diff --git a/components/stopwatch.rst b/components/stopwatch.rst index d2791f5bbb5..27d30cce6db 100644 --- a/components/stopwatch.rst +++ b/components/stopwatch.rst @@ -34,13 +34,24 @@ microtime by yourself. Instead, use the simple $event = $stopwatch->stop('eventName'); The :class:`Symfony\\Component\\Stopwatch\\StopwatchEvent` object can be retrieved -from the :method:`Symfony\\Component\\Stopwatch\\Stopwatch::start`, -:method:`Symfony\\Component\\Stopwatch\\Stopwatch::stop`, -:method:`Symfony\\Component\\Stopwatch\\Stopwatch::lap` and -:method:`Symfony\\Component\\Stopwatch\\Stopwatch::getEvent` methods. +from the :method:`Symfony\\Component\\Stopwatch\\Stopwatch::start`, +:method:`Symfony\\Component\\Stopwatch\\Stopwatch::stop`, +:method:`Symfony\\Component\\Stopwatch\\Stopwatch::lap` and +:method:`Symfony\\Component\\Stopwatch\\Stopwatch::getEvent` methods. The latter should be used when you need to retrieve the duration of an event while it is still running. +.. tip:: + + By default, the stopwatch truncates any sub-millisecond time measure to ``0``, + so you can't measure microseconds or nanoseconds. If you need more precision, + pass ``true`` to the ``Stopwatch`` class constructor to enable full precision:: + + $stopwatch = new Stopwatch(true); + + .. versionadded:: 3.4 + The full precision feature was introduced in Symfony 3.4. + You can also provide a category name to an event:: $stopwatch->start('eventName', 'categoryName');