std::optional CgroupContext::getMemoryProtection()

in src/oomd/CgroupContext.cpp [371:405]

• 31 lines of code
• 8 McCabe index (conditional complexity)

std::optional<int64_t> CgroupContext::getMemoryProtection(Error* err) const {
  if (cgroup_.isRoot()) {
    return current_usage(err);
  }

  auto parent_cgroup = cgroup_.getParent();
  if (parent_cgroup.isRoot()) {
    // We're at a top level cgroup where P(cgrp) == R(cgrp)
    return rawProtection(*this, err);
  }
  auto parent_ctx = ctx_.addToCacheAndGet(parent_cgroup);
  if (!parent_ctx) {
    if (err) {
      *err = Error::INVALID_CGROUP;
    }
    return std::nullopt;
  }

  std::unordered_set<CgroupPath> sibling_cgroups;
  std::vector<OomdContext::ConstCgroupContextRef> siblings;
  if (auto children = parent_ctx->get().children(err)) {
    for (const auto& name : *children) {
      sibling_cgroups.insert(parent_cgroup.getChild(name));
    }
    siblings = ctx_.addToCacheAndGet(sibling_cgroups);
  } else {
    return std::nullopt;
  }

  int64_t protection_sum = 0;
  for (auto sibling_ctx : siblings) {
    protection_sum += rawProtection(sibling_ctx).value_or(0);
  }
  return normalizedProtection(*this, *parent_ctx, protection_sum, err);
}