// See comments on request_old_gen_expansion()
bool AdjoiningGenerations::request_young_gen_expansion(size_t expand_in_bytes) {
assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
// If eden is not empty, the boundary can be moved but no advantage
// can be made of the move since eden cannot be moved.
if (!young_gen()->eden_space()->is_empty()) {
return false;
}
bool result = false;
const size_t young_gen_available = young_gen()->available_for_expansion();
const size_t old_gen_available = old_gen()->available_for_contraction();
const size_t alignment = virtual_spaces()->alignment();
size_t change_in_bytes = MIN3(young_gen_available,
old_gen_available,
align_size_up_(expand_in_bytes, alignment));
if (change_in_bytes == 0) {
return false;
}
if (TraceAdaptiveGCBoundary) {
gclog_or_tty->print_cr("Before expansion of young gen with boundary move");
gclog_or_tty->print_cr(" Requested change: 0x%zx Attempted change: 0x%zx",
expand_in_bytes, change_in_bytes);
if (!PrintHeapAtGC) {
Universe::print_on(gclog_or_tty);
}
gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K",
young_gen()->max_size()/K);
}
// Move the boundary between the generations down (smaller old gen).
MutexLocker x(ExpandHeap_lock);
if (virtual_spaces()->adjust_boundary_down(change_in_bytes)) {
young_gen()->reset_after_change();
old_gen()->reset_after_change();
result = true;
}
// The total reserved for the generations should match the sum
// of the two even if the boundary is moving.
assert(reserved_byte_size() ==
old_gen()->max_gen_size() + young_gen()->max_size(),
"Space is missing");
young_gen()->space_invariants();
old_gen()->space_invariants();
if (TraceAdaptiveGCBoundary) {
gclog_or_tty->print_cr("After expansion of young gen with boundary move");
if (!PrintHeapAtGC) {
Universe::print_on(gclog_or_tty);
}
gclog_or_tty->print_cr(" PSYoungGen max size: " SIZE_FORMAT "K",
young_gen()->max_size()/K);
}
return result;
}
// Make checks on the current sizes of the generations and
// the constraints on the sizes of the generations. Push
// up the boundary within the constraints. A partial
// push can occur.
void AdjoiningGenerations::request_old_gen_expansion(size_t expand_in_bytes) {
assert(UseAdaptiveSizePolicy && UseAdaptiveGCBoundary, "runtime check");
assert_lock_strong(ExpandHeap_lock);
assert_locked_or_safepoint(Heap_lock);
// These sizes limit the amount the boundaries can move. Effectively,
// the generation says how much it is willing to yield to the other
// generation.
const size_t young_gen_available = young_gen()->available_for_contraction();
const size_t old_gen_available = old_gen()->available_for_expansion();
const size_t alignment = virtual_spaces()->alignment();
size_t change_in_bytes = MIN3(young_gen_available,
old_gen_available,
align_size_up_(expand_in_bytes, alignment));
if (change_in_bytes == 0) {
return;
}
if (TraceAdaptiveGCBoundary) {
gclog_or_tty->print_cr("Before expansion of old gen with boundary move");
gclog_or_tty->print_cr(" Requested change: " SIZE_FORMAT_HEX
" Attempted change: " SIZE_FORMAT_HEX,
expand_in_bytes, change_in_bytes);
if (!PrintHeapAtGC) {
Universe::print_on(gclog_or_tty);
}
gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K",
old_gen()->max_gen_size()/K);
}
// Move the boundary between the generations up (smaller young gen).
if (virtual_spaces()->adjust_boundary_up(change_in_bytes)) {
young_gen()->reset_after_change();
old_gen()->reset_after_change();
}
// The total reserved for the generations should match the sum
// of the two even if the boundary is moving.
assert(reserved_byte_size() ==
old_gen()->max_gen_size() + young_gen()->max_size(),
"Space is missing");
young_gen()->space_invariants();
old_gen()->space_invariants();
if (TraceAdaptiveGCBoundary) {
gclog_or_tty->print_cr("After expansion of old gen with boundary move");
if (!PrintHeapAtGC) {
Universe::print_on(gclog_or_tty);
}
gclog_or_tty->print_cr(" PSOldGen max size: " SIZE_FORMAT "K",
old_gen()->max_gen_size()/K);
}
}
inline intptr_t align_size_up(intptr_t size, intptr_t alignment) {
return align_size_up_(size, alignment);
}
inline void ParallelScavengeHeap::set_generation_alignment(size_t val) {
assert(align_size_up_(val, os::vm_page_size()) == val, "not aligned");
_generation_alignment = val;
}
inline void* align_pointer_up(const void* addr, size_t size) {
return (void*) align_size_up_((uintptr_t)addr, size);
}
inline bool is_ptr_aligned(void* ptr, size_t alignment) {
return align_size_up_((intptr_t)ptr, (intptr_t)alignment) == (intptr_t)ptr;
}
inline bool is_size_aligned(size_t size, size_t alignment) {
return align_size_up_(size, alignment) == size;
}
