void TwoGenerationCollectorPolicy::initialize_flags() {
GenCollectorPolicy::initialize_flags();
if (!is_size_aligned(OldSize, _gen_alignment)) {
FLAG_SET_ERGO(uintx, OldSize, align_size_down(OldSize, _gen_alignment));
}
if (FLAG_IS_CMDLINE(OldSize) && FLAG_IS_DEFAULT(MaxHeapSize)) {
// NewRatio will be used later to set the young generation size so we use
// it to calculate how big the heap should be based on the requested OldSize
// and NewRatio.
assert(NewRatio > 0, "NewRatio should have been set up earlier");
size_t calculated_heapsize = (OldSize / NewRatio) * (NewRatio + 1);
calculated_heapsize = align_size_up(calculated_heapsize, _heap_alignment);
FLAG_SET_ERGO(uintx, MaxHeapSize, calculated_heapsize);
_max_heap_byte_size = MaxHeapSize;
FLAG_SET_ERGO(uintx, InitialHeapSize, calculated_heapsize);
_initial_heap_byte_size = InitialHeapSize;
}
// adjust max heap size if necessary
if (NewSize + OldSize > MaxHeapSize) {
if (_max_heap_size_cmdline) {
// somebody set a maximum heap size with the intention that we should not
// exceed it. Adjust New/OldSize as necessary.
uintx calculated_size = NewSize + OldSize;
double shrink_factor = (double) MaxHeapSize / calculated_size;
uintx smaller_new_size = align_size_down((uintx)(NewSize * shrink_factor), _gen_alignment);
FLAG_SET_ERGO(uintx, NewSize, MAX2(young_gen_size_lower_bound(), smaller_new_size));
_initial_gen0_size = NewSize;
// OldSize is already aligned because above we aligned MaxHeapSize to
// _heap_alignment, and we just made sure that NewSize is aligned to
// _gen_alignment. In initialize_flags() we verified that _heap_alignment
// is a multiple of _gen_alignment.
FLAG_SET_ERGO(uintx, OldSize, MaxHeapSize - NewSize);
} else {
FLAG_SET_ERGO(uintx, MaxHeapSize, align_size_up(NewSize + OldSize, _heap_alignment));
_max_heap_byte_size = MaxHeapSize;
}
}
always_do_update_barrier = UseConcMarkSweepGC;
DEBUG_ONLY(TwoGenerationCollectorPolicy::assert_flags();)
}
// Call this method during the sizing of the gen1 to make
// adjustments to gen0 because of gen1 sizing policy. gen0 initially has
// the most freedom in sizing because it is done before the
// policy for gen1 is applied. Once gen1 policies have been applied,
// there may be conflicts in the shape of the heap and this method
// is used to make the needed adjustments. The application of the
// policies could be more sophisticated (iterative for example) but
// keeping it simple also seems a worthwhile goal.
