libplugin: generalize the plugin_timer callback type

We don't take the callback result into account, so it can better be void.
Having a general callback parameter is handy, because for bcli we want
to pass it the struct bcli.

plugins/autoclean.c

@@ -9,7 +9,7 @@
 static u64 cycle_seconds = 0, expired_by = 86400;
 static struct plugin_timer *cleantimer;
 
-static struct command_result *do_clean(struct plugin *p);
+static void do_clean(void *cb_arg);
 
 static struct command_result *ignore(struct command *timer,
 				     const char *buf,
@@ -17,19 +17,20 @@ static struct command_result *ignore(struct command *timer,
 				     void *arg)
 {
 	struct plugin *p = arg;
-	cleantimer = plugin_timer(p, time_from_sec(cycle_seconds), do_clean);
+	cleantimer = plugin_timer(p, time_from_sec(cycle_seconds), do_clean, p);
 	return timer_complete(p);
 }
 
-static struct command_result *do_clean(struct plugin *p)
+static void do_clean(void *cb_arg)
 {
+	struct plugin *p = cb_arg;
 	/* FIXME: delexpiredinvoice should be in our plugin too! */
 	struct out_req *req = jsonrpc_request_start(p, NULL, "delexpiredinvoice",
 						    ignore, ignore, p);
 	json_add_u64(req->js, "maxexpirytime",
 		     time_now().ts.tv_sec - expired_by);
 
-	return send_outreq(p, req);
+	send_outreq(p, req);
 }
 
 static struct command_result *json_autocleaninvoice(struct command *cmd,
@@ -53,7 +54,8 @@ static struct command_result *json_autocleaninvoice(struct command *cmd,
 		return command_success_str(cmd, "Autoclean timer disabled");
 	}
 	tal_free(cleantimer);
-	cleantimer = plugin_timer(cmd->plugin, time_from_sec(cycle_seconds), do_clean);
+	cleantimer = plugin_timer(cmd->plugin, time_from_sec(cycle_seconds),
+				  do_clean, cmd->plugin);
 
 	return command_success_str(cmd,
 				   tal_fmt(cmd, "Autocleaning %"PRIu64
@@ -68,7 +70,7 @@ static void init(struct plugin *p,
 	if (cycle_seconds) {
 		plugin_log(p, LOG_INFORM, "autocleaning every %"PRIu64" seconds", cycle_seconds);
 		cleantimer = plugin_timer(p, time_from_sec(cycle_seconds),
-					  do_clean);
+					  do_clean, p);
 	} else
 		plugin_log(p, LOG_DBG, "autocleaning not active");
 }

plugins/libplugin.c

@@ -25,7 +25,8 @@ bool deprecated_apis;
 
 struct plugin_timer {
 	struct timer timer;
-	struct command_result *(*cb)(struct plugin *p);
+	void (*cb)(void *cb_arg);
+	void *cb_arg;
 };
 
 struct rpc_conn {
@@ -820,7 +821,7 @@ static void call_plugin_timer(struct plugin *p, struct timer *timer)
 	p->in_timer++;
 	/* Free this if they don't. */
 	tal_steal(tmpctx, t);
-	t->cb(p);
+	t->cb(t->cb_arg);
 }
 
 static void destroy_plugin_timer(struct plugin_timer *timer, struct plugin *p)
@@ -829,10 +830,12 @@ static void destroy_plugin_timer(struct plugin_timer *timer, struct plugin *p)
 }
 
 struct plugin_timer *plugin_timer(struct plugin *p, struct timerel t,
-				  struct command_result *(*cb)(struct plugin *p))
+				  void (*cb)(void *cb_arg),
+				  void *cb_arg)
 {
 	struct plugin_timer *timer = tal(NULL, struct plugin_timer);
 	timer->cb = cb;
+	timer->cb_arg = cb_arg;
 	timer_init(&timer->timer);
 	timer_addrel(&p->timers, &timer->timer, t);
 	tal_add_destructor2(timer, destroy_plugin_timer, p);

plugins/libplugin.h

@@ -212,7 +212,8 @@ struct command_result *timer_complete(struct plugin *p);
  */
 struct plugin_timer *plugin_timer(struct plugin *p,
 				  struct timerel t,
-				  struct command_result *(*cb)(struct plugin *p));
+				  void (*cb)(void *cb_arg),
+				  void *cb_arg);
 
 /* Log something */
 void plugin_log(struct plugin *p, enum log_level l, const char *fmt, ...) PRINTF_FMT(3, 4);