src/rt/persist.c

/* Copyright (c) 1996 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 * Routines for persistent rtrace and rpict processes.
 */

#include "standard.h"

#ifdef F_SETLKW
#include "paths.h"
#include <signal.h>
#include <sys/types.h>
#ifdef INCL_SEL_H
#include <sys/select.h>
#endif
#include <sys/stat.h>
                                        /* select call compatibility stuff */
#ifndef FD_SETSIZE
#include <sys/param.h>
#define FD_SETSIZE      NOFILE          /* maximum # select file descriptors */
#endif
#ifndef FD_SET
#ifndef NFDBITS
#define NFDBITS         (8*sizeof(int)) /* number of bits per fd_mask */
#endif
#define FD_SET(n, p)    ((p)->fds_bits[(n)/NFDBITS] |= (1 << ((n) % NFDBITS)))
#define FD_CLR(n, p)    ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
#define FD_ISSET(n, p)  ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
#define FD_ZERO(p)      bzero((char *)(p), sizeof(*(p)))
#endif

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

extern char     *strcpy(), *index();

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];


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;
}


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);
}


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 int sig_io() { got_io++; }

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


pfhold()                /* holding pattern for idle rendering process */
{
        int     (*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 (mknod(mktemp(strcpy(inpname,TEMPLATE)), S_IFIFO|0600, 0) < 0)
                goto createrr;
        if (mknod(mktemp(strcpy(outpname,TEMPLATE)), S_IFIFO|0600, 0) < 0)
                goto createrr;
        if (errfile == NULL &&
                mknod(mktemp(strcpy(errname,TEMPLATE)), S_IFIFO|0600, 0) < 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, 0L, 0);
                                /* wait TIMELIM for someone to signal us */
        got_io = 0;
        signal(SIGIO, sig_io);
        oldalrm = (int (*)())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;
        if (errname[0]) {
                if (freopen(errname, "w", stderr) == NULL)
                        goto openerr;
                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");
}


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     fdin, fdout, fderr = -1;
        fd_set  readfds, writefds, 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(15);              /* wait until ready */
                pflock(1);
        }
        if (nr < 0)
                error(SYSTEM, "error reading persist file");
        ftruncate(persistfd, 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");
                                        /* open named pipes, in order */
        if ((fdin = open(pfin, O_WRONLY)) < 0)
                error(SYSTEM, "cannot open input pipe in io_process");
        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 ( ; ; ) {                   /* loop on select call */
                FD_ZERO(&readfds);
                FD_ZERO(&writefds);
                FD_ZERO(&excepfds);
                nfds = 0;
                if (fdin >= 0) {
                        FD_SET(fdin, &writefds);
                        FD_SET(fdin, &excepfds);
                        nfds = fdin+1;
                }
                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, &writefds, &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
                                do {            /* write it all */
                                        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);
                }
                                                /* renderer stdin */
                if (fdin >= 0 && (FD_ISSET(fdin, &writefds) ||
                                FD_ISSET(fdin, &excepfds))) {
                        nr = read(0, buf, 512); /* use minimal buffer */
                        if (nr < 0)
                                goto readerr;
                        if (nr == 0) {
                                close(0);
                                close(fdin);
                                fdin = -1;
                        } else if (write(fdin, buf, nr) < nr)
                                goto writerr;   /* what else to do? */
                }
        }
        _exit(0);               /* we ought to return renderer error 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

