These are regression tests for the P1003.1B scheduler.

Approved by:	jkh

tools/regression/README

@@ -1,3 +1,5 @@
+$FreeBSD$
+
 This directory is for regression test programs.
 
 A regression test program is one that will exercise a particular bit of the
@@ -6,3 +8,4 @@ system to check that we have not reintroduced an old bug.
 Please make a subdir per program, and add a brief description to this file.
 
 nfsmmap		Some tests to exercise some tricky cases in NFS and mmap
+p1003_1b	Exercise 1003.1B scheduler

tools/regression/p1003_1b/Makefile

@@ -0,0 +1,17 @@
+# $FreeBSD$
+
+PROG=p1003_1b
+
+SRCS=\
+	fifo.c \
+	main.c \
+	memlock.c \
+	prutil.c \
+	p26.c \
+	sched.c \
+	yield.c
+
+NOMAN=1
+
+COPTS+=-DNO_MEMLOCK
+.include <bsd.prog.mk>

tools/regression/p1003_1b/README

@@ -0,0 +1,14 @@
+$FreeBSD$
+
+p1003_1b: Regression tests for the scheduling facilities.
+The following should always work as of the release of 4.0:
+
+p1003_1b fifo : Check that the FIFO scheduler seems to work.
+p1003_1b p26 :  Check that we support the expected features.
+p1003_1b sched: Check that schedule switching seems to work.
+p1003_1b yield: Check that yielding runs the expected process.
+
+As of today "p1003_1b yield" doesn't work.  I have a minimal set
+of patches I'm waiting for approval to commit.
+
+Peter dufault@freebsd.org

tools/regression/p1003_1b/fifo.c

@@ -0,0 +1,227 @@
+/*
+ * Copyright (c) 1996 - 2000
+ *	HD Associates, Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by HD Associates, Inc
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <err.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <sched.h>
+#include <signal.h>
+
+volatile int ticked;
+#define CAN_USE_ALARMS
+
+#ifdef CAN_USE_ALARMS
+void tick(int arg)
+{
+	ticked = 1;
+}
+#endif
+
+/* Fifo: Verify that fifo and round-robin scheduling seem to work.
+ *
+ * This tests:
+ * 1. That sched_rr_get_interval seems to work;
+ * 2. That FIFO scheduling doesn't seeem to be round-robin;
+ * 3. That round-robin scheduling seems to work.
+ * 
+ */
+static pid_t child;
+static void tidyup(void)
+{
+	if (child)
+		kill(child, SIGHUP);
+}
+
+static double
+tvsub(const struct timeval *a, const struct timeval *b)
+{
+	long sdiff;
+	long udiff;
+
+	sdiff = a->tv_sec - b->tv_sec;
+	udiff = a->tv_usec - b->tv_usec;
+
+	return (double)(sdiff * 1000000 + udiff) / 1e6;
+}
+
+int fifo(int argc, char *argv[])
+{
+	int e = 0;
+	volatile long *p, pid;
+	int i;
+	struct sched_param fifo_param;
+	struct timespec interval;
+#define MAX_RANAT 32
+	struct timeval ranat[MAX_RANAT];
+
+#ifdef CAN_USE_ALARMS
+	static struct itimerval itimerval;
+#endif
+
+	/* What is the round robin interval?
+	 */
+
+	if (sched_rr_get_interval(0, &interval) == -1) {
+		perror("sched_rr_get_interval");
+		exit(errno);
+	}
+
+#ifdef CAN_USE_ALARMS
+	signal(SIGALRM, tick);
+#endif
+
+	fifo_param.sched_priority = 1;
+
+	p = (long *)mmap(0, sizeof(*p),
+	PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED|MAP_INHERIT, -1, 0);
+
+	if (p == (long *)-1)
+		err(errno, "mmap");
+
+	*p = 0;
+
+	if (sched_setscheduler(0, SCHED_FIFO, &fifo_param) == -1)
+	{
+		perror("sched_setscheduler");
+		return -1;
+	}
+
+	pid = getpid();
+
+	if ((child = fork()) == 0)
+	{
+		/* Child process.  Just keep setting the pointer to our
+		 * PID.  The parent will kill us when it wants to.
+		 */
+
+		pid = getpid();
+		while (1)
+			*p = pid;
+	}
+	else
+	{
+		atexit(tidyup);
+		*p = pid;
+
+
+		ticked = 0;
+
+#ifdef CAN_USE_ALARMS
+		/* Set an alarm for 250 times the round-robin interval.
+		 * Then we will verify that a similar priority process
+		 * will not run when we are using the FIFO scheduler.
+		 */
+		itimerval.it_value.tv_usec = interval.tv_nsec / (1000 / 250);
+
+		itimerval.it_value.tv_sec = itimerval.it_value.tv_usec / 1000000;
+		itimerval.it_value.tv_usec %= 1000000;
+
+
+		if (setitimer(ITIMER_REAL, &itimerval, 0) == -1) {
+			perror("setitimer");
+			exit(errno);
+		}
+#endif
+
+
+		gettimeofday(ranat, 0);
+		i = 1;
+		while (!ticked && i < MAX_RANAT)
+			if (*p == child) {
+				gettimeofday(ranat + i, 0);
+				*p = 0;
+				e = -1;
+				i++;
+			}
+
+		if (e) {
+			int j;
+
+			fprintf(stderr,
+			"SCHED_FIFO had erroneous context switches:\n");
+			for (j = 1; j < i; j++) {
+				fprintf(stderr, "%d %g\n", j,
+					tvsub(ranat + j, ranat + j - 1));
+			}
+			return e;
+		}
+
+		/* Switch to the round robin scheduler and the child
+		 * should run within twice the interval.
+		 */
+		if (sched_setscheduler(child, SCHED_RR, &fifo_param) == -1 ||
+		sched_setscheduler(0, SCHED_RR, &fifo_param) == -1)
+		{
+			perror("sched_setscheduler");
+			return -1;
+		}
+
+		e = -1;
+
+		ticked = 0;
+
+#ifdef CAN_USE_ALARMS
+
+		/* Now we do want to see it run.  But only set
+		 * the alarm for twice the interval:
+		 */
+		itimerval.it_value.tv_usec = interval.tv_nsec / 500;
+
+		if (setitimer(ITIMER_REAL, &itimerval, 0) == -1) {
+			perror("setitimer");
+			exit(errno);
+		}
+#endif
+
+		for (i = 0; !ticked; i++)
+			if (*p == child) {
+				e = 0;
+				break;
+			}
+
+		if (e)
+			fprintf(stderr,"Child never ran when it should have.\n");
+	}
+
+	exit(e);
+}
+
+#ifdef STANDALONE_TESTS
+int main(int argc, char *argv[]) { return fifo(argc, argv); }
+#endif

