sd_bus_get_current

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.

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_get_current_handler(), sd_bus_get_current_message(), sd_bus_get_current_slot(), and sd_bus_get_current_userdata() were added in version 221.