git: kqueue: Make EVFILT_USER event behaviour more consistent.
ivadasz at crater.dragonflybsd.org
Wed Aug 23 12:03:42 PDT 2017
Author: Imre VadÃ¡sz <imre at vdsz.com>
Date: Sat Aug 19 21:50:28 2017 +0200
kqueue: Make EVFILT_USER event behaviour more consistent.
* Stop abusing the kn->kn_sfflags value for storing the current state of
the EVFILT_USER filter. Instead use kn->kn_fflags like other filters.
Similarly store the data value in kn->kn_data instead of kn->kn_sdata.
This means that the fflags value gets reset when EV_CLEAR was specified
when adding the event, and the event is received by userspace. This
behaviour is consistent with existing kqueue filters, and allows using
EVFILT_USER properly as an edge-triggered event when using the fflags,
and not just level-triggered.
* Don't clear kn->kn_fflags when the event is modified with EV_CLEAR. Doing
this wasn't affecting the actual state of the EVFILT_USER event before
this change (since the state was kept in kn->kn_sfflags instead).
* All this also avoids blindly copying the fflags value that was specified
when adding the event. Instead the NOTE_FFLAGSMASK mask is applied, and
the NOTE_FF* options are used, so the returned fflags value should now
always only have the lower 24 bits set.
* Make setting the fflags and data value when adding the event work as
might be expected.
Summary of changes:
sys/kern/kern_event.c | 50 +++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 43 insertions(+), 7 deletions(-)
DragonFly BSD source repository
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