jdk/src/hotspot/share/gc/g1/g1CardTableClaimTable.cpp
Thomas Schatzl afbb3a0415 8375620: G1: Convert G1CardTableClaimTable to use Atomic<T>
Reviewed-by: kbarrett, shade
2026-01-20 10:31:22 +00:00

98 lines
3.6 KiB
C++

/*
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#include "gc/g1/g1CardTableClaimTable.inline.hpp"
#include "gc/g1/g1CollectedHeap.inline.hpp"
#include "gc/g1/g1HeapRegion.inline.hpp"
#include "gc/shared/workerThread.hpp"
#include "memory/allocation.hpp"
#include "utilities/checkedCast.hpp"
#include "utilities/powerOfTwo.hpp"
G1CardTableClaimTable::G1CardTableClaimTable(uint chunks_per_region) :
_max_reserved_regions(0),
_card_claims(nullptr),
_cards_per_chunk(checked_cast<uint>(G1HeapRegion::CardsPerRegion / chunks_per_region))
{
guarantee(chunks_per_region > 0, "%u chunks per region", chunks_per_region);
}
G1CardTableClaimTable::~G1CardTableClaimTable() {
FREE_C_HEAP_ARRAY(uint, _card_claims);
}
void G1CardTableClaimTable::initialize(uint max_reserved_regions) {
assert(_card_claims == nullptr, "Must not be initialized twice");
_card_claims = NEW_C_HEAP_ARRAY(Atomic<uint>, max_reserved_regions, mtGC);
_max_reserved_regions = max_reserved_regions;
reset_all_to_unclaimed();
}
void G1CardTableClaimTable::reset_all_to_unclaimed() {
for (uint i = 0; i < _max_reserved_regions; i++) {
_card_claims[i].store_relaxed(0);
}
}
void G1CardTableClaimTable::reset_all_to_claimed() {
for (uint i = 0; i < _max_reserved_regions; i++) {
_card_claims[i].store_relaxed((uint)G1HeapRegion::CardsPerRegion);
}
}
void G1CardTableClaimTable::heap_region_iterate_from_worker_offset(G1HeapRegionClosure* cl, uint worker_id, uint max_workers) {
// Every worker will actually look at all regions, skipping over regions that
// are completed.
const size_t n_regions = _max_reserved_regions;
const uint start_index = (uint)(worker_id * n_regions / max_workers);
for (uint count = 0; count < n_regions; count++) {
const uint index = (start_index + count) % n_regions;
assert(index < n_regions, "sanity");
// Skip over fully processed regions
if (!has_unclaimed_cards(index)) {
continue;
}
G1HeapRegion* r = G1CollectedHeap::heap()->region_at(index);
bool res = cl->do_heap_region(r);
if (res) {
return;
}
}
}
G1CardTableChunkClaimer::G1CardTableChunkClaimer(G1CardTableClaimTable* scan_state, uint region_idx) :
_claim_values(scan_state),
_region_idx(region_idx),
_cur_claim(0) {
guarantee(size() <= G1HeapRegion::CardsPerRegion, "Should not claim more space than possible.");
}
G1ChunkScanner::G1ChunkScanner(CardValue* const start_card, CardValue* const end_card) :
_start_card(start_card),
_end_card(end_card) {
assert(is_word_aligned(start_card), "precondition");
assert(is_word_aligned(end_card), "precondition");
}