hires.t

source of perl for linux application,

#!./perl -w

BEGIN {
    if ($ENV{PERL_CORE}) {
	chdir 't' if -d 't';
	@INC = '../lib';
	require Config; import Config;
	if (" $Config{'extensions'} " !~ m[ Time/HiRes ]) {
	    print "1..0 # Skip -- Perl configured without Time::HiRes module\n";
	    exit 0;
	}
    }
}

BEGIN { $| = 1; print "1..38\n"; }

END { print "not ok 1\n" unless $loaded }

use Time::HiRes 1.9704; # Remember to bump this once in a while.
use Time::HiRes qw(tv_interval);

$loaded = 1;

print "ok 1\n";

use strict;

my $have_gettimeofday	 = &Time::HiRes::d_gettimeofday;
my $have_usleep		 = &Time::HiRes::d_usleep;
my $have_nanosleep	 = &Time::HiRes::d_nanosleep;
my $have_ualarm		 = &Time::HiRes::d_ualarm;
my $have_clock_gettime	 = &Time::HiRes::d_clock_gettime;
my $have_clock_getres	 = &Time::HiRes::d_clock_getres;
my $have_clock_nanosleep = &Time::HiRes::d_clock_nanosleep;
my $have_clock           = &Time::HiRes::d_clock;
my $have_hires_stat      = &Time::HiRes::d_hires_stat;

sub has_symbol {
    my $symbol = shift;
    eval "use Time::HiRes qw($symbol)";
    return 0 unless $@ eq '';
    eval "my \$a = $symbol";
    return $@ eq '';
}

printf "# have_gettimeofday    = %d\n", $have_gettimeofday;
printf "# have_usleep          = %d\n", $have_usleep;
printf "# have_nanosleep       = %d\n", $have_nanosleep;
printf "# have_ualarm          = %d\n", $have_ualarm;
printf "# have_clock_gettime   = %d\n", $have_clock_gettime;
printf "# have_clock_getres    = %d\n", $have_clock_getres;
printf "# have_clock_nanosleep = %d\n", $have_clock_nanosleep;
printf "# have_clock           = %d\n", $have_clock;
printf "# have_hires_stat      = %d\n", $have_hires_stat;

import Time::HiRes 'gettimeofday'	if $have_gettimeofday;
import Time::HiRes 'usleep'		if $have_usleep;
import Time::HiRes 'nanosleep'		if $have_nanosleep;
import Time::HiRes 'ualarm'		if $have_ualarm;
import Time::HiRes 'clock_gettime'	if $have_clock_gettime;
import Time::HiRes 'clock_getres'	if $have_clock_getres;
import Time::HiRes 'clock_nanosleep'	if $have_clock_nanosleep;
import Time::HiRes 'clock'		if $have_clock;

use Config;

use Time::HiRes qw(gettimeofday);

my $have_alarm = $Config{d_alarm};
my $have_fork  = $Config{d_fork};
my $waitfor = 180; # 30-45 seconds is normal (load affects this).
my $timer_pid;
my $TheEnd;

if ($have_fork) {
    print "# I am the main process $$, starting the timer process...\n";
    $timer_pid = fork();
    if (defined $timer_pid) {
	if ($timer_pid == 0) { # We are the kid, set up the timer.
	    my $ppid = getppid();
	    print "# I am the timer process $$, sleeping for $waitfor seconds...\n";
	    sleep($waitfor);
	    warn "\n$0: overall time allowed for tests (${waitfor}s) exceeded!\n";
	    print "# Terminating main process $ppid...\n";
	    kill('TERM', $ppid);
	    print "# This is the timer process $$, over and out.\n";
	    exit(0);
	} else {
	    print "# The timer process $timer_pid launched, continuing testing...\n";
	    $TheEnd = time() + $waitfor;
	}
    } else {
	warn "$0: fork failed: $!\n";
    }
} else {
    print "# No timer process (need fork)\n";
}

my $xdefine = ''; 

if (open(XDEFINE, "xdefine")) {
    chomp($xdefine = <XDEFINE>);
    close(XDEFINE);
}

