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983513d901
hlua burst timeout was introduced in58e36e5b1("MEDIUM: hlua: introduce tune.lua.burst-timeout"). It is a safety measure that allows to detect when too much time is spent on a single lua execution (between 2 interruptions/yields), meaning that the current thread is not able to perform other tasks. Such scenario should be avoided because it will cause thread contention which may have negative performance impact and could cause the watchdog to trigger. When the burst timeout is exceeded, the current Lua execution is aborted and a timeout error is reported to the user. Unfortunately, the same error is currently being reported for cumulative (AKA execution) timeout and for burst timeout, which may be confusing to the user. Indeed, "execution timeout" error historically results from the current hlua context exceeding the total (cumulative) time it's allowed to run. It is set per lua context using the dedicated tunables: - tune.lua.session-timeout - tune.lua.task-timeout - tune.lua.service-timeout We've already faced an user report where the user was able to trigger the burst timeout and got "Lua task: execution timeout." error while the user didn't set cumulative timeout. Thus the error was actually confusing because it was indeed the burst timeout which was causing it due to the use of cpu-intensive call from within the task without sufficient manual "yield" keypoints around the cpu-intensive call to ensure it runs on a dedicated scheduler cycle. In this patch we make it so burst timeout related errors are reported as "burst timeout" errors instead of "execution timeout" errors (which in fact became the generic timeout errors catchall with58e36e5b1). To do this, hlua_timer_check() now returns a different value depending if the exeeded timeout is the burst one or the cumulative one, which allows us to return either HLUA_E_ETMOUT or HLUA_E_BTMOUT in hlua_ctx_resume(). It should improve the situation described in GH #2356 and may possibly be backported with58e36e5b1to improve error reporting if it applies without resistance.