From 7776beacf720cf4478767f5b75440c4a359d8bcf Mon Sep 17 00:00:00 2001 From: "Bradley T. Hughes" Date: Tue, 10 Jan 2012 13:43:51 +0100 Subject: Document timer accuracy behavior on UNIX. Change-Id: I5e8b383cc4d8ce0d249be164c5ef596328bdc50c Reviewed-by: Thiago Macieira --- src/corelib/global/qnamespace.qdoc | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/src/corelib/global/qnamespace.qdoc b/src/corelib/global/qnamespace.qdoc index dbc399809f..3c2697e1f8 100644 --- a/src/corelib/global/qnamespace.qdoc +++ b/src/corelib/global/qnamespace.qdoc @@ -2876,9 +2876,17 @@ \value CoarseTimer Coarse timers try to keep accuracy within 5% of the desired interval \value VeryCoarseTimer Very coarse timers only keep full second accuracy + On UNIX (including Linux and Mac OS X), Qt will keep millisecond accuracy + for Qt::PreciseTimer. For Qt::CoarseTimer, the interval will be adjusted up + to 5% to align the timer with other timers that are expected to fire at or + around the same time. The objective is to make most timers wake up at the + same time, thereby reducing CPU wakeups and power consumption. + On Windows, Qt will use Windows's Multimedia timer facility (if available) for Qt::PreciseTimer and normal Windows timers for Qt::CoarseTimer and - Qt::VeryCoarseTimer. The interval for Qt::VeryCoarseTimer is rounded to the + Qt::VeryCoarseTimer. + + On all platforms, the interval for Qt::VeryCoarseTimer is rounded to the nearest full second (e.g. an interval of 23500ms will be rounded to 24000ms, and 20300ms to 20000ms). */ -- cgit v1.2.3