((cite: hotspot/src/share/vm/gc_interface/gcCause.hpp))
    //
    // This class exposes implementation details of the various
    // collector(s), and we need to be very careful with it. If
    // use of this class grows, we should split it into public
    // and implemenation-private "causes".
    //

    class GCCause : public AllStatic {

    ((cite: hotspot/src/share/vm/gc_interface/gcCause.hpp))
      enum Cause {
        /* public */
        _java_lang_system_gc,
        _full_gc_alot,
        _scavenge_alot,
        _allocation_profiler,
        _jvmti_force_gc,
        _gc_locker,
        _heap_inspection,
        _heap_dump,

        /* implementation independent, but reserved for GC use */
        _no_gc,
        _no_cause_specified,
        _allocation_failure,

        /* implementation specific */

        _tenured_generation_full,
        _permanent_generation_full,

        _cms_generation_full,
        _cms_initial_mark,
        _cms_final_remark,

        _old_generation_expanded_on_last_scavenge,
        _old_generation_too_full_to_scavenge,
        _adaptive_size_policy,

        _g1_inc_collection_pause,

        _last_ditch_collection,
        _last_gc_cause
      };