# Ideally, we'd like to test that the timers are rather precise.
# However, if the system is busy, there are no guarantees on how
# quickly we will return.  This limit used to be 10%, but that
# was occasionally triggered falsely.  
# So let's try 25%.
# Another possibility might be to print "ok" if the test completes fine
# with (say) 10% slosh, "skip - system may have been busy?" if the test
# completes fine with (say) 30% slosh, and fail otherwise.  If you do that,
# consider changing over to test.pl at the same time.
# --A.D., Nov 27, 2001
my $limit = 0.25; # 25% is acceptable slosh for testing timers

sub skip {
    map { print "ok $_ # skipped\n" } @_;
}

sub ok {
    my ($n, $result, @info) = @_;
    if ($result) {
    	print "ok $n\n";
    }
    else {
	print "not ok $n\n";
    	print "# @info\n" if @info;
    }
}

unless ($have_gettimeofday) {
    skip 2..6;
}
else {
    my @one = gettimeofday();
    ok 2, @one == 2, 'gettimeofday returned ', 0+@one, ' args';
    ok 3, $one[0] > 850_000_000, "@one too small";

    sleep 1;

    my @two = gettimeofday();
    ok 4, ($two[0] > $one[0] || ($two[0] == $one[0] && $two[1] > $one[1])),
    	    "@two is not greater than @one";

    my $f = Time::HiRes::time();
    ok 5, $f > 850_000_000, "$f too small";
    ok 6, $f - $two[0] < 2, "$f - $two[0] >= 2";
}

unless ($have_usleep) {
    skip 7..8;
}
else {
    use Time::HiRes qw(usleep);
    my $one = time;
    usleep(10_000);
    my $two = time;
    usleep(10_000);
    my $three = time;
    ok 7, $one == $two || $two == $three, "slept too long, $one $two $three";

    unless ($have_gettimeofday) {
    	skip 8;
    }
    else {
    	my $f = Time::HiRes::time();
	usleep(500_000);
        my $f2 = Time::HiRes::time();
	my $d = $f2 - $f;
	ok 8, $d > 0.4 && $d < 0.9, "slept $d secs $f to $f2";
    }
}

# Two-arg tv_interval() is always available.
{
    my $f = tv_interval [5, 100_000], [10, 500_000];
    ok 9, abs($f - 5.4) < 0.001, $f;
}

unless ($have_gettimeofday) {
    skip 10;
}
else {
    my $r = [gettimeofday()];
    my $f = tv_interval $r;
    ok 10, $f < 2, $f;
}

unless ($have_usleep && $have_gettimeofday) {
    skip 11;
}
else {
    my $r = [ gettimeofday() ];
    Time::HiRes::sleep( 0.5 );
    my $f = tv_interval $r;
    ok 11, $f > 0.4 && $f < 0.9, "slept $f instead of 0.5 secs.";
}

unless ($have_ualarm && $have_alarm) {
    skip 12..13;
}
else {
    my $tick = 0;
    local $SIG{ ALRM } = sub { $tick++ };

    my $one = time; $tick = 0; ualarm(10_000); while ($tick == 0) { }
    my $two = time; $tick = 0; ualarm(10_000); while ($tick == 0) { }
    my $three = time;
    ok 12, $one == $two || $two == $three, "slept too long, $one $two $three";
    print "# tick = $tick, one = $one, two = $two, three = $three\n";

    $tick = 0; ualarm(10_000, 10_000); while ($tick < 3) { }
    ok 13, 1;
    ualarm(0);
    print "# tick = $tick, one = $one, two = $two, three = $three\n";
}

# Did we even get close?

unless ($have_gettimeofday) {
    skip 14;
} else {
 my ($s, $n, $i) = (0);
 for $i (1 .. 100) {
     $s += Time::HiRes::time() - time();
     $n++;
 }
 # $s should be, at worst, equal to $n
 # (time() may be rounding down, up, or closest),
 # but allow 10% of slop.
 ok 14, abs($s) / $n <= 1.10, "Time::HiRes::time() not close to time()";
 print "# s = $s, n = $n, s/n = ", abs($s)/$n, "\n";
}

my $has_ualarm = $Config{d_ualarm};

$has_ualarm ||= $xdefine =~ /-DHAS_UALARM/;

unless (   defined &Time::HiRes::gettimeofday
	&& defined &Time::HiRes::ualarm
	&& defined &Time::HiRes::usleep
	&& $has_ualarm) {
    for (15..17) {
	print "ok $_ # Skip: no gettimeofday or no ualarm or no usleep\n";
    }
} else {
    use Time::HiRes qw(time alarm sleep);
    eval { require POSIX };
    my $use_sigaction =
	!$@ && defined &POSIX::sigaction && &POSIX::SIGALRM > 0;

    my ($f, $r, $i, $not, $ok);

    $f = time; 
    print "# time...$f\n";
    print "ok 15\n";

    $r = [Time::HiRes::gettimeofday()];
    sleep (0.5);
    print "# sleep...", Time::HiRes::tv_interval($r), "\nok 16\n";

    $r = [Time::HiRes::gettimeofday()];
    $i = 5;
    my $oldaction;
    if ($use_sigaction) {
	$oldaction = new POSIX::SigAction;
	printf "# sigaction tick, ALRM = %d\n", &POSIX::SIGALRM;

	# Perl's deferred signals may be too wimpy to break through
	# a restartable select(), so use POSIX::sigaction if available.

	sub tick {
	    $i--;
	    my $ival = Time::HiRes::tv_interval ($r);
	    print "# Tick! $i $ival\n";
	    my $exp = 0.3 * (5 - $i);
	    # This test is more sensitive, so impose a softer limit.
	    if (abs($ival/$exp - 1) > 4*$limit) {
		my $ratio = abs($ival/$exp);
		$not = "tick: $exp sleep took $ival ratio $ratio";
		$i = 0;
	    }
	}

	POSIX::sigaction(&POSIX::SIGALRM,
			 POSIX::SigAction->new("tick"),
			 $oldaction)
	    or die "Error setting SIGALRM handler with sigaction: $!\n";
    } else {
	print "# SIG tick\n";
	$SIG{ALRM} = "tick";
    }

    # On VMS timers can not interrupt select.
    if ($^O eq 'VMS') {
	$ok = "Skip: VMS select() does not get interrupted.";
    } else {
	while ($i > 0) {
	    alarm(0.3);
	    select (undef, undef, undef, 3);
	    my $ival = Time::HiRes::tv_interval ($r);
	    print "# Select returned! $i $ival\n";
	    print "# ", abs($ival/3 - 1), "\n";
	    # Whether select() gets restarted after signals is
	    # implementation dependent.  If it is restarted, we
	    # will get about 3.3 seconds: 3 from the select, 0.3
	    # from the alarm.  If this happens, let's just skip
	    # this particular test.  --jhi
	    if (abs($ival/3.3 - 1) < $limit) {
		$ok = "Skip: your select() may get restarted by your SIGALRM (or just retry test)";
		undef $not;
		last;
	    }
	    my $exp = 0.3 * (5 - $i);
	    # This test is more sensitive, so impose a softer limit.
	    if (abs($ival/$exp - 1) > 3*$limit) {
		my $ratio = abs($ival/$exp);
		$not = "while: $exp sleep took $ival ratio $ratio";
		last;
	    }
	    $ok = $i;
	}
    }

    if ($use_sigaction) {
	POSIX::sigaction(&POSIX::SIGALRM, $oldaction);
    } else {
	alarm(0); # can't cancel usig %SIG
    }

    print $not ? "not ok 17 # $not\n" : "ok 17 # $ok\n";
}

unless (   defined &Time::HiRes::setitimer
	&& defined &Time::HiRes::getitimer
	&& has_symbol('ITIMER_VIRTUAL')
	&& $Config{sig_name} =~ m/\bVTALRM\b/
        && $^O !~ /^(nto)$/) { # nto: QNX 6 has the API but no implementation
    for (18..19) {
	print "ok $_ # Skip: no virtual interval timers\n";
    }
} else {
    use Time::HiRes qw(setitimer getitimer ITIMER_VIRTUAL);

    my $i = 3;
    my $r = [Time::HiRes::gettimeofday()];

    $SIG{VTALRM} = sub {
	$i ? $i-- : setitimer(&ITIMER_VIRTUAL, 0);
	print "# Tick! $i ", Time::HiRes::tv_interval($r), "\n";
    };	

    print "# setitimer: ", join(" ", setitimer(ITIMER_VIRTUAL, 0.5, 0.4)), "\n";

    # Assume interval timer granularity of $limit * 0.5 seconds.  Too bold?
    my $virt = getitimer(&ITIMER_VIRTUAL);
    print "not " unless defined $virt && abs($virt / 0.5) - 1 < $limit;
    print "ok 18\n";

    print "# getitimer: ", join(" ", getitimer(ITIMER_VIRTUAL)), "\n";