trans_free: tear down conn when last transaction is done

In trans_free(), call subscr_conn_release_when_unused(), so that we are sure to
clean up after the last transaction is done.

This fixes an error where a conn lingered after a CC failure, because that code
path forgot to trigger cleanup.

Rationale: so far we were triggering the release check after each DTAP dispatch
(compl_l3 and "normal" DTAP), which is sufficient for properly closed
transactions. We also need a check for when a timeout clears an erratic trans.

Adjust test expectation of test_call_mo_to_unknown_timeout to show that the
error is now fixed.

msc_vlr_test_reject_concurrency now sees an additional release checking event
when the SMS transaction is done, which is expected and does not affect the
test otherwise.

Related: OS#2779
Change-Id: I46ff2e9b09b67e4e0d79cccf8c04936f17281fcb

3 files changed, 7 insertions, 17 deletions

diff --git a/tests/msc_vlr/msc_vlr_test_call.c b/tests/msc_vlr/msc_vlr_test_call.c
index 3e9da6291..7f97c3596 100644
--- a/tests/msc_vlr/msc_vlr_test_call.c
+++ b/tests/msc_vlr/msc_vlr_test_call.c
@@ -482,20 +482,13 @@ static void test_call_mo_to_unknown_timeout()
 	fake_time_passes(10, 23);
 
 	btw("The CC Release times out and we still properly clear the conn");
-	btw("ERROR: currently this is broken and will be fixed in a subsequent commit");
 	cc_to_mncc_expect_tx("", MNCC_REL_CNF);
-	expect_iu_release(); /* <-- will currently not work out */
+	expect_iu_release();
 	fake_time_passes(10, 23);
 	OSMO_ASSERT(cc_to_mncc_tx_confirmed);
-	/* EXPECTING ERROR: here, we should be able to do:
 	OSMO_ASSERT(iu_release_sent);
-	EXPECT_CONN_COUNT(0);
-	*/
-	BTW("This test is currently expecting erratic behavior:");
-	EXPECT_CONN_COUNT(1);
-	/* need to free manually for the sake of this test suite */
-	msc_subscr_conn_close(g_conn, 0);
 
