diff options
authorPhilipp Maier <pmaier@sysmocom.de>2018-02-14 18:20:07 +0100
committerHarald Welte <laforge@gnumonks.org>2018-02-19 08:30:21 +0000
commitd1f5793b5e89426927d57cff7f6951e0c2e29d92 (patch)
parent4a8a9f4210b01c3b8b75eb3b984c9127e90d8c54 (diff)
fsm: allow graceful exit on FSM termination
The function _osmo_fsm_inst_term() terminates all child FSMs befor it calls fi->fsm_cleanup(). This prevents the cleanup callback to perform last actions on the child FSMs (e.g. osmo_fsm_inst_unlink_parent()). - Since moving the cleanup callack to the beginning of the function would alter the termination behavior and possibly cause malfunction in already existing implementation that use OSMO fsm, a new optional callback that is called immediately at the beginning of the terminatopn process is added. Change-Id: I0fdda9fe994753f975a658c0f3fb3615949cc8bb Closes: OS#2915
3 files changed, 16 insertions, 2 deletions
index 782ba199..928b18d6 100644
@@ -10,3 +10,4 @@
core msgb_queue_free() add inline func to msgb.h
coding gsm0503_rach_ext-encode() add func to gsm0503_coding.h
codec ecu.c / ecu.h implement ECU for FR (Error Concealment Unit)
+fsm fsmc / fsm.h added callback for graceful exit => ABI changed \ No newline at end of file
diff --git a/include/osmocom/core/fsm.h b/include/osmocom/core/fsm.h
index bbfe3123..2c2a9961 100644
--- a/include/osmocom/core/fsm.h
+++ b/include/osmocom/core/fsm.h
@@ -78,6 +78,8 @@ struct osmo_fsm {
int log_subsys;
/*! human-readable names of events */
const struct value_string *event_names;
+ /*! graceful exit function, called at the beginning of termination */
+ void (*pre_term)(struct osmo_fsm_inst *fi, enum osmo_fsm_term_cause cause);
/*! a single instanceof an osmocom finite state machine */
diff --git a/src/fsm.c b/src/fsm.c
index a1273624..176aa8ab 100644
--- a/src/fsm.c
+++ b/src/fsm.c
@@ -298,7 +298,11 @@ struct osmo_fsm_inst *osmo_fsm_inst_alloc_child(struct osmo_fsm *fsm,
/*! unlink child FSM from its parent FSM.
* \param[in] fi Descriptor of the child FSM to unlink.
- * \param[in] ctx New talloc context */
+ * \param[in] ctx New talloc context
+ *
+ * Never call this function from the cleanup callback, because at that time
+ * the child FSMs will already be terminated. If unlinking should be performed
+ * on FSM termination, use the grace callback instead. */
void osmo_fsm_inst_unlink_parent(struct osmo_fsm_inst *fi, void *ctx)
if (fi->proc.parent) {
@@ -312,7 +316,10 @@ void osmo_fsm_inst_unlink_parent(struct osmo_fsm_inst *fi, void *ctx)
/*! change parent instance of an FSM.
* \param[in] fi Descriptor of the to-be-allocated FSM.
* \param[in] new_parent New parent FSM instance.
- * \param[in] new_parent_term_event Event to be sent to parent when terminating. */
+ * \param[in] new_parent_term_event Event to be sent to parent when terminating.
+ *
+ * Never call this function from the cleanup callback!
+ * (see also osmo_fsm_inst_unlink_parent()).*/
void osmo_fsm_inst_change_parent(struct osmo_fsm_inst *fi,
struct osmo_fsm_inst *new_parent,
uint32_t new_parent_term_event)
@@ -528,6 +535,10 @@ void _osmo_fsm_inst_term(struct osmo_fsm_inst *fi,
LOGPFSMSRC(fi, file, line, "Terminating (cause = %s)\n",
+ /* graceful exit (optional) */
+ if (fi->fsm->pre_term)
+ fi->fsm->pre_term(fi, cause);
_osmo_fsm_inst_term_children(fi, OSMO_FSM_TERM_PARENT, NULL,
file, line);