src/hotspot/share/gc/g1/g1NMethodClosure.cpp

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#include "code/nmethod.hpp"
#include "gc/g1/g1CollectedHeap.inline.hpp"
#include "gc/g1/g1ConcurrentMark.inline.hpp"
#include "gc/g1/g1HeapRegion.hpp"
#include "gc/g1/g1HeapRegionRemSet.inline.hpp"
#include "gc/g1/g1NMethodClosure.hpp"
#include "gc/shared/barrierSetNMethod.hpp"
#include "oops/access.inline.hpp"
#include "oops/compressedOops.inline.hpp"
#include "oops/oop.inline.hpp"

template <typename T>
void G1NMethodClosure::HeapRegionGatheringOopClosure::do_oop_work(T* p) {
  _work->do_oop(p);
  T oop_or_narrowoop = RawAccess<>::oop_load(p);
  if (!CompressedOops::is_null(oop_or_narrowoop)) {
    oop o = CompressedOops::decode_not_null(oop_or_narrowoop);
    G1HeapRegion* hr = _g1h->heap_region_containing(o);
    assert(!_g1h->is_in_cset(o) || hr->rem_set()->code_roots_list_contains(_nm), "if o still in collection set then evacuation failed and nm must already be in the remset");
    hr->add_code_root(_nm);
  }
}

void G1NMethodClosure::HeapRegionGatheringOopClosure::do_oop(oop* o) {
  do_oop_work(o);
}

void G1NMethodClosure::HeapRegionGatheringOopClosure::do_oop(narrowOop* o) {
  do_oop_work(o);
}

template<typename T>
void G1NMethodClosure::MarkingOopClosure::do_oop_work(T* p) {
  T oop_or_narrowoop = RawAccess<>::oop_load(p);
  if (!CompressedOops::is_null(oop_or_narrowoop)) {
    oop o = CompressedOops::decode_not_null(oop_or_narrowoop);
    _cm->mark_in_bitmap(_worker_id, o);
  }
}

G1NMethodClosure::MarkingOopClosure::MarkingOopClosure(uint worker_id) :
  _cm(G1CollectedHeap::heap()->concurrent_mark()), _worker_id(worker_id) { }

void G1NMethodClosure::MarkingOopClosure::do_oop(oop* o) {
  do_oop_work(o);
}

void G1NMethodClosure::MarkingOopClosure::do_oop(narrowOop* o) {
  do_oop_work(o);
}

void G1NMethodClosure::do_evacuation_and_fixup(nmethod* nm) {
  _oc.set_nm(nm);

  // Evacuate objects pointed to by the nmethod
  nm->oops_do(&_oc);

  if (_strong) {
    // CodeCache unloading support
    nm->mark_as_maybe_on_stack();

    BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
    bs_nm->disarm(nm);
  }

  nm->fix_oop_relocations();
}

void G1NMethodClosure::do_marking(nmethod* nm) {
  // Mark through oops in the nmethod
  nm->oops_do(&_marking_oc);

  // CodeCache unloading support
  nm->mark_as_maybe_on_stack();

  BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();
  bs_nm->disarm(nm);

  // The oops were only marked, no need to update oop relocations.
}

class G1NmethodProcessor : public nmethod::OopsDoProcessor {
  G1NMethodClosure* _cl;

public:
  G1NmethodProcessor(G1NMethodClosure* cl) : _cl(cl) { }

  void do_regular_processing(nmethod* nm) {
    _cl->do_evacuation_and_fixup(nm);
  }

  void do_remaining_strong_processing(nmethod* nm) {
    _cl->do_marking(nm);
  }
};

void G1NMethodClosure::do_nmethod(nmethod* nm) {
  assert(nm != nullptr, "Sanity");

  G1NmethodProcessor cl(this);

  if (_strong) {
    nm->oops_do_process_strong(&cl);
  } else {
    nm->oops_do_process_weak(&cl);
  }
}