this rather large patch changes the way cells are handled in the SS.
It moves RLC and PDCP entities to the cell map of the SS, such that each cell
has its own entities. This allows to support HO operation, for example,
in which two cells need to send SRB messages.
It also extends most of the syssim interface to include the cell name
in all commands so they can be applied on the specified cell only.
* split existing BSR test into dedicated test for short, long, and trunc
BSR tests
* update MAC tests that include packing UL BSR.
(After checking TS 36.321 again it seems we have reported old UL buffer states)
before the BSR was extracted but the actual index (between 0 and 63)
was not stored but directly converted into bytes.
for log parsing and debugging it is easier to follow the index
value. this patch therefore adds both values to the log message
and extends the API accordingly.
* add locked and unlocked version of has_data() since one is
called from stack and one from PHY threads
* add comments in each interface section as to why locking
is required or not
* remove RLC rwlock when not required
* move calls only used by RRC to RRC section
this patch refactors the SDU queuing and dropping policy of the RLC and PDCP layer.
the previous design had issues when packets have been generated at a higher
rate above the PDCP than they could be consumed below the RLC.
When the RLC SDU queues were full, we allowed two policies, one to block on the write
and the other to drop the SDU. Both options are not ideal because they either
lead to a blocking stack thread or to lost PDCP PDUs.
To avoid this, this patch makes the following changes:
* PDCP monitors RLC's SDU queue and drops packets on its north-bound SAP if queues are full
* a new method sdu_queue_is_full() has been added to the RLC interface for PDCP
* remove blocking write from pdcp and rlc write_sdu() interface
* all writes into queues need to be non-blocking
* if Tx queues are overflowing, SDUs are dropped above PDCP, not RLC
* log warning if RLC still needs to drop SDUs
* this case should be avoided with the monitoring mechanism
reducing the sync queue len to 1 caused an issue when the
PHY was locking the mutex while trying to push a TTI event
on the stack.
instead of signaling the new TTI within the PHY, we now do it outside
in the DUT (after releasing the PHY mutex)
apply same change that we've done on the eNB also on the UE
to avoid the PHY processing TTIs faster than the stack.
Without that, we see lots of those in the logs:
...
08:39:17.580325 [STCK] [W] Detected slow task processing (sync_queue_len=7).
...
unfortunately, the rapidjson version shipped with Ubuntu 16.04
doesn't support the GetArray() API so we need to use
normal iterator to loop over the array
extend GW-NAS interface to signal test mode activation.
The method is a noop in the normal GW but is implemented in
the TTCN3 DUT according to TS 36.509 for Mode B
this is to better differentiate from "send_attach_request" that
only packs and send the actual attach request message. The
entire attach procedure may include PLMN search, etc.
The test TC_9_2_1_1_1 sends a Cell->AddOrReconfigure->Basic message
without a "StaticCellInfo" member. This is used to change SIB1 of
the cell and simulate a different PLMN/TAC in the test.
handle_request_cell_basic() ignored the json message if "StaticCellInfo"
is missing which results in the SIB not being updated (PLMN stays as
00102 for example).
With this patch the SIBs after the json are now parsed even if there
"StaticCellInfo" is missing. A confirmation of the json is not sent
because the test does not seem to expect one in that case.
Related: TC_9_2_1_1_1