Neels Hofmeyr has uploaded this change for review. (
https://gerrit.osmocom.org/12842
Change subject: comments: clarify usage of conn.assignment and .handover scopes
......................................................................
comments: clarify usage of conn.assignment and .handover scopes
Change-Id: I7ef602c3ce086aecbc3ae3ae6d3fd33ad2b9f85c
---
M include/osmocom/bsc/gsm_data.h
1 file changed, 13 insertions(+), 2 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/42/12842/1
diff --git a/include/osmocom/bsc/gsm_data.h b/include/osmocom/bsc/gsm_data.h
index 867a46c..389f9a5 100644
--- a/include/osmocom/bsc/gsm_data.h
+++ b/include/osmocom/bsc/gsm_data.h
@@ -99,6 +99,9 @@
SUBSCR_SCCP_ST_CONNECTED
};
+/* Information retrieved during an Assignment Request from the MSC. This used
as storage of the Assignment instructions
+ * parsed from the Assignment Request message, to pass on until the gscon and
assignment FSMs have decided whether an
+ * Assignment is actually going to be carried out. Must remain unchanged after
initial decoding. */
struct assignment_request {
bool aoip;
@@ -112,6 +115,9 @@
uint16_t s15_s0;
};
+/* State of an ongoing Assignment, while the assignment_fsm is still busy.
This serves as state separation to keep the
+ * currently used lchan and gscon unmodified until the outcome of an
Assignment is known. If the Assignment fails, this
+ * state is simply discarded, and the gscon carries on with the original lchan
remaining unchanged. */
struct assignment_fsm_data {
struct assignment_request req;
bool requires_voice_stream;
@@ -204,12 +210,17 @@
/* back pointers */
struct gsm_network *network;
- /* the primary / currently active lchan to the BTS/subscriber */
+ /* the primary / currently active lchan to the BTS/subscriber. During
Assignment and Handover, separate lchans
+ * are kept in the .assignment or .handover sub-structs, respectively,
so that this lchan remains unaffected
+ * until Assignment or Handover have actually succeeded. */
struct gsm_lchan *lchan;
+ /* Only valid during an ongoing Assignment; might be overwritten at any
time by a failed Assignment attempt.
+ * Once an Assignment was successful, all relevant state must be copied
out of this sub-struct. */
struct assignment_fsm_data assignment;
- /* handover information, if a handover is pending for this conn. */
+ /* handover information, if a handover is pending for this conn. Valid
only during an ongoing Handover
+ * operation. If a Handover was successful, all relevant state must be
copied out of this sub-struct. */
struct handover ho;
/* buffer/cache for classmark of the ME of the subscriber */
--
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Gerrit-Project: osmo-bsc
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: I7ef602c3ce086aecbc3ae3ae6d3fd33ad2b9f85c
Gerrit-Change-Number: 12842
Gerrit-PatchSet: 1
Gerrit-Owner: Neels Hofmeyr <[email protected]>
