--- ray/src/util/rpiece.c	1992/08/09 12:12:48	2.8
+++ ray/src/util/rpiece.c	1993/05/04 09:30:27	2.20
@@ -1,4 +1,4 @@
-/* Copyright (c) 1992 Regents of the University of California */
+/* Copyright (c) 1993 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -10,11 +10,44 @@ static char SCCSid[] = "$SunId$ LBL";
  
 #include "standard.h"
 #include <fcntl.h>
+
+#ifndef F_SETLKW
+
+main(argc, argv)
+int argc;
+char *argv[];
+{
+	fprintf(stderr, "%s: no NFS lock manager on this machine\n", argv[0]);
+	exit(1);
+}
+
+#else
+
 #include <signal.h>
 #include "color.h"
 #include "view.h"
 #include "resolu.h"
 
+#ifndef NFS
+#define  NFS			1
+#endif
+				/* set the following to 0 to forgo forking */
+#ifndef MAXFORK
+#if NFS
+#define  MAXFORK		3	/* allotment of duped processes */
+#else
+#define  MAXFORK		0
+#endif
+#endif
+					/* protection from SYSV signals(!) */
+#if defined(sgi) || defined(hpux)
+#define guard_io()	sighold(SIGALRM)
+#define unguard()	sigrelse(SIGALRM)
+#endif
+#ifndef guard_io
+#define guard_io()	0
+#define unguard()	0
+#endif
 				/* rpict command */
 char  *rpargv[128] = {"rpict", "-S", "1", "-x", "512", "-y", "512", "-pa", "1"};
 int  rpargc = 9;
@@ -30,6 +63,7 @@ char  *outfile = NULL;
 int  outfd;
 long  scanorig;
 int  syncfd = -1;		/* lock file descriptor */
+int  nforked = 0;
 
 char  *progname;
 int  verbose = 0;
@@ -96,12 +130,17 @@ char  *argv[];
 			case 'F':		/* syncronization file */
 				if (argv[i][2])
 					break;
-				if ((syncfd = open(argv[++i], O_RDWR)) < 0) {
+				if ((syncfd = open(argv[++i],
+						O_RDWR|O_CREAT, 0666)) < 0) {
 					fprintf(stderr, "%s: cannot open\n",
 							argv[i]);
 					exit(1);
 				}
 				continue;
+			case 'z':		/* z-file ist verbotten */
+				fprintf(stderr, "%s: -z option not allowed\n",
+						argv[0]);
+				exit(1);
 			case 'o':		/* output file */
 				if (argv[i][2])
 					break;
@@ -117,8 +156,7 @@ char  *argv[];
 	}
 	init(argc, argv);
 	rpiece();
-	rval = cleanup();
-	exit(rval);
+	exit(cleanup(0));
 }
 
 
@@ -158,8 +196,8 @@ char  **av;
 	} else if ((outfd = open(outfile, O_RDWR)) >= 0) {
 		if ((fp = fdopen(dup(outfd), "r+")) == NULL)
 			goto filerr;
-		getheader(fp, NULL);		/* skip header */
-		if (fscnresolu(&hr, &vr, fp) < 0 ||	/* check resolution */
+		getheader(fp, NULL, NULL);	/* skip header */
+		if (!fscnresolu(&hr, &vr, fp) ||	/* check resolution */
 				hr != hres*hmult || vr != vres*vmult) {
 			fprintf(stderr, "%s: resolution mismatch on file \"%s\"\n",
 					progname, outfile);
@@ -173,7 +211,9 @@ char  **av;
 	scanorig = ftell(fp);		/* record position of first scanline */
 	if (fclose(fp) == -1)		/* done with stream i/o */
 		goto filerr;
+#if NFS
 	sync();				/* flush NFS buffers */
+#endif
 					/* start rpict process */
 	if (open_process(rpd, rpargv) <= 0) {
 		fprintf(stderr, "%s: cannot start %s\n", progname, rpargv[0]);
@@ -226,7 +266,7 @@ int  *xp, *yp;
 				return(0);
 			}
 		}
-		sprintf(buf, "%d %d\n%d %d\n", hmult, vmult, *xp, *yp);
+		sprintf(buf, "%4d %4d\n%4d %4d\n", hmult, vmult, *xp, *yp);
 		lseek(syncfd, 0L, 0);		/* write new position */
 		write(syncfd, buf, strlen(buf));
 		fls.l_type = F_UNLCK;		/* release sync file */
@@ -238,22 +278,23 @@ int  *xp, *yp;
 	if (sscanf(buf, "%d %d", xp, yp) == 2)
 		return(1);
 	fprintf(stderr, "%s: input format error\n", progname);
-	exit(1);
+	exit(cleanup(1));
 }
 
