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

#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:	2.21
Committed:	Tue Oct 28 14:00:02 1997 UTC (26 years, 6 months ago) by gregl
Content type:	text/plain
Branch:	MAIN
Changes since 2.20:	+1 -18 lines
Log Message:	created selcall.h include file for select(2) compatibility
#	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	gregl	2.21	#include "selcall.h"
16	greg	2.1	#include <signal.h>
17			#include <sys/stat.h>
18
19	greg	2.2	#ifndef TIMELIM
20			#define TIMELIM (83600) / time limit for holding pattern */
21			#endif
22
23	greg	2.1	extern char strcpy(), index();
24
25			extern int headismine; /* boolean true if header belongs to me */
26
27	greg	2.12	extern char progname; / global program name */
28
29	greg	2.14	extern char errfile; / global error file name */
30
31	greg	2.1	static char persistfname = NULL; / persist file name */
32			static int persistfd = -1; /* persist file descriptor */
33
34	greg	2.14	static char inpname[TEMPLEN+1], outpname[TEMPLEN+1], errname[TEMPLEN+1];
35	greg	2.1
36
37			pfdetach() /* release persist (and header) resources */
38			{
39			if (persistfd >= 0)
40			close(persistfd);
41			persistfd = -1;
42			persistfname = NULL;
43			inpname[0] = '\0';
44			outpname[0] = '\0';
45	greg	2.14	errname[0] = '\0';
46	greg	2.1	headismine = 0;
47			}
48
49
50			pfclean() /* clean up persist files */
51			{
52			if (persistfd >= 0)
53			close(persistfd);
54			if (persistfname != NULL)
55			unlink(persistfname);
56			if (inpname[0])
57			unlink(inpname);
58			if (outpname[0])
59			unlink(outpname);
60	greg	2.14	if (errname[0])
61			unlink(errname);
62	greg	2.1	}
63
64
65			pflock(lf) /* place or release exclusive lock on file */
66			int lf;
67			{
68			struct flock fls;
69
70			fls.l_type = lf ? F_WRLCK : F_UNLCK;
71			fls.l_whence = 0;
72			fls.l_start = 0L;
73			fls.l_len = 0L;
74			if (fcntl(persistfd, F_SETLKW, &fls) < 0)
75			error(SYSTEM, "cannot (un)lock persist file");
76			}
77
78
79			persistfile(pfn) /* open persist file and lock it */
80			char *pfn;
81			{
82	greg	2.13	persistfd = open(pfn, O_WRONLY\|O_CREAT\|O_EXCL, 0644);
83	greg	2.1	if (persistfd >= 0) {
84			persistfname = pfn;
85			pflock(1);
86			return;
87			}
88			/* file exists -- switch to i/o process */
89			persistfd = open(pfn, O_RDWR);
90			if (persistfd < 0) {
91			sprintf(errmsg, "cannot open persist file \"%s\"", pfn);
92			error(SYSTEM, errmsg);
93			}
94			pflock(1);
95			io_process(); /* never returns */
96			}
97
98
99	greg	2.13	static int got_io;
100	greg	2.1
101	greg	2.13	static int sig_io() { got_io++; }
102	greg	2.1
103	greg	2.13	static int sig_alrm() { quit(0); }
104
105
106	greg	2.1	pfhold() /* holding pattern for idle rendering process */
107			{
108	greg	2.13	int (*oldalrm)();
109	greg	2.12	char buf[512];
110	greg	2.1	register int n;
111			/* close input and output descriptors */
112			close(fileno(stdin));
113			close(fileno(stdout));
114	greg	2.16	if (errfile == NULL)
115			close(fileno(stderr));
116	greg	2.1	/* create named pipes for input and output */
