src/hotspot/share/gc/parallel/psClosure.inline.hpp

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#ifndef SHARE_GC_PARALLEL_PSCLOSURE_INLINE_HPP
#define SHARE_GC_PARALLEL_PSCLOSURE_INLINE_HPP

// No psClosure.hpp

#include "gc/parallel/psPromotionManager.inline.hpp"
#include "gc/parallel/psScavenge.inline.hpp"
#include "memory/iterator.hpp"
#include "oops/access.inline.hpp"
#include "oops/oop.inline.hpp"
#include "utilities/globalDefinitions.hpp"

class PSAdjustWeakRootsClosure final: public OopClosure {
public:
  virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }

  virtual void do_oop(oop* p)       {
    if (PSScavenge::should_scavenge(p)) {
      oop o = RawAccess<IS_NOT_NULL>::oop_load(p);
      assert(o->is_forwarded(), "Objects are already forwarded before weak processing");
      oop new_obj = o->forwardee();
      if (log_develop_is_enabled(Trace, gc, scavenge)) {
        ResourceMark rm; // required by internal_name()
        log_develop_trace(gc, scavenge)("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (" SIZE_FORMAT ")}",
                                        "forwarding",
                                        new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
      }
      RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
    }
  }
};

template <bool promote_immediately>
class PSRootsClosure: public OopClosure {
private:
  PSPromotionManager* _promotion_manager;

  template <class T> void do_oop_work(T *p) {
    assert(!ParallelScavengeHeap::heap()->is_in_reserved(p), "roots should be outside of heap");
    oop o = RawAccess<>::oop_load(p);
    if (PSScavenge::is_obj_in_young(o)) {
      assert(!PSScavenge::is_obj_in_to_space(o), "Revisiting roots?");
      oop new_obj = _promotion_manager->copy_to_survivor_space<promote_immediately>(o);
      RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
    }
  }
public:
  PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
  void do_oop(oop* p)       { PSRootsClosure::do_oop_work(p); }
  void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }
};

typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;
typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;

// Scavenges a single oop in a ClassLoaderData.
class PSScavengeFromCLDClosure: public OopClosure {
private:
  PSPromotionManager* _pm;
  // Used to redirty a scanned cld if it has oops
  // pointing to the young generation after being scanned.
  ClassLoaderData*    _scanned_cld;
public:
  PSScavengeFromCLDClosure(PSPromotionManager* pm) : _pm(pm), _scanned_cld(nullptr) { }
  void do_oop(narrowOop* p) { ShouldNotReachHere(); }
  void do_oop(oop* p)       {
    ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();
    assert(!psh->is_in_reserved(p), "GC barrier needed");
    if (PSScavenge::should_scavenge(p)) {
      assert(PSScavenge::should_scavenge(p, true), "revisiting object?");

      oop o = RawAccess<IS_NOT_NULL>::oop_load(p);
      oop new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);
      RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);

      if (PSScavenge::is_obj_in_young(new_obj)) {
        do_cld_barrier();
      }
    }
  }

  void set_scanned_cld(ClassLoaderData* cld) {
    assert(_scanned_cld == nullptr || cld == nullptr, "Should always only handling one cld at a time");
    _scanned_cld = cld;
  }

private:
  void do_cld_barrier() {
    assert(_scanned_cld != nullptr, "Should not be called without having a scanned cld");
    _scanned_cld->record_modified_oops();
  }
};

// Scavenges the oop in a ClassLoaderData.
class PSScavengeCLDClosure: public CLDClosure {
private:
  PSScavengeFromCLDClosure _oop_closure;
public:
  PSScavengeCLDClosure(PSPromotionManager* pm) : _oop_closure(pm) { }
  void do_cld(ClassLoaderData* cld) {
    // If the cld has not been dirtied we know that there's
    // no references into  the young gen and we can skip it.

    if (cld->has_modified_oops()) {
      // Setup the promotion manager to redirty this cld
      // if references are left in the young gen.
      _oop_closure.set_scanned_cld(cld);

      // Clean the cld since we're going to scavenge all the metadata.
      cld->oops_do(&_oop_closure, ClassLoaderData::_claim_none, /*clear_modified_oops*/true);

      _oop_closure.set_scanned_cld(nullptr);
    }
  }
};

#endif // SHARE_GC_PARALLEL_PSCLOSURE_INLINE_HPP