cygrunsrv + sshd + rsync = 20 times too slow -- throttled?
Takashi Yano
takashi.yano@nifty.ne.jp
Wed Sep 8 09:01:42 GMT 2021
On Wed, 8 Sep 2021 13:11:41 +0900
Takashi Yano wrote:
> On Wed, 8 Sep 2021 09:07:48 +0900
> Takashi Yano wrote:
> > On Tue, 7 Sep 2021 19:50:23 +0900
> > Takashi Yano wrote:
> >
> > > @@ -796,7 +792,8 @@ pipe_cleanup (select_record *, select_stuff *stuff)
> > > pi->stop_thread = true;
> > > SetEvent (pi->bye);
> > ~~~~~~~~~~~~~~~~~~~
> > This is not correct. SetEvent() wakes-up one of thread_pipe()s,
> > but it may be other thread than one which should be stopped.
> >
> > > pi->thread->detach ();
> > > - CloseHandle (pi->bye);
> > > + if (me->fh->get_select_evt () == NULL)
> > > + CloseHandle (pi->bye);
> > > }
> > > delete pi;
> > > stuff->device_specific_pipe = NULL;
> >
> > I think it also should be
> > > + for (ULONG i = 0; i < get_obj_handle_count (select_evt); i++)
> > > + SetEvent (select_evt);
> >
> > Actually I want to use PulseEvent() here if it is not **UNRELIABLE**.
> > https://docs.microsoft.com/en-us/windows-hardware/drivers/devtest/28648-pulseevent-is-an-unreliable-function
> >
> > Does using semaphore object instead of event, and releasing
> > resources equal to the number of handles make sense?
>
> No it does not. One thread may consume semaphore multiple times....
I wrote a simple test program which counts wake-up 1000 times in 100
threads, and confirmed that semaphore method works as expected as well
as PulseEvent(). All 100000 (100*1000) wake-up were counted without
miscount.
Therefore, patch attached should work.
--
Takashi Yano <takashi.yano@nifty.ne.jp>
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