message: meshable-arena: after fork debugging
diff: @@ -644,7 +644,22 @@ void MeshableArena::afterForkChild() {
  for (size_t j = 1; j < meshCount; j++) {
  const auto remove = mh->spans()[j];
  + const auto removeOff = offsetFor(remove);
  +
  + d_assert(getMetadataFlags(keepOff) == internal::PageType::Identity);
  + d_assert(getMetadataFlags(removeOff) != internal::PageType::Unallocated);
  +
  +#ifndef NDEBUG
  + const Length pageCount = sz / kPageSize;
  + for (size_t i = 0; i < pageCount; i++) {
  + // TODO: remove duplication of meshed metadata between the low
  + // bits here and the meshed bitmap
  + d_assert(_metadata[removeOff + i] == (internal::PageType::Meshed | getMetadataPtr(keepOff)));
  + }
  +#endif
  +
  void *ptr = mmap(remove, sz, HL_MMAP_PROTECTION_MASK, MAP_SHARED | MAP_FIXED, _fd, keepOff * kPageSize);
  +
  hard_assert_msg(ptr != MAP_FAILED, "mesh remap failed: %d", errno);
  }
  }
  