tools/regression/p1003_1b/main.c

@@ -0,0 +1,78 @@
+/* $FreeBSD$ */
+#include <stdio.h>
+
+int fifo(int argc, char *argv[]);
+int memlock(int argc, char *argv[]);
+int p26(int argc, char *argv[]);
+int sched(int argc, char *argv[]);
+int yield(int argc, char *argv[]);
+
+static struct {
+	const char *t;
+	int (*f)(int, char *[]);
+	int works;
+} tab[] = {
+	{ "fifo", fifo, 1 },
+	{ "memlock", memlock, 0 },
+	{ "p26", p26, 1 },
+	{ "sched", sched, 1 },
+	{ "yield", yield, 1 },
+};
+
+#define N(T) (sizeof (T)/ sizeof(T[0]))
+
+static int usage(int argc, char *argv[])
+{
+	int i;
+	if (argc > 1)
+		fprintf(stderr, "%s is unknown\n", argv[1]);
+
+	fprintf(stderr, "usage: %s [-a] or one of [", argv[0]);
+	for (i = 0; i < (sizeof(tab) / sizeof(tab[0])); i++)
+		fprintf(stderr, "%s%s", (i)? " | " : "", tab[i].t);
+	fprintf(stderr, "]\n");
+
+	return -1;
+}
+
+int main(int argc, char *argv[])
+{
+	int i;
+
+	if (argc == 2 && strcmp(argv[1], "-a") == 0) {
+#if 1
+		fprintf(stderr,
+			"-a should but doesn't really work"
+			" (my notes say \"because things detach\");\n"
+			"meanwhile do these individual tests and look"
+			" for a non-zero exit code:\n");
+		for (i = 0; i < N(tab); i++)
+			if (tab[i].works)
+				fprintf(stderr, "p1003_1b %s\n", tab[i].t);
+		return -1;
+#else
+		{
+			int r;
+			for (i = 0; i < N(tab); i++) {
+				if (tab[i].works) {
+					if ( (r =
+					(*tab[i].f)(argc - 1, argv + 1)) ) {
+						fprintf(stderr,
+						"%s failed\n", tab[i].t);
+						return r;
+					}
+				}
+			}
+			return 0;
+		}
+#endif
+	}
+	
+	if (argc > 1) {
+		for (i = 0; i < N(tab); i++)
+			if (strcmp(tab[i].t, argv[1]) == 0)
+				return (*tab[i].f)(argc - 1, argv + 1);
+	}
+
+	return usage(argc, argv);
+}

tools/regression/p1003_1b/memlock.c

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 1996 - 1999
+ *	HD Associates, Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by HD Associates, Inc
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/mman.h>
+
+#include "prutil.h"
+
+int memlock(int argc, char *argv[])
+{
+	int e = 0;
+
+	/* Is memory locking configured?
+	 */
+	errno = 0;
+	if (sysconf(_SC_MEMLOCK) == -1) {
+		if (errno != 0) {
+			/* This isn't valid - may be a standard violation
+			 */
+			quit("(should not happen) sysconf(_SC_MEMLOCK)");
+		}
+		else {
+			fprintf(stderr,
+			"Memory locking is not supported in this environment.\n");
+			e = -1;
+		}
+	}
+
+	/* Lock yourself in memory:
+	 */
+	if (mlockall(MCL_CURRENT | MCL_FUTURE) == -1) {
+		perror("mlockall(MCL_CURRENT | MCL_FUTURE)");
+		e = errno;
+	}
+	else if (munlockall() == -1) {
+		perror("munlockall");
+		e = errno;
+	}
+
+	return e;
+}
+
+#ifdef NO_MEMLOCK
+int mlockall(int flags)
+{
+	return EOPNOTSUPP;
+}
+
+int munlockall(void)
+{
+	return EOPNOTSUPP;
+}
+	
+
+#endif
+
+#ifdef STANDALONE_TESTS
+int main(int argc, char *argv[]) { return memlock(argc, argv); }
+#endif

tools/regression/p1003_1b/p26.c

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 1996-1999
+ *	HD Associates, Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by HD Associates, Inc
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+#define _POSIX_SOURCE
+#define _POSIX_C_SOURCE 199309L
+#include <unistd.h>
+#include <stdio.h>
+
+int p26(int ac, char *av[])
+{
+	int ret = 0;
+
+	#ifndef _POSIX_VERSION
+	printf("POSIX is not supported.\n");
+	ret = -1;
+	#else	/* _POSIX_VERSION */
+
+	#if (_POSIX_VERSION == 198808L)
+	printf("POSIX.1 is supported but not POSIX.1B (FIPS 151-1)\n");
+	#elif (_POSIX_VERSION == 199009L)
+	printf("POSIX.1 is supported but not POSIX.1B (FIPS 151-2)\n");
+	#elif (_POSIX_VERSION >= 199309L)
+	printf("POSIX.1 and POSIX.1B are supported.\n");
+	#else
+	printf("_POSIX_VERSION (%ld) not 198808, 199009, or >= 199309.\n",
+		_POSIX_VERSION);
+	ret = -1;
+	#endif
+
+	#endif	/* _POSIX_VERSION */
+	return ret;
+}
+#ifdef STANDALONE_TESTS
+int main(int argc, char *argv[]) { return p26(argc, argv); }
+#endif

tools/regression/p1003_1b/prutil.c

@@ -0,0 +1,61 @@
+#include <errno.h>
+#include <unistd.h>
+#include <sched.h>
+#include <stdio.h>
+
+#include <err.h>
+#include <sysexits.h>
+#include "prutil.h"
+
+/*
+ * $FreeBSD$
+ */
+void quit(const char *text)
+{
+	err(errno, text);
+}
+
+char *sched_text(int scheduler)
+{
+	switch(scheduler)
+	{
+		case SCHED_FIFO:
+		return "SCHED_FIFO";
+
+		case SCHED_RR:
+		return "SCHED_RR";
+
+		case SCHED_OTHER:
+		return "SCHED_OTHER";
+
+		default:
+		return "Illegal scheduler value";
+	}
+}
+
+int sched_is(int line, struct sched_param *p, int shouldbe)
+{
+	int scheduler;
+	struct sched_param param;
+
+	/* What scheduler are we running now?
+	 */
+	errno = 0;
+	scheduler = sched_getscheduler(0);
+	if (sched_getparam(0, &param))
+		quit("sched_getparam");
+
+	if (p)
+		*p = param;
+
+	if (shouldbe != -1 && scheduler != shouldbe)
+	{
+		fprintf(stderr,
+		"At line %d the scheduler should be %s yet it is %s.\n",
+		line, sched_text(shouldbe), sched_text(scheduler));
+
+		exit(-1);
+	}
+
+	return scheduler;
+}

