--- ray/src/common/unix_process.c	2006/06/07 17:52:03	3.8
+++ ray/src/common/unix_process.c	2019/05/14 18:37:36	3.14
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: unix_process.c,v 3.8 2006/06/07 17:52:03 schorsch Exp $";
+static const char	RCSid[] = "$Id: unix_process.c,v 3.14 2019/05/14 18:37:36 greg Exp $";
 #endif
 /*
  * Routines to communicate with separate process via dual pipes
@@ -28,14 +28,22 @@ char	*av[]
 	char	*compath;
 	int	p0[2], p1[2];
 
-	pd->running = 0; /* not yet */
-					/* find executable */
-	compath = getpath(av[0], getenv("PATH"), 1);
-	if (compath == 0)
+	pd->pid = -1;
+	pd->running = 0;		/* not going yet */
+	
+	if (av == NULL)			/* cloning operation? */
+		compath = NULL;
+	else if ((compath = getpath(av[0], getenv("PATH"), X_OK)) == NULL)
 		return(0);
 	if (pipe(p0) < 0 || pipe(p1) < 0)
 		return(-1);
-	if ((pd->pid = fork()) == 0) {		/* if child */
+#ifdef BSD
+	if (compath != NULL)
+		pd->pid = vfork();	/* more efficient with exec() */
+	else
+#endif
+	pd->pid = fork();
+	if (pd->pid == 0) {		/* if child... */
 		close(p0[1]);
 		close(p1[0]);
 		if (p0[0] != 0) {	/* connect p0 to stdin */
@@ -46,7 +54,9 @@ char	*av[]
 			dup2(p1[1], 1);
 			close(p1[1]);
 		}
-		execv(compath, av);	/* exec command */
+		if (compath == NULL)	/* just cloning? */
+			return(0);
+		execv(compath, av);	/* else exec command */
 		perror(compath);
 		_exit(127);
 	}
@@ -68,22 +78,45 @@ char	*av[]
 }
 
 
-
 int
-close_process(		/* close pipes and wait for process */
-SUBPROC *pd
+close_processes(	/* close pipes and wait for processes to finish */
+SUBPROC pd[],
+int nproc
 )
 {
-	int	status;
+	int	togo = nproc;
+	int	status, rtn_status = 0;
+	RT_PID	pid;
+	int	i;
 
-	if (!pd->running)
-		return(0);
-	close(pd->r);
-	close(pd->w);
-	pd->running = 0;
-	if (waitpid(pd->pid, &status, 0) == pd->pid)
+	for (i = 0; i < nproc; i++)		/* close pipes, first */
+		if (pd[i].running) {
+			close(pd[i].w);
+			close(pd[i].r);
+			pd[i].running = 0;
+		} else 
+			togo -= (pd[i].pid < 0);
+	if (nproc == 1) {			/* await specific process? */
+		if (waitpid(pd->pid, &status, 0) != pd->pid)
+			return(-1);
+		pd->pid = -1;
 		return(status>>8 & 0xff);
-	return(-1);		/* ? unknown status */
+	}
+						/* else unordered wait */
+	while (togo > 0 && (pid = wait(&status)) >= 0) {
+		for (i = nproc; i-- > 0; )
+			if (pd[i].pid == pid) {
+				pd[i].pid = -1;
+				--togo;
+				break;
+			}
+		if (i < 0)
+			continue;		/* child we don't know? */
+		status = status>>8 & 0xff;
+		if (status)			/* record non-zero status */
+			rtn_status = status;
+	}
+	if (togo)				/* child went missing? */
+		return(-1);
+	return(rtn_status);
 }
-
-