| /* |
| * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "gc/parallel/mutableSpace.hpp" |
| #include "gc/shared/spaceDecorator.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/atomic.hpp" |
| #include "runtime/safepoint.hpp" |
| #include "runtime/thread.hpp" |
| #include "utilities/align.hpp" |
| #include "utilities/macros.hpp" |
| |
| MutableSpace::MutableSpace(size_t alignment): ImmutableSpace(), _top(NULL), _alignment(alignment) { |
| assert(MutableSpace::alignment() % os::vm_page_size() == 0, |
| "Space should be aligned"); |
| _mangler = new MutableSpaceMangler(this); |
| } |
| |
| MutableSpace::~MutableSpace() { |
| delete _mangler; |
| } |
| |
| void MutableSpace::numa_setup_pages(MemRegion mr, bool clear_space) { |
| if (!mr.is_empty()) { |
| size_t page_size = UseLargePages ? alignment() : os::vm_page_size(); |
| HeapWord *start = align_up(mr.start(), page_size); |
| HeapWord *end = align_down(mr.end(), page_size); |
| if (end > start) { |
| size_t size = pointer_delta(end, start, sizeof(char)); |
| if (clear_space) { |
| // Prefer page reallocation to migration. |
| os::free_memory((char*)start, size, page_size); |
| } |
| os::numa_make_global((char*)start, size); |
| } |
| } |
| } |
| |
| void MutableSpace::pretouch_pages(MemRegion mr) { |
| os::pretouch_memory(mr.start(), mr.end()); |
| } |
| |
| void MutableSpace::initialize(MemRegion mr, |
| bool clear_space, |
| bool mangle_space, |
| bool setup_pages) { |
| |
| assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()), |
| "invalid space boundaries"); |
| |
| if (setup_pages && (UseNUMA || AlwaysPreTouch)) { |
| // The space may move left and right or expand/shrink. |
| // We'd like to enforce the desired page placement. |
| MemRegion head, tail; |
| if (last_setup_region().is_empty()) { |
| // If it's the first initialization don't limit the amount of work. |
| head = mr; |
| tail = MemRegion(mr.end(), mr.end()); |
| } else { |
| // Is there an intersection with the address space? |
| MemRegion intersection = last_setup_region().intersection(mr); |
| if (intersection.is_empty()) { |
| intersection = MemRegion(mr.end(), mr.end()); |
| } |
| // All the sizes below are in words. |
| size_t head_size = 0, tail_size = 0; |
| if (mr.start() <= intersection.start()) { |
| head_size = pointer_delta(intersection.start(), mr.start()); |
| } |
| if(intersection.end() <= mr.end()) { |
| tail_size = pointer_delta(mr.end(), intersection.end()); |
| } |
| // Limit the amount of page manipulation if necessary. |
| if (NUMASpaceResizeRate > 0 && !AlwaysPreTouch) { |
| const size_t change_size = head_size + tail_size; |
| const float setup_rate_words = NUMASpaceResizeRate >> LogBytesPerWord; |
| head_size = MIN2((size_t)(setup_rate_words * head_size / change_size), |
| head_size); |
| tail_size = MIN2((size_t)(setup_rate_words * tail_size / change_size), |
| tail_size); |
| } |
| head = MemRegion(intersection.start() - head_size, intersection.start()); |
| tail = MemRegion(intersection.end(), intersection.end() + tail_size); |
| } |
| assert(mr.contains(head) && mr.contains(tail), "Sanity"); |
| |
| if (UseNUMA) { |
| numa_setup_pages(head, clear_space); |
| numa_setup_pages(tail, clear_space); |
| } |
| |
| if (AlwaysPreTouch) { |
| pretouch_pages(head); |
| pretouch_pages(tail); |
| } |
| |
| // Remember where we stopped so that we can continue later. |
| set_last_setup_region(MemRegion(head.start(), tail.end())); |
| } |
| |
| set_bottom(mr.start()); |
| set_end(mr.end()); |
| |
| if (clear_space) { |
| clear(mangle_space); |
| } |
| } |
| |
| void MutableSpace::clear(bool mangle_space) { |
| set_top(bottom()); |
| if (ZapUnusedHeapArea && mangle_space) { |
| mangle_unused_area(); |
| } |
| } |
| |
