diff options
Diffstat (limited to 'doc/ts-and-lchan-fsm-lifecycle.msc')
| -rw-r--r-- | doc/ts-and-lchan-fsm-lifecycle.msc | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/doc/ts-and-lchan-fsm-lifecycle.msc b/doc/ts-and-lchan-fsm-lifecycle.msc new file mode 100644 index 000000000..79d32c530 --- /dev/null +++ b/doc/ts-and-lchan-fsm-lifecycle.msc @@ -0,0 +1,116 @@ +msc { + hscale=2; + bts [label="MS/BTS"], bsc[label="BSC"], bsc_ts[label="BSC timeslot FSM"], bsc_lchan[label="BSC lchan FSM"]; + + bsc box bsc [label="gsm_bts_alloc()"]; + bsc box bsc [label="bts->c0 = gsm_bts_trx_alloc()"]; + bsc -> bsc_ts; + bsc_ts box bsc_ts [label="trx->ts[*].fi = osmo_fsm_inst_alloc(timeslot_fsm)"]; + bsc_ts abox bsc_ts [label="TS_ST_NOT_INITIALIZED"]; + bsc -> bsc_lchan; + bsc_lchan box bsc_lchan [label="ts->lchan[*].ts = ts;\nts->lchan[*].nr = i;"]; + bsc_lchan box bsc_lchan [label="ts->lchan[*].fi = NULL"]; + bsc_ts note bsc_lchan [label="lchan_select() will only pick lchans from initialized timeslots of + the right pchan kind. lchan_select() shall OSMO_ASSERT(lchan->fi)."]; + ...; + ...; + + bts rbox bsc_lchan [label="reading config file"]; + ...; + bsc box bsc [label="timeslot N"]; + bsc box bsc [label="phys_chan_config X"]; + bsc_ts box bsc_ts [label="ts->pchan_from_config = X"]; + bsc_ts note bsc_ts [label="still TS_ST_NOT_INITIALIZED"]; + ...; + bsc box bsc [label="trx 1..*"]; + bsc box bsc [label="bts->trx_list add gsm_bts_trx_alloc()"]; + bsc_ts rbox bsc_lchan [label="same as for c0 above"]; + ...; + ...; + bts rbox bsc_lchan [label="Starting Operation"]; + bts => bsc_ts [label="OML Channel OPSTART ACK"]; + bsc_ts box bsc_ts [label="ts_on_oml_opstart()"]; + bsc_ts box bsc_ts [label="ts->pchan_on_init = pchan_from_config"]; + --- [label="IF dedicated TS"]; + bsc_ts box bsc_ts [label="ts->pchan = ts->pchan_on_init"]; + --- [label="ELSE: dyn TS"]; + bsc_ts box bsc_ts [label="ts->pchan = NONE"]; + --- [label="END: dyn TS"]; + bsc_ts note bsc_lchan [label="Normally, the lchan FSM never terminates. Logic dictates that + the lchan is a child of the timeslot FSM, but it's not actually of functional importance + beyond basic sanity. Parent term event: TS_EV_LCHAN_UNUSED"]; + bsc_ts box bsc_ts [label="Determine N = maximum number of lchans applicable to pchan_on_init"]; + bsc_ts -> bsc_lchan; + bsc_lchan box bsc_lchan [label="ts->lchan[all N].type = osmo_fsm_inst_alloc(lchan_fsm)"]; + bsc_lchan abox bsc_lchan [label="LCHAN_ST_UNUSED\n(initial state)"]; + bsc_ts -> bsc_ts [label="ts_check_init()"]; + ...; + bsc -> bsc_ts [label="RSL bootstrapped"]; + bsc_ts -> bsc_ts [label="ts_check_init()"]; + ...; + bsc_ts box bsc_ts [label="ts_check_init()"]; + --- [label="as