--- ray/src/rt/persist.c	1993/01/25 19:17:36	2.5
+++ ray/src/rt/persist.c	1998/01/03 20:07:31	2.25
@@ -1,7 +1,7 @@
-/* Copyright (c) 1993 Regents of the University of California */
+/* Copyright (c) 1997 Silicon Graphics, Inc. */
 
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static char SCCSid[] = "$SunId$ SGI";
 #endif
 
 /*
@@ -9,9 +9,12 @@ static char SCCSid[] = "$SunId$ LBL";
  */
 
 #include "standard.h"
+#include "random.h"
+
+#ifdef F_SETLKW
 #include "paths.h"
+#include "selcall.h"
 #include <signal.h>
-#include <sys/types.h>
 #include <sys/stat.h>
 
 #ifndef TIMELIM
@@ -22,10 +25,14 @@ 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];
+static char	inpname[TEMPLEN+1], outpname[TEMPLEN+1], errname[TEMPLEN+1];
 
 
 pfdetach()		/* release persist (and header) resources */
@@ -36,6 +43,7 @@ pfdetach()		/* release persist (and header) resources 
 	persistfname = NULL;
 	inpname[0] = '\0';
 	outpname[0] = '\0';
+	errname[0] = '\0';
 	headismine = 0;
 }
 
@@ -50,6 +58,8 @@ pfclean()		/* clean up persist files */
 		unlink(inpname);
 	if (outpname[0])
 		unlink(outpname);
+	if (errname[0])
+		unlink(errname);
 }
 
 
@@ -70,7 +80,7 @@ int	lf;
 persistfile(pfn)	/* open persist file and lock it */
 char	*pfn;
 {
-	persistfd = open(pfn, O_WRONLY|O_CREAT|O_EXCL, 0666);
+	persistfd = open(pfn, O_WRONLY|O_CREAT|O_EXCL, 0644);
 	if (persistfd >= 0) {
 		persistfname = pfn;
 		pflock(1);
@@ -87,40 +97,61 @@ char	*pfn;
 }
 
 
-int sig_noop() {}
+static int	got_io;
 
+static int sig_io() { got_io++; }
 
+static int sig_alrm() { quit(0); }
+
+
 pfhold()		/* holding pattern for idle rendering process */
 {
-	char	buf[128];
+	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)
+	if (mknod(mktemp(strcpy(inpname,TEMPLATE)), S_IFIFO|0600, 0) < 0)
 		goto createrr;
-	if (mknod(mktemp(strcpy(outpname,TEMPLATE)), S_IFIFO|0600) < 0)
+	if (mknod(mktemp(strcpy(outpname,TEMPLATE)), S_IFIFO|0600, 0) < 0)
 		goto createrr;
-	sprintf(buf, "%d\n%s\n%s\n", getpid(), inpname, outpname);
-	if (lseek(persistfd, 0L, 0) < 0)
-		error(SYSTEM, "seek error on persist file in pfhold");
+	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 in pfhold");
+		error(SYSTEM, "error writing persist file");
+	lseek(persistfd, 0L, 0);
 				/* wait TIMELIM for someone to signal us */
-	signal(SIGIO, sig_noop);
+	got_io = 0;
+	signal(SIGIO, sig_io);
+	oldalrm = (int (*)())signal(SIGALRM, sig_alrm);
 	alarm(TIMELIM);
-	pflock(0);
-	pause();
-	alarm(0);
+	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);
+	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;
+	sleep(3);		/* give them a chance to open their pipes */
+	if (errname[0]) {
+		if (freopen(errname, "w", stderr) == NULL)
+			goto openerr;
+		unlink(errname);
+		errname[0] = '\0';
+	}
 	unlink(inpname);
 	inpname[0] = '\0';
 	unlink(outpname);
@@ -133,63 +164,165 @@ openerr:
 }
 
 
-io_process()		/* just act as conduits to and from actual process */
+io_process()		/* just act as go-between for actual process */
 {
 	register char	*cp;
 	register int	nr, n;
-	char	buf[4096], *pfin, *pfout;
-	int	pid;
-				/* load and close persist file */
-	nr = read(persistfd, buf, sizeof(buf));
-	pfdetach();
+	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, "cannot read persist file");
-	buf[nr] = '\0';
-	if ((cp = index(buf, '\n')) == NULL)
+		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(buf)) <= 0)
+	if ((pid = atoi(cp)) <= 0)
 		goto formerr;
-	pfin = cp;
 	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;
-				/* wake up rendering process */
+	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");
-	pid = fork();		/* fork i/o process */
+					/* fork child feeder process */
+	pid = fork();
 	if (pid < 0)
 		error(SYSTEM, "fork failed in io_process");
-				/* connect to appropriate pipe */
-	if (pid) {			/* parent passes renderer output */
-		if (freopen(pfout, "r", stdin) == NULL)
-			error(SYSTEM, "cannot open input pipe in io_process");
-	} else {			/* child passes renderer input */
-		if (freopen(pfin, "w", stdout) == NULL)
-			error(SYSTEM, "cannot open input pipe 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);
 	}
-				/* pass input to output */
-	cp = buf; n = sizeof(buf);
-	while ((nr = read(fileno(stdin), cp, n)) > 0) {
-		nr += cp-buf;
-		if ((n = write(fileno(stdout), buf, nr)) <= 0)
-			error(SYSTEM, "write error in io_process");
-		cp = buf;
-		while (n < nr)
-			*cp++ = buf[n++];
-		n = sizeof(buf) - (cp-buf);
+	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);
+		}
 	}
-	fclose(stdin);
-	fclose(stdout);
-	if (pid)		/* parent waits for child */
-		wait(0);
-	exit(0);		/* all done, exit (not quit!) */
+	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
+
+pfclean() {}
+
+#endif