sd_bus_wait — Wait for I/O on a bus connection
sd_bus_wait() synchronously waits for I/O on the specified bus connection object. This
function is supposed to be called whenever
sd_bus_process(3) returns zero,
indicating that no work is pending on the connection. Internally, this call invokes ppoll(2), to wait for I/O on
the bus connection. If the
timeout_usec parameter is specified, the call will block at most
for the specified amount of time in μs. Pass
UINT64_MAX to permit it to sleep
After each invocation of
should be invoked in order to process any now pending I/O work.
sd_bus_wait() is suitable only for simple programs as it does not permit
waiting for other I/O events. For more complex programs either connect the bus connection object to an external
event loop using sd_bus_get_fd(3)
or to an sd-event(3) event loop
If any I/O was seen, a positive value is returned, zero otherwise. If an error occurs, a negative
errno-style error code is returned.
Functions described here are available as a shared
library, which can be compiled against and linked to with the
The code described here uses
which is declared to be not multi-thread-safe. This means that the code calling the functions described
here must not call
from a parallel thread. It is recommended to only do calls to
from an early phase of the program when no other threads have been started.
sd_bus_wait() was added in version 240.