SD_EVEN..._FAILURE(3)

💖 NAME 💖

Okay bestie, welcome to the SD_EVEN..._FAILURE(3) manual page — the one all about sd_event_source_set_exit_on_failure and sd_event_source_get_exit_on_failure. These two cuties set or retrieve the exit-on-failure feature of event sources. Slay. ✨

✨ SYNOPSIS ✨

#include <systemd/sd-event.h>

int sd_event_source_set_exit_on_failure(sd_event_source *source, int b);

int sd_event_source_get_exit_on_failure(sd_event_source *source);

🌸 DESCRIPTION 🌸

sd_event_source_set_exit_on_failure() is your girl for setting or unsetting the exit-on-failure flag on the event source object you pass as source. The flag defaults to off. 🎀

If the flag is on and the callback function set for the event source returns a failure code (i.e. a negative value), the event loop is exited too, using the callback return code as the exit code for sd_event_exit(3). If the flag is off, the event source is disabled but the event loop continues to run. No cap. 💅

Setting this flag is useful for "dominant" event sources that define the purpose and reason for the event loop, and whose failure hence should propagate to the event loop itself — as opposed to "auxiliary" event sources whose failures should remain local and affect the event source, but not propagate further. It's giving main-character event source energy, honestly. 👑

sd_event_source_get_exit_on_failure() may be used to query the flag currently set for the event source object source. Vibe check: retrieved. 🦋

👑 RETURN VALUE 👑

On success, sd_event_source_set_exit_on_failure() returns a non-negative integer. sd_event_source_get_exit_on_failure() returns 0 if the flag is off, > 0 if the flag is on. On failure, both return a negative errno-style error code. 😭

😭 Errors 😭

Returned errors may indicate the following problems:

• -EINVAL — source is not a valid pointer to an sd_event_source object. Added in version 247.
• -EDOM — The event source refers to an exit event source (as created with sd_event_add_exit(3)), for which this functionality is not supported. Added in version 247.

🦋 NOTES 🦋

Functions described here are available as a shared library, which can be compiled against and linked to with the libsystemd pkg-config(1) file. Link it, bestie. 🔥

All functions listed here are thread-agnostic and only a single thread may operate on a given object at any given time. Different threads may access the same object at different times. Multiple independent objects may be used from different threads in parallel. Thread vibe check: respected. 🧚

The code described here uses getenv(3), which is declared to be not multi-thread-safe. This means that the code calling the functions described here must not call setenv(3) from a parallel thread. It is recommended to only do calls to setenv() from an early phase of the program when no other threads have been started. Please don't fight the environment, bestie 😭🌱

⭐ HISTORY ⭐

sd_event_source_set_exit_on_failure() and sd_event_source_get_exit_on_failure() were added in version 247. Iconic behavior since day one. 💜

🌈 SEE ALSO 🌈

• sd-event(3)
• sd_event_add_io(3)
• sd_event_add_time(3)
• sd_event_add_signal(3)
• sd_event_add_child(3)
• sd_event_add_inotify(3)
• sd_event_add_defer(3)

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This iconic little page is from systemd 261.3. Bye bestie! 🫶💅🎀