g1CollectedHeap.inline.hpp

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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP

#include "gc_implementation/g1/concurrentMark.hpp"
#include "gc_implementation/g1/g1CollectedHeap.hpp"
#include "gc_implementation/g1/g1AllocRegion.inline.hpp"
#include "gc_implementation/g1/g1CollectorPolicy.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#include "gc_implementation/g1/heapRegionSet.inline.hpp"
#include "gc_implementation/g1/heapRegionSeq.inline.hpp"
#include "runtime/orderAccess.inline.hpp"
#include "utilities/taskqueue.hpp"

// Inline functions for G1CollectedHeap

// Return the region with the given index. It assumes the index is valid.
inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrs.at(index); }

template <class T>
inline HeapRegion*
G1CollectedHeap::heap_region_containing(const T addr) const {
  HeapRegion* hr = _hrs.addr_to_region((HeapWord*) addr);
  // hr can be null if addr in perm_gen
  if (hr != NULL && hr->continuesHumongous()) {
    hr = hr->humongous_start_region();
  }
  return hr;
}

template <class T>
inline HeapRegion*
G1CollectedHeap::heap_region_containing_raw(const T addr) const {
  assert(_g1_reserved.contains((const void*) addr), "invariant");
  HeapRegion* res = _hrs.addr_to_region_unsafe((HeapWord*) addr);
  return res;
}

inline void G1CollectedHeap::reset_gc_time_stamp() {
  _gc_time_stamp = 0;
  OrderAccess::fence();
  // Clear the cached CSet starting regions and time stamps.
  // Their validity is dependent on the GC timestamp.
  clear_cset_start_regions();
}

inline void G1CollectedHeap::increment_gc_time_stamp() {
  ++_gc_time_stamp;
  OrderAccess::fence();
}

inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
  _old_set.remove(hr);
}

inline bool G1CollectedHeap::obj_in_cs(oop obj) {
  HeapRegion* r = _hrs.addr_to_region((HeapWord*) obj);
  return r != NULL && r->in_collection_set();
}

inline HeapWord*
G1CollectedHeap::attempt_allocation(size_t word_size,
                                    unsigned int* gc_count_before_ret,
                                    int* gclocker_retry_count_ret) {
  assert_heap_not_locked_and_not_at_safepoint();
  assert(!isHumongous(word_size), "attempt_allocation() should not "
         "be called for humongous allocation requests");

  HeapWord* result = _mutator_alloc_region.attempt_allocation(word_size,
                                                      false /* bot_updates */);
  if (result == NULL) {
    result = attempt_allocation_slow(word_size,
                                     gc_count_before_ret,
                                     gclocker_retry_count_ret);
  }
  assert_heap_not_locked();
  if (result != NULL) {
    dirty_young_block(result, word_size);
  }
  return result;
}

inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t
                                                              word_size) {
  assert(!isHumongous(word_size),
         "we should not be seeing humongous-size allocations in this path");

  HeapWord* result = _survivor_gc_alloc_region.attempt_allocation(word_size,
                                                      false /* bot_updates */);
  if (result == NULL) {
    MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
    result = _survivor_gc_alloc_region.attempt_allocation_locked(word_size,
                                                      false /* bot_updates */);
  }
  if (result != NULL) {
    dirty_young_block(result, word_size);
  }
  return result;
}

inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size) {
  assert(!isHumongous(word_size),
         "we should not be seeing humongous-size allocations in this path");

  HeapWord* result = _old_gc_alloc_region.attempt_allocation(word_size,
                                                       true /* bot_updates */);
  if (result == NULL) {
    MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
    result = _old_gc_alloc_region.attempt_allocation_locked(word_size,
                                                       true /* bot_updates */);
  }
  return result;
}

// It dirties the cards that cover the block so that so that the post
// write barrier never queues anything when updating objects on this
// block. It is assumed (and in fact we assert) that the block
// belongs to a young region.
inline void
G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
  assert_heap_not_locked();

  // Assign the containing region to containing_hr so that we don't
  // have to keep calling heap_region_containing_raw() in the
  // asserts below.
  DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);)
  assert(containing_hr != NULL && start != NULL && word_size > 0,
         "pre-condition");
  assert(containing_hr->is_in(start), "it should contain start");
  assert(containing_hr->is_young(), "it should be young");
  assert(!containing_hr->isHumongous(), "it should not be humongous");

  HeapWord* end = start + word_size;
  assert(containing_hr->is_in(end - 1), "it should also contain end - 1");

  MemRegion mr(start, end);
  g1_barrier_set()->g1_mark_as_young(mr);
}

inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const {
  return _task_queues->queue(i);
}

inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
  return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
}

inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
  return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
}


// This is a fast test on whether a reference points into the
// collection set or not. Assume that the reference
// points into the heap.
inline bool G1CollectedHeap::in_cset_fast_test(oop obj) {
  bool ret = _in_cset_fast_test.get_by_address((HeapWord*)obj);
  // let's make sure the result is consistent with what the slower
  // test returns
  assert( ret || !obj_in_cs(obj), "sanity");
  assert(!ret ||  obj_in_cs(obj), "sanity");
  return ret;
}

#ifndef PRODUCT
// Support for G1EvacuationFailureALot

inline bool
G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
                                                     bool during_initial_mark,
                                                     bool during_marking) {
  bool res = false;
  if (during_marking) {
    res |= G1EvacuationFailureALotDuringConcMark;
  }
  if (during_initial_mark) {
    res |= G1EvacuationFailureALotDuringInitialMark;
  }
  if (gcs_are_young) {
    res |= G1EvacuationFailureALotDuringYoungGC;
  } else {
    // GCs are mixed
    res |= G1EvacuationFailureALotDuringMixedGC;
  }
  return res;
}

inline void
G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
  if (G1EvacuationFailureALot) {
    // Note we can't assert that _evacuation_failure_alot_for_current_gc
    // is clear here. It may have been set during a previous GC but that GC
    // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
    // trigger an evacuation failure and clear the flags and and counts.

