Different threads (e.g., RRC, DU tasks) might access the scheduler at
the same time as the thread that drivers the scheduler itself
(ru_thread). To avoid data races, introduce this mutex.
Most functions of the scheduler are only used internally and have been
marked static in the previous commit. The remaining ones, in this
commit, either lock the scheduler mutex sched_lock, or a comment has
been added of the assumption of how such function is to be locked (e.g.,
if it might be called from different places, or if it is called by a
function that already locks the scheduler).
To know which functions are used from outside and which are
module-local, make many functions static. This will allow us to protect
only those functions with a mutex for which it is necessary.
The CellGroupConfig should come from the DU. Currently, any update made
to the CellGroupConfig is done at CU. In split-operation, we have no way
of telling the DU about this update. Hence, in this commit, check if we
are in F1 split mode operation during a CellGroupConfig update, and if
so, suppress any updates to the CellGroupConfig, alongside a warning.
It may happen that the drb to configure is not 1, so we may need
this array in rrc_gNB_generate_dedicatedRRCReconfiguration().
Not tested, this commit is mostly to harmonize with other places in
openair2/RRC/NR/rrc_gNB.c
fill_default_secondaryCellGroup() is moved to nr_rrc_config.c.
Furthermore, the signature is changes to return the NR_CellGroupConfig
from the functions, instead of filling a pre-allocated structure (which
is, in all cases, allocated just before calling
fill_default_secondaryCellGroup().
There is a problem with this function: the function also fills the
ServingCellConfig (a parameter to this function). This behavior has not
been changed.
nr_DRB_preconfiguration() does a "pre-configuration" for the default DRB
for "noS1" mode, i.e., when there is no connection to core network. In
this case, there is no PDU session to be set up, and hence we need to
preconfigure the DRBs.
We replace this function with partially existing functions and a new
function fill_nr_noS1_bearer_config() which returns a bearer
configuration for the noS1 case, also better reflected in the function
name. It has also been moved to asn1_msg.c, away from the actual PDCP
layer.
Robert Schmidt