117	greg	2.11	if (mknod(mktemp(strcpy(inpname,TEMPLATE)), S_IFIFO\|0600, 0) < 0)
118	greg	2.1	goto createrr;
119	greg	2.11	if (mknod(mktemp(strcpy(outpname,TEMPLATE)), S_IFIFO\|0600, 0) < 0)
120	greg	2.1	goto createrr;
121	greg	2.14	if (errfile == NULL &&
122			mknod(mktemp(strcpy(errname,TEMPLATE)), S_IFIFO\|0600, 0) < 0)
123			goto createrr;
124			sprintf(buf, "%s %d\n%s\n%s\n%s\n", progname, getpid(),
125			inpname, outpname, errname);
126	greg	2.1	n = strlen(buf);
127			if (write(persistfd, buf, n) < n)
128	greg	2.10	error(SYSTEM, "error writing persist file");
129	greg	2.18	lseek(persistfd, 0L, 0);
130	greg	2.2	/* wait TIMELIM for someone to signal us */
131	greg	2.13	got_io = 0;
132			signal(SIGIO, sig_io);
133			oldalrm = (int (*)())signal(SIGALRM, sig_alrm);
134	greg	2.2	alarm(TIMELIM);
135	greg	2.15	pflock(0); /* unlock persist file for attach */
136	greg	2.13	while (!got_io)
137	greg	2.15	pause(); /* wait for attach */
138			alarm(0); /* turn off alarm */
139	greg	2.13	signal(SIGALRM, oldalrm);
140	greg	2.2	signal(SIGIO, SIG_DFL);
141	greg	2.17	pflock(1); /* grab persist file back */
142	greg	2.1	/* someone wants us; reopen stdin and stdout */
143			if (freopen(inpname, "r", stdin) == NULL)
144			goto openerr;
145			if (freopen(outpname, "w", stdout) == NULL)
146			goto openerr;
147	greg	2.14	if (errname[0]) {
148			if (freopen(errname, "w", stderr) == NULL)
149			goto openerr;
150			unlink(errname);
151			errname[0] = '\0';
152			}
153	greg	2.1	unlink(inpname);
154			inpname[0] = '\0';
155			unlink(outpname);
156			outpname[0] = '\0';
157			return;
158			createrr:
159			error(SYSTEM, "cannot create named pipes in pfhold");
160			openerr:
161			error(SYSTEM, "cannot open named pipes in pfhold");
162			}
163
164
165	greg	2.16	io_process() /* just act as go-between for actual process */
166	greg	2.1	{
167			register char *cp;
168			register int nr, n;
169	greg	2.16	char buf[BUFSIZ], pfin, pfout, *pferr;
170			int pid, nfds;
171			int fdin, fdout, fderr = -1;
172			fd_set readfds, writefds, excepfds;
173	greg	2.15	/* load persist file */
174	greg	2.17	n = 40;
175	greg	2.15	while ((nr = read(persistfd, buf, sizeof(buf)-1)) == 0) {
176	greg	2.17	if (!n--)
177			error(USER, "unattended persist file?");
178	greg	2.15	pflock(0);
179			sleep(15); /* wait until ready */
180			pflock(1);
181			}
182			if (nr < 0)
183	greg	2.14	error(SYSTEM, "error reading persist file");
184	greg	2.17	ftruncate(persistfd, 0L); /* truncate persist file */
185			pfdetach(); /* close & release persist file */
186			buf[nr] = '\0'; /* parse what we got */
187	greg	2.12	if ((cp = index(buf, ' ')) == NULL)
188	greg	2.1	goto formerr;
189			*cp++ = '\0';
190	greg	2.12	if ((pid = atoi(cp)) <= 0)
191	greg	2.1	goto formerr;
192			if ((cp = index(cp, '\n')) == NULL)
193			goto formerr;
194	greg	2.12	pfin = ++cp;
195			if ((cp = index(cp, '\n')) == NULL)
196			goto formerr;
197	greg	2.1	*cp++ = '\0';
198			pfout = cp;
199			if ((cp = index(cp, '\n')) == NULL)
200			goto formerr;
201			*cp++ = '\0';
202	greg	2.14	pferr = cp;
203			if ((cp = index(cp, '\n')) == NULL)
204			goto formerr;
205			*cp++ = '\0';
206	greg	2.1	if (cp-buf != nr)
207			goto formerr;
208	greg	2.12	if (strcmp(buf, progname)) {
209			sprintf(errmsg, "persist file for %s, not %s", buf, progname);
210			error(USER, errmsg);
211			}
212	greg	2.16	/* wake up rendering process */
213	greg	2.2	if (kill(pid, SIGIO) < 0)
214	greg	2.1	error(SYSTEM, "cannot signal rendering process in io_process");
215	greg	2.16	/* open named pipes, in order */
216			if ((fdin = open(pfin, O_WRONLY)) < 0)
217			error(SYSTEM, "cannot open input pipe in io_process");
218			if ((fdout = open(pfout, O_RDONLY)) < 0)
219			error(SYSTEM, "cannot open output pipe in io_process");
220			if (pferr[0] && (fderr = open(pferr, O_RDONLY)) < 0)
221			error(SYSTEM, "cannot open error pipe in io_process");
222			for ( ; ; ) { /* loop on select call */
223			FD_ZERO(&readfds);
224			FD_ZERO(&writefds);
225			FD_ZERO(&excepfds);
226			nfds = 0;
227			if (fdin >= 0) {
228			FD_SET(fdin, &writefds);
229			FD_SET(fdin, &excepfds);
230			nfds = fdin+1;
231	greg	2.14	}
232	greg	2.16	if (fdout >= 0) {
233			FD_SET(fdout, &readfds);
234			FD_SET(fdout, &excepfds);
235			nfds = fdout+1;
236	greg	2.14	}
237	greg	2.16	if (fderr >= 0) {
238			FD_SET(fderr, &readfds);
239			FD_SET(fderr, &excepfds);
240			nfds = fderr+1;
241			}
242			if (nfds == 0)
243			break; /* all done, exit */
244			if (select(nfds, &readfds, &writefds, &excepfds, NULL) < 0)
245			error(SYSTEM, "error in select call in io_process");
246			/* renderer stderr */
247			if (fderr >= 0 && (FD_ISSET(fderr, &readfds) \|\|
248			FD_ISSET(fderr, &excepfds))) {
249			nr = read(fderr, cp=buf, sizeof(buf));
250			if (nr < 0)
251			goto readerr;
252			if (nr == 0) {
253			close(fderr);
254	greg	2.18	/* close(2); don't close stderr! */
255	greg	2.16	fderr = -1;
256			} else
257			do { /* write it all */
258			if ((n = write(2, cp, nr)) <= 0)
259			goto writerr;
260			cp += n;
261			} while ((nr -= n) > 0);
262			}
263			/* renderer stdout */
264			if (fdout >= 0 && (FD_ISSET(fdout, &readfds) \|\|
265			FD_ISSET(fdout, &excepfds))) {
266			nr = read(fdout, cp=buf, sizeof(buf));
267			if (nr < 0)
268			goto readerr;
269			if (nr == 0) { /* EOF */
270			close(fdout);
271			close(1);
272			fdout = -1;
273			} else
274			do { /* write it all */
275			if ((n = write(1, cp, nr)) <= 0)
276			goto writerr;
277			cp += n;
278			} while ((nr -= n) > 0);
279			}
280			/* renderer stdin */
281			if (fdin >= 0 && (FD_ISSET(fdin, &writefds) \|\|
282			FD_ISSET(fdin, &excepfds))) {
283			nr = read(0, buf, 512); /* use minimal buffer */
284			if (nr < 0)
285			goto readerr;
286			if (nr == 0) {
287			close(0);
288			close(fdin);
289			fdin = -1;
290			} else if (write(fdin, buf, nr) < nr)
291			goto writerr; /* what else to do? */
292			}
293	greg	2.1	}
294	greg	2.16	_exit(0); /* we ought to return renderer error status! */
295	greg	2.1	formerr:
296			error(USER, "format error in persist file");
297	greg	2.16	readerr:
298			error(SYSTEM, "read error in io_process");
299			writerr:
300			error(SYSTEM, "write error in io_process");
301	greg	2.1	}
302	greg	2.6
303	greg	2.8	#else
304
305			pfclean() {}
306
307	greg	2.6	#endif