TITLE defaults to "timethis COUNT" if none is provided. STYLE
determines the format of the output, as described for timestr() below.
+The COUNT can be zero or negative: this means the I<minimum number of
+CPU seconds> to run. A zero signifies the default of 3 seconds. For
+example to run at least for 10 seconds:
+
+ timethis(-10, $code)
+
+or to run two pieces of code tests for at least 3 seconds:
+
+ timethese(0, { test1 => '...', test2 => '...'})
+
+CPU seconds is, in UNIX terms, the user time plus the system time of
+the process itself, as opposed to the real (wallclock) time and the
+time spent by the child processes. Less than 0.1 seconds is not
+accepted (-0.01 as the count, for example, will cause a fatal runtime
+exception).
+
+Note that the CPU seconds is the B<minimum> time: CPU scheduling and
+other operating system factors may complicate the attempt so that a
+little bit more time is spent. The benchmark output will, however,
+also tell the number of C<$code> runs/second, which should be a more
+interesting number than the actually spent seconds.
+
+Returns a Benchmark object.
+
=item timethese ( COUNT, CODEHASHREF, [ STYLE ] )
The CODEHASHREF is a reference to a hash containing names as keys
timethis(COUNT, VALUE, KEY, STYLE)
+The Count can be zero or negative, see timethis().
+
=item timediff ( T1, T2 )
Returns the difference between two Benchmark times as a Benchmark
object suitable for passing to timestr().
-=item timestr ( TIMEDIFF, [ STYLE, [ FORMAT ]] )
+=item timestr ( TIMEDIFF, [ STYLE, [ FORMAT ] ] )
Returns a string that formats the times in the TIMEDIFF object in
the requested STYLE. TIMEDIFF is expected to be a Benchmark object
references and the already documented 'debug' method; revamped
documentation.
+April 04-07th, 1997: by Jarkko Hietaniemi, added the run-for-some-time
+functionality.
+
=cut
use Carp;
# --- Functions to process the 'time' data type
-sub new { my @t = (time, times); print "new=@t\n" if $debug; bless \@t; }
+sub new { my @t = (time, times, @_ == 2 ? $_[1] : 0);
+ print "new=@t\n" if $debug;
+ bless \@t; }
sub cpu_p { my($r,$pu,$ps,$cu,$cs) = @{$_[0]}; $pu+$ps ; }
sub cpu_c { my($r,$pu,$ps,$cu,$cs) = @{$_[0]}; $cu+$cs ; }
sub timestr {
my($tr, $style, $f) = @_;
my @t = @$tr;
- warn "bad time value" unless @t==5;
- my($r, $pu, $ps, $cu, $cs) = @t;
+ warn "bad time value (@t)" unless @t==6;
+ my($r, $pu, $ps, $cu, $cs, $n) = @t;
my($pt, $ct, $t) = ($tr->cpu_p, $tr->cpu_c, $tr->cpu_a);
$f = $defaultfmt unless defined $f;
# format a time in the required style, other formats may be added here
$style ||= $defaultstyle;
$style = ($ct>0) ? 'all' : 'noc' if $style eq 'auto';
my $s = "@t $style"; # default for unknown style
- $s=sprintf("%2d secs (%$f usr %$f sys + %$f cusr %$f csys = %$f cpu)",
+ $s=sprintf("%2d wallclock secs (%$f usr %$f sys + %$f cusr %$f csys = %$f CPU secs)",
@t,$t) if $style eq 'all';
- $s=sprintf("%2d secs (%$f usr %$f sys = %$f cpu)",
- $r,$pu,$ps,$pt) if $style eq 'noc';
- $s=sprintf("%2d secs (%$f cusr %$f csys = %$f cpu)",
- $r,$cu,$cs,$ct) if $style eq 'nop';
+ $s=sprintf("%$f CPU secs (%$f usr + %$f sys)",
+ $pt,$pu,$ps) if $style eq 'noc';
+ $s=sprintf("%$f CPU secs (%$f cusr %$f csys)",
+ $ct,$cu,$cs) if $style eq 'nop';
+ $s .= sprintf(" @ %$f/s (n=$n)", $n / ( $pu + $ps )) if $n;
$s;
}
croak "runloop unable to compile '$c': $@\ncode: $subcode\n" if $@;
print STDERR "runloop $n '$subcode'\n" if $debug;
- $t0 = &new;
+ $t0 = Benchmark->new(0);
&$subref;
- $t1 = &new;
+ $t1 = Benchmark->new($n);
$td = &timediff($t1, $t0);
timedebug("runloop:",$td);
$wd;
}
+
+my $default_for = 3;
+my $min_for = 0.1;
+
+sub runfor {
+ my ($code, $tmax) = @_;
+
+ if ( not defined $tmax or $tmax == 0 ) {
+ $tmax = $default_for;
+ } elsif ( $tmax < 0 ) {
+ $tmax = -$tmax;
+ }
+
+ die "runfor(..., $tmax): timelimit cannot be less than $min_for.\n"
+ if $tmax < $min_for;
+
+ my ($n, $td, $tc, $ntot, $rtot, $utot, $stot, $cutot, $cstot );
+
+ # First find the minimum $n that gives a non-zero timing.
