--- ray/src/rt/devcomm.c	2004/03/30 16:13:01	2.12
+++ ray/src/rt/devcomm.c	2011/10/05 17:20:55	2.16
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: devcomm.c,v 2.12 2004/03/30 16:13:01 schorsch Exp $";
+static const char	RCSid[] = "$Id: devcomm.c,v 2.16 2011/10/05 17:20:55 greg Exp $";
 #endif
 /*
  *  devcomm.c - communication routines for separate drivers.
@@ -10,8 +10,11 @@ static const char	RCSid[] = "$Id: devcomm.c,v 2.12 200
 #include "copyright.h"
 
 #include <sys/types.h>
-#include <sys/wait.h> /* XXX platform specific */
+#ifndef _WIN32
+#include <sys/wait.h>
+#endif
 
+#include "paths.h"
 #include "platform.h"
 #include "standard.h"
 #include "driver.h"
@@ -54,8 +57,10 @@ final_connect(void)				/* verify and initialize connec
 	getstate();
 						/* set error vectors */
 	erract[COMMAND].pf = comm_comout;
+	/*					doesn't work with raypcalls.c
 	if (erract[WARNING].pf != NULL)
 		erract[WARNING].pf = comm_comout;
+	*/
 	return(&comm_driver);
 }
 
@@ -97,7 +102,7 @@ comm_init(			/* set up and execute driver */
 		close(p2[0]);
 		sprintf(pin, "%d", p1[0]);
 		sprintf(pout, "%d", p2[1]);
-		execl(dvcname, dname, pin, pout, id, 0);
+		execl(dvcname, dname, pin, pout, id, NULL);
 		perror(dvcname);
 		_exit(127);
 	}
@@ -105,6 +110,12 @@ comm_init(			/* set up and execute driver */
 		goto syserr;
 	close(p1[0]);
 	close(p2[1]);
+	/*
+	 * Close write stream on exec to avoid multiprocessing deadlock.
+	 * No use in read stream without it, so set flag there as well.
+	 */
+	fcntl(p1[1], F_SETFD, FD_CLOEXEC);
+	fcntl(p2[0], F_SETFD, FD_CLOEXEC);
 	if ((devout = fdopen(p1[1], "w")) == NULL)
 		goto syserr;
 	if ((devin = fdopen(p2[0], "r")) == NULL)
@@ -136,8 +147,10 @@ comm_close(void)			/* done with driver */
 	fclose(devin);
 	if (devchild < 0)
 		return;
+#ifndef _WIN32
 	while ((pid = wait(0)) != -1 && pid != devchild)
 		;
+#endif
 }