sd_bus_set_method_call_timeout, sd_bus_get_method_call_timeout — Set or query the default D-Bus method call timeout of a bus object
#include <systemd/sd-bus.h>
| int sd_bus_set_method_call_timeout( | sd_bus *bus, | 
| uint64_t usec ); | 
| int sd_bus_get_method_call_timeout( | sd_bus *bus, | 
| uint64_t *ret ); | 
sd_bus_set_method_call_timeout() sets the default D-Bus method call
    timeout of bus to usec microseconds.
sd_bus_get_method_call_timeout() queries the default D-Bus method
    call timeout of bus. If no method call timeout was set using
    sd_bus_set_method_call_timeout(), the timeout is read from the
    $SYSTEMD_BUS_TIMEOUT environment variable. If this environment variable is
    unset or does not contain a valid timeout, the implementation falls back to a predefined method
    call timeout of 25 seconds. Note that $SYSTEMD_BUS_TIMEOUT is read once and
    cached so callers should not rely on being able to change the default method call timeout at
    runtime by changing the value of $SYSTEMD_BUS_TIMEOUT. Instead, call
    sd_bus_set_method_call_timeout() to change the default method call timeout.
    
On success, these functions return a non-negative integer. On failure, they return 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.
sd_bus_set_method_call_timeout() and
    sd_bus_get_method_call_timeout() were added in version 246.