NAME

       sd_bus_get_n_queued_read, sd_bus_get_n_queued_write - Get the number of pending bus
       messages in the read and write queues of a bus connection object

SYNOPSIS

       #include <systemd/sd-bus.h>

       int sd_bus_get_n_queued_read(sd_bus *bus, uint64_t *ret);

       int sd_bus_get_n_queued_write(sd_bus *bus, uint64_t *ret);

DESCRIPTION

       sd_bus_get_n_queued_read() may be used to query the number of bus messages in the read
       queue of a bus connection object. The read queue contains all messages read from the
       transport medium (e.g. network socket) but not yet processed locally. The function expects
       two arguments: the bus object to query, and a pointer to a 64-bit counter variable to
       write the current queue size to. Use sd_bus_process() in order to process queued messages,
       i.e. to reduce the size of the read queue (as well as, in fact, the write queue, see
       below).

       Similarly, sd_bus_get_n_queued_write() may be used to query the number of currently
       pending bus messages in the write queue of a bus connection object. The write queue
       contains all messages enqueued into the connection with a call such as sd_bus_send() but
       not yet written to the transport medium. The expected arguments are similar to
       sd_bus_get_n_queued_read(). Here too, use sd_bus_process() to reduce the size of the write
       queue. Alternatively, use sd_bus_flush() to synchronously write out any pending bus
       messages until the write queue is empty.

RETURN VALUE

       On success, these functions return 0 or a positive integer. On failure, they return a
       negative errno-style error code.

   Errors
       Returned errors may indicate the following problems:

       -ECHILD
           The bus connection was created in a different process, library or module instance.

HISTORY

       sd_bus_get_n_queued_read() and sd_bus_get_n_queued_write() were added in version 238.

SEE ALSO

       systemd(1), sd-bus(3), sd_bus_process(3), sd_bus_send(3), sd_bus_flush(3)