+
+ my $nmin;
+
+ for ($n = 1, $tc = 0; $tc <= 0; $n *= 2 ) {
+ $td = timeit($n, $code);
+ $tc = $td->[1] + $td->[2];
+ }
+
+ $nmin = $n;
+
+ my $ttot = 0;
+ my $tpra = 0.05 * $tmax; # Target/time practice.
+
+ # Double $n until we have think we have practiced enough.
+ for ( $n = 1; $ttot < $tpra; $n *= 2 ) {
+ $td = timeit($n, $code);
+ $tc = $td->cpu_p;
+ $ntot += $n;
+ $rtot += $td->[0];
+ $utot += $td->[1];
+ $stot += $td->[2];
+ $ttot = $utot + $stot;
+ $cutot += $td->[3];
+ $cstot += $td->[4];
+ }
+
+ my $r;
+
+ # Then iterate towards the $tmax.
+ while ( $ttot < $tmax ) {
+ $r = $tmax / $ttot - 1; # Linear approximation.
+ $n = int( $r * $n );
+ $n = $nmin if $n < $nmin;
+ $td = timeit($n, $code);
+ $ntot += $n;
+ $rtot += $td->[0];
+ $utot += $td->[1];
+ $stot += $td->[2];
+ $ttot = $utot + $stot;
+ $cutot += $td->[3];
+ $cstot += $td->[4];
+ }
+
+ return bless [ $rtot, $utot, $stot, $cutot, $cstot, $ntot ];
+}
+
# --- Functions implementing high-level time-then-print utilities
+sub n_to_for {
+ my $n = shift;
+ return $n == 0 ? $default_for : $n < 0 ? -$n : undef;
+}
+
sub timethis{
my($n, $code, $title, $style) = @_;
- my $t = timeit($n, $code);
+ my($t, $for, $forn);
+
+ if ( $n > 0 ) {
+ croak "non-integer loopcount $n, stopped" if int($n)<$n;
+ $t = timeit($n, $code);
+ $title = "timethis $n" unless defined $title;
+ } else {
+ $fort = n_to_for( $n );
+ $t = runfor($code, $fort);
+ $title = "timethis for $fort" unless defined $title;
+ $forn = $t->[-1];
+ }
local $| = 1;
- $title = "timethis $n" unless defined $title;
$style = "" unless defined $style;
printf("%10s: ", $title);
- print timestr($t, $style),"\n";
+ print timestr($t, $style, $defaultfmt),"\n";
+
+ $n = $forn if defined $forn;
# A conservative warning to spot very silly tests.
# Don't assume that your benchmark is ok simply because
unless ref $alt eq HASH;
my @names = sort keys %$alt;
$style = "" unless defined $style;
- print "Benchmark: timing $n iterations of ",join(', ',@names),"...\n";
+ print "Benchmark: ";
+ if ( $n > 0 ) {
+ croak "non-integer loopcount $n, stopped" if int($n)<$n;
+ print "timing $n iterations of";
+ } else {
+ print "running";
+ }
+ print " ", join(', ',@names);
+ unless ( $n > 0 ) {
+ my $for = n_to_for( $n );
+ print ", each for at least $for CPU seconds";
+ }
+ print "...\n";
# we could save the results in an array and produce a summary here
# sum, min, max, avg etc etc
projects / p5sagit/p5-mst-13.2.git / commitdiff