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authorNeels Hofmeyr <neels@hofmeyr.de>2019-01-28 15:38:09 +0100
committerHarald Welte <laforge@gnumonks.org>2019-01-29 10:25:26 +0000
commitbd5a1dc84f0124d99a89ac187f15c7d34beea210 (patch)
tree6b932212102ca5fad56a6f2cff3a3deb896cc688
parent4ff41d94ce72afca20f9faaab1ab2f367f1e51aa (diff)
osmo_fsm_inst_state_chg(): set T also for zero timeout
Before this patch, if timeout_secs == 0 was passed to osmo_fsm_inst_state_chg(), the previous T value remained set in the osmo_fsm_inst->T. For example: osmo_fsm_inst_state_chg(fi, ST_X, 23, 42); // timer == 23 seconds; fi->T == 42 osmo_fsm_inst_state_chg(fi, ST_Y, 0, 0); // no timer; fi->T == 42! Instead, always set to the T value passed to osmo_fsm_inst_state_chg(). Adjust osmo_fsm_inst_state_chg() API doc; need to rephrase to accurately describe the otherwise unchanged behaviour independently from T. Verify in fsm_test.c. Rationale: it is confusing to have a T number remaining from some past state, especially since the user explicitly passed a T number to osmo_fsm_inst_state_chg(). (Usually we are passing timeout_secs=0, T=0). I first thought this behavior was introduced with osmo_fsm_inst_state_chg_keep_timer(), but in fact osmo_fsm_inst_state_chg() behaved this way from the start. This shows up in the C test for the upcoming tdef API, where the test result printout was showing some past T value sticking around after FSM state transitions. After this patch, there will be no such confusion. Change-Id: I65c7c262674a1bc5f37faeca6aa0320ab0174f3c
-rw-r--r--src/fsm.c21
-rw-r--r--tests/fsm/fsm_test.c38
-rw-r--r--tests/fsm/fsm_test.err15
-rw-r--r--tests/fsm/fsm_test.ok4
4 files changed, 71 insertions, 7 deletions
diff --git a/src/fsm.c b/src/fsm.c
index 1f6141f..ae7c0f5 100644
--- a/src/fsm.c
+++ b/src/fsm.c
@@ -458,9 +458,10 @@ static int state_chg(struct osmo_fsm_inst *fi, uint32_t new_state,
fi->state = new_state;
st = &fsm->states[new_state];
- if (!keep_timer && timeout_secs) {
+ if (!keep_timer) {
fi->T = T;
- osmo_timer_schedule(&fi->timer, timeout_secs, 0);
+ if (timeout_secs)
+ osmo_timer_schedule(&fi->timer, timeout_secs, 0);
}
/* Call 'onenter' last, user might terminate FSM from there */
@@ -480,11 +481,17 @@ static int state_chg(struct osmo_fsm_inst *fi, uint32_t new_state,
* function. It verifies that the existing state actually permits a
* transition to new_state.
*
- * timeout_secs and T are optional parameters, and only have any effect
- * if timeout_secs is not 0. If the timeout function is used, then the
- * new_state is entered, and the FSM instances timer is set to expire
- * in timeout_secs functions. At that time, the FSM's timer_cb
- * function will be called for handling of the timeout by the user.
+ * If timeout_secs is 0, stay in the new state indefinitely, without a timeout
+ * (stop the FSM instance's timer if it was runnning).
+ *
+ * If timeout_secs > 0, start or reset the FSM instance's timer with this
+ * timeout. On expiry, invoke the FSM instance's timer_cb -- if no timer_cb is
+ * set, an expired timer immediately terminates the FSM instance with
+ * OSMO_FSM_TERM_TIMEOUT.
+ *
+ * The value of T is stored in fi->T and is then available for query in
+ * timer_cb. If passing timeout_secs == 0, it is recommended to also pass T ==
+ * 0, so that fi->T is reset to 0 when no timeout is invoked.