pfclean() {}

#endif
Revision:	2.20
Committed:	Thu Oct 16 13:49:22 1997 UTC (26 years, 6 months ago) by gregl
Content type:	text/plain
Branch:	MAIN
Changes since 2.19:	+2 -0 lines
Log Message:	added ifdef for INCL_SEL_H since not every system has it
#	User	Rev	Content
1	greg	2.13	/* Copyright (c) 1996 Regents of the University of California */
2	greg	2.1
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	greg	2.6
13			#ifdef F_SETLKW
14	greg	2.1	#include "paths.h"
15			#include <signal.h>
16			#include <sys/types.h>
17	gregl	2.20	#ifdef INCL_SEL_H
18	gregl	2.19	#include <sys/select.h>
19	gregl	2.20	#endif
20	greg	2.1	#include <sys/stat.h>
21	greg	2.16	/* select call compatibility stuff */
22			#ifndef FD_SETSIZE
23			#include <sys/param.h>
24			#define FD_SETSIZE NOFILE /* maximum # select file descriptors */
25			#endif
26			#ifndef FD_SET
27			#ifndef NFDBITS
28			#define NFDBITS (8sizeof(int)) / number of bits per fd_mask */
29			#endif
30			#define FD_SET(n, p) ((p)->fds_bits[(n)/NFDBITS] \|= (1 << ((n) % NFDBITS)))
31			#define FD_CLR(n, p) ((p)->fds_bits[(n)/NFDBITS] &= ~(1 << ((n) % NFDBITS)))
32			#define FD_ISSET(n, p) ((p)->fds_bits[(n)/NFDBITS] & (1 << ((n) % NFDBITS)))
33			#define FD_ZERO(p) bzero((char )(p), sizeof((p)))
34			#endif
35	greg	2.1
36	greg	2.2	#ifndef TIMELIM
37			#define TIMELIM (83600) / time limit for holding pattern */
38			#endif
39
40	greg	2.1	extern char strcpy(), index();
41
42			extern int headismine; /* boolean true if header belongs to me */
43
44	greg	2.12	extern char progname; / global program name */
45
46	greg	2.14	extern char errfile; / global error file name */
47
48	greg	2.1	static char persistfname = NULL; / persist file name */
49			static int persistfd = -1; /* persist file descriptor */
50
51	greg	2.14	static char inpname[TEMPLEN+1], outpname[TEMPLEN+1], errname[TEMPLEN+1];
52	greg	2.1
53
54			pfdetach() /* release persist (and header) resources */
55			{
56			if (persistfd >= 0)
57			close(persistfd);
58			persistfd = -1;
59			persistfname = NULL;
60			inpname[0] = '\0';
61			outpname[0] = '\0';
62	greg	2.14	errname[0] = '\0';
63	greg	2.1	headismine = 0;
64			}
65
66
67			pfclean() /* clean up persist files */
68			{
69			if (persistfd >= 0)
70			close(persistfd);
71			if (persistfname != NULL)
72			unlink(persistfname);
73			if (inpname[0])
74			unlink(inpname);
75			if (outpname[0])
76			unlink(outpname);
77	greg	2.14	if (errname[0])
78			unlink(errname);
79	greg	2.1	}
80
81
82			pflock(lf) /* place or release exclusive lock on file */
83			int lf;
84			{
85			struct flock fls;
86
87			fls.l_type = lf ? F_WRLCK : F_UNLCK;
88			fls.l_whence = 0;
89			fls.l_start = 0L;
90			fls.l_len = 0L;
91			if (fcntl(persistfd, F_SETLKW, &fls) < 0)
92			error(SYSTEM, "cannot (un)lock persist file");
93			}
94
95
96			persistfile(pfn) /* open persist file and lock it */
97			char *pfn;
98			{
99	greg	2.13	persistfd = open(pfn, O_WRONLY\|O_CREAT\|O_EXCL, 0644);
100	greg	2.1	if (persistfd >= 0) {
101			persistfname = pfn;
102			pflock(1);
103			return;
104			}
105			/* file exists -- switch to i/o process */
106			persistfd = open(pfn, O_RDWR);
107			if (persistfd < 0) {
108			sprintf(errmsg, "cannot open persist file \"%s\"", pfn);
109			error(SYSTEM, errmsg);
110			}
111			pflock(1);
112			io_process(); /* never returns */
113			}
114
115
116	greg	2.13	static int got_io;
117	greg	2.1
118	greg	2.13	static int sig_io() { got_io++; }
119	greg	2.1
120	greg	2.13	static int sig_alrm() { quit(0); }
121
122
123	greg	2.1	pfhold() /* holding pattern for idle rendering process */
124			{
125	greg	2.13	int (*oldalrm)();
126	greg	2.12	char buf[512];
127	greg	2.1	register int n;
128			/* close input and output descriptors */
129			close(fileno(stdin));
130			close(fileno(stdout));
131	greg	2.16	if (errfile == NULL)
132			close(fileno(stderr));
133	greg	2.1	/* create named pipes for input and output */
134	greg	2.11	if (mknod(mktemp(strcpy(inpname,TEMPLATE)), S_IFIFO\|0600, 0) < 0)
135	greg	2.1	goto createrr;
136	greg	2.11	if (mknod(mktemp(strcpy(outpname,TEMPLATE)), S_IFIFO\|0600, 0) < 0)
137	greg	2.1	goto createrr;
138	greg	2.14	if (errfile == NULL &&
139			mknod(mktemp(strcpy(errname,TEMPLATE)), S_IFIFO\|0600, 0) < 0)
140			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	2.18	lseek(persistfd, 0L, 0);
147	greg	2.2	/* wait TIMELIM for someone to signal us */
148	greg	2.13	got_io = 0;
149			signal(SIGIO, sig_io);
150			oldalrm = (int (*)())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			if (freopen(inpname, "r", stdin) == NULL)
161			goto openerr;
