Name
sd_bus_get_current_handler, sd_bus_get_current_message, sd_bus_get_current_slot, sd_bus_get_current_userdata — Query information of the callback a bus object is currently running
Synopsis
#include <systemd/sd-bus.h>
typedef int (*sd_bus_message_handler_t)( | sd_bus_message *m,  | 
|   | void *userdata,  | 
|   | sd_bus_error *ret_error); | 
 
sd_bus_message_handler_t sd_bus_get_current_handler( | sd_bus *bus); | 
 
sd_bus_message* sd_bus_get_current_message( | sd_bus *bus); | 
 
sd_bus_slot* sd_bus_get_current_slot( | sd_bus *bus); | 
 
void* sd_bus_get_current_userdata( | sd_bus *bus); | 
 
Description
Whenever sd-bus is about to invoke a user-supplied callback function, it stores the
    current callback, D-Bus message, slot and userdata pointer and allows these to be queried via
    sd_bus_get_current_handler(),
    sd_bus_get_current_message(),
    sd_bus_get_current_slot() and
    sd_bus_get_current_userdata(), respectively. If bus
    cannot be resolved or if execution does not reside in a user-supplied callback of
    bus, these functions return NULL.
Return Value
On success, these functions return the requested object. On failure, they return
    NULL.
Notes
These APIs are implemented as a shared
  library, which can be compiled and linked to with the
  libsystemd pkg-config(1)
  file.