+	EXPECT_CONN_COUNT(0);
 	clear_vlr();
 	comment_end();
 }
diff --git a/tests/msc_vlr/msc_vlr_test_call.err b/tests/msc_vlr/msc_vlr_test_call.err
index 7aa26d251..425762d12 100644
--- a/tests/msc_vlr/msc_vlr_test_call.err
+++ b/tests/msc_vlr/msc_vlr_test_call.err
@@ -349,7 +349,6 @@ DCC Sending 'MNCC_REL_CNF' to MNCC.
 DCC (ti 08 sub MSISDN:42342) new state RELEASE_REQ -> NULL
 DREF VLR subscr MSISDN:42342 usage decreases to: 2
 DREF MSISDN:42342: MSC conn use - trans_cc == 2 (0x6)
-DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_COMMUNICATING
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_RELEASE_WHEN_UNUSED
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: subscr_conn_fsm_release_when_unused: releasing conn
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: state_chg to SUBSCR_CONN_S_RELEASED
@@ -732,7 +731,6 @@ DCC Sending 'MNCC_REL_CNF' to MNCC.
 DCC (ti 00 sub MSISDN:42342) new state RELEASE_REQ -> NULL
 DREF VLR subscr MSISDN:42342 usage decreases to: 2
 DREF MSISDN:42342: MSC conn use - trans_cc == 2 (0x6)
-DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_COMMUNICATING
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_RELEASE_WHEN_UNUSED
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: subscr_conn_fsm_release_when_unused: releasing conn
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: state_chg to SUBSCR_CONN_S_RELEASED
@@ -1069,7 +1067,6 @@ DCC Sending 'MNCC_REL_CNF' to MNCC.
 DCC (ti 08 sub MSISDN:42342) new state RELEASE_REQ -> NULL
 DREF VLR subscr MSISDN:42342 usage decreases to: 2
 DREF MSISDN:42342: MSC conn use - trans_cc == 2 (0x6)
-DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_COMMUNICATING
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_RELEASE_WHEN_UNUSED
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: subscr_conn_fsm_release_when_unused: releasing conn
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: state_chg to SUBSCR_CONN_S_RELEASED
@@ -1397,7 +1394,6 @@ DMSC msc_tx 2 bytes to MSISDN:42342 via RAN_UTRAN_IU
 - DTAP --RAN_UTRAN_IU--> MS: GSM48_MT_CC_RELEASE: 832d
 - DTAP matches expected message
 - The CC Release times out and we still properly clear the conn
-- ERROR: currently this is broken and will be fixed in a subsequent commit
 - Total time passed: 20.000046 s
   MS <--Call Release-- MSC: subscr=MSISDN:42342 callref=0x80000003
 DMNCC transmit message MNCC_REL_CNF
@@ -1406,10 +1402,8 @@ DCC Sending 'MNCC_REL_CNF' to MNCC.
 DCC (ti 08 sub MSISDN:42342) new state RELEASE_REQ -> NULL
 DREF VLR subscr MSISDN:42342 usage decreases to: 2
 DREF MSISDN:42342: MSC conn use - trans_cc == 1 (0x4)
----
-- This test is currently expecting erratic behavior:
-  llist_count(&net->subscr_conns) == 1
-DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_CN_CLOSE
+DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_RELEASE_WHEN_UNUSED
+DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: subscr_conn_fsm_release_when_unused: releasing conn
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_COMMUNICATING}: state_chg to SUBSCR_CONN_S_RELEASED
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_RELEASED}: Terminating (cause = OSMO_FSM_TERM_REGULAR)
 DVLR Process_Access_Request_VLR(901700000010650){PR_ARQ_S_DONE}: Terminating (cause = OSMO_FSM_TERM_PARENT)
@@ -1423,6 +1417,7 @@ DRLL subscr MSISDN:42342: Freeing subscriber connection
 DREF VLR subscr MSISDN:42342 usage decreases to: 1
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_RELEASED}: Freeing instance
 DMM Subscr_Conn(901700000010650){SUBSCR_CONN_S_RELEASED}: Deallocated
+  llist_count(&net->subscr_conns) == 0
 DREF freeing VLR subscr MSISDN:42342
 ===== test_call_mo_to_unknown_timeout: SUCCESS
 
diff --git a/tests/msc_vlr/msc_vlr_test_reject_concurrency.err b/tests/msc_vlr/msc_vlr_test_reject_concurrency.err
index 17e8c8933..e963ba632 100644
--- a/tests/msc_vlr/msc_vlr_test_reject_concurrency.err
+++ b/tests/msc_vlr/msc_vlr_test_reject_concurrency.err
@@ -1560,6 +1560,8 @@ DREF VLR subscr MSISDN:46071 usage decreases to: 2
 DREF MSISDN:46071: MSC conn use - trans_sms == 2 (0x6)
 DMM Subscr_Conn(901700000004620){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_RELEASE_WHEN_UNUSED
 DMM Subscr_Conn(901700000004620){SUBSCR_CONN_S_COMMUNICATING}: subscr_conn_fsm_release_when_unused: still awaiting first request after a CM Service Request
+DMM Subscr_Conn(901700000004620){SUBSCR_CONN_S_COMMUNICATING}: Received Event SUBSCR_CONN_E_RELEASE_WHEN_UNUSED
+DMM Subscr_Conn(901700000004620){SUBSCR_CONN_S_COMMUNICATING}: subscr_conn_fsm_release_when_unused: still awaiting first request after a CM Service Request
 DREF MSISDN:46071: MSC conn use - dtap == 1 (0x4)
   dtap_tx_confirmed == 1
 - SMS is done