannot open named pipes in pfhold");
183			}
184
185
186	greg	2.26	void
187	greg	2.16	io_process() /* just act as go-between for actual process */
188	greg	2.1	{
189			register char *cp;
190			register int nr, n;
191	greg	2.16	char buf[BUFSIZ], pfin, pfout, *pferr;
192			int pid, nfds;
193	gregl	2.22	int fdout, fderr = -1;
194	gregl	2.23	int status = 0;
195	gregl	2.22	fd_set readfds, excepfds;
196	greg	2.15	/* load persist file */
197	greg	2.17	n = 40;
198	greg	2.15	while ((nr = read(persistfd, buf, sizeof(buf)-1)) == 0) {
199	greg	2.17	if (!n--)
200			error(USER, "unattended persist file?");
201	greg	2.15	pflock(0);
202	gregl	2.25	sleep(3+(3getpid()+random())%13); / wait until ready */
203	greg	2.15	pflock(1);
204			}
205			if (nr < 0)
206	greg	2.14	error(SYSTEM, "error reading persist file");
207	greg	2.26	ftruncate(persistfd, (off_t)0L); /* truncate persist file */
208	greg	2.17	pfdetach(); /* close & release persist file */
209			buf[nr] = '\0'; /* parse what we got */
210	greg	2.12	if ((cp = index(buf, ' ')) == NULL)
211	greg	2.1	goto formerr;
212			*cp++ = '\0';
213	greg	2.12	if ((pid = atoi(cp)) <= 0)
214	greg	2.1	goto formerr;
215			if ((cp = index(cp, '\n')) == NULL)
216			goto formerr;
217	greg	2.12	pfin = ++cp;
218			if ((cp = index(cp, '\n')) == NULL)
219			goto formerr;
220	greg	2.1	*cp++ = '\0';
221			pfout = cp;
222			if ((cp = index(cp, '\n')) == NULL)
223			goto formerr;
224			*cp++ = '\0';
225	greg	2.14	pferr = cp;
226			if ((cp = index(cp, '\n')) == NULL)
227			goto formerr;
228			*cp++ = '\0';
229	greg	2.1	if (cp-buf != nr)
230			goto formerr;
231	greg	2.12	if (strcmp(buf, progname)) {
232			sprintf(errmsg, "persist file for %s, not %s", buf, progname);
233			error(USER, errmsg);
234			}
235	greg	2.16	/* wake up rendering process */
236	greg	2.2	if (kill(pid, SIGIO) < 0)
237	greg	2.1	error(SYSTEM, "cannot signal rendering process in io_process");
238	gregl	2.22	/* fork child feeder process */
239			pid = fork();
240			if (pid < 0)
241			error(SYSTEM, "fork failed in io_process");
242			if (pid == 0) { /* feeder loop */
243			int fdin;
244			close(1); /* open input pipe */
245			if ((fdin = open(pfin, O_WRONLY)) < 0)
246			error(SYSTEM, "cannot open feed pipe in io_process");
247			/* renderer stdin */
248			while ((nr = read(0, cp=buf, sizeof(buf))) > 0) {
249			do {
250			if ((n = write(fdin, cp, nr)) <= 0)
251			goto writerr;
252			cp += n;
253			} while ((nr -= n) > 0);
254			}
255			if (nr < 0)
256			goto readerr;
257			_exit(0);
258			}
259			close(0);
260			/* open output pipes, in order */
261	greg	2.16	if ((fdout = open(pfout, O_RDONLY)) < 0)
262			error(SYSTEM, "cannot open output pipe in io_process");
263			if (pferr[0] && (fderr = open(pferr, O_RDONLY)) < 0)
264			error(SYSTEM, "cannot open error pipe in io_process");
265	gregl	2.22	for ( ; ; ) { /* eater loop */
266	greg	2.16	FD_ZERO(&readfds);
267			FD_ZERO(&excepfds);
268			nfds = 0;
269			if (fdout >= 0) {
270			FD_SET(fdout, &readfds);
271			FD_SET(fdout, &excepfds);
272			nfds = fdout+1;
273	greg	2.14	}
274	greg	2.16	if (fderr >= 0) {
275			FD_SET(fderr, &readfds);
276			FD_SET(fderr, &excepfds);
277			nfds = fderr+1;
278			}
279			if (nfds == 0)
280			break; /* all done, exit */
281	gregl	2.22	if (select(nfds, &readfds, NULL, &excepfds, NULL) < 0)
282	greg	2.16	error(SYSTEM, "error in select call in io_process");
283			/* renderer stderr */
284			if (fderr >= 0 && (FD_ISSET(fderr, &readfds) \|\|
285			FD_ISSET(fderr, &excepfds))) {
286			nr = read(fderr, cp=buf, sizeof(buf));
287			if (nr < 0)
288			goto readerr;
289			if (nr == 0) {
290			close(fderr);
291	greg	2.18	/* close(2); don't close stderr! */
292	greg	2.16	fderr = -1;
293	gregl	2.24	} else {
294	gregl	2.23	cp[nr] = '\0'; /* deduce status if we can */
295			n = strlen(progname);
296			if (!strncmp(cp, progname, n) &&
297			cp[n++] == ':' &&
298			cp[n++] == ' ') {
299			register struct erract *ep;
300			for (ep = erract; ep < erract+NERRS;
301			ep++)
302			if (ep->pre[0] &&
303			!strncmp(cp+n, ep->pre,
304			strlen(ep->pre))) {
305			status = ep->ec;
306			break;
307			}
308			}
309			do { /* write message */
310	greg	2.16	if ((n = write(2, cp, nr)) <= 0)
311			goto writerr;
312			cp += n;
313			} while ((nr -= n) > 0);
314	gregl	2.24	}
315	greg	2.16	}
316			/* renderer stdout */
317			if (fdout >= 0 && (FD_ISSET(fdout, &readfds) \|\|
318			FD_ISSET(fdout, &excepfds))) {
319			nr = read(fdout, cp=buf, sizeof(buf));
320			if (nr < 0)
321			goto readerr;
322			if (nr == 0) { /* EOF */
323			close(fdout);
324			close(1);
325			fdout = -1;
326			} else
327			do { /* write it all */
328			if ((n = write(1, cp, nr)) <= 0)
329			goto writerr;
330			cp += n;
331			} while ((nr -= n) > 0);
332			}
333	greg	2.1	}
334	gregl	2.23	wait(0); /* wait for feeder process */
335			_exit(status);
336	greg	2.1	formerr:
337			error(USER, "format error in persist file");
338	greg	2.16	readerr:
339			error(SYSTEM, "read error in io_process");
340			writerr:
341			error(SYSTEM, "write error in io_process");
342	greg	2.1	}
343	greg	2.6
344	greg	2.8	#else
345
346	greg	2.26	void pfclean() {}
347	greg	2.8
348	greg	2.6	#endif