duke@435: /*
brutisso@3711:  * Copyright (c) 2001, 2012, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #ifndef SERIALGC
stefank@2314: #include "gc_implementation/shared/mutableSpace.hpp"
stefank@2314: #include "gc_implementation/shared/spaceDecorator.hpp"
stefank@2314: #include "oops/oop.inline.hpp"
stefank@2314: #include "runtime/safepoint.hpp"
stefank@2314: #include "runtime/thread.hpp"
stefank@2314: #endif
duke@435: 
iveresov@970: MutableSpace::MutableSpace(size_t alignment): ImmutableSpace(), _top(NULL), _alignment(alignment) {
iveresov@970:   assert(MutableSpace::alignment() >= 0 &&
iveresov@970:          MutableSpace::alignment() % os::vm_page_size() == 0,
iveresov@970:          "Space should be aligned");
jmasa@698:   _mangler = new MutableSpaceMangler(this);
jmasa@698: }
jmasa@698: 
jmasa@698: MutableSpace::~MutableSpace() {
jmasa@698:   delete _mangler;
jmasa@698: }
jmasa@698: 
iveresov@970: void MutableSpace::numa_setup_pages(MemRegion mr, bool clear_space) {
iveresov@970:   if (!mr.is_empty()) {
iveresov@970:     size_t page_size = UseLargePages ? alignment() : os::vm_page_size();
iveresov@970:     HeapWord *start = (HeapWord*)round_to((intptr_t) mr.start(), page_size);
iveresov@970:     HeapWord *end =  (HeapWord*)round_down((intptr_t) mr.end(), page_size);
iveresov@970:     if (end > start) {
iveresov@970:       size_t size = pointer_delta(end, start, sizeof(char));
iveresov@970:       if (clear_space) {
iveresov@970:         // Prefer page reallocation to migration.
iveresov@3363:         os::free_memory((char*)start, size, page_size);
iveresov@970:       }
iveresov@970:       os::numa_make_global((char*)start, size);
iveresov@970:     }
iveresov@970:   }
iveresov@970: }
iveresov@970: 
iveresov@970: void MutableSpace::pretouch_pages(MemRegion mr) {
iveresov@970:   for (volatile char *p = (char*)mr.start(); p < (char*)mr.end(); p += os::vm_page_size()) {
iveresov@970:     char t = *p; *p = t;
iveresov@970:   }
iveresov@970: }
iveresov@970: 
jmasa@698: void MutableSpace::initialize(MemRegion mr,
jmasa@698:                               bool clear_space,
iveresov@970:                               bool mangle_space,
iveresov@970:                               bool setup_pages) {
duke@435: 
iveresov@970:   assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
duke@435:          "invalid space boundaries");
iveresov@970: 
iveresov@970:   if (setup_pages && (UseNUMA || AlwaysPreTouch)) {
iveresov@970:     // The space may move left and right or expand/shrink.
iveresov@970:     // We'd like to enforce the desired page placement.
iveresov@970:     MemRegion head, tail;
iveresov@970:     if (last_setup_region().is_empty()) {
iveresov@970:       // If it's the first initialization don't limit the amount of work.
iveresov@970:       head = mr;
iveresov@970:       tail = MemRegion(mr.end(), mr.end());
iveresov@970:     } else {
iveresov@970:       // Is there an intersection with the address space?
iveresov@970:       MemRegion intersection = last_setup_region().intersection(mr);
iveresov@970:       if (intersection.is_empty()) {
iveresov@970:         intersection = MemRegion(mr.end(), mr.end());
iveresov@970:       }
iveresov@970:       // All the sizes below are in words.
iveresov@970:       size_t head_size = 0, tail_size = 0;
iveresov@970:       if (mr.start() <= intersection.start()) {
iveresov@970:         head_size = pointer_delta(intersection.start(), mr.start());
iveresov@970:       }
iveresov@970:       if(intersection.end() <= mr.end()) {
iveresov@970:         tail_size = pointer_delta(mr.end(), intersection.end());
iveresov@970:       }
iveresov@970:       // Limit the amount of page manipulation if necessary.
iveresov@970:       if (NUMASpaceResizeRate > 0 && !AlwaysPreTouch) {
iveresov@970:         const size_t change_size = head_size + tail_size;
iveresov@970:         const float setup_rate_words = NUMASpaceResizeRate >> LogBytesPerWord;
iveresov@970:         head_size = MIN2((size_t)(setup_rate_words * head_size / change_size),
iveresov@970:                          head_size);
iveresov@970:         tail_size = MIN2((size_t)(setup_rate_words * tail_size / change_size),
iveresov@970:                          tail_size);
iveresov@970:       }
iveresov@970:       head = MemRegion(intersection.start() - head_size, intersection.start());
iveresov@970:       tail = MemRegion(intersection.end(), intersection.end() + tail_size);
iveresov@970:     }
iveresov@970:     assert(mr.contains(head) && mr.contains(tail), "Sanity");
iveresov@970: 
iveresov@970:     if (UseNUMA) {
iveresov@970:       numa_setup_pages(head, clear_space);
iveresov@970:       numa_setup_pages(tail, clear_space);
iveresov@970:     }
iveresov@970: 
iveresov@970:     if (AlwaysPreTouch) {
iveresov@970:       pretouch_pages(head);
iveresov@970:       pretouch_pages(tail);
iveresov@970:     }
iveresov@970: 
iveresov@970:     // Remember where we stopped so that we can continue later.