*
* \param[in] fi FSM instance whose state is to change
* \param[in] new_state The new state into which we should change
diff --git a/tests/fsm/fsm_test.c b/tests/fsm/fsm_test.c
index 34a8399..7aac8d3 100644
--- a/tests/fsm/fsm_test.c
+++ b/tests/fsm/fsm_test.c
@@ -349,6 +349,43 @@ static void test_state_chg_keep_timer()
fprintf(stderr, "--- %s() done\n", __func__);
}
+static void test_state_chg_T()
+{
+ struct osmo_fsm_inst *fi;
+
+ fprintf(stderr, "\n--- %s()\n", __func__);
+
+ fsm.timer_cb = NULL;
+
+ /* Test setting to timeout_secs = 0, T = 0 */
+ fi = osmo_fsm_inst_alloc(&fsm, g_ctx, NULL, LOGL_DEBUG, NULL);
+ OSMO_ASSERT(fi);
+
+ osmo_fsm_inst_state_chg(fi, ST_ONE, 23, 42);
+ printf("T = %d\n", fi->T);
+ OSMO_ASSERT(fi->T == 42);
+ osmo_fsm_inst_state_chg(fi, ST_TWO, 0, 0);
+ printf("T = %d\n", fi->T);
+ OSMO_ASSERT(fi->T == 0);
+
+ osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REQUEST, NULL);
+
+ /* Test setting to timeout_secs = 0, T != 0 */
+ fi = osmo_fsm_inst_alloc(&fsm, g_ctx, NULL, LOGL_DEBUG, NULL);
+ OSMO_ASSERT(fi);
+
+ osmo_fsm_inst_state_chg(fi, ST_ONE, 23, 42);
+ printf("T = %d\n", fi->T);
+ OSMO_ASSERT(fi->T == 42);
+ osmo_fsm_inst_state_chg(fi, ST_TWO, 0, 11);
+ printf("T = %d\n", fi->T);
+ OSMO_ASSERT(fi->T == 11);
+
+ osmo_fsm_inst_term(fi, OSMO_FSM_TERM_REQUEST, NULL);
+
+ fprintf(stderr, "--- %s() done\n", __func__);
+}
+
static const struct log_info_cat default_categories[] = {
[DMAIN] = {
.name = "DMAIN",
@@ -390,6 +427,7 @@ int main(int argc, char **argv)
test_id_api();
test_state_chg_keep_timer();
+ test_state_chg_T();
osmo_fsm_unregister(&fsm);
exit(0);
diff --git a/tests/fsm/fsm_test.err b/tests/fsm/fsm_test.err
index 85606e2..bf474ab 100644
--- a/tests/fsm/fsm_test.err
+++ b/tests/fsm/fsm_test.err
@@ -101,3 +101,18 @@ Test_FSM{TWO}: Timeout of T10
Test_FSM{TWO}: Freeing instance
Test_FSM{TWO}: Deallocated
--- test_state_chg_keep_timer() done
+
+--- test_state_chg_T()
+Test_FSM{NULL}: Allocated
+Test_FSM{NULL}: state_chg to ONE
+Test_FSM{ONE}: state_chg to TWO
+Test_FSM{TWO}: Terminating (cause = OSMO_FSM_TERM_REQUEST)
+Test_FSM{TWO}: Freeing instance
+Test_FSM{TWO}: Deallocated
+Test_FSM{NULL}: Allocated
+Test_FSM{NULL}: state_chg to ONE
+Test_FSM{ONE}: state_chg to TWO
+Test_FSM{TWO}: Terminating (cause = OSMO_FSM_TERM_REQUEST)
+Test_FSM{TWO}: Freeing instance
+Test_FSM{TWO}: Deallocated
+--- test_state_chg_T() done
diff --git a/tests/fsm/fsm_test.ok b/tests/fsm/fsm_test.ok
index e69de29..c3536fb 100644
--- a/tests/fsm/fsm_test.ok
+++ b/tests/fsm/fsm_test.ok
@@ -0,0 +1,4 @@
+T = 42
+T = 0
+T = 42
+T = 11