src/hotspot/share/gc/cms/parOopClosures.inline.hpp
author stefank
Sat, 26 May 2018 06:59:49 +0200
changeset 50752 9d62da00bf15
parent 50728 9375184cec98
child 53244 9807daeb47c4
permissions -rw-r--r--
8204540: Automatic oop closure devirtualization Reviewed-by: kbarrett, eosterlund

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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * accompanied this code).
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef SHARE_VM_GC_CMS_PAROOPCLOSURES_INLINE_HPP
#define SHARE_VM_GC_CMS_PAROOPCLOSURES_INLINE_HPP

#include "gc/cms/cmsHeap.hpp"
#include "gc/cms/parNewGeneration.hpp"
#include "gc/cms/parOopClosures.hpp"
#include "gc/shared/cardTableRS.hpp"
#include "gc/shared/genOopClosures.inline.hpp"
#include "logging/log.hpp"
#include "logging/logStream.hpp"
#include "oops/access.inline.hpp"
#include "oops/compressedOops.inline.hpp"
#include "oops/oop.inline.hpp"

template <class T> inline void ParScanWeakRefClosure::do_oop_work(T* p) {
  oop obj = RawAccess<IS_NOT_NULL>::oop_load(p);
  // weak references are sometimes scanned twice; must check
  // that to-space doesn't already contain this object
  if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
    // we need to ensure that it is copied (see comment in
    // ParScanClosure::do_oop_work).
    Klass* objK = obj->klass();
    markOop m = obj->mark_raw();
    oop new_obj;
    if (m->is_marked()) { // Contains forwarding pointer.
      new_obj = ParNewGeneration::real_forwardee(obj);
    } else {
      size_t obj_sz = obj->size_given_klass(objK);
      new_obj = ((ParNewGeneration*)_g)->copy_to_survivor_space(_par_scan_state,
                                                                obj, obj_sz, m);
    }
    RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
  }
}

inline void ParScanWeakRefClosure::do_oop(oop* p)       { ParScanWeakRefClosure::do_oop_work(p); }
inline void ParScanWeakRefClosure::do_oop(narrowOop* p) { ParScanWeakRefClosure::do_oop_work(p); }

template <class T> inline void ParScanClosure::par_do_barrier(T* p) {
  assert(generation()->is_in_reserved(p), "expected ref in generation");
  oop obj = RawAccess<IS_NOT_NULL>::oop_load(p);
  // If p points to a younger generation, mark the card.
  if ((HeapWord*)obj < gen_boundary()) {
    rs()->write_ref_field_gc_par(p, obj);
  }
}

template <class T>
inline void ParScanClosure::do_oop_work(T* p,
                                        bool gc_barrier,
                                        bool root_scan) {
  assert((!CMSHeap::heap()->is_in_reserved(p) ||
          generation()->is_in_reserved(p))
         && (CMSHeap::heap()->is_young_gen(generation()) || gc_barrier),
         "The gen must be right, and we must be doing the barrier "
         "in older generations.");
  T heap_oop = RawAccess<>::oop_load(p);
  if (!CompressedOops::is_null(heap_oop)) {
    oop obj = CompressedOops::decode_not_null(heap_oop);
    if ((HeapWord*)obj < _boundary) {
#ifndef PRODUCT
      if (_g->to()->is_in_reserved(obj)) {
        Log(gc) log;
        log.error("Scanning field (" PTR_FORMAT ") twice?", p2i(p));
        CMSHeap* heap = CMSHeap::heap();
        Space* sp = heap->space_containing(p);
        oop obj = oop(sp->block_start(p));
        assert((HeapWord*)obj < (HeapWord*)p, "Error");
        log.error("Object: " PTR_FORMAT, p2i((void *)obj));
        log.error("-------");
        LogStream ls(log.error());
        obj->print_on(&ls);
        log.error("-----");
        log.error("Heap:");
        log.error("-----");
        heap->print_on(&ls);
        ShouldNotReachHere();
      }
#endif
      // OK, we need to ensure that it is copied.
      // We read the klass and mark in this order, so that we can reliably
      // get the size of the object: if the mark we read is not a
      // forwarding pointer, then the klass is valid: the klass is only
      // overwritten with an overflow next pointer after the object is
      // forwarded.
      Klass* objK = obj->klass();
      markOop m = obj->mark_raw();
      oop new_obj;
      if (m->is_marked()) { // Contains forwarding pointer.
        new_obj = ParNewGeneration::real_forwardee(obj);
        RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
        log_develop_trace(gc, scavenge)("{%s %s ( " PTR_FORMAT " ) " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
                                        "forwarded ",
                                        new_obj->klass()->internal_name(), p2i(p), p2i((void *)obj), p2i((void *)new_obj), new_obj->size());
      } else {
        size_t obj_sz = obj->size_given_klass(objK);
        new_obj = _g->copy_to_survivor_space(_par_scan_state, obj, obj_sz, m);
        RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
        if (root_scan) {
          // This may have pushed an object.  If we have a root
          // category with a lot of roots, can't let the queue get too
          // full:
          (void)_par_scan_state->trim_queues(10 * ParallelGCThreads);
        }
      }
      if (is_scanning_a_cld()) {
        do_cld_barrier();
      } else if (gc_barrier) {
        // Now call parent closure
        par_do_barrier(p);
      }
    }
  }
}

inline void ParScanWithBarrierClosure::do_oop(oop* p)       { ParScanClosure::do_oop_work(p, true, false); }
inline void ParScanWithBarrierClosure::do_oop(narrowOop* p) { ParScanClosure::do_oop_work(p, true, false); }

inline void ParScanWithoutBarrierClosure::do_oop(oop* p)       { ParScanClosure::do_oop_work(p, false, false); }
inline void ParScanWithoutBarrierClosure::do_oop(narrowOop* p) { ParScanClosure::do_oop_work(p, false, false); }

#endif // SHARE_VM_GC_CMS_PAROOPCLOSURES_INLINE_HPP