tools/regression/p1003_1b/prutil.h

@@ -0,0 +1,14 @@
+#ifndef _PRUTIL_H_
+#define _PRUTIL_H_
+
+/*
+ * $FreeBSD$
+ */
+
+struct sched_param;
+
+void quit(const char *);
+char *sched_text(int);
+int sched_is(int line, struct sched_param *, int);
+
+#endif /* _PRUTIL_H_ */

tools/regression/p1003_1b/sched.c

@@ -0,0 +1,294 @@
+/*
+ * Copyright (c) 1996-1999
+ *	HD Associates, Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by HD Associates, Inc
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * $FreeBSD$
+ *
+ */
+
+/* XXX: The spec says that if _POSIX_C_SOURCE is defined then
+ *      _POSIX_SOURCE is ignored.  However, this is similar to
+ *      the code in the O'Reilly "POSIX.4" book
+ */
+
+#define _POSIX_VERSION 199309L
+#define _POSIX_SOURCE
+#define _POSIX_C_SOURCE 199309L
+
+#include <unistd.h>
+#include <stdlib.h>
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+
+#include <sched.h>
+
+#include "prutil.h"
+
+static FILE *verbose;
+
+static void
+checkpris(int sched)
+{
+	int smin;
+	int smax;
+
+	errno = 0;
+
+	if ( (smin = sched_get_priority_min(sched)) == -1 && errno)
+		quit("sched_get_priority_min");
+
+	if ( (smax = sched_get_priority_max(sched)) == -1 && errno)
+		quit("sched_get_priority_max");
+
+	if (smax - smin + 1 < 32 || smax < smin) {
+		fprintf(stderr, "Illegal priority range for %s: %d to %d\n",
+		sched_text(sched), smin, smax);
+		exit(-1);
+	}
+
+	if (verbose)
+		fprintf(verbose, "%12s: sched_min %2d sched_max %2d\n",
+		sched_text(sched), smin, smax);
+}
+
+/* Set "try_anyway" to quit if you don't want to go on when
+ * it doesn't look like something should work.
+ */
+static void try_anyway(const char *s)
+{
+	fputs(s, stderr);
+	fprintf(stderr, "(trying anyway)\n");
+	errno = 0;
+}
+
+static void q(int line, int code, const char *text)
+{
+	if (code == -1)
+	{
+		fprintf(stderr, "Error at line %d:\n", line);
+		perror(text);
+		exit(errno);
+	}
+}
+
+int sched(int ac, char *av[])
+{
+	int fifo_schedmin, fifo_schedmax;
+	int i;
+	struct sched_param rt_param;
+	int n_instances = 10;
+	int sched;
+
+	verbose = 0;
+
+#if _POSIX_VERSION < 199309
+	try_anyway("The _POSIX_VERSION predates P1003.1B\n");
+#endif
+
+#if !defined(_POSIX_PRIORITY_SCHEDULING)
+	try_anyway(
+	"The environment does not claim to support Posix scheduling.\n");
+#endif
+
+	/* Is priority scheduling configured?
+	 */
+	errno = 0;
+	if (sysconf(_SC_PRIORITY_SCHEDULING) == -1) {
+		if (errno != 0) {
+			/* This isn't valid - may be a standard violation
+			 */
+			quit("(should not happen) sysconf(_SC_PRIORITY_SCHEDULING)");
+		}
+		else {
+			try_anyway(
+			"The environment does not have run-time "
+			"support for Posix scheduling.\n");
+		}
+	}
+
+	/* Check that the priorities seem reasonable.
+	 */
+
+	checkpris(SCHED_FIFO);
+	checkpris(SCHED_RR);
+	checkpris(SCHED_OTHER);
+
+/* BSD extensions?
+ */
+#if defined(SCHED_IDLE)
+	checkpris(SCHED_IDLE);
+#endif
+
+	fifo_schedmin = sched_get_priority_min(SCHED_FIFO);
+	fifo_schedmax = sched_get_priority_max(SCHED_FIFO);
+
+	/* Make sure we can do some basic schedule switching:
+	 */
+	{
+		struct sched_param orig_param, shouldbe;
+		int orig_scheduler = sched_is(__LINE__, &orig_param, -1);
+
+		if (verbose)
+			fprintf(verbose,