| #ifndef PRODUCT |
| void MutableSpace::check_mangled_unused_area(HeapWord* limit) { |
| mangler()->check_mangled_unused_area(limit); |
| } |
| |
| void MutableSpace::check_mangled_unused_area_complete() { |
| mangler()->check_mangled_unused_area_complete(); |
| } |
| |
| // Mangle only the unused space that has not previously |
| // been mangled and that has not been allocated since being |
| // mangled. |
| void MutableSpace::mangle_unused_area() { |
| mangler()->mangle_unused_area(); |
| } |
| |
| void MutableSpace::mangle_unused_area_complete() { |
| mangler()->mangle_unused_area_complete(); |
| } |
| |
| void MutableSpace::mangle_region(MemRegion mr) { |
| SpaceMangler::mangle_region(mr); |
| } |
| |
| void MutableSpace::set_top_for_allocations(HeapWord* v) { |
| mangler()->set_top_for_allocations(v); |
| } |
| |
| void MutableSpace::set_top_for_allocations() { |
| mangler()->set_top_for_allocations(top()); |
| } |
| #endif |
| |
| // This version requires locking. */ |
| HeapWord* MutableSpace::allocate(size_t size) { |
| assert(Heap_lock->owned_by_self() || |
| (SafepointSynchronize::is_at_safepoint() && |
| Thread::current()->is_VM_thread()), |
| "not locked"); |
| HeapWord* obj = top(); |
| if (pointer_delta(end(), obj) >= size) { |
| HeapWord* new_top = obj + size; |
| set_top(new_top); |
| assert(is_object_aligned(obj) && is_object_aligned(new_top), |
| "checking alignment"); |
| return obj; |
| } else { |
| return NULL; |
| } |
| } |
| |
| // This version is lock-free. |
| HeapWord* MutableSpace::cas_allocate(size_t size) { |
| do { |
| HeapWord* obj = top(); |
| if (pointer_delta(end(), obj) >= size) { |
| HeapWord* new_top = obj + size; |
| HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj); |
| // result can be one of two: |
| // the old top value: the exchange succeeded |
| // otherwise: the new value of the top is returned. |
| if (result != obj) { |
| continue; // another thread beat us to the allocation, try again |
| } |
| assert(is_object_aligned(obj) && is_object_aligned(new_top), |
| "checking alignment"); |
| return obj; |
| } else { |
| return NULL; |
| } |
| } while (true); |
| } |
| |
| // Try to deallocate previous allocation. Returns true upon success. |
| bool MutableSpace::cas_deallocate(HeapWord *obj, size_t size) { |
| HeapWord* expected_top = obj + size; |
| return (HeapWord*)Atomic::cmpxchg_ptr(obj, top_addr(), expected_top) == expected_top; |
| } |
| |
| void MutableSpace::oop_iterate_no_header(OopClosure* cl) { |
| HeapWord* obj_addr = bottom(); |
| HeapWord* t = top(); |
| // Could call objects iterate, but this is easier. |
| while (obj_addr < t) { |
| obj_addr += oop(obj_addr)->oop_iterate_no_header(cl); |
| } |
| } |
| |
| void MutableSpace::object_iterate(ObjectClosure* cl) { |
| HeapWord* p = bottom(); |
| while (p < top()) { |
| cl->do_object(oop(p)); |
| p += oop(p)->size(); |
| } |
| } |
| |
| void MutableSpace::print_short() const { print_short_on(tty); } |
| void MutableSpace::print_short_on( outputStream* st) const { |
| st->print(" space " SIZE_FORMAT "K, %d%% used", capacity_in_bytes() / K, |
| (int) ((double) used_in_bytes() * 100 / capacity_in_bytes())); |
| } |
| |
| void MutableSpace::print() const { print_on(tty); } |
| void MutableSpace::print_on(outputStream* st) const { |
| MutableSpace::print_short_on(st); |
| st->print_cr(" [" INTPTR_FORMAT "," INTPTR_FORMAT "," INTPTR_FORMAT ")", |
| p2i(bottom()), p2i(top()), p2i(end())); |
| } |
| |
| void MutableSpace::verify() { |
| HeapWord* p = bottom(); |
| HeapWord* t = top(); |
| HeapWord* prev_p = NULL; |
| while (p < t) { |
| oop(p)->verify(); |
| prev_p = p; |
| p += oop(p)->size(); |
| } |
| guarantee(p == top(), "end of last object must match end of space"); |
| } |