--- ray/src/rt/raypcalls.c	2020/04/06 21:49:16	2.31
+++ ray/src/rt/raypcalls.c	2024/04/30 22:25:46	2.38
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: raypcalls.c,v 2.31 2020/04/06 21:49:16 greg Exp $";
+static const char	RCSid[] = "$Id: raypcalls.c,v 2.38 2024/04/30 22:25:46 greg Exp $";
 #endif
 /*
  *  raypcalls.c - interface for parallel rendering using Radiance
@@ -147,7 +147,7 @@ static const char	RCSid[] = "$Id: raypcalls.c,v 2.31 2
 #include  "selcall.h"
 
 #ifndef RAYQLEN
-#define RAYQLEN		96		/* # rays to send at once */
+#define RAYQLEN		24		/* # rays to send at once */
 #endif
 
 #ifndef MAX_RPROCS
@@ -212,7 +212,7 @@ ray_pflush(void)			/* send queued rays to idle childre
 	for (i = ray_pnprocs; nc && i--; ) {
 		if (r_proc[i].npending > 0)
 			continue;	/* child looks busy */
-		n = (r_send_next - sfirst)/nc--;
+		n = (r_send_next - sfirst) / nc--;
 		if (!n)
 			continue;
 					/* smuggle set size in crtype */
@@ -456,6 +456,8 @@ ray_popen(			/* open the specified # processes */
 		nadd = MAX_NPROCS - ray_pnprocs;
 	if (nadd <= 0)
 		return;
+	if (nobjects <= 0)
+		error(CONSISTENCY, "ray_popen() called before scene loaded");
 	ambsync();			/* load any new ambient values */
 	if (shm_boundary == NULL) {	/* first child process? */
 		preload_objs();		/* preload auxiliary data */
@@ -510,20 +512,25 @@ ray_pclose(		/* close one or more child processes */
 	static int	inclose = 0;
 	RAY		res;
 	int		i, status = 0;
+					/* check no child / in child */
+	if (ray_pnprocs <= 0)
+		return;
 					/* check recursion */
 	if (inclose)
 		return;
 	inclose++;
-					/* check no child / in child */
-	if (ray_pnprocs <= 0)
-		return;
 					/* check argument */
 	if ((nsub <= 0) | (nsub > ray_pnprocs))
 		nsub = ray_pnprocs;
 					/* clear our ray queue */
+	i = r_send_next;
+	r_send_next = 0;
 	while (ray_presult(&res,0) > 0)
-		;
-	r_send_next = 0;		/* hard reset in case of error */
+		++i;
+	if (i) {
+		sprintf(errmsg, "dropped %d rays in ray_pclose()", i);
+		error(WARNING, errmsg);
+	}
 	r_recv_first = r_recv_next = RAYQLEN;
 					/* close send pipes */
 	for (i = ray_pnprocs-nsub; i < ray_pnprocs; i++)
@@ -537,6 +544,10 @@ ray_pclose(		/* close one or more child processes */
 		for (i = 0; i < nsub; ) {
 			int	j, mystatus;
 			RT_PID	pid = wait(&mystatus);
+			if (pid < 0) {
+				status = 127<<8;
+				break;
+			}
 			for (j = ray_pnprocs-nsub; j < ray_pnprocs; j++)
 				if (r_proc[j].pid == pid) {
 					if (mystatus)