sd_event_set_signal_exit — Automatically leave event loop on SIGINT and SIGTERM
#include <systemd/sd-event.h>
int sd_event_set_signal_exit( | sd_event *event, |
int b); |
sd_event_set_signal_exit() may be used to ensure the event loop terminates
once a SIGINT or SIGTERM signal is received. It is a
convenience wrapper around invocations of
sd_event_add_signal(3)
for both signals. The two signals are automatically added to the calling thread's signal mask (if a
program is multi-threaded care should be taken to either invoke this function before the first thread is
started or to manually block the two signals process-wide first).
If the parameter b is specified as true, the event loop will terminate on
SIGINT and SIGTERM. If specified as false, it will no
longer. When this functionality is turned off the calling thread's signal mask is restored to match the
state before it was turned on, for the two signals. By default the two signals are not handled by the
event loop, and Linux' default signal handling for them is in effect.
It's customary for UNIX programs to exit on either of these two signals, hence it's typically a good idea to enable this functionality for the main event loop of a program.
sd_event_set_signal_exit() returns a positive non-zero value when the setting
was successfully changed. It returns a zero when the specified setting was already in effect. On failure,
it returns a negative errno-style error code.
Functions described here are available as a shared
library, which can be compiled against and linked to with the
libsystemd pkg-config(1)
file.
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.