// This method contains all heap specific policy for invoking scavenge.
// PSScavenge::invoke_no_policy() will do nothing but attempt to
// scavenge. It will not clean up after failed promotions, bail out if
// we've exceeded policy time limits, or any other special behavior.
// All such policy should be placed here.
//
// Note that this method should only be called from the vm_thread while
// at a safepoint!

void PSScavenge::invoke() {

  {- -------------------------------------------
  (1) (assert)
      ---------------------------------------- -}

      assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
      assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
      assert(!Universe::heap()->is_gc_active(), "not reentrant");

  {- -------------------------------------------
  (1) (変数宣言など)
      ---------------------------------------- -}

      ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
      assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");

      PSAdaptiveSizePolicy* policy = heap->size_policy();
      IsGCActiveMark mark;

  {- -------------------------------------------
  (1) PSScavenge::invoke_no_policy() を呼び出して Minor GC 処理を行う.
      ---------------------------------------- -}

      bool scavenge_was_done = PSScavenge::invoke_no_policy();

  {- -------------------------------------------
  (1) (変数宣言など)
      ---------------------------------------- -}

      PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();

  {- -------------------------------------------
  (1) (プロファイル情報の記録) (See: PSGCAdaptivePolicyCounters)
      ---------------------------------------- -}

      if (UsePerfData)
        counters->update_full_follows_scavenge(0);

  {- -------------------------------------------
  (1) もし, Minor GC 処理が失敗していたり, あるいは... #TODO であれば, Full GC 処理も行う.
      ---------------------------------------- -}

      if (!scavenge_was_done ||
          policy->should_full_GC(heap->old_gen()->free_in_bytes())) {

    {- -------------------------------------------
  (1.1) (プロファイル情報の記録) (See: PSGCAdaptivePolicyCounters)
        ---------------------------------------- -}

        if (UsePerfData)
          counters->update_full_follows_scavenge(full_follows_scavenge);

    {- -------------------------------------------
  (1.1) 
        ---------------------------------------- -}

        GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
        CollectorPolicy* cp = heap->collector_policy();
        const bool clear_all_softrefs = cp->should_clear_all_soft_refs();

    {- -------------------------------------------
  (1.1) Full GC の実行
        ---------------------------------------- -}

        if (UseParallelOldGC) {
          PSParallelCompact::invoke_no_policy(clear_all_softrefs);
        } else {
          PSMarkSweep::invoke_no_policy(clear_all_softrefs);
        }
      }
    }