bool TwoGenerationCollectorPolicy::adjust_gen0_sizes(size_t* gen0_size_ptr,
size_t* gen1_size_ptr,
const size_t heap_size) {
bool result = false;
if ((*gen0_size_ptr + *gen1_size_ptr) > heap_size) {
uintx smallest_new_size = young_gen_size_lower_bound();
if ((heap_size < (*gen0_size_ptr + _min_gen1_size)) &&
(heap_size >= _min_gen1_size + smallest_new_size)) {
// Adjust gen0 down to accommodate _min_gen1_size
*gen0_size_ptr = align_size_down_bounded(heap_size - _min_gen1_size, _gen_alignment);
result = true;
} else {
*gen1_size_ptr = align_size_down_bounded(heap_size - *gen0_size_ptr, _gen_alignment);
}
}
return result;
}
void GenCollectorPolicy::initialize_flags() {
CollectorPolicy::initialize_flags();
assert(_gen_alignment != 0, "Generation alignment not set up properly");
assert(_heap_alignment >= _gen_alignment,
err_msg("heap_alignment: " SIZE_FORMAT " less than gen_alignment: " SIZE_FORMAT,
_heap_alignment, _gen_alignment));
assert(_gen_alignment % _space_alignment == 0,
err_msg("gen_alignment: " SIZE_FORMAT " not aligned by space_alignment: " SIZE_FORMAT,
_gen_alignment, _space_alignment));
assert(_heap_alignment % _gen_alignment == 0,
err_msg("heap_alignment: " SIZE_FORMAT " not aligned by gen_alignment: " SIZE_FORMAT,
_heap_alignment, _gen_alignment));
// All generational heaps have a youngest gen; handle those flags here
// Make sure the heap is large enough for two generations
uintx smallest_new_size = young_gen_size_lower_bound();
uintx smallest_heap_size = align_size_up(smallest_new_size + align_size_up(_space_alignment, _gen_alignment),
_heap_alignment);
if (MaxHeapSize < smallest_heap_size) {
FLAG_SET_ERGO(uintx, MaxHeapSize, smallest_heap_size);
_max_heap_byte_size = MaxHeapSize;
}
// If needed, synchronize _min_heap_byte size and _initial_heap_byte_size
if (_min_heap_byte_size < smallest_heap_size) {
_min_heap_byte_size = smallest_heap_size;
if (InitialHeapSize < _min_heap_byte_size) {
FLAG_SET_ERGO(uintx, InitialHeapSize, smallest_heap_size);
_initial_heap_byte_size = smallest_heap_size;
}
}
// Now take the actual NewSize into account. We will silently increase NewSize
// if the user specified a smaller or unaligned value.
smallest_new_size = MAX2(smallest_new_size, (uintx)align_size_down(NewSize, _gen_alignment));
if (smallest_new_size != NewSize) {
// Do not use FLAG_SET_ERGO to update NewSize here, since this will override
// if NewSize was set on the command line or not. This information is needed
// later when setting the initial and minimum young generation size.
NewSize = smallest_new_size;
}
_initial_gen0_size = NewSize;
if (!FLAG_IS_DEFAULT(MaxNewSize)) {
uintx min_new_size = MAX2(_gen_alignment, _min_gen0_size);
if (MaxNewSize >= MaxHeapSize) {
// Make sure there is room for an old generation
uintx smaller_max_new_size = MaxHeapSize - _gen_alignment;
if (FLAG_IS_CMDLINE(MaxNewSize)) {
warning("MaxNewSize (" SIZE_FORMAT "k) is equal to or greater than the entire "
"heap (" SIZE_FORMAT "k). A new max generation size of " SIZE_FORMAT "k will be used.",
MaxNewSize/K, MaxHeapSize/K, smaller_max_new_size/K);
}
FLAG_SET_ERGO(uintx, MaxNewSize, smaller_max_new_size);
if (NewSize > MaxNewSize) {
FLAG_SET_ERGO(uintx, NewSize, MaxNewSize);
_initial_gen0_size = NewSize;
}
} else if (MaxNewSize < min_new_size) {
FLAG_SET_ERGO(uintx, MaxNewSize, min_new_size);
} else if (!is_size_aligned(MaxNewSize, _gen_alignment)) {
FLAG_SET_ERGO(uintx, MaxNewSize, align_size_down(MaxNewSize, _gen_alignment));
}
_max_gen0_size = MaxNewSize;
}
if (NewSize > MaxNewSize) {
// At this point this should only happen if the user specifies a large NewSize and/or
// a small (but not too small) MaxNewSize.
