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.

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 246.