diff options
| -rw-r--r-- | INSTALL | 8 | ||||
| -rw-r--r-- | ext/Time/HiRes/HiRes.t | 41 |
2 files changed, 37 insertions, 12 deletions
@@ -1925,6 +1925,14 @@ things like: exec, `backquoted command`, system, open("|...") or open("...|"). All these mean that Perl is trying to run some external program. +=item Timing problems + +Several tests in the test suite check timing functions, such as sleep(), +and see if they return in a reasonable amount of time. If your system is +quite busy and doesn't return quickly enough, these tests might fail. +If possible, try running the tests again with the system under a +lighter load. + =item Out of memory On some systems, particularly those with smaller amounts of RAM, some diff --git a/ext/Time/HiRes/HiRes.t b/ext/Time/HiRes/HiRes.t index 2046fed39a..489829ec9d 100644 --- a/ext/Time/HiRes/HiRes.t +++ b/ext/Time/HiRes/HiRes.t @@ -26,6 +26,18 @@ import Time::HiRes 'ualarm' if $have_ualarm; use Config; +# 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. +# Try 20%. +# 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 = 0.20; # 20% is acceptable slosh for testing timers + sub skip { map { print "ok $_ (skipped)\n" } @_; } @@ -57,7 +69,7 @@ else { my $f = Time::HiRes::time(); ok 5, $f > 850_000_000, "$f too small"; - ok 6, $f - $two[0] < 2, "$f - @two >= 2"; + ok 6, $f - $two[0] < 2, "$f - $two[0] >= 2"; } if (!$have_usleep) { @@ -79,7 +91,7 @@ else { usleep(500_000); my $f2 = Time::HiRes::time(); my $d = $f2 - $f; - ok 8, $d > 0.4 && $d < 0.8, "slept $d secs $f to $f2"; + ok 8, $d > 0.4 && $d < 0.9, "slept $d secs $f to $f2"; } } @@ -106,7 +118,7 @@ else { #jTime::HiRes::sleep 0.5; Time::HiRes::sleep( 0.5 ); my $f = tv_interval $r; - ok 11, $f > 0.4 && $f < 0.8, "slept $f secs"; + ok 11, $f > 0.4 && $f < 0.9, "slept $f instead of 0.5 secs."; } if (!$have_ualarm) { @@ -174,8 +186,10 @@ unless (defined &Time::HiRes::gettimeofday my $ival = Time::HiRes::tv_interval ($r); print "# Select returned! $i $ival\n"; my $exp = 0.3 * (5 - $i); - if (abs($ival/$exp) - 1 > 0.1) { - $not = "$exp sleep took $ival"; + # This test is more sensitive, so impose a softer limit. + if (abs($ival/$exp) - 1 > 3*$limit) { + my $ratio = abs($ival/$exp); + $not = "while: $exp sleep took $ival ratio $ratio"; last; } } @@ -186,8 +200,10 @@ unless (defined &Time::HiRes::gettimeofday my $ival = Time::HiRes::tv_interval ($r); print "# Tick! $i $ival\n"; my $exp = 0.3 * (5 - $i); - if (abs($ival/$exp) - 1 > 0.1) { - $not = "$exp sleep took $ival"; + # This test is more sensitive, so impose a softer limit. + if (abs($ival/$exp) - 1 > 3*$limit) { + my $ratio = abs($ival/$exp); + $not = "tick: $exp sleep took $ival ratio $ratio"; $i = 0; } } @@ -218,8 +234,8 @@ unless (defined &Time::HiRes::setitimer print "# setitimer: ", join(" ", setitimer(ITIMER_VIRTUAL, 0.5, 0.4)), "\n"; - # Assume interval timer granularity of 0.05 seconds. Too bold? - print "not " unless abs(getitimer(ITIMER_VIRTUAL) / 0.5) - 1 < 0.1; + # Assume interval timer granularity of $limit * 0.5 seconds. Too bold? + print "not " unless abs(getitimer(ITIMER_VIRTUAL) / 0.5) - 1 < $limit; print "ok 18\n"; print "# getitimer: ", join(" ", getitimer(ITIMER_VIRTUAL)), "\n"; @@ -240,14 +256,14 @@ if ($have_gettimeofday) { my ($t0, $td); my $sleep = 1.5; # seconds - my $limit = 0.1; # 10% is acceptable slosh for timers my $msg; $t0 = gettimeofday(); $a = abs(sleep($sleep) / $sleep - 1.0); $td = gettimeofday() - $t0; + my $ratio = 1.0 + $a; - $msg = "$td went by while sleeping $sleep, ratio $a\n"; + $msg = "$td went by while sleeping $sleep, ratio $ratio.\n"; if ($td < $sleep * (1 + $limit)) { print $a < $limit ? "ok 20 # $msg" : "not ok 20 # $msg"; @@ -258,8 +274,9 @@ if ($have_gettimeofday) { $t0 = gettimeofday(); $a = abs(usleep($sleep * 1E6) / ($sleep * 1E6) - 1.0); $td = gettimeofday() - $t0; + $ratio = 1.0 + $a; - $msg = "$td went by while sleeping $sleep, ratio $a\n"; + $msg = "$td went by while sleeping $sleep, ratio $ratio.\n"; if ($td < $sleep * (1 + $limit)) { print $a < $limit ? "ok 21 # $msg" : "not ok 21 # $msg"; |