2 Commits

Author	SHA1	Message	Date
Michal Schmidt	e0209d83e7	core: add NOP jobs, job type collapsing ... Two of our current job types are special: JOB_TRY_RESTART, JOB_RELOAD_OR_START. They differ from other job types by being sensitive to the unit active state. They perform some action when the unit is active and some other action otherwise. This raises a question: when exactly should the unit state be checked to make the decision? Currently the unit state is checked when the job becomes runnable. It's more sensible to check the state immediately when the job is added by the user. When the user types "systemctl try-restart foo.service", he really intends to restart the service if it's running right now. If it isn't running right now, the restart is pointless. Consider the example (from Bugzilla[1]): sleep.service takes some time to start. hello.service has After=sleep.service. Both services get started. Two jobs will appear: hello.service/start waiting sleep.service/start running Then someone runs "systemctl try-restart hello.service". Currently the try-restart operation will block and wait for sleep.service/start to complete. The correct result is to complete the try-restart operation immediately with success, because hello.service is not running. The two original jobs must not be disturbed by this. To fix this we introduce two new concepts: - a new job type: JOB_NOP A JOB_NOP job does not do anything to the unit. It does not pull in any dependencies. It is always immediately runnable. When installed to a unit, it sits in a special slot (u->nop_job) where it never conflicts with the installed job (u->job) of a different type. It never merges with jobs of other types, but it can merge into an already installed JOB_NOP job. - "collapsing" of job types When a job of one of the two special types is added, the state of the unit is checked immediately and the job type changes: JOB_TRY_RESTART -> JOB_RESTART or JOB_NOP JOB_RELOAD_OR_START -> JOB_RELOAD or JOB_START Should a job type JOB_RELOAD_OR_START appear later during job merging, it collapses immediately afterwards. Collapsing actually makes some things simpler, because there are now fewer job types that are allowed in the transaction. [1] Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=753586	2012-04-25 18:38:27 +02:00
Lennart Poettering	379079ba6b	test: test tools should still be in the src/ directory	2012-04-12 13:48:01 +02:00