On Thursday, March 19, 2015, David Herrmann <<a href="mailto:dh.herrmann@gmail.com">dh.herrmann@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi On Mon, Mar 9, 2015 at 3:21 PM, WaLyong Cho <<a href="javascript:;" onclick="_e(event, 'cvml', 'walyong.cho@samsung.com')">walyong.cho@samsung.com</a>> wrote: > Hi, > > I want to find best solution on our case. Our product is mobile device. > But I don't think that is only problem of mobile device. That also can > be problem of laptop. So, please comment to me. > > We have some of services are always running after system is started up > as default. They don't need to be running always. They are just needed > only charger is plugged in. > So I thought lets only active them when only charger is plugged in. > > I thought two methods. > > method 1: > Charger also can be detected by udev. So udev hardware activation can be > used. > I wrote below udev rules. > > SUBSYSTEM=="power_supply", ENV{POWER_SUPPLY_CHARGE_NOW}=="1", > TAG+="systemd", ENV{SYSTEMD_WANTS}+="foo.service" I guess the problem is, the .device unit is never stopped. Therefore, when you unplug it, it will not be stopped, as the device is still there. You could try this: SUBSYSTEM=="power_supply", ENV{POWER_SUPPLY_CHARGE_NOW}=="1", \ TAG+="systemd", ENV{SYSTEMD_WANTS}+="foo.service", \ ENV{SYSTEMD_READY}=1 SUBSYSTEM=="power_supply", ENV{POWER_SUPPLY_CHARGE_NOW}=="0", \ ENV{SYSTEMD_READY}=0 It's not particularly nice, as other dependencies on the power-supply device will now be borked. But as a hack it should work.</blockquote><div> </div><div>There are some hard test-case. Connect & disconnect within short time and several time. Then does it handle it at udev activation based service launch?</div><div> </div><div>Another one is that there are lots of services has dependency with charging. Then dose it add it all cases like above? Doesn't better to use target? E.g., charging.target?</div><div> </div><div>Thank you,</div><div>Kyungmin Park</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> I cannot think of a better way to support udev-activation based on attribute-changes. We never explicitly supported it. Hmm..</blockquote> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> Thanks David > It looked working well. foo.service is only activated when charger was > plugged in. > But I have some of problems with hardware activation. > I want to be stopped foo.service when the charger is plugged out. As I > know, this is impossible with udev hardware activation. > To do this, foo.service have to determine the charger state itself and > if the charger is plugged out, it have to stop itself. > And it is working only at the first time. > After foo.service was activated, I stopped foo.service by "systemctl > stop foo.service". And plug out and plug in the charger again. Then > foo.service was not activated. (Is it normal? I did not try to find the > reason. If you say it's a problem, then I will try to find.) > > > method 2: > We have another device daemon. Let's call that as deviced and its > service name is deviced.service. deviced know about plug in/out of the > charger. > So, I made a new charging.target. foo.service have Wants= dependency for > charging.target. (Installed on charging.target.wants.) And I added > "BindsTo=charging.target" to foo.service. > Then foo.service is activated well when the charging.target is entered > to active state. And also deactivated when charging.target was deactivated. > > In this method, there are limitations what some of other daemon is > needed and new charging.target is needed. > > > Is there any more good way for this? > I want to find best appropriate way. > > Thank you in advance for comment. > > WaLyong > _______________________________________________ > systemd-devel mailing list > <a href="javascript:;" onclick="_e(event, 'cvml', 'systemd-devel@lists.freedesktop.org')">systemd-devel@lists.freedesktop.org</a> > <a href="http://lists.freedesktop.org/mailman/listinfo/systemd-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/systemd-devel</a> _______________________________________________ systemd-devel mailing list <a href="javascript:;" onclick="_e(event, 'cvml', 'systemd-devel@lists.freedesktop.org')">systemd-devel@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/systemd-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/systemd-devel</a> </blockquote>