162			if (freopen(outpname, "w", stdout) == NULL)
163			goto openerr;
164	greg	2.14	if (errname[0]) {
165			if (freopen(errname, "w", stderr) == NULL)
166			goto openerr;
167			unlink(errname);
168			errname[0] = '\0';
169			}
170	greg	2.1	unlink(inpname);
171			inpname[0] = '\0';
172			unlink(outpname);
173			outpname[0] = '\0';
174			return;
175			createrr:
176			error(SYSTEM, "cannot create named pipes in pfhold");
177			openerr:
178			error(SYSTEM, "cannot open named pipes in pfhold");
179			}
180
181
182	greg	2.16	io_process() /* just act as go-between for actual process */
183	greg	2.1	{
184			register char *cp;
185			register int nr, n;
186	greg	2.16	char buf[BUFSIZ], pfin, pfout, *pferr;
187			int pid, nfds;
188			int fdin, fdout, fderr = -1;
189			fd_set readfds, writefds, excepfds;
190	greg	2.15	/* load persist file */
191	greg	2.17	n = 40;
192	greg	2.15	while ((nr = read(persistfd, buf, sizeof(buf)-1)) == 0) {
193	greg	2.17	if (!n--)
194			error(USER, "unattended persist file?");
195	greg	2.15	pflock(0);
196			sleep(15); /* wait until ready */
197			pflock(1);
198			}
199			if (nr < 0)
200	greg	2.14	error(SYSTEM, "error reading persist file");
201	greg	2.17	ftruncate(persistfd, 0L); /* truncate persist file */
202			pfdetach(); /* close & release persist file */
203			buf[nr] = '\0'; /* parse what we got */
204	greg	2.12	if ((cp = index(buf, ' ')) == NULL)
205	greg	2.1	goto formerr;
206			*cp++ = '\0';
207	greg	2.12	if ((pid = atoi(cp)) <= 0)
208	greg	2.1	goto formerr;
209			if ((cp = index(cp, '\n')) == NULL)
210			goto formerr;
211	greg	2.12	pfin = ++cp;
212			if ((cp = index(cp, '\n')) == NULL)
213			goto formerr;
214	greg	2.1	*cp++ = '\0';
215			pfout = cp;
216			if ((cp = index(cp, '\n')) == NULL)
217			goto formerr;
218			*cp++ = '\0';
219	greg	2.14	pferr = cp;
220			if ((cp = index(cp, '\n')) == NULL)
221			goto formerr;
222			*cp++ = '\0';
223	greg	2.1	if (cp-buf != nr)
224			goto formerr;
225	greg	2.12	if (strcmp(buf, progname)) {
226			sprintf(errmsg, "persist file for %s, not %s", buf, progname);
227			error(USER, errmsg);
228			}
229	greg	2.16	/* wake up rendering process */
230	greg	2.2	if (kill(pid, SIGIO) < 0)
231	greg	2.1	error(SYSTEM, "cannot signal rendering process in io_process");
232	greg	2.16	/* open named pipes, in order */
233			if ((fdin = open(pfin, O_WRONLY)) < 0)
234			error(SYSTEM, "cannot open input pipe in io_process");
235			if ((fdout = open(pfout, O_RDONLY)) < 0)
236			error(SYSTEM, "cannot open output pipe in io_process");
237			if (pferr[0] && (fderr = open(pferr, O_RDONLY)) < 0)
238			error(SYSTEM, "cannot open error pipe in io_process");
239			for ( ; ; ) { /* loop on select call */
240			FD_ZERO(&readfds);
241			FD_ZERO(&writefds);
242			FD_ZERO(&excepfds);
243			nfds = 0;
244			if (fdin >= 0) {
245			FD_SET(fdin, &writefds);
246			FD_SET(fdin, &excepfds);
247			nfds = fdin+1;
248	greg	2.14	}
249	greg	2.16	if (fdout >= 0) {
250			FD_SET(fdout, &readfds);
251			FD_SET(fdout, &excepfds);
252			nfds = fdout+1;
253	greg	2.14	}
254	greg	2.16	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, &writefds, &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	greg	2.18	/* close(2); don't close stderr! */
272	greg	2.16	fderr = -1;
273			} else
274			do { /* write it all */
275			if ((n = write(2, cp, nr)) <= 0)
276			goto writerr;
277			cp += n;
278			} while ((nr -= n) > 0);
279			}
280			/* renderer stdout */
281			if (fdout >= 0 && (FD_ISSET(fdout, &readfds) \|\|
282			FD_ISSET(fdout, &excepfds))) {
283			nr = read(fdout, cp=buf, sizeof(buf));
284			if (nr < 0)
285			goto readerr;
286			if (nr == 0) { /* EOF */
287			close(fdout);
288			close(1);
289			fdout = -1;
290			} else
291			do { /* write it all */
292			if ((n = write(1, cp, nr)) <= 0)
293			goto writerr;
294			cp += n;
295			} while ((nr -= n) > 0);
296			}
297			/* renderer stdin */
298			if (fdin >= 0 && (FD_ISSET(fdin, &writefds) \|\|
299			FD_ISSET(fdin, &excepfds))) {
300			nr = read(0, buf, 512); /* use minimal buffer */
301			if (nr < 0)
302			goto readerr;
303			if (nr == 0) {
304			close(0);
305			close(fdin);
306			fdin = -1;
307			} else if (write(fdin, buf, nr) < nr)
308			goto writerr; /* what else to do? */
309			}
310	greg	2.1	}
311	greg	2.16	_exit(0); /* we ought to return renderer error status! */
312	greg	2.1	formerr:
313			error(USER, "format error in persist file");
314	greg	2.16	readerr:
315			error(SYSTEM, "read error in io_process");
316			writerr:
317			error(SYSTEM, "write error in io_process");
318	greg	2.1	}
319	greg	2.6
320	greg	2.8	#else
321
322			pfclean() {}
323
324	greg	2.6	#endif