void DefNewGeneration::compute_space_boundaries(uintx minimum_eden_size) {
// All space sizes must be multiples of car size in order for the CarTable to work.
// Note that the CarTable is used with and without train gc (for fast lookup).
uintx alignment = CarSpace::car_size();
// Compute sizes
uintx size = _virtual_space.committed_size();
uintx survivor_size = compute_survivor_size(size, alignment);
uintx eden_size = size - (2*survivor_size);
assert(eden_size > 0 && survivor_size <= eden_size, "just checking");
if (eden_size < minimum_eden_size) {
// May happen due to 64Kb rounding, if so adjust eden size back up
minimum_eden_size = align_size_up(minimum_eden_size, alignment);
uintx maximum_survivor_size = (size - minimum_eden_size) / 2;
uintx unaligned_survivor_size =
align_size_down(maximum_survivor_size, alignment);
survivor_size = MAX2(unaligned_survivor_size, alignment);
eden_size = size - (2*survivor_size);
assert(eden_size > 0 && survivor_size <= eden_size, "just checking");
assert(eden_size >= minimum_eden_size, "just checking");
}
char *eden_start = _virtual_space.low();
char *from_start = eden_start + eden_size;
char *to_start = from_start + survivor_size;
char *to_end = to_start + survivor_size;
assert(to_end == _virtual_space.high(), "just checking");
assert(Space::is_aligned((HeapWord*)eden_start), "checking alignment");
assert(Space::is_aligned((HeapWord*)from_start), "checking alignment");
assert(Space::is_aligned((HeapWord*)to_start), "checking alignment");
MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)from_start);
MemRegion fromMR((HeapWord*)from_start, (HeapWord*)to_start);
MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end);
eden()->initialize(edenMR, (minimum_eden_size == 0));
from()->initialize(fromMR, true);
to()->initialize(toMR , true);
if (jvmpi::is_event_enabled(JVMPI_EVENT_ARENA_NEW)) {
CollectedHeap* ch = Universe::heap();
jvmpi::post_arena_new_event(ch->addr_to_arena_id(eden_start), "Eden");
jvmpi::post_arena_new_event(ch->addr_to_arena_id(from_start), "Semi");
jvmpi::post_arena_new_event(ch->addr_to_arena_id(to_start), "Semi");
}
}
void DefNewGeneration::swap_spaces() {
CollectedHeap* ch = Universe::heap();
if (jvmpi::is_event_enabled(JVMPI_EVENT_ARENA_DELETE)) {
jvmpi::post_arena_delete_event(ch->addr_to_arena_id(from()->bottom()));
}
if (jvmpi::is_event_enabled(JVMPI_EVENT_ARENA_NEW)) {
jvmpi::post_arena_new_event(ch->addr_to_arena_id(from()->bottom()), "Semi");
}
ContiguousSpace* s = from();
_from_space = to();
_to_space = s;
if (UsePerfData) {
CSpaceCounters* c = _from_counters;
_from_counters = _to_counters;
_to_counters = c;
}
}