+			"The original scheduler is %s and the priority is %d.\n",
+			sched_text(orig_scheduler), orig_param.sched_priority);
+
+		/* Basic check: Try to set current settings:
+		 */
+		q(__LINE__, sched_setscheduler(0, orig_scheduler, &orig_param),
+			"sched_setscheduler: Can't set original scheduler");
+
+		rt_param.sched_priority = fifo_schedmin;
+
+		q(__LINE__, sched_setscheduler(0, SCHED_FIFO, &rt_param),
+		"sched_setscheduler SCHED_FIFO");
+
+		(void)sched_is(__LINE__, 0, SCHED_FIFO);
+
+		q(__LINE__, sched_getparam(0, &shouldbe), "sched_getparam");
+
+		if (shouldbe.sched_priority != fifo_schedmin)
+			quit("sched_setscheduler wrong priority (min)");
+
+		rt_param.sched_priority = fifo_schedmin;
+
+		q(__LINE__, sched_setparam(0, &rt_param),
+			"sched_setparam to fifo_schedmin");
+
+		rt_param.sched_priority = fifo_schedmin + 1;
+
+		q(__LINE__, sched_setparam(0, &rt_param),
+			"sched_setparam to fifo_schedmin + 1");
+
+		q(__LINE__, sched_getparam(0, &shouldbe),
+			"sched_getparam");
+
+		if (shouldbe.sched_priority != fifo_schedmin + 1)
+			quit("sched_setscheduler wrong priority (min + 1)");
+
+		q(__LINE__, sched_setscheduler(0, SCHED_RR, &rt_param),
+			"sched_setscheduler SCHED_RR");
+
+		(void)sched_is(__LINE__, 0, SCHED_RR);
+
+		q(__LINE__, sched_setscheduler(0, orig_scheduler, &orig_param),
+			"sched_setscheduler restoring original scheduler");
+
+		(void)sched_is(__LINE__, 0, orig_scheduler);
+	}
+
+
+	{
+#define NAM "P1003_1b_schedXXXX"
+		char nam[L_tmpnam];
+		int fd;
+		pid_t p;
+		pid_t *lastrun;
+
+		strcpy(nam, NAM);
+		if (tmpnam(nam) != nam)
+			q(__LINE__, errno, "tmpnam " NAM);
+		q(__LINE__, (fd = open(nam, O_RDWR|O_CREAT, 0666)),
+			"open " NAM);
+
+		(void)unlink(nam);
+
+		p = (pid_t)0;
+
+		write(fd, &p, sizeof(p));
+
+		q(__LINE__,  (int)(lastrun = mmap(0, sizeof(*lastrun), PROT_READ|PROT_WRITE,
+		MAP_SHARED, fd, 0)), "mmap");
+
+		/* Set our priority at the highest:
+		 */
+		sched = SCHED_FIFO;
+		rt_param.sched_priority = fifo_schedmax;
+		q(__LINE__, sched_setscheduler(0, sched, &rt_param),
+		"sched_setscheduler sched");
+
+		for (i = 0; i < n_instances; i++)
+		{
+			pid_t me;
+
+			/* XXX This is completely bogus.  The children never run.
+			 */
+			if ((me = fork()) != 0)
+			{
+				/* Parent.
+				 */
+				(void)sched_is(__LINE__, 0, sched);
+
+				/* Lower our priority:
+				 */
+				rt_param.sched_priority--;
+
+				q(__LINE__, sched_setscheduler(0, sched, &rt_param),
+				"sched_setscheduler sched");
+
+				while (1)
+				{
+					q(__LINE__, sched_getparam(0, &rt_param), "sched_getparam");
+
+					rt_param.sched_priority--;
+
+
+					if (rt_param.sched_priority < fifo_schedmin)
+						exit(0);
+
+					*lastrun = me;
+					q(__LINE__, sched_setparam(0, &rt_param), "sched_setparam");
+
+					if (*lastrun == me)
+					{
+						/* The child will run twice
+						 * at  the end:
+						 */
+						if (!me || rt_param.sched_priority != 0)
+						{
+							fprintf(stderr,
+							"ran process %ld twice at priority %d\n",
+							(long)me, rt_param.sched_priority + 1);
+							exit(-1);
+						}
+					}
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+#ifdef STANDALONE_TESTS
+int main(int argc, char *argv[]) { return sched(argc, argv); }
+#endif

