8025852: Remove unnecessary setters in collector policy classes
Summary: Use instance variables directly within the collector policy classes and remove unused setters.
Reviewed-by: tschatzl, jcoomes
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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP
#include "gc_implementation/g1/heapRegion.hpp"
#include "utilities/growableArray.hpp"
class CollectionSetChooser: public CHeapObj<mtGC> {
GrowableArray<HeapRegion*> _regions;
// Unfortunately, GrowableArray uses ints for length and indexes. To
// avoid excessive casting in the rest of the class the following
// wrapper methods are provided that use uints.
uint regions_length() { return (uint) _regions.length(); }
HeapRegion* regions_at(uint i) { return _regions.at((int) i); }
void regions_at_put(uint i, HeapRegion* hr) {
_regions.at_put((int) i, hr);
}
void regions_at_put_grow(uint i, HeapRegion* hr) {
_regions.at_put_grow((int) i, hr);
}
void regions_trunc_to(uint i) { _regions.trunc_to((uint) i); }
// The index of the next candidate old region to be considered for
// addition to the CSet.
uint _curr_index;
// The number of candidate old regions added to the CSet chooser.
// Note: this is not updated when removing a region using
// remove_and_move_to_next() below.
uint _length;
// Keeps track of the start of the next array chunk to be claimed by
// parallel GC workers.
uint _first_par_unreserved_idx;
// If a region has more live bytes than this threshold, it will not
// be added to the CSet chooser and will not be a candidate for
// collection.
size_t _region_live_threshold_bytes;
// The sum of reclaimable bytes over all the regions in the CSet chooser.
size_t _remaining_reclaimable_bytes;
public:
// Return the current candidate region to be considered for
// collection without removing it from the CSet chooser.
HeapRegion* peek() {
HeapRegion* res = NULL;
if (_curr_index < _length) {
res = regions_at(_curr_index);
assert(res != NULL,
err_msg("Unexpected NULL hr in _regions at index %u",
_curr_index));
}
return res;
}
// Remove the given region from the CSet chooser and move to the
// next one. The given region should be the current candidate region
// in the CSet chooser.
void remove_and_move_to_next(HeapRegion* hr) {
assert(hr != NULL, "pre-condition");
assert(_curr_index < _length, "pre-condition");
assert(regions_at(_curr_index) == hr, "pre-condition");
regions_at_put(_curr_index, NULL);
assert(hr->reclaimable_bytes() <= _remaining_reclaimable_bytes,
err_msg("remaining reclaimable bytes inconsistent "
"from region: "SIZE_FORMAT" remaining: "SIZE_FORMAT,
hr->reclaimable_bytes(), _remaining_reclaimable_bytes));
_remaining_reclaimable_bytes -= hr->reclaimable_bytes();
_curr_index += 1;
}
CollectionSetChooser();
void sort_regions();
// Determine whether to add the given region to the CSet chooser or
// not. Currently, we skip humongous regions (we never add them to
// the CSet, we only reclaim them during cleanup) and regions whose
// live bytes are over the threshold.
bool should_add(HeapRegion* hr) {
assert(hr->is_marked(), "pre-condition");
assert(!hr->is_young(), "should never consider young regions");
return !hr->isHumongous() &&
hr->live_bytes() < _region_live_threshold_bytes;
}
// Returns the number candidate old regions added
uint length() { return _length; }
// Serial version.
void add_region(HeapRegion *hr);
// Must be called before calls to claim_array_chunk().
// n_regions is the number of regions, chunk_size the chunk size.
void prepare_for_par_region_addition(uint n_regions, uint chunk_size);
// Returns the first index in a contiguous chunk of chunk_size indexes
// that the calling thread has reserved. These must be set by the
// calling thread using set_region() (to NULL if necessary).
uint claim_array_chunk(uint chunk_size);
// Set the marked array entry at index to hr. Careful to claim the index
// first if in parallel.
void set_region(uint index, HeapRegion* hr);
// Atomically increment the number of added regions by region_num
// and the amount of reclaimable bytes by reclaimable_bytes.
void update_totals(uint region_num, size_t reclaimable_bytes);
void clear();
// Return the number of candidate regions that remain to be collected.
uint remaining_regions() { return _length - _curr_index; }
// Determine whether the CSet chooser has more candidate regions or not.
bool is_empty() { return remaining_regions() == 0; }
// Return the reclaimable bytes that remain to be collected on
// all the candidate regions in the CSet chooser.
size_t remaining_reclaimable_bytes() { return _remaining_reclaimable_bytes; }
// Returns true if the used portion of "_regions" is properly
// sorted, otherwise asserts false.
void verify() PRODUCT_RETURN;
};
class CSetChooserParUpdater : public StackObj {
private:
CollectionSetChooser* _chooser;
bool _parallel;
uint _chunk_size;
uint _cur_chunk_idx;
uint _cur_chunk_end;
uint _regions_added;
size_t _reclaimable_bytes_added;
public:
CSetChooserParUpdater(CollectionSetChooser* chooser,
bool parallel, uint chunk_size) :
_chooser(chooser), _parallel(parallel), _chunk_size(chunk_size),
_cur_chunk_idx(0), _cur_chunk_end(0),
_regions_added(0), _reclaimable_bytes_added(0) { }
~CSetChooserParUpdater() {
if (_parallel && _regions_added > 0) {
_chooser->update_totals(_regions_added, _reclaimable_bytes_added);
}
}
void add_region(HeapRegion* hr) {
if (_parallel) {
if (_cur_chunk_idx == _cur_chunk_end) {
_cur_chunk_idx = _chooser->claim_array_chunk(_chunk_size);
_cur_chunk_end = _cur_chunk_idx + _chunk_size;
}
assert(_cur_chunk_idx < _cur_chunk_end, "invariant");
_chooser->set_region(_cur_chunk_idx, hr);
_cur_chunk_idx += 1;
} else {
_chooser->add_region(hr);
}
_regions_added += 1;
_reclaimable_bytes_added += hr->reclaimable_bytes();
}
bool should_add(HeapRegion* hr) { return _chooser->should_add(hr); }
};
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP