Re: Facing GC infinite loop in Lua 5.1

[nerditation <nerditation@...>]

On 2021/1/28 2:15, Wagner Fernando Fazio wrote:
> I’m looping forever when calling luaC_fullgc and can not realize why it is happening. Every call do singlestep() does nothing and sweeplist() keeps trying to mark objects as white in every call.
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> At this moment, my debugger shows deadmask==33(0x21) and all are gch.marked==2.
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> Can someone figure out situations where it may happen?
> 
> [...]


do you use a patched Lua or official release version? which exact version of Lua do you use?
or do you have a custom memory allocator?

if the gc got stuck in the sweep phase, I can only imagine there exists a cycle in the `allgc`
list, which should be a singly linked list through the `gch->next` field in every gc object.

so I suspect your allocator might caused a memory corruption and overwritten the `gch->next`
field of some gc objects, which happened to point to some other objects, thus making the `allgc`
list `infinitely` long.