threading: improve safety posture of modifying global bindings #35761
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Ensures that we are holding some lock (a new one) while mutating the internal global `jl_current_modules` table. While reading these binding values is not memory-safe to do simultaneously (it may invent pointers from thin-air and segfault), this commit ensures that a data conflict during the writes to them will not corrupt the values written into memory.
JeffBezanson
approved these changes
May 6, 2020
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Ensures that we are holding some lock (a new one) while mutating the
internal global
jl_current_modulestable.While reading these binding values is not memory-safe to do
simultaneously (it may invent pointers from thin-air and segfault), this
commit ensures that a data conflict during the writes to them will
not corrupt the values written into memory.
This is some of the non-controversial content extracted from #35535. While it doesn't make particularly useful promises without the rest of that PR (docs here are updated accordingly), it is a much smaller semantic change.