lightningd: disable topology timers on shutdown.

Not necessary yet, but it will be once shutdown starts waiting for
plugins to respond: we don't want these to try to access the bcli
plugin once it's freed.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

lightningd/bitcoind.h

@@ -32,6 +32,9 @@ struct bitcoind {
 	/* Ignore results, we're shutting down. */
 	bool shutdown;
 
+	/* Timer if we're waiting for it to warm up. */
+	struct oneshot *checkchain_timer;
+
 	struct list_head pending_getfilteredblock;
 
 	/* Map each method to a plugin, so we can have multiple plugins

lightningd/chaintopology.c

@@ -46,10 +46,10 @@ static void maybe_completed_init(struct chain_topology *topo)
 
 static void next_topology_timer(struct chain_topology *topo)
 {
-	/* This takes care of its own lifetime. */
-	notleak(new_reltimer(topo->ld->timers, topo,
-			     time_from_sec(topo->poll_seconds),
-			     try_extend_tip, topo));
+	assert(!topo->extend_timer);
+	topo->extend_timer = new_reltimer(topo->ld->timers, topo,
+					  time_from_sec(topo->poll_seconds),
+					  try_extend_tip, topo);
 }
 
 static bool we_broadcast(const struct chain_topology *topo,
@@ -437,6 +437,7 @@ static void update_feerates(struct bitcoind *bitcoind,
 
 static void start_fee_estimate(struct chain_topology *topo)
 {
+	topo->updatefee_timer = NULL;
 	/* Once per new block head, update fee estimates. */
 	bitcoind_estimate_fees(topo->bitcoind, NUM_FEERATES, update_feerates,
 			       topo);
@@ -582,10 +583,10 @@ AUTODATA(json_command, &parse_feerate_command);
 
 static void next_updatefee_timer(struct chain_topology *topo)
 {
-	/* This takes care of its own lifetime. */
-	notleak(new_reltimer(topo->ld->timers, topo,
-			     time_from_sec(topo->poll_seconds),
-			     start_fee_estimate, topo));
+	assert(!topo->updatefee_timer);
+	topo->updatefee_timer = new_reltimer(topo->ld->timers, topo,
+					     time_from_sec(topo->poll_seconds),
+					     start_fee_estimate, topo);
 }
 
 struct sync_waiter {
@@ -935,6 +936,7 @@ static void get_new_block(struct bitcoind *bitcoind,
 
 static void try_extend_tip(struct chain_topology *topo)
 {
+	topo->extend_timer = NULL;
 	bitcoind_getrawblockbyheight(topo->bitcoind, topo->tip->height + 1,
 				     get_new_block, topo);
 }
@@ -1144,15 +1146,18 @@ check_chain(struct bitcoind *bitcoind, const char *chain,
 		return;
 	}
 
-	notleak(new_reltimer(bitcoind->ld->timers, bitcoind,
-			     /* Be 4x more aggressive in this case. */
-			     time_divide(time_from_sec(bitcoind->ld->topology
-						       ->poll_seconds), 4),
-			     retry_check_chain, bitcoind->ld->topology));
-	}
+	assert(!bitcoind->checkchain_timer);
+	bitcoind->checkchain_timer
+		= new_reltimer(bitcoind->ld->timers, bitcoind,
+			       /* Be 4x more aggressive in this case. */
+			       time_divide(time_from_sec(bitcoind->ld->topology
+							 ->poll_seconds), 4),
+			       retry_check_chain, bitcoind->ld->topology);
+}
 
 static void retry_check_chain(struct chain_topology *topo)
 {
+	topo->bitcoind->checkchain_timer = NULL;
 	bitcoind_getchaininfo(topo->bitcoind, false, check_chain, topo);
 }
 
@@ -1171,6 +1176,7 @@ void setup_topology(struct chain_topology *topo,
 	log_debug(topo->ld->log, "All Bitcoin plugin commands registered");
 
 	/* Sanity checks, then topology initialization. */
+	topo->bitcoind->checkchain_timer = NULL;
 	bitcoind_getchaininfo(topo->bitcoind, true, check_chain, topo);
 
 	tal_add_destructor(topo, destroy_chain_topology);
@@ -1185,3 +1191,12 @@ void begin_topology(struct chain_topology *topo)
 {
 	try_extend_tip(topo);
 }
+
+void stop_topology(struct chain_topology *topo)
+{
+	/* Remove timers while we're cleaning up plugins. */
+	tal_free(topo->bitcoind->checkchain_timer);
+	tal_free(topo->extend_timer);
+	tal_free(topo->updatefee_timer);
+}
+

lightningd/chaintopology.h

@@ -113,6 +113,9 @@ struct chain_topology {
 	/* The bitcoind. */
 	struct bitcoind *bitcoind;
 
+	/* Timers we're running. */
+	struct oneshot *extend_timer, *updatefee_timer;
+
 	/* Bitcoin transactions we're broadcasting */
 	struct list_head outgoing_txs;
 
@@ -195,6 +198,8 @@ void setup_topology(struct chain_topology *topology,
 
 void begin_topology(struct chain_topology *topo);
 
+void stop_topology(struct chain_topology *topo);
+
 struct txlocator *locate_tx(const void *ctx, const struct chain_topology *topo, const struct bitcoin_txid *txid);
 
 static inline bool topology_synced(const struct chain_topology *topo)

lightningd/lightningd.c

@@ -1141,6 +1141,9 @@ int main(int argc, char *argv[])
 		stop_response = tal_steal(NULL, ld->stop_response);
 	}
 
+	/* Stop topology callbacks. */
+	stop_topology(ld->topology);
+
 	/* We're not going to collect our children. */
 	remove_sigchild_handler();
 	shutdown_subdaemons(ld);

lightningd/test/run-find_my_abspath.c

@@ -205,6 +205,9 @@ void setup_color_and_alias(struct lightningd *ld UNNEEDED)
 void setup_topology(struct chain_topology *topology UNNEEDED,
 		    u32 min_blockheight UNNEEDED, u32 max_blockheight UNNEEDED)
 { fprintf(stderr, "setup_topology called!\n"); abort(); }
+/* Generated stub for stop_topology */
+void stop_topology(struct chain_topology *topo UNNEEDED)
+{ fprintf(stderr, "stop_topology called!\n"); abort(); }
 /* Generated stub for timer_expired */
 void timer_expired(tal_t *ctx UNNEEDED, struct timer *timer UNNEEDED)
 { fprintf(stderr, "timer_expired called!\n"); abort(); }