 
 int
-cleanup()			/* close rpict process and clean up */
+cleanup(rstat)			/* close rpict process and clean up */
+int  rstat;
 {
-	register int  rpstat;
+	int  status;
 
 	free((char *)pbuf);
 	fclose(torp);
 	fclose(fromrp);
-	rpstat = close_process(rpd);
-	if (rpstat == -1)
-		rpstat = 0;
-	return(rpstat);
+	while (wait(&status) != -1)
+		if (rstat == 0)
+			rstat = status>>8 & 0xff;
+	return(rstat);
 }
 
 
@@ -261,98 +302,135 @@ rpiece()			/* render picture piece by piece */
 {
 	VIEW  pview;
 	int  xorg, yorg;
-	
+					/* compute view parameters */
+	copystruct(&pview, &ourview);
+	switch (ourview.type) {
+	case VT_PER:
+		pview.horiz = 2.*180./PI*atan(
+				tan(PI/180./2.*ourview.horiz)/hmult );
+		pview.vert = 2.*180./PI*atan(
+				tan(PI/180./2.*ourview.vert)/vmult );
+		break;
+	case VT_PAR:
+	case VT_ANG:
+		pview.horiz = ourview.horiz / hmult;
+		pview.vert = ourview.vert / vmult;
+		break;
+	case VT_HEM:
+		pview.horiz = 2.*180./PI*asin(
+				sin(PI/180./2.*ourview.horiz)/hmult );
+		pview.vert = 2.*180./PI*asin(
+				sin(PI/180./2.*ourview.vert)/vmult );
+		break;
+	default:
+		fprintf(stderr, "%s: unknown view type '-vt%c'\n",
+				progname, ourview.type);
+		exit(cleanup(1));
+	}
+					/* render each piece */
 	while (nextpiece(&xorg, &yorg)) {
-		copystruct(&pview, &ourview);	/* compute view for piece */
-		switch (ourview.type) {
-		case VT_PER:
-			pview.horiz = 2.*180./PI*atan(
-					tan(PI/180./2.*ourview.horiz)/hmult );
-			pview.vert = 2.*180./PI*atan(
-					tan(PI/180./2.*ourview.vert)/vmult );
-			break;
-		case VT_PAR:
-		case VT_ANG:
-			pview.horiz = ourview.horiz / hmult;
-			pview.vert = ourview.vert / vmult;
-			break;
-		case VT_HEM:
-			pview.horiz = 2.*180./PI*asin(
-					sin(PI/180./2.*ourview.horiz)/hmult );
-			pview.vert = 2.*180./PI*asin(
-					sin(PI/180./2.*ourview.vert)/vmult );
-			break;
-		default:
-			fprintf(stderr, "%s: unknown view type '-vt%c'\n",
-					progname, ourview.type);
-			exit(1);
-		}
-		pview.hoff += xorg - 0.5*(hmult-1);
-		pview.voff += yorg - 0.5*(vmult-1);
+		pview.hoff = ourview.hoff + xorg - 0.5*(hmult-1);
+		pview.voff = ourview.voff + yorg - 0.5*(vmult-1);
 		fputs(VIEWSTR, torp);
 		fprintview(&pview, torp);
 		putc('\n', torp);
-		fflush(torp);			/* assign piece to rpict */
+		fflush(torp);			/* assigns piece to rpict */
 		putpiece(xorg, yorg);		/* place piece in output */
-		if (verbose) {			/* notify caller */
-			printf("%d %d done\n", xorg, yorg);
-			fflush(stdout);
-		}
 	}
 }
 
 
+int
 putpiece(xpos, ypos)		/* get next piece from rpict */
 int  xpos, ypos;
 {
 	struct flock  fls;
+	int  pid, status;
 	int  hr, vr;
 	register int  y;
 				/* check bounds */
 	if (xpos < 0 | ypos < 0 | xpos >= hmult | ypos >= vmult) {
 		fprintf(stderr, "%s: requested piece (%d,%d) out of range\n",
 				progname, xpos, ypos);
-		exit(1);
+		exit(cleanup(1));
 	}
 				/* check header from rpict */
-	getheader(fromrp, NULL);
-	if (fscnresolu(&hr, &vr, fromrp) < 0 || hr != hres || vr != vres) {
+	guard_io();
+	getheader(fromrp, NULL, NULL);
+	if (!fscnresolu(&hr, &vr, fromrp) || hr != hres | vr != vres) {
 		fprintf(stderr, "%s: resolution mismatch from %s\n",
 				progname, rpargv[0]);
-		exit(1);
+		exit(cleanup(1));
 	}
+	unguard();
 				/* load new piece into buffer */
-	for (y = 0; y < vr; y++)
+	for (y = 0; y < vr; y++) {
+		guard_io();
 		if (freadcolrs(pbuf+y*hr, hr, fromrp) < 0) {
 			fprintf(stderr, "%s: read error from %s\n",
 					progname, rpargv[0]);
-			exit(1);
+			exit(cleanup(1));
 		}
+		unguard();
+	}
+#if MAXFORK
+				/* fork so we don't slow rpict down */
+	if ((pid = fork()) > 0) {
+		if (++nforked >= MAXFORK) {
+			wait(&status);		/* reap a child */
+			if (status)
+				exit(cleanup(status>>8 & 0xff));
+			nforked--;
+		}
+		return(pid);
+	}
+#else
+	pid = -1;		/* no forking */
+#endif
+	fls.l_start = scanorig +
+		((long)(vmult-1-ypos)*vres*hmult+xpos)*hres*sizeof(COLR);
+#if NFS
+	fls.l_len = ((long)(vres-1)*hmult+1)*hres*sizeof(COLR);
 				/* lock file section so NFS doesn't mess up */
 	fls.l_whence = 0;
-	fls.l_len = (long)vres*hmult*hres*sizeof(COLR);
-	fls.l_start = scanorig + (vmult-1-ypos)*fls.l_len;
 	fls.l_type = F_WRLCK;
 	fcntl(outfd, F_SETLKW, &fls);
+#endif
 				/* write new piece to file */
-	if (lseek(outfd, fls.l_start+(long)xpos*hres*sizeof(COLR), 0) == -1)
+	if (lseek(outfd, fls.l_start, 0) == -1)
 		goto seekerr;
-	for (y = 0; y < vr; y++) {
-		if (writebuf(outfd, (char *)(pbuf+y*hr), hr*sizeof(COLR)) !=
-				hr*sizeof(COLR)) {
-			fprintf(stderr, "%s: write error on file \"%s\"\n",
-					progname, outfile);
-			exit(1);
+	if (hmult == 1) {
+		if (writebuf(outfd, (char *)pbuf,
+				vr*hr*sizeof(COLR)) != vr*hr*sizeof(COLR))
+			goto writerr;
+	} else
+		for (y = 0; y < vr; y++) {
+			if (writebuf(outfd, (char *)(pbuf+y*hr),
+					hr*sizeof(COLR)) != hr*sizeof(COLR))
+				goto writerr;
+			if (y < vr-1 && lseek(outfd,
+					(long)(hmult-1)*hr*sizeof(COLR),
+					1) == -1)
+				goto seekerr;
 		}
-		if (hmult != 1 && y < vr-1 && lseek(outfd,
-				(long)(hmult-1)*hr*sizeof(COLR), 1) == -1)
-			goto seekerr;
+	if (verbose) {				/* notify caller */
+		printf("%d %d done\n", xpos, ypos);
+		fflush(stdout);
 	}
-				/* unlock file section */
-	fls.l_type = F_UNLCK;
-	fcntl(outfd, F_SETLKW, &fls);
-	return;
+	if (pid == -1) {	/* didn't fork or fork failed */
+#if NFS
+		fls.l_type = F_UNLCK;		/* release lock */
+		fcntl(outfd, F_SETLKW, &fls);
+#endif
+		return(0);
+	}
+	_exit(0);		/* else exit child process (releasing lock) */
 seekerr:
 	fprintf(stderr, "%s: seek error on file \"%s\"\n", progname, outfile);
-	exit(1);
+	_exit(1);
+writerr:
+	fprintf(stderr, "%s: write error on file \"%s\"\n", progname, outfile);
+	_exit(1);
 }
+
+#endif