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44a1f7e7ca
The `ProcessElfCore::FindModuleUUID` function can be called by multiple
threads at the same time when `target.parallel-module-load` is true. We
were using the `operator[]` to lookup the UUID which will mutate the map
when the key is not present. This is unsafe in a multi-threaded contex
so we now use a read-only `find` operation and explicitly return an
invalid UUID when the key is not present.
The `m_uuids` map can follow a create-then-query pattern. It is
populated in the `DoLoadCore` function which looks like it is only
called in a single-threaded context so we do not need extra locking as
long as we keep the other accesses read-only.
Other fixes I considered
* Use a lock to protect access - We don't need to modify the map after
creation so we can allow concurrent read-only access.
* Store the map in a const pointer container to prevent accidental
mutation in other places.
- Only accessed in one place currently so just added a comment.
* Store the UUID in the NT_FILE_Entry after building the mapping
correctly in `UpdateBuildIdForNTFileEntries`. - The map lets us avoid a
linear search in `FindModuleUUID`.
This commit also reverts the temporary workaround from #159395 which
disabled parallel module loading to avoid the test failure.
Fixes #159377