From e3957f83e070fab55853d4803fcb3aba890091ce Mon Sep 17 00:00:00 2001 From: Willy Tarreau Date: Thu, 30 Sep 2021 16:17:37 +0200 Subject: [PATCH] BUG/MAJOR: lua: use task_wakeup() to properly run a task once The Lua tasks registered vi core.register_task() use a dangerous task_schedule(task, now_ms) to start them, that will most of the time work by accident, except when the time wraps every 49.7 days, if now_ms is 0, because it's not valid to queue a task with an expiration date set to TICK_ETERNITY, as it will fail all wakeup checks and prevent all subsequent timers from being seen as expired. The only solution in this case is to restart the process. Fortunately for the vast majority of users it is extremely unlikely to ever be met (only one millisecond every 49.7 days is at risk), but this can be systematic for a process dealing with 1000 req/s, hence the major tag. The bug was introduced in 1.6-dev with commit 24f335340 ("MEDIUM: lua: add coroutine as tasks."), so the fix must be backported to all stable branches. --- src/hlua.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/hlua.c b/src/hlua.c index 02dffe7d7..df463492b 100644 --- a/src/hlua.c +++ b/src/hlua.c @@ -8268,7 +8268,7 @@ static int hlua_register_task(lua_State *L) hlua->nargs = 0; /* Schedule task. */ - task_schedule(task, now_ms); + task_wakeup(task, TASK_WOKEN_INIT); return 0;