bool
ParMarkBitMap::initialize(MemRegion covered_region)
{
const idx_t bits = bits_required(covered_region);
// The bits will be divided evenly between two bitmaps; each of them should be
// an integral number of words.
assert(bits % (BitsPerWord * 2) == 0, "region size unaligned");
const size_t words = bits / BitsPerWord;
const size_t raw_bytes = words * sizeof(idx_t);
const size_t page_sz = os::page_size_for_region(raw_bytes, raw_bytes, 10);
const size_t granularity = os::vm_allocation_granularity();
const size_t bytes = align_size_up(raw_bytes, MAX2(page_sz, granularity));
const size_t rs_align = page_sz == (size_t) os::vm_page_size() ? 0 :
MAX2(page_sz, granularity);
ReservedSpace rs(bytes, rs_align, rs_align > 0);
os::trace_page_sizes("par bitmap", raw_bytes, raw_bytes, page_sz,
rs.base(), rs.size());
MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
_virtual_space = new PSVirtualSpace(rs, page_sz);
if (_virtual_space != NULL && _virtual_space->expand_by(bytes)) {
_region_start = covered_region.start();
_region_size = covered_region.word_size();
idx_t* map = (idx_t*)_virtual_space->reserved_low_addr();
_beg_bits.set_map(map);
_beg_bits.set_size(bits / 2);
_end_bits.set_map(map + words / 2);
_end_bits.set_size(bits / 2);
return true;
}
_region_start = 0;
_region_size = 0;
if (_virtual_space != NULL) {
delete _virtual_space;
_virtual_space = NULL;
// Release memory reserved in the space.
rs.release();
}
return false;
}
inline ParMarkBitMap::idx_t
ParMarkBitMap::words_required(MemRegion covered_region)
{
return bits_required(covered_region) / BitsPerWord;
}
inline ParMarkBitMap::idx_t
ParMarkBitMap::bits_required(MemRegion covered_region)
{
return bits_required(covered_region.word_size());
}
