bool CardGeneration::expand(size_t bytes, size_t expand_bytes) {
assert_locked_or_safepoint(Heap_lock);
if (bytes == 0) {
return true; // That's what grow_by(0) would return
}
size_t aligned_bytes = ReservedSpace::page_align_size_up(bytes);
if (aligned_bytes == 0) {
// The alignment caused the number of bytes to wrap. An expand_by(0) will
// return true with the implication that an expansion was done when it
// was not. A call to expand implies a best effort to expand by "bytes"
// but not a guarantee. Align down to give a best effort. This is likely
// the most that the generation can expand since it has some capacity to
// start with.
aligned_bytes = ReservedSpace::page_align_size_down(bytes);
}
size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes);
bool success = false;
if (aligned_expand_bytes > aligned_bytes) {
success = grow_by(aligned_expand_bytes);
}
if (!success) {
success = grow_by(aligned_bytes);
}
if (!success) {
success = grow_to_reserved();
}
if (PrintGC && Verbose) {
if (success && GC_locker::is_active_and_needs_gc()) {
gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead");
}
}
return success;
}
bool OneContigSpaceCardGeneration::grow_to_reserved() {
assert_locked_or_safepoint(ExpandHeap_lock);
bool success = true;
const size_t remaining_bytes = _virtual_space.uncommitted_size();
if (remaining_bytes > 0) {
success = grow_by(remaining_bytes);
DEBUG_ONLY(if (!success) warning("grow to reserved failed");)
}
bool CardGeneration::grow_to_reserved() {
assert_correct_size_change_locking();
bool success = true;
const size_t remaining_bytes = _virtual_space.uncommitted_size();
if (remaining_bytes > 0) {
success = grow_by(remaining_bytes);
DEBUG_ONLY(if (!success) log_warning(gc)("grow to reserved failed");)
}
