lightningd: free timers on shutdown.

Direct leak of 1024 byte(s) in 2 object(s) allocated from:
    #0 0x7f4c84ce4448 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10c448)
    #1 0x55d11b782c96 in timer_default_alloc ccan/ccan/timer/timer.c:16
    #2 0x55d11b7832b7 in add_level ccan/ccan/timer/timer.c:166
    #3 0x55d11b783864 in timer_fast_forward ccan/ccan/timer/timer.c:334
    #4 0x55d11b78396a in timers_expire ccan/ccan/timer/timer.c:359
    #5 0x55d11b774993 in io_loop ccan/ccan/io/poll.c:395
    #6 0x55d11b72322f in plugins_init lightningd/plugin.c:1013
    #7 0x55d11b7060ea in main lightningd/lightningd.c:664
    #8 0x7f4c84696b6a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x26b6a)

To fix this, we actually make 'ld->timers' a pointer, so we can clean
it up last of all.  We can't free it before ld, because that causes
timers to be destroyed.

Signed-off-by: Rusty Russell <[email protected]>

Author: rustyrussell

lightningd/bitcoind.c

@@ -161,7 +161,7 @@ static void bcli_failure(struct bitcoind *bitcoind,
 	bitcoind->error_count++;
 
 	/* Retry in 1 second (not a leak!) */
-	new_reltimer(&bitcoind->ld->timers, notleak(bcli), time_from_sec(1),
+	new_reltimer(bitcoind->ld->timers, notleak(bcli), time_from_sec(1),
 		     retry_bcli, bcli);
 }
 

lightningd/connect_control.c

@@ -222,7 +222,7 @@ void delay_then_reconnect(struct channel *channel, u32 seconds_delay,
 
 	/* We fuzz the timer by up to 1 second, to avoid getting into
 	 * simultanous-reconnect deadlocks with peer. */
-	notleak(new_reltimer(&ld->timers, d,
+	notleak(new_reltimer(ld->timers, d,
 			     timerel_add(time_from_sec(seconds_delay),
 					 time_from_usec(pseudorand(1000000))),
 			     maybe_reconnect, d));

lightningd/io_loop_with_timers.c

@@ -21,7 +21,7 @@ void *io_loop_with_timers(struct lightningd *ld)
 		 * It will only exit if there's an expired timer, *or* someone
 		 * calls io_break, or if there are no more file descriptors
 		 * (which never happens in our code). */
-		retval = io_loop(&ld->timers, &expired);
+		retval = io_loop(ld->timers, &expired);
 
 		/*~ Notice that timers are called here in the event loop like
 		 * anything else, so there are no weird concurrency issues. */

lightningd/jsonrpc.c

@@ -265,7 +265,7 @@ static void slowcmd_finish(struct slowcmd *sc)
 static void slowcmd_start(struct slowcmd *sc)
 {
 	sc->js = json_stream_success(sc->cmd);
-	new_reltimer(&sc->cmd->ld->timers, sc, time_from_msec(*sc->msec),
+	new_reltimer(sc->cmd->ld->timers, sc, time_from_msec(*sc->msec),
 		     slowcmd_finish, sc);
 }
 
@@ -282,7 +282,7 @@ static struct command_result *json_slowcmd(struct command *cmd,
 		   NULL))
 		return command_param_failed();
 
-	new_reltimer(&cmd->ld->timers, sc, time_from_msec(0), slowcmd_start, sc);
+	new_reltimer(cmd->ld->timers, sc, time_from_msec(0), slowcmd_start, sc);
 	return command_still_pending(cmd);
 }
 

lightningd/lightningd.c

@@ -189,7 +189,8 @@ static struct lightningd *new_lightningd(const tal_t *ctx)
 	 * ingenious bucket system which more precisely sorts timers as they
 	 * approach expiry.  It's a fascinating implementation you should read
 	 * if you have a spare few hours. */
-	timers_init(&ld->timers, time_mono());
+	ld->timers = tal(ld, struct timers);
+	timers_init(ld->timers, time_mono());
 
 	/*~ This is detailed in chaintopology.c */
 	ld->topology = new_topology(ld, ld->log);
@@ -619,6 +620,7 @@ int main(int argc, char *argv[])
 	u32 min_blockheight, max_blockheight;
 	int connectd_gossipd_fd, pid_fd;
 	int stop_fd;
+	struct timers *timers;
 	const char *stop_response;
 
 	/*~ What happens in strange locales should stay there. */
@@ -677,7 +679,7 @@ int main(int argc, char *argv[])
 	/*~ Our "wallet" code really wraps the db, which is more than a simple
 	 * bitcoin wallet (though it's that too).  It also stores channel
 	 * states, invoices, payments, blocks and bitcoin transactions. */
-	ld->wallet = wallet_new(ld, ld->log, &ld->timers);
+	ld->wallet = wallet_new(ld, ld->log, ld->timers);
 
 	/*~ We keep a filter of scriptpubkeys we're interested in. */
 	ld->owned_txfilter = txfilter_new(ld);
@@ -750,7 +752,7 @@ int main(int argc, char *argv[])
 
 	/*~ Initialize block topology.  This does its own io_loop to
 	 * talk to bitcoind, so does its own db transactions. */
-	setup_topology(ld->topology, &ld->timers,
+	setup_topology(ld->topology, ld->timers,
 		       min_blockheight, max_blockheight);
 
 	/*~ Pull peers, channels and HTLCs from db. Needs to happen after the
@@ -854,7 +856,13 @@ int main(int argc, char *argv[])
 	/* FIXME: pay can have children off tmpctx which unlink from
 	 * ld->payments, so clean that up. */
 	clean_tmpctx();
+
+	/* Free this last: other things may clean up timers. */
+	timers = tal_steal(NULL, ld->timers);
 	tal_free(ld);
+
+	timers_cleanup(timers);
+	tal_free(timers);
 	opt_free_table();
 
 	daemon_shutdown();

lightningd/lightningd.h

@@ -112,7 +112,7 @@ struct lightningd {
 	u8 *rgb; /* tal_len() == 3. */
 
 	/* Any pending timers. */
-	struct timers timers;
+	struct timers *timers;
 
 	/* Port we're listening on */
 	u16 portnum;

lightningd/memdump.c

@@ -209,7 +209,7 @@ static void report_leak_info(struct command *cmd, struct subd *leaker)
 	leak_info->leaker = leaker;
 
 	/* Leak detection in a reply handler thinks we're leaking conn. */
-	notleak(new_reltimer(&leak_info->cmd->ld->timers, leak_info->cmd,
+	notleak(new_reltimer(leak_info->cmd->ld->timers, leak_info->cmd,
 			     time_from_sec(0),
 			     report_leak_info2, leak_info));
 }

lightningd/pay.c

@@ -921,7 +921,7 @@ static struct command_result *json_waitsendpay(struct command *cmd,
 		return res;
 
 	if (timeout)
-		new_reltimer(&cmd->ld->timers, cmd, time_from_sec(*timeout),
+		new_reltimer(cmd->ld->timers, cmd, time_from_sec(*timeout),
 			     &waitsendpay_timeout, cmd);
 	return command_still_pending(cmd);
 }

lightningd/peer_control.c

@@ -336,7 +336,7 @@ register_close_command(struct lightningd *ld,
 	tal_add_destructor2(channel,
 			    &destroy_close_command_on_channel_destroy,
 			    cc);
-	new_reltimer(&ld->timers, cc, time_from_sec(timeout),
+	new_reltimer(ld->timers, cc, time_from_sec(timeout),
 		     &close_command_timeout, cc);
 }
 

lightningd/peer_htlcs.c

@@ -456,7 +456,7 @@ enum onion_type send_htlc_out(struct channel *out,
 
 	/* Give channel 30 seconds to commit (first) htlc. */
 	if (!out->htlc_timeout)
-		out->htlc_timeout = new_reltimer(&out->peer->ld->timers,
+		out->htlc_timeout = new_reltimer(out->peer->ld->timers,
 						 out, time_from_sec(30),
 						 htlc_offer_timeout,
 						 out);