[PATCH] D157459: Make DWARFContext more thread safe.

[Jonas Devlieghere via Phabricator via llvm-commits]

JDevlieghere added a comment.

To Adrian's point: what are the guarantees provided by the `DWARFContext`? I'm slightly worried about overhead but care more about providing clear expectations. For example, the `LLVMContext` explicitly provides no locking guarantees [1] and leaves it up to the consumer.

[1] https://llvm.org/doxygen/classllvm_1_1LLVMContext.html#details



================
Comment at: llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h:51
+  // Mutex protecting multi-threaded access to the DWARFContext.
+  std::recursive_mutex Mutex;
   std::optional<DenseMap<uint64_t, DWARFTypeUnit *>> NormalTypeUnits;
----------------
Does this have to be a recursive mutex? I was under the impression that they're somewhat frowned upon. I think the CppCoreGuidelines called it something along the lines of working around bad reasoning and adding unnecessary overhead. 


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D157459/new/

https://reviews.llvm.org/D157459