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
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.