tools/regression/p1003_1b/yield.c

@@ -0,0 +1,197 @@
+/*
+ * Copyright (c) 1996-1999
+ *	HD Associates, Inc.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by HD Associates, Inc
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * $FreeBSD$
+ *
+ */
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <err.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+
+#include "prutil.h"
+
+/* buzz: busy wait a random amount of time.
+ */
+static void buzz(int n)
+{
+	volatile int i;
+	int m = random() & 0x0ffff;
+	for (i = 0; i < m; i++)
+		;
+}
+
+/* Yield: Verify that "sched_yield" works for the FIFO case.
+ * This runs several processes and verifies that the yield seems
+ * to permit the next one on the ready queue to run.
+ */
+int yield(int argc, char *argv[])
+{
+	volatile int *p;
+	int i;
+	int nslaves, n;
+	int master, slave;
+	pid_t youngest = !0;	/* Our youngest child */
+	struct sched_param set, got;
+	int nloops = 1000;
+
+	errno = 0;
+
+	set.sched_priority = sched_get_priority_max(SCHED_FIFO);
+	if (set.sched_priority == -1 && errno) {
+		perror("sched_get_priority_max");
+		exit(errno);
+	}
+
+	if (argc == 1)
+		n = nslaves = 10;
+
+	else if (argc != 2) {
+		fprintf(stderr, "Usage: prog [n_instances]\n");
+		exit(-1);
+	}
+	else
+		n = nslaves = atoi(argv[1]);
+
+	p = (int *)mmap(0, sizeof(int),
+	PROT_READ|PROT_WRITE, MAP_ANON|MAP_SHARED|MAP_INHERIT, -1, 0);
+
+	if (p == (int *)-1)
+		err(errno, "mmap");
+
+	*p = 0;
+
+	if (sched_setscheduler(0, SCHED_FIFO, &set) == -1)
+		err(errno, "sched_setscheduler");
+
+	/* I better still be SCHED_FIFO and RT_PRIO_MAX:
+	 */
+	(void)sched_is(__LINE__, &got, SCHED_FIFO);
+	if (got.sched_priority != set.sched_priority) {
+		fprintf(stderr, "line %d: scheduler screwup\n",
+		__LINE__);
+		exit(-1);
+	}
+
+	slave = 0;
+	master = 1;
+
+	/* Fork off the slaves.
+	 */
+	for (i = 0; i < nslaves; i++) {
+		if ((youngest = fork()) == 0) {
+			/* I better still be SCHED_FIFO and RT_PRIO_MAX:
+			 */
+			(void)sched_is(__LINE__, &got, SCHED_FIFO);
+
+			if (got.sched_priority != set.sched_priority) {
+				fprintf(stderr, "line %d: scheduler screwup\n",
+				__LINE__);
+				exit(-1);
+			}
+
+			master = 0;	/* I'm a slave */
+			slave = i + 1;	/* With this flag */
+			*p = slave;	/* And I live */
+			break;
+		}
+	}
+
+	if (master) {
+		/* If we conform the slave processes haven't run yet.
+		 * The master must yield to let the first slave run.
+		 */
+		if (*p != 0) {
+			fprintf(stderr,
+			"Error at line %d: Writer %d has run\n", __LINE__, *p);
+			exit(-1);
+		}
+	}
+
+	/* Now the master yields, the first slave runs, and yields,
+	 * next runs, yields, ...
+	 *
+	 * So the master should get through this first.
+	 */
+
+	if (sched_yield() == -1)
+		err(errno, "sched_yield");
+
+	if (master) {
+		int status;
+
+		/* The final slave process should be the last one started.
+		 */
+		if (*p != nslaves) {
+			fprintf(stderr,
+			"Error at line %d: Final slave is %d not %d.\n",
+			__LINE__, *p, nslaves);
+			exit(-1);
+		}
+
+		/* Wait for our youngest to exit:
+		 */
+		waitpid(youngest, &status, 0);
+
+		exit(WEXITSTATUS(status));	/* Let the slaves continue */
+	}
+
+	/* Now the first one has started up.
+	 */
+	for (i = 0; i < nloops; i++) {
+		if (((*p) % nslaves) !=
+		((slave + nslaves - 1) % nslaves)) {
+			fprintf(stderr, "%d ran before %d on iteration %d.\n",
+			*p, slave, i);
+			exit(-1);
+		}
+		*p = slave;
+
+		/* Delay some random amount of time.
+		 */
+		buzz(slave);
+
+		if (sched_yield() == -1)
+			err(errno, "sched_yield");
+	}
+
+	exit(0);
+}
+#ifdef STANDALONE_TESTS
+int main(int argc, char *argv[]) { return yield(argc, argv); }
+#endif