How does launch daemons and agents work in Apple?

How does launch daemons and agents work in Apple?

It registers the sockets and file descriptors requested by those daemons. It launches any daemons that requested to be running all the time. As requests for a particular service arrive, it launches the corresponding daemon and passes the request to it.

What’s the difference between launchd and launchd in OS X?

If you are running per-user background processes for OS X, launchd is also the preferred way to start these processes. These per-user processes are referred to as user agents. A user agent is essentially identical to a daemon, but is specific to a given logged-in user and executes only while that user is logged in.

What should be the response of a launchd daemon?

Your daemon should always provide a reasonable response (rather than an error) when processing requests. Register the sockets and file descriptors used by your daemon in your launchd configuration property list file. If your daemon advertises a socket, check in with launchd as part of your daemon initialization.

What happens if launchd shuts down after launch?

Important: If your daemon shuts down too quickly after being launched, launchd may think it has crashed. Daemons that continue this behavior may be suspended and not launched again when future requests arrive. To avoid this behavior, do not shut down for at least 10 seconds after launch.

How to show all running launchctl daemons / agents?

… it shows all the running /System daemons, but I have some running from /Library/LaunchDaemons and it is not showing those. How can I show them all? From launchctl’s man page (apple seem to have misplaced the man pages so an external one is here https://www.unix.com/man-page/osx/1/launchctl/)

Where do I find launch on demand daemons?

It loads the parameters for each launch-on-demand system-level daemon from the property list files found in /System/Library/LaunchDaemons/ and /Library/LaunchDaemons/. It registers the sockets and file descriptors requested by those daemons. It launches any daemons that requested to be running all the time.

What’s the difference between a daemon and a user agent?

These per-user processes are referred to as user agents. A user agent is essentially identical to a daemon, but is specific to a given logged-in user and executes only while that user is logged in. Unless otherwise noted, for the purposes of this chapter, the terms “daemon” and “agent” can be used interchangeably.

Is there a command to list all running daemons?

But I do not think that the command is listing all daemons because NetworkManager, a daemon which is currently running in my Ubuntu 14.04 system, is not listed by the command. Is there some command to list the running daemons or else is there some way to find the daemons from the filesystem itself?

What happens when launchd shuts down a daemon?

When a client sends a request to the port, launchd may have to launch the daemon so that it can handle the request. Once launched, the daemon can continue running or shut itself down to free up the memory and resources it holds. If a daemon shuts itself down, launchd once again relaunches it as needed to process requests.

When does launchd have to launch a daemon?

To client programs, the port representing your daemon’s service is always available and ready to handle requests. In reality, the daemon may or may not be running. When a client sends a request to the port, launchd may have to launch the daemon so that it can handle the request.

What happens when a daemon is not running?

If a request comes in for a daemon that is not yet running, the requesting process is suspended until the target daemon finishes launching and responds. If a daemon does not receive any requests over a specific period of time, it can choose to shut itself down and release the resources it holds.

What do you need to know about daemons and agents?

Daemons and Agents provides additional details about implementing launch daemons and agents. Kernel Programming Guide and Kernel Extension Programming Topics describe how to write kernel extensions and other kernel-level background processes. Networking Overview describes the APIs available for sending and receiving data across the network.

How to delete launch Daemons on MacBook Air?

Using Finder (Under the folder “Library”), go to your “LaunchDaemons” folder and delete everything in there. Then go to “Internet Plug-ins” folder and delete everything except for “default browser”. I also deleted everything in my “LaunchAgents” folder. Restart your macbook and TaDaaaa!

How do I get rid of unwanted startup items on my Mac?

Go to the Startup Boost feature. It will list the full startup items on your mac. Check the location to view the real startup process and background processes. Click the switch button to disable or enable the unwanted application and service. Then click “Apply Changes” button to save the changes.