tree 74a43db041dc581124796a7c02a15ca3b73862b2
parent a561ffb978937e6fd2c7092978681b8e88bdff04
author Christopher Faulet <cfaulet@haproxy.com> 1616163388 +0100
committer Christopher Faulet <cfaulet@haproxy.com> 1616166983 +0100

MEDIUM: lua: Use a per-thread counter to track some non-reentrant parts of lua

Some parts of the Lua are non-reentrant. We must be sure to carefully track
these parts to not dump the lua stack when it is interrupted inside such
parts. For now, we only identified the custom lua allocator. If the thread
is interrupted during the memory allocation, we must not try to print the
lua stack wich also allocate memory. Indeed, realloc() is not
async-signal-safe.

In this patch we introduce a thread-local counter. It is incremented before
entering in a non-reentrant part and decremented when exiting. It is only
performed in hlua_alloc() for now.