Index · Directives systemd 261.2

Name

sd_bus_slot_get_bus, sd_bus_slot_get_current_handler, sd_bus_slot_get_current_message, sd_bus_slot_get_current_userdata — Query information attached to a bus slot object

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 *sd_bus_slot_get_bus(sd_bus_slot *slot);
 
sd_bus_message_handler_t sd_bus_slot_get_current_handler (sd_bus_slot *slot);
 
sd_bus_message *sd_bus_slot_get_current_message(sd_bus_slot *slot);
 
void *sd_bus_slot_get_current_userdata(sd_bus_slot *slot);
 

Description

sd_bus_slot_get_bus() returns the bus object that message slot is attached to.

sd_bus_slot_get_current_handler(), sd_bus_slot_get_current_message() and sd_bus_slot_get_current_userdata() return the current handler, message and userdata respectively of the bus slot is attached to if we're currently executing the callback associated with slot.

Return Value

sd_bus_slot_get_bus() always returns the bus object.

On success, sd_bus_slot_get_current_handler(), sd_bus_slot_get_current_message() and sd_bus_slot_get_current_userdata() 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.

All functions listed here are thread-agnostic and only a single thread may operate on a given object at any given time. Different threads may access the same object at different times. Multiple independent objects may be used from different threads in parallel.

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.

History

sd_bus_slot_get_bus(), sd_bus_slot_get_current_handler(), sd_bus_slot_get_current_message(), and sd_bus_slot_get_current_userdata() were added in version 246.

See Also

systemd(1), sd-bus(3)