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Diffstat (limited to 'pod/perldelta.pod')
| -rw-r--r-- | pod/perldelta.pod | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/pod/perldelta.pod b/pod/perldelta.pod index b4d4d217de..3ff77cc1c4 100644 --- a/pod/perldelta.pod +++ b/pod/perldelta.pod @@ -1035,25 +1035,43 @@ The Dumpvalue module provides screen dumps of Perl data. =item Benchmark +Overall, Benchmark results exhibit lower average error and better timing +accuracy. + You can now run tests for I<n> seconds instead of guessing the right number of tests to run: e.g. timethese(-5, ...) will run each code for at least 5 CPU seconds. Zero as the "number of repetitions" means "for at least 3 CPU seconds". The output format has also changed. For example: -use Benchmark;$x=3;timethese(-5,{a=>sub{$x*$x},b=>sub{$x**2}}) + use Benchmark;$x=3;timethese(-5,{a=>sub{$x*$x},b=>sub{$x**2}}) will now output something like this: -Benchmark: running a, b, each for at least 5 CPU seconds... - a: 5 wallclock secs ( 5.77 usr + 0.00 sys = 5.77 CPU) @ 200551.91/s (n=1156516) - b: 4 wallclock secs ( 5.00 usr + 0.02 sys = 5.02 CPU) @ 159605.18/s (n=800686) + Benchmark: running a, b, each for at least 5 CPU seconds... + a: 5 wallclock secs ( 5.77 usr + 0.00 sys = 5.77 CPU) @ 200551.91/s (n=1156516) + b: 4 wallclock secs ( 5.00 usr + 0.02 sys = 5.02 CPU) @ 159605.18/s (n=800686) New features: "each for at least N CPU seconds...", "wallclock secs", and the "@ operations/CPU second (n=operations)". -change#4265,4266,4292 -[TODO - Barrie Slaymaker <barries@slaysys.com>] +timethese() now returns a reference to a hash of Benchmark objects containing +the test results, keyed on the names of the tests. + +timethis() now returns the iterations field in the Benchmark result object +instead of 0. + +timethese(), timethis(), and the new cmpthese() (see below) can also take +a format specifier of 'none' to suppress output. + +A new function countit() is just like timeit() except that it takes a +TIME instead of a COUNT. + +A new function cmpthese() prints a chart comparing the results of each test +returned from a timethese() call. For each possible pair of tests, the +percentage speed difference (iters/sec or seconds/iter) is shown. + +For other details, see L<Benchmark>. =item Devel::Peek |