void handle_signal()

in include/unifex/stop_immediately.hpp [151:186]

• 26 lines of code
• 5 McCabe index (conditional complexity)

    void handle_signal(Func deliverSignalTo) noexcept {
      auto& strm = stream_;
      strm.nextOp_.destruct();

      auto oldState = strm.state_.load(std::memory_order_acquire);

      if (oldState == state::source_next_active) {
        if (strm.state_.compare_exchange_strong(
              oldState, state::source_next_completed,
              std::memory_order_relaxed)) {
          // We acquired ownership of the receiver before it was cancelled.
          auto* receiver = std::exchange(strm.nextReceiver_, nullptr);
          UNIFEX_ASSERT(receiver != nullptr);
          deliverSignalTo(receiver);
          return;
        }
      }

      if (oldState == state::source_next_active_stream_stopped) {
        if (strm.state_.compare_exchange_strong(
              oldState, state::source_next_completed,
              std::memory_order_release,
              std::memory_order_acquire)) {
          // Successfully signalled that 'next' completed before 'cleanup'
          // operation started. Discard this signal without forwarding it on.
          return;
        }
      }

      // Otherwise, cleanup() was requested before this operation completed.
      // We are responsible for starting cleanup now that next() has finished.

      UNIFEX_ASSERT(oldState == state::source_next_active_cleanup_requested);
      UNIFEX_ASSERT(stream_.cleanupOp_ != nullptr);
      stream_.cleanupOp_->start_cleanup();
    }