if (FLAG_IS_CMDLINE(MaxNewSize)) {
warning("NewSize (" SIZE_FORMAT "k) is greater than the MaxNewSize (" SIZE_FORMAT "k). "
"A new max generation size of " SIZE_FORMAT "k will be used.",
NewSize/K, MaxNewSize/K, NewSize/K);
}
FLAG_SET_ERGO(uintx, MaxNewSize, NewSize);
_max_gen0_size = MaxNewSize;
}
if (SurvivorRatio < 1 || NewRatio < 1) {
vm_exit_during_initialization("Invalid young gen ratio specified");
}
DEBUG_ONLY(GenCollectorPolicy::assert_flags();)
}
void GenCollectorPolicy::initialize_flags() {
CollectorPolicy::initialize_flags();
assert(_gen_alignment != 0, "Generation alignment not set up properly");
assert(_heap_alignment >= _gen_alignment,
"heap_alignment: " SIZE_FORMAT " less than gen_alignment: " SIZE_FORMAT,
_heap_alignment, _gen_alignment);
assert(_gen_alignment % _space_alignment == 0,
"gen_alignment: " SIZE_FORMAT " not aligned by space_alignment: " SIZE_FORMAT,
_gen_alignment, _space_alignment);
assert(_heap_alignment % _gen_alignment == 0,
"heap_alignment: " SIZE_FORMAT " not aligned by gen_alignment: " SIZE_FORMAT,
_heap_alignment, _gen_alignment);
// All generational heaps have a young gen; handle those flags here
// Make sure the heap is large enough for two generations
size_t smallest_new_size = young_gen_size_lower_bound();
size_t smallest_heap_size = align_size_up(smallest_new_size + old_gen_size_lower_bound(),
_heap_alignment);
if (MaxHeapSize < smallest_heap_size) {
FLAG_SET_ERGO(size_t, MaxHeapSize, smallest_heap_size);
_max_heap_byte_size = MaxHeapSize;
}
// If needed, synchronize _min_heap_byte size and _initial_heap_byte_size
if (_min_heap_byte_size < smallest_heap_size) {
_min_heap_byte_size = smallest_heap_size;
if (InitialHeapSize < _min_heap_byte_size) {
FLAG_SET_ERGO(size_t, InitialHeapSize, smallest_heap_size);
_initial_heap_byte_size = smallest_heap_size;
}
}
// Make sure NewSize allows an old generation to fit even if set on the command line
if (FLAG_IS_CMDLINE(NewSize) && NewSize >= _initial_heap_byte_size) {
log_warning(gc, ergo)("NewSize was set larger than initial heap size, will use initial heap size.");
FLAG_SET_ERGO(size_t, NewSize, bound_minus_alignment(NewSize, _initial_heap_byte_size));
}
// Now take the actual NewSize into account. We will silently increase NewSize
// if the user specified a smaller or unaligned value.
size_t bounded_new_size = bound_minus_alignment(NewSize, MaxHeapSize);
bounded_new_size = MAX2(smallest_new_size, (size_t)align_size_down(bounded_new_size, _gen_alignment));
if (bounded_new_size != NewSize) {
FLAG_SET_ERGO(size_t, NewSize, bounded_new_size);
}
_min_young_size = smallest_new_size;
_initial_young_size = NewSize;
if (!FLAG_IS_DEFAULT(MaxNewSize)) {
if (MaxNewSize >= MaxHeapSize) {
// Make sure there is room for an old generation
size_t smaller_max_new_size = MaxHeapSize - _gen_alignment;
if (FLAG_IS_CMDLINE(MaxNewSize)) {
log_warning(gc, ergo)("MaxNewSize (" SIZE_FORMAT "k) is equal to or greater than the entire "
"heap (" SIZE_FORMAT "k). A new max generation size of " SIZE_FORMAT "k will be used.",
MaxNewSize/K, MaxHeapSize/K, smaller_max_new_size/K);
}
FLAG_SET_ERGO(size_t, MaxNewSize, smaller_max_new_size);
if (NewSize > MaxNewSize) {
FLAG_SET_ERGO(size_t, NewSize, MaxNewSize);
_initial_young_size = NewSize;
}
} else if (MaxNewSize < _initial_young_size) {
FLAG_SET_ERGO(size_t, MaxNewSize, _initial_young_size);
} else if (!is_size_aligned(MaxNewSize, _gen_alignment)) {
FLAG_SET_ERGO(size_t, MaxNewSize, align_size_down(MaxNewSize, _gen_alignment));
}
_max_young_size = MaxNewSize;
}
if (NewSize > MaxNewSize) {
// At this point this should only happen if the user specifies a large NewSize and/or
// a small (but not too small) MaxNewSize.
if (FLAG_IS_CMDLINE(MaxNewSize)) {
log_warning(gc, ergo)("NewSize (" SIZE_FORMAT "k) is greater than the MaxNewSize (" SIZE_FORMAT "k). "
"A new max generation size of " SIZE_FORMAT "k will be used.",
NewSize/K, MaxNewSize/K, NewSize/K);
}
FLAG_SET_ERGO(size_t, MaxNewSize, NewSize);
_max_young_size = MaxNewSize;
}
if (SurvivorRatio < 1 || NewRatio < 1) {
vm_exit_during_initialization("Invalid young gen ratio specified");
}
if (OldSize < old_gen_size_lower_bound()) {
FLAG_SET_ERGO(size_t, OldSize, old_gen_size_lower_bound());
}
if (!is_size_aligned(OldSize, _gen_alignment)) {
FLAG_SET_ERGO(size_t, OldSize, align_size_down(OldSize, _gen_alignment));
}
if (FLAG_IS_CMDLINE(OldSize) && FLAG_IS_DEFAULT(MaxHeapSize)) {
// NewRatio will be used later to set the young generation size so we use
// it to calculate how big the heap should be based on the requested OldSize
// and NewRatio.
assert(NewRatio > 0, "NewRatio should have been set up earlier");
size_t calculated_heapsize = (OldSize / NewRatio) * (NewRatio + 1);
calculated_heapsize = align_size_up(calculated_heapsize, _heap_alignment);
FLAG_SET_ERGO(size_t, MaxHeapSize, calculated_heapsize);
_max_heap_byte_size = MaxHeapSize;
FLAG_SET_ERGO(size_t, InitialHeapSize, calculated_heapsize);
_initial_heap_byte_size = InitialHeapSize;
}
// Adjust NewSize and OldSize or MaxHeapSize to match each other
if (NewSize + OldSize > MaxHeapSize) {
if (FLAG_IS_CMDLINE(MaxHeapSize)) {
// Somebody has set a maximum heap size with the intention that we should not
// exceed it. Adjust New/OldSize as necessary.
size_t calculated_size = NewSize + OldSize;
double shrink_factor = (double) MaxHeapSize / calculated_size;
size_t smaller_new_size = align_size_down((size_t)(NewSize * shrink_factor), _gen_alignment);
FLAG_SET_ERGO(size_t, NewSize, MAX2(young_gen_size_lower_bound(), smaller_new_size));
_initial_young_size = NewSize;
// OldSize is already aligned because above we aligned MaxHeapSize to
// _heap_alignment, and we just made sure that NewSize is aligned to
// _gen_alignment. In initialize_flags() we verified that _heap_alignment
// is a multiple of _gen_alignment.
FLAG_SET_ERGO(size_t, OldSize, MaxHeapSize - NewSize);
} else {
FLAG_SET_ERGO(size_t, MaxHeapSize, align_size_up(NewSize + OldSize, _heap_alignment));
_max_heap_byte_size = MaxHeapSize;
}
}
// Update NewSize, if possible, to avoid sizing the young gen too small when only
// OldSize is set on the command line.
if (FLAG_IS_CMDLINE(OldSize) && !FLAG_IS_CMDLINE(NewSize)) {
if (OldSize < _initial_heap_byte_size) {
size_t new_size = _initial_heap_byte_size - OldSize;
// Need to compare against the flag value for max since _max_young_size
// might not have been set yet.
if (new_size >= _min_young_size && new_size <= MaxNewSize) {
FLAG_SET_ERGO(size_t, NewSize, new_size);
_initial_young_size = NewSize;
}
}
}
always_do_update_barrier = UseConcMarkSweepGC;
DEBUG_ONLY(GenCollectorPolicy::assert_flags();)
}
