377d3a31e6
The descriptions of various options are reworked: first say what protocol actually is, i.e. describe what type of notification the manager waits for. Only after that describe various steps and things the service should do. Also, apply some paragraph breaks. Instead of recommending Type=simple, recommend Type=exec. Say explicitly that Type=simple, Type=forking are not recommended. Type=simple ignores failure in a way that doesn't make any sense except as a historical accident. We introduced 'exec' instead of changing 'simple' to keep backwards-compatiblity, but 'simple' is not very useful. 'forking' works, but is inefficient: correctly programming the interface requires a lot of work, and at runtime, the additional one or two forks are just a waste of CPU resources. Furthermore, we now understand that because of COW traps, they may also increase memory requirements. There is really no reason to use 'forking', except if it's already implemented and the code cannot be changed to use 'notify'. Also, remove the recommendations to use Type=simple to avoid delaying boot. In most cases, if the service can support notifications about startup, those should be done. Overall, for new services, "notify", "notify-reload", and "dbus" are the types that make sense.
System and Service Manager
Details
Most documentation is available on systemd's web site.
Assorted, older, general information about systemd can be found in the systemd Wiki.
Information about build requirements is provided in the README file.
Consult our NEWS file for information about what's new in the most recent systemd versions.
Please see the Code Map for information about this repository's layout and content.
Please see the Hacking guide for information on how to hack on systemd and test your modifications.
Please see our Contribution Guidelines for more information about filing GitHub Issues and posting GitHub Pull Requests.
When preparing patches for systemd, please follow our Coding Style Guidelines.
If you are looking for support, please contact our mailing list or join our IRC channel.
Stable branches with backported patches are available in the stable repo.