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| author | Marc Mutz <marc.mutz@kdab.com> | 2016-04-03 13:02:47 +0200 |
|---|---|---|
| committer | Marc Mutz <marc.mutz@kdab.com> | 2016-04-11 11:01:25 +0000 |
| commit | 045e417eff0a0efabd15d22361af7e6dff5f44f4 (patch) | |
| tree | 88fc728dc854d0216b3cc7795ff00c54ce10e308 /src/corelib/tools | |
| parent | 7b4c02d527c448a3c8b3e9fa771e42f8bd7778ff (diff) | |
[doc] QElapsedTimer: mention more clearly which functions cause undefined behavior
Change-Id: Ic7ab0d81689e2cc78f39f5f32beaea74ca10ce38
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'src/corelib/tools')
| -rw-r--r-- | src/corelib/tools/qelapsedtimer_generic.cpp | 22 |
1 files changed, 14 insertions, 8 deletions
diff --git a/src/corelib/tools/qelapsedtimer_generic.cpp b/src/corelib/tools/qelapsedtimer_generic.cpp index 210d372e15..8679aec810 100644 --- a/src/corelib/tools/qelapsedtimer_generic.cpp +++ b/src/corelib/tools/qelapsedtimer_generic.cpp @@ -79,7 +79,8 @@ void QElapsedTimer::start() Q_DECL_NOTHROW and then starting the timer again with start(), but it does so in one single operation, avoiding the need to obtain the clock value twice. - Restarting the timer makes it valid again. + Calling this function on a QElapsedTimer that is invalid + results in undefined behavior. The following example illustrates how to use this function to calibrate a parameter to a slow operation (for example, an iteration count) so that @@ -87,7 +88,7 @@ void QElapsedTimer::start() Q_DECL_NOTHROW \snippet qelapsedtimer/main.cpp 3 - \sa start(), invalidate(), elapsed() + \sa start(), invalidate(), elapsed(), isValid() */ qint64 QElapsedTimer::restart() Q_DECL_NOTHROW { @@ -100,8 +101,10 @@ qint64 QElapsedTimer::restart() Q_DECL_NOTHROW /*! \since 4.8 Returns the number of nanoseconds since this QElapsedTimer was last - started. Calling this function in a QElapsedTimer that was invalidated - will result in undefined results. + started. + + Calling this function on a QElapsedTimer that is invalid + results in undefined behavior. On platforms that do not provide nanosecond resolution, the value returned will be the best estimate available. @@ -115,10 +118,12 @@ qint64 QElapsedTimer::nsecsElapsed() const Q_DECL_NOTHROW /*! Returns the number of milliseconds since this QElapsedTimer was last - started. Calling this function in a QElapsedTimer that was invalidated - will result in undefined results. + started. - \sa start(), restart(), hasExpired(), invalidate() + Calling this function on a QElapsedTimer that is invalid + results in undefined behavior. + + \sa start(), restart(), hasExpired(), isValid(), invalidate() */ qint64 QElapsedTimer::elapsed() const Q_DECL_NOTHROW { @@ -166,7 +171,8 @@ qint64 QElapsedTimer::msecsTo(const QElapsedTimer &other) const Q_DECL_NOTHROW \a other was started before this object, the returned value will be negative. If it was started later, the returned value will be positive. - The return value is undefined if this object or \a other were invalidated. + Calling this function on or with a QElapsedTimer that is invalid + results in undefined behavior. \sa msecsTo(), elapsed() */ |