soon as both OML and RSL are ready:"]; + bsc_ts box bsc_ts [label="ts_on_init()"]; + bsc_ts abox bsc_ts [label="TS_ST_UNUSED"]; + --- [label="dyn TS"]; + bsc_ts box bsc_ts [label="onenter of TS_ST_UNUSED:"]; + bsc_ts abox bsc_ts [label="TS_ST_WAIT_PDCH_ACT"]; + ...; + bsc_ts abox bsc_ts [label="PDCH"]; + --- [label="END: dyn TS"]; + --- [label="END: OML and RSL ready"]; + ...; + bsc box bsc [label="lchan_select() picks an unused lchan"]; + bsc -> bsc_lchan [label="lchan_allocate()"]; + bsc_lchan -> bsc_ts [label="TS_EV_LCHAN_REQUESTED"]; + + --- [label="dyn TS"]; + bsc_ts note bsc_ts [label="possibly switch from PDCH...\n(see timeslot FSM)"]; + bsc_ts box bsc_ts [label="ts->pchan =\n requested GSM_PCHAN_XXX type"]; + ---; + + bsc_ts -> bsc_lchan [label="LCHAN_EV_TS_READY"]; + bsc_lchan note bsc_lchan [label="RSL Chan Alloc and so fort..."]; + bsc_lchan abox bsc_lchan [label="LCHAN_ST_ACTIVE"]; + ...; + bsc -> bsc_lchan [label="LCHAN_EV_RELEASE"]; + bsc_lchan note bsc_lchan [label="...RSL RF Chan Release..."]; + bsc_lchan abox bsc_lchan [label="LCHAN_ST_UNUSED"]; + bsc_ts <- bsc_lchan [label="TS_EV_LCHAN_UNUSED"]; + bsc_ts abox bsc_ts [label="TS_ST_UNUSED"]; + --- [label="dyn TS"]; + bsc_ts note bsc_ts [label="possibly switch to PDCH"]; + ---; + ...; + ...; + bts rbox bsc_lchan [label="BTS RSL is dropped"]; + bsc box bsc [label="ipaccess_drop_rsl()"]; + bsc -> bsc_ts [label="ts[*]:"]; + bsc_ts abox bsc_ts [label="TS_ST_NOT_INITIALIZED"]; + bsc_ts note bsc_lchan [label="If it's just the RSL being dropped, transition lchan FSMs to + LCHAN_ST_UNUSED, but keep them allocated. Unless OML is re-established, any vty pchan + modifications must not take effect."]; + bsc_ts -> bsc_lchan [label="lchan[*]:"]; + bsc_lchan abox bsc_lchan [label="LCHAN_ST_UNUSED"]; + bsc_ts <- bsc_lchan [label="TS_EV_LCHAN_UNUSED (ignored)"]; + ...; + --- [label="when RSL comes back later:"]; + bsc -> bsc_ts [label="RSL bootstrapped"]; + bsc_ts box bsc_ts [label="ts_check_init()"]; + bsc_ts rbox bsc_ts [label="see ts_check_init() above"]; + ...; + ...; + bts rbox bsc_lchan [label="BTS OML is dropped"]; + bsc note bsc [label="As part of OML drop, RSL is also dropped:"]; + bsc box bsc [label="ipaccess_drop_rsl()"]; + bsc -> bsc_ts [label="ts[*]:"]; + bsc_ts abox bsc_ts [label="TS_ST_NOT_INITIALIZED"]; + bsc rbox bsc [label="see 'BTS RSL is dropped' above"]; + bsc -> bsc_ts [label="ts[*]:"]; + bsc_ts -> bsc_lchan [label="lchan[*]:"]; + bsc_lchan box bsc_lchan [label="osmo_fsm_inst_term()"]; + bsc_ts <- bsc_lchan [label="TS_EV_LCHAN_UNUSED (ignored)"]; + bsc_lchan box bsc_lchan [label="lchan->fi = NULL"]; + bsc rbox bsc [label="Continue at 'Starting Operation'"]; + +} |