    // Check if we have gone over the interval.
    const size_t gc_num = total_collections();
    const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;

    _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);

    // Now check if G1EvacuationFailureALot is enabled for the current GC type.
    const bool gcs_are_young = g1_policy()->gcs_are_young();
    const bool during_im = g1_policy()->during_initial_mark_pause();
    const bool during_marking = mark_in_progress();

    _evacuation_failure_alot_for_current_gc &=
      evacuation_failure_alot_for_gc_type(gcs_are_young,
                                          during_im,
                                          during_marking);
  }
}

inline bool
G1CollectedHeap::evacuation_should_fail() {
  if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
    return false;
  }
  // G1EvacuationFailureALot is in effect for current GC
  // Access to _evacuation_failure_alot_count is not atomic;
  // the value does not have to be exact.
  if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
    return false;
  }
  _evacuation_failure_alot_count = 0;
  return true;
}

inline void G1CollectedHeap::reset_evacuation_should_fail() {
  if (G1EvacuationFailureALot) {
    _evacuation_failure_alot_gc_number = total_collections();
    _evacuation_failure_alot_count = 0;
    _evacuation_failure_alot_for_current_gc = false;
  }
}
#endif  // #ifndef PRODUCT

inline bool G1CollectedHeap::is_in_young(const oop obj) {
  HeapRegion* hr = heap_region_containing(obj);
  return hr != NULL && hr->is_young();
}

// We don't need barriers for initializing stores to objects
// in the young gen: for the SATB pre-barrier, there is no
// pre-value that needs to be remembered; for the remembered-set
// update logging post-barrier, we don't maintain remembered set
// information for young gen objects.
inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
  return is_in_young(new_obj);
}

inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
  const HeapRegion* hr = heap_region_containing(obj);
  if (hr == NULL) {
    if (obj == NULL) return false;
    else return true;
  }
  else return is_obj_dead(obj, hr);
}

inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
  const HeapRegion* hr = heap_region_containing(obj);
  if (hr == NULL) {
    if (obj == NULL) return false;
    else return true;
  }
  else return is_obj_ill(obj, hr);
}

template <class T> inline void G1ParScanThreadState::immediate_rs_update(HeapRegion* from, T* p, int tid) {
  if (!from->is_survivor()) {
    _g1_rem->par_write_ref(from, p, tid);
  }
}

template <class T> void G1ParScanThreadState::update_rs(HeapRegion* from, T* p, int tid) {
  if (G1DeferredRSUpdate) {
    deferred_rs_update(from, p, tid);
  } else {
    immediate_rs_update(from, p, tid);
  }
}


inline void G1ParScanThreadState::do_oop_partial_array(oop* p) {
  assert(has_partial_array_mask(p), "invariant");
  oop from_obj = clear_partial_array_mask(p);

  assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap.");
  assert(from_obj->is_objArray(), "must be obj array");
  objArrayOop from_obj_array = objArrayOop(from_obj);
  // The from-space object contains the real length.
  int length                 = from_obj_array->length();

  assert(from_obj->is_forwarded(), "must be forwarded");
  oop to_obj                 = from_obj->forwardee();
  assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
  objArrayOop to_obj_array   = objArrayOop(to_obj);
  // We keep track of the next start index in the length field of the
  // to-space object.
  int next_index             = to_obj_array->length();
  assert(0 <= next_index && next_index < length,
         err_msg("invariant, next index: %d, length: %d", next_index, length));

  int start                  = next_index;
  int end                    = length;
  int remainder              = end - start;
  // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
  if (remainder > 2 * ParGCArrayScanChunk) {
    end = start + ParGCArrayScanChunk;
    to_obj_array->set_length(end);
    // Push the remainder before we process the range in case another
    // worker has run out of things to do and can steal it.
    oop* from_obj_p = set_partial_array_mask(from_obj);
    push_on_queue(from_obj_p);
  } else {
    assert(length == end, "sanity");
    // We'll process the final range for this object. Restore the length
    // so that the heap remains parsable in case of evacuation failure.
    to_obj_array->set_length(end);
  }
  _scanner.set_region(_g1h->heap_region_containing_raw(to_obj));
  // Process indexes [start,end). It will also process the header
  // along with the first chunk (i.e., the chunk with start == 0).
  // Note that at this point the length field of to_obj_array is not
  // correct given that we are using it to keep track of the next
  // start index. oop_iterate_range() (thankfully!) ignores the length
  // field and only relies on the start / end parameters.  It does
  // however return the size of the object which will be incorrect. So
  // we have to ignore it even if we wanted to use it.
  to_obj_array->oop_iterate_range(&_scanner, start, end);
}

template <class T> inline void G1ParScanThreadState::deal_with_reference(T* ref_to_scan) {
  if (!has_partial_array_mask(ref_to_scan)) {
    // Note: we can use "raw" versions of "region_containing" because
    // "obj_to_scan" is definitely in the heap, and is not in a
    // humongous region.
    HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
    do_oop_evac(ref_to_scan, r);
  } else {
    do_oop_partial_array((oop*)ref_to_scan);
  }
}

inline void G1ParScanThreadState::deal_with_reference(StarTask ref) {
  assert(verify_task(ref), "sanity");
  if (ref.is_narrow()) {
    deal_with_reference((narrowOop*)ref);
  } else {
    deal_with_reference((oop*)ref);
  }
}

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP