hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp
author johnc
Thu, 09 May 2013 11:16:39 -0700
changeset 17327 4bd0581aa231
parent 16604 800a65bfe347
child 20309 7445302daff6
permissions -rw-r--r--
7176479: G1: JVM crashes on T5-8 system with 1.5 TB heap Summary: Refactor G1's hot card cache and card counts table into their own files. Simplify the card counts table, including removing the encoding of the card index in each entry. The card counts table now has a 1:1 correspondence with the cards spanned by heap. Space for the card counts table is reserved from virtual memory (rather than C heap) during JVM startup and is committed/expanded when the heap is expanded. Changes were also reviewed-by Vitaly Davidovich. Reviewed-by: tschatzl, jmasa

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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/heapRegionSeq.inline.hpp"
#include "utilities/taskqueue.hpp"

// Inline functions for G1CollectedHeap

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 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);
  ((CardTableModRefBS*)_g1h->barrier_set())->dirty(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);
}

#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

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP