src/share/vm/gc/cms/concurrentMarkSweepGeneration.cpp

rev 11971 : [mq]: overflow_list_3

*** 7827,7848 ****
  // Single-threaded
  bool CMSCollector::take_from_overflow_list(size_t num, CMSMarkStack* stack) {
    assert(stack->isEmpty(), "Expected precondition");
    assert(stack->capacity() > num, "Shouldn't bite more than can chew");
    size_t i = num;
!   oop  cur = _overflow_list;
    const markOop proto = markOopDesc::prototype();
    NOT_PRODUCT(ssize_t n = 0;)
    for (oop next; i > 0 && cur != NULL; cur = next, i--) {
      next = oop(cur->mark());
      cur->set_mark(proto);   // until proven otherwise
      assert(cur->is_oop(), "Should be an oop");
      bool res = stack->push(cur);
      assert(res, "Bit off more than can chew?");
      NOT_PRODUCT(n++;)
    }
!   _overflow_list = cur;
  #ifndef PRODUCT
    assert(_num_par_pushes >= n, "Too many pops?");
    _num_par_pushes -=n;
  #endif
    return !stack->isEmpty();
--- 7827,7848 ----
  // Single-threaded
  bool CMSCollector::take_from_overflow_list(size_t num, CMSMarkStack* stack) {
    assert(stack->isEmpty(), "Expected precondition");
    assert(stack->capacity() > num, "Shouldn't bite more than can chew");
    size_t i = num;
!   oop  cur = oop(_overflow_list);
    const markOop proto = markOopDesc::prototype();
    NOT_PRODUCT(ssize_t n = 0;)
    for (oop next; i > 0 && cur != NULL; cur = next, i--) {
      next = oop(cur->mark());
      cur->set_mark(proto);   // until proven otherwise
      assert(cur->is_oop(), "Should be an oop");
      bool res = stack->push(cur);
      assert(res, "Bit off more than can chew?");
      NOT_PRODUCT(n++;)
    }
!   _overflow_list = (oopDesc*)cur;
  #ifndef PRODUCT
    assert(_num_par_pushes >= n, "Too many pops?");
    _num_par_pushes -=n;
  #endif
    return !stack->isEmpty();
*** 7933,7943 ****
      cur->set_mark(NULL);           // break off suffix
      // It's possible that the list is still in the empty(busy) state
      // we left it in a short while ago; in that case we may be
      // able to place back the suffix without incurring the cost
      // of a walk down the list.
!     oop observed_overflow_list = _overflow_list;
      oop cur_overflow_list = observed_overflow_list;
      bool attached = false;
      while (observed_overflow_list == BUSY || observed_overflow_list == NULL) {
        observed_overflow_list =
          (oop) Atomic::cmpxchg_ptr(suffix_head, &_overflow_list, cur_overflow_list);
--- 7933,7943 ----
      cur->set_mark(NULL);           // break off suffix
      // It's possible that the list is still in the empty(busy) state
      // we left it in a short while ago; in that case we may be
      // able to place back the suffix without incurring the cost
      // of a walk down the list.
!     oop observed_overflow_list = oop(_overflow_list);
      oop cur_overflow_list = observed_overflow_list;
      bool attached = false;
      while (observed_overflow_list == BUSY || observed_overflow_list == NULL) {
        observed_overflow_list =
          (oop) Atomic::cmpxchg_ptr(suffix_head, &_overflow_list, cur_overflow_list);
*** 7952,7962 ****
        // list.
        for (cur = suffix_head; cur->mark() != NULL; cur = (oop)(cur->mark()));
        oop suffix_tail = cur;
        assert(suffix_tail != NULL && suffix_tail->mark() == NULL,
               "Tautology");
!       observed_overflow_list = _overflow_list;
        do {
          cur_overflow_list = observed_overflow_list;
          if (cur_overflow_list != BUSY) {
            // Do the splice ...
            suffix_tail->set_mark(markOop(cur_overflow_list));
--- 7952,7962 ----
        // list.
        for (cur = suffix_head; cur->mark() != NULL; cur = (oop)(cur->mark()));
        oop suffix_tail = cur;
        assert(suffix_tail != NULL && suffix_tail->mark() == NULL,
               "Tautology");
!       observed_overflow_list = oop(_overflow_list);
        do {
          cur_overflow_list = observed_overflow_list;
          if (cur_overflow_list != BUSY) {
            // Do the splice ...
            suffix_tail->set_mark(markOop(cur_overflow_list));
*** 7995,8013 ****
  void CMSCollector::push_on_overflow_list(oop p) {
    NOT_PRODUCT(_num_par_pushes++;)
    assert(p->is_oop(), "Not an oop");
    preserve_mark_if_necessary(p);
    p->set_mark((markOop)_overflow_list);
!   _overflow_list = p;
  }
  
  // Multi-threaded; use CAS to prepend to overflow list
  void CMSCollector::par_push_on_overflow_list(oop p) {
    NOT_PRODUCT(Atomic::inc_ptr(&_num_par_pushes);)
    assert(p->is_oop(), "Not an oop");
    par_preserve_mark_if_necessary(p);
!   oop observed_overflow_list = _overflow_list;
    oop cur_overflow_list;
    do {
      cur_overflow_list = observed_overflow_list;
      if (cur_overflow_list != BUSY) {
        p->set_mark(markOop(cur_overflow_list));
--- 7995,8013 ----
  void CMSCollector::push_on_overflow_list(oop p) {
    NOT_PRODUCT(_num_par_pushes++;)
    assert(p->is_oop(), "Not an oop");
    preserve_mark_if_necessary(p);
    p->set_mark((markOop)_overflow_list);
!   _overflow_list = (oopDesc*)p;
  }
  
  // Multi-threaded; use CAS to prepend to overflow list
  void CMSCollector::par_push_on_overflow_list(oop p) {
    NOT_PRODUCT(Atomic::inc_ptr(&_num_par_pushes);)
    assert(p->is_oop(), "Not an oop");
    par_preserve_mark_if_necessary(p);
!   oop observed_overflow_list = oop(_overflow_list);
    oop cur_overflow_list;
    do {
      cur_overflow_list = observed_overflow_list;
      if (cur_overflow_list != BUSY) {
        p->set_mark(markOop(cur_overflow_list));