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|
use strict;
use Test::More tests => 10;
BEGIN { push @INC, '.' }
use t::Watchdog;
BEGIN { require_ok "Time::HiRes"; }
use Config;
my $limit = 0.25; # 25% is acceptable slosh for testing timers
my $xdefine = '';
if (open(XDEFINE, "<", "xdefine")) {
chomp($xdefine = <XDEFINE> || "");
close(XDEFINE);
}
my $can_subsecond_alarm =
defined &Time::HiRes::gettimeofday &&
defined &Time::HiRes::ualarm &&
defined &Time::HiRes::usleep &&
($Config{d_ualarm} || $xdefine =~ /-DHAS_UALARM/);
SKIP: {
skip "no subsecond alarm", 1 unless $can_subsecond_alarm;
eval { require POSIX };
my $use_sigaction =
!$@ && defined &POSIX::sigaction && &POSIX::SIGALRM > 0;
my ($r, $i, $not, $ok);
$not = "";
$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.
# In perl 5.6.2 you will get a likely bogus warning of
# "Use of uninitialized value in subroutine entry" from
# the following line.
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) {
Time::HiRes::alarm(0.3);
select (undef, undef, undef, 3);
my $ival = Time::HiRes::tv_interval ($r);
print("# Select returned! $i $ival\n");
printf("# %s\n", abs($ival/3 - 1));
# 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 - $i);
if ($exp == 0) {
$not = "while: divisor became zero";
last;
}
# This test is more sensitive, so impose a softer limit.
if (abs($ival/$exp - 1) > 4*$limit) {
my $ratio = abs($ival/$exp);
$not = "while: $exp sleep took $ival ratio $ratio";
last;
}
$ok = $i;
}
}
sub tick {
$i--;
my $ival = Time::HiRes::tv_interval ($r);
print("# Tick! $i $ival\n");
my $exp = 0.3 * (5 - $i);
if ($exp == 0) {
$not = "tick: divisor became zero";
last;
}
# This test is more sensitive, so impose a softer limit.
if (abs($ival/$exp - 1) > 4*$limit) {
my $ratio = abs($ival/$exp);
$not = "tick: $exp sleep took $ival ratio $ratio";
$i = 0;
}
}
if ($use_sigaction) {
POSIX::sigaction(&POSIX::SIGALRM, $oldaction);
} else {
Time::HiRes::alarm(0); # can't cancel usig %SIG
}
print("# $not\n");
ok !$not;
}
SKIP: {
skip "no ualarm", 1 unless &Time::HiRes::d_ualarm;
eval { Time::HiRes::alarm(-3) };
like $@, qr/::alarm\(-3, 0\): negative time not invented yet/,
"negative time error";
}
# Find the loop size N (a for() loop 0..N-1)
# that will take more than T seconds.
SKIP: {
skip "no ualarm", 1 unless &Time::HiRes::d_ualarm;
skip "perl bug", 1 unless $] >= 5.008001;
# http://groups.google.com/group/perl.perl5.porters/browse_thread/thread/adaffaaf939b042e/20dafc298df737f0%2320dafc298df737f0?sa=X&oi=groupsr&start=0&num=3
# Perl changes [18765] and [18770], perl bug [perl #20920]
print("# Finding delay loop...\n");
my $T = 0.01;
my $DelayN = 1024;
my $i;
N: {
do {
my $t0 = Time::HiRes::time();
for ($i = 0; $i < $DelayN; $i++) { }
my $t1 = Time::HiRes::time();
my $dt = $t1 - $t0;
print("# N = $DelayN, t1 = $t1, t0 = $t0, dt = $dt\n");
last N if $dt > $T;
$DelayN *= 2;
} while (1);
}
# The time-burner which takes at least T (default 1) seconds.
my $Delay = sub {
my $c = @_ ? shift : 1;
my $n = $c * $DelayN;
my $i;
for ($i = 0; $i < $n; $i++) { }
};
# Next setup a periodic timer (the two-argument alarm() of
# Time::HiRes, behind the curtains the libc getitimer() or
# ualarm()) which has a signal handler that takes so much time (on
# the first initial invocation) that the first periodic invocation
# (second invocation) will happen before the first invocation has
# finished. In Perl 5.8.0 the "safe signals" concept was
# implemented, with unfortunately at least one bug that caused a
# core dump on reentering the handler. This bug was fixed by the
# time of Perl 5.8.1.
# Do not try mixing sleep() and alarm() for testing this.
my $a = 0; # Number of alarms we receive.
my $A = 2; # Number of alarms we will handle before disarming.
# (We may well get $A + 1 alarms.)
$SIG{ALRM} = sub {
$a++;
printf("# Alarm $a - %s\n", Time::HiRes::time());
Time::HiRes::alarm(0) if $a >= $A; # Disarm the alarm.
$Delay->(2); # Try burning CPU at least for 2T seconds.
};
Time::HiRes::alarm($T, $T); # Arm the alarm.
$Delay->(10); # Try burning CPU at least for 10T seconds.
ok 1; # Not core dumping by now is considered to be the success.
}
SKIP: {
skip "no subsecond alarm", 6 unless $can_subsecond_alarm;
{
my $alrm;
$SIG{ALRM} = sub { $alrm++ };
Time::HiRes::alarm(0.1);
my $t0 = Time::HiRes::time();
1 while Time::HiRes::time() - $t0 <= 1;
ok $alrm;
}
{
my $alrm;
$SIG{ALRM} = sub { $alrm++ };
Time::HiRes::alarm(1.1);
my $t0 = Time::HiRes::time();
1 while Time::HiRes::time() - $t0 <= 2;
ok $alrm;
}
{
my $alrm = 0;
$SIG{ALRM} = sub { $alrm++ };
my $got = Time::HiRes::alarm(2.7);
ok $got == 0 or print("# $got\n");
my $t0 = Time::HiRes::time();
1 while Time::HiRes::time() - $t0 <= 1;
$got = Time::HiRes::alarm(0);
ok $got > 0 && $got < 1.8 or print("# $got\n");
ok $alrm == 0 or print("# $alrm\n");
$got = Time::HiRes::alarm(0);
ok $got == 0 or print("# $got\n");
}
}
1;
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