// This method should contain all heap-specific policy for invoking a full
// collection.  invoke_no_policy() will only attempt to compact the heap; it
// will do nothing further.  If we need to bail out for policy reasons, scavenge
// before full gc, or any other specialized behavior, it needs to be added here.
//
// Note that this method should only be called from the vm_thread while at a
// safepoint.
//
// Note that the all_soft_refs_clear flag in the collector policy
// may be true because this method can be called without intervening
// activity.  For example when the heap space is tight and full measure
// are being taken to free space.

void PSParallelCompact::invoke(bool maximum_heap_compaction) {

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

      assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
      assert(Thread::current() == (Thread*)VMThread::vm_thread(),
             "should be in vm thread");

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

      ParallelScavengeHeap* heap = gc_heap();
      GCCause::Cause gc_cause = heap->gc_cause();
      assert(!heap->is_gc_active(), "not reentrant");

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

  {- -------------------------------------------
  (1) ScavengeBeforeFullGC オプションが指定されていれば, Major GC を実行する前に
      PSScavenge::invoke_no_policy() を呼んで Minor GC を実行しておく.
      ---------------------------------------- -}

      if (ScavengeBeforeFullGC) {
        PSScavenge::invoke_no_policy();
      }

  {- -------------------------------------------
  (1) PSParallelCompact::invoke_no_policy() を呼び出す
      ---------------------------------------- -}

      const bool clear_all_soft_refs =
        heap->collector_policy()->should_clear_all_soft_refs();

      PSParallelCompact::invoke_no_policy(clear_all_soft_refs ||
                                          maximum_heap_compaction);
    }