[Tarantool-patches] [PATCH 1/2] src/lua: fix running init lua script

[Artem Starshov <artemreyt@tarantool.org>]

When tarantool launched with -e flag
and in script after there is an error,
programm hangs. This happens because
shed fiber launches separate fiber for
init user script and starts auxiliary event
loop. It's supposed that fiber will stop this
loop, but in case of error in script, fiber tries
to stop a loop when the last one isn't started yet.

Added a flag, which will watch is loop started and
when fiber tries to call `ev_break()` we can be sure
that loop is runnig already.

Part of #4983
---
 src/lua/init.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/lua/init.c b/src/lua/init.c
index a0b2fc775..92bdb82c0 100644
--- a/src/lua/init.c
+++ b/src/lua/init.c
@@ -569,6 +569,7 @@ run_script_f(va_list ap)
 	 * never really dead. It never returns from its function.
 	 */
 	struct diag *diag = va_arg(ap, struct diag *);
+	bool aux_loop_is_run = false;
 
 	/*
 	 * Load libraries and execute chunks passed by -l and -e
@@ -611,6 +612,7 @@ run_script_f(va_list ap)
 	 * loop and re-schedule this fiber.
 	 */
 	fiber_sleep(0.0);
+	aux_loop_is_run = true;
 
 	if (path && strcmp(path, "-") != 0 && access(path, F_OK) == 0) {
 		/* Execute script. */
@@ -650,6 +652,13 @@ run_script_f(va_list ap)
 	 * return control back to tarantool_lua_run_script.
 	 */
 end:
+	/*
+	 * Auxiliary loop in tarantool_lua_run_script
+	 * should start (ev_run()) before this fiber
+	 * invokes ev_break().
+	 */
+	if (!aux_loop_is_run)
+		fiber_sleep(0.0);
 	ev_break(loop(), EVBREAK_ALL);
 	return 0;
 
-- 
2.28.0