Fix t_spawnattr test for attributes handling by posix_spawn(3).

Connect it to the build.

The code assumed that SCHED_* constants form a contiguous set of
numbers, remove the assumption by using schedulers[] array in
get_different_scheduler().  This is no-op on FreeBSD, but improves
code portability.

The selection of different priority used the min/max priority range of
the current scheduler class, instead of the priority to be changed to.
The bug caused the test failure.

Remove duplication of POSIX_SPAWN_SETSIGDEF flag and now unused
duplications of MIN/MAX definitions.

Reviewed by:	jilles, pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D3533

contrib/netbsd-tests/lib/libc/gen/posix_spawn/t_spawnattr.c

@@ -30,6 +30,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <sys/param.h>
 #include <atf-c.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -42,51 +43,56 @@
 #include <unistd.h>
 #include <sys/wait.h>
 
-#define MAX(a, b)	(a) > (b) ? (a) : (b)
-#define MIN(a, b)	(a) > (b) ? (b) : (a)
-
 static int get_different_scheduler(void);
-static int get_different_priority(void);
+static int get_different_priority(int scheduler);
+
+static const int schedulers[] = {
+	SCHED_OTHER,
+	SCHED_FIFO,
+	SCHED_RR
+};
 
 static int
-get_different_scheduler()
+get_different_scheduler(void)
 {
-	int scheduler, max, min, new;
-
-	max = MAX(MAX(SCHED_FIFO, SCHED_OTHER), SCHED_RR);
-	min = MIN(MIN(SCHED_FIFO, SCHED_OTHER), SCHED_RR);
+	u_int i;
+	int scheduler;
 
 	/* get current schedule policy */
 	scheduler = sched_getscheduler(0);
+	for (i = 0; i < nitems(schedulers); i++) {
+		if (schedulers[i] == scheduler)
+			break;
+	}
+	ATF_REQUIRE_MSG(i < nitems(schedulers),
+	    "Unknown current scheduler %d", scheduler);
 					
 	/* new scheduler */
-	new = (scheduler + 1);
-	if (new > max)
-		new = min;
-								
-	return new;
+	i++;
+	if (i >= nitems(schedulers))
+		i = 0;
+	return schedulers[i];
 }
 
 static int
-get_different_priority()
+get_different_priority(int scheduler)
 {
-	int scheduler, max, min, new, priority;
+	int max, min, new, priority;
 	struct sched_param param;
 
-	/* get current schedule policy */
-	scheduler = sched_getscheduler(0);
-
 	max = sched_get_priority_max(scheduler);
 	min = sched_get_priority_min(scheduler);
 
 	sched_getparam(0, &param);
 	priority = param.sched_priority;
 	
-	/* new schedule policy */
-	new = (priority + 1);
+	/*
+	 * Change numerical value of the priority, to ensure that it
+	 * was set for the spawned child.
+	 */
+	new = priority + 1;
 	if (new > max)
 		new = min;
-	
 	return new;
 }
 
@@ -119,16 +125,15 @@ ATF_TC_BODY(t_spawnattr, tc)
 	posix_spawnattr_init(&attr);
 
 	scheduler = get_different_scheduler();
-	priority = get_different_priority();
+	priority = get_different_priority(scheduler);
 	sp.sched_priority = priority;
 	
 	sigemptyset(&sig);
 	sigaddset(&sig, SIGUSR1);
 
-	posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSCHEDULER | 
-		POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETPGROUP |
-		POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF |
-		POSIX_SPAWN_SETSIGDEF); 
+	posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSCHEDULER |
+	    POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETPGROUP |
+	    POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF);
 	posix_spawnattr_setpgroup(&attr, 0);
 	posix_spawnattr_setschedparam(&attr, &sp);
 	posix_spawnattr_setschedpolicy(&attr, scheduler);

lib/libc/tests/gen/posix_spawn/Makefile

@@ -10,9 +10,9 @@ TESTSDIR=	${TESTSBASE}/lib/libc/gen/posix_spawn
 
 BINDIR=		${TESTSDIR}
 
-# TODO: t_spawnattr (fix from pho@ needs additional review)
 NETBSD_ATF_TESTS_C=	fileactions_test
 NETBSD_ATF_TESTS_C+=	spawn_test
+NETBSD_ATF_TESTS_C+=	spawnattr_test
 
 PROGS=		h_fileactions
 PROGS+=		h_spawn