Re: Performance degradation in commit ac1d794

On Sun, Mar 20, 2016 at 7:13 AM, Andres Freund <andres@anarazel.de> wrote:
>
> On 2016-03-19 15:43:27 +0530, Amit Kapila wrote:
> > On Sat, Mar 19, 2016 at 12:40 PM, Andres Freund <andres@anarazel.de> wrote:
> > >
> > > On March 18, 2016 11:52:08 PM PDT, Amit Kapila <amit.kapila16@gmail.com>
> > wrote:
> > > >> >Won't the new code needs to ensure that ResetEvent(latchevent)
> > > >should
> > > >> >get
> > > >> >called in case WaitForMultipleObjects() comes out when both
> > > >> >pgwin32_signal_event and latchevent are signalled at the same time?
>
> > > >> WaitForMultiple only reports the readiness of on event at a time, no?
> > > >>
> > > >
> > > >I don't think so, please read link [1] with a focus on below paragraph
> > > >which states how it reports the readiness or signaled state when
> > > >multiple
> > > >objects become signaled.
> > > >
> > > >"When *bWaitAll* is *FALSE*, this function checks the handles in the
> > > >array
> > > >in order starting with index 0, until one of the objects is signaled.
> > > >If
> > > >multiple objects become signaled, the function returns the index of the
> > > >first handle in the array whose object was signaled."
>
> I think this is just incredibly bad documentation. See
> https://blogs.msdn.microsoft.com/oldnewthing/20150409-00/?p=44273
> (Raymond Chen can be considered an authority here imo).
>