iveresov@970:     set_last_setup_region(MemRegion(head.start(), tail.end()));
iveresov@970:   }
iveresov@970: 
iveresov@970:   set_bottom(mr.start());
iveresov@970:   set_end(mr.end());
duke@435: 
jmasa@698:   if (clear_space) {
jmasa@698:     clear(mangle_space);
jmasa@698:   }
duke@435: }
duke@435: 
jmasa@698: void MutableSpace::clear(bool mangle_space) {
duke@435:   set_top(bottom());
jmasa@698:   if (ZapUnusedHeapArea && mangle_space) {
jmasa@698:     mangle_unused_area();
jmasa@698:   }
duke@435: }
duke@435: 
jmasa@698: #ifndef PRODUCT
jmasa@698: void MutableSpace::check_mangled_unused_area(HeapWord* limit) {
jmasa@698:   mangler()->check_mangled_unused_area(limit);
jmasa@698: }
jmasa@698: 
jmasa@698: void MutableSpace::check_mangled_unused_area_complete() {
jmasa@698:   mangler()->check_mangled_unused_area_complete();
jmasa@698: }
jmasa@698: 
jmasa@698: // Mangle only the unused space that has not previously
jmasa@698: // been mangled and that has not been allocated since being
jmasa@698: // mangled.
jmasa@698: void MutableSpace::mangle_unused_area() {
jmasa@698:   mangler()->mangle_unused_area();
jmasa@698: }
jmasa@698: 
jmasa@698: void MutableSpace::mangle_unused_area_complete() {
jmasa@698:   mangler()->mangle_unused_area_complete();
jmasa@698: }
jmasa@698: 
jmasa@698: void MutableSpace::mangle_region(MemRegion mr) {
jmasa@698:   SpaceMangler::mangle_region(mr);
jmasa@698: }
jmasa@698: 
jmasa@698: void MutableSpace::set_top_for_allocations(HeapWord* v) {
jmasa@698:   mangler()->set_top_for_allocations(v);
jmasa@698: }
jmasa@698: 
jmasa@698: void MutableSpace::set_top_for_allocations() {
jmasa@698:   mangler()->set_top_for_allocations(top());
jmasa@698: }
jmasa@698: #endif
jmasa@698: 
duke@435: // This version requires locking. */
duke@435: HeapWord* MutableSpace::allocate(size_t size) {
duke@435:   assert(Heap_lock->owned_by_self() ||
duke@435:          (SafepointSynchronize::is_at_safepoint() &&
duke@435:           Thread::current()->is_VM_thread()),
duke@435:          "not locked");
duke@435:   HeapWord* obj = top();
duke@435:   if (pointer_delta(end(), obj) >= size) {
duke@435:     HeapWord* new_top = obj + size;
duke@435:     set_top(new_top);
duke@435:     assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
duke@435:            "checking alignment");
duke@435:     return obj;
duke@435:   } else {
duke@435:     return NULL;
duke@435:   }
duke@435: }
duke@435: 
duke@435: // This version is lock-free.
duke@435: HeapWord* MutableSpace::cas_allocate(size_t size) {
duke@435:   do {
duke@435:     HeapWord* obj = top();
duke@435:     if (pointer_delta(end(), obj) >= size) {
duke@435:       HeapWord* new_top = obj + size;
duke@435:       HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
duke@435:       // result can be one of two:
duke@435:       //  the old top value: the exchange succeeded
duke@435:       //  otherwise: the new value of the top is returned.
duke@435:       if (result != obj) {
duke@435:         continue; // another thread beat us to the allocation, try again
duke@435:       }
duke@435:       assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
duke@435:              "checking alignment");
duke@435:       return obj;
duke@435:     } else {
duke@435:       return NULL;
duke@435:     }
duke@435:   } while (true);
duke@435: }
duke@435: 
duke@435: // Try to deallocate previous allocation. Returns true upon success.
duke@435: bool MutableSpace::cas_deallocate(HeapWord *obj, size_t size) {
duke@435:   HeapWord* expected_top = obj + size;
duke@435:   return (HeapWord*)Atomic::cmpxchg_ptr(obj, top_addr(), expected_top) == expected_top;
duke@435: }
duke@435: 
coleenp@4037: void MutableSpace::oop_iterate(ExtendedOopClosure* cl) {
duke@435:   HeapWord* obj_addr = bottom();
duke@435:   HeapWord* t = top();
duke@435:   // Could call objects iterate, but this is easier.
duke@435:   while (obj_addr < t) {
duke@435:     obj_addr += oop(obj_addr)->oop_iterate(cl);
duke@435:   }
duke@435: }
duke@435: 
coleenp@4037: void MutableSpace::oop_iterate_no_header(OopClosure* cl) {
coleenp@4037:   HeapWord* obj_addr = bottom();
coleenp@4037:   HeapWord* t = top();
coleenp@4037:   // Could call objects iterate, but this is easier.
coleenp@4037:   while (obj_addr < t) {
coleenp@4037:     obj_addr += oop(obj_addr)->oop_iterate_no_header(cl);
coleenp@4037:   }
coleenp@4037: }
coleenp@4037: 
duke@435: void MutableSpace::object_iterate(ObjectClosure* cl) {
duke@435:   HeapWord* p = bottom();
duke@435:   while (p < top()) {
duke@435:     cl->do_object(oop(p));
duke@435:     p += oop(p)->size();
duke@435:   }
duke@435: }
duke@435: 
duke@435: void MutableSpace::print_short() const { print_short_on(tty); }
duke@435: void MutableSpace::print_short_on( outputStream* st) const {
duke@435:   st->print(" space " SIZE_FORMAT "K, %d%% used", capacity_in_bytes() / K,
duke@435:             (int) ((double) used_in_bytes() * 100 / capacity_in_bytes()));
duke@435: }
duke@435: 
duke@435: void MutableSpace::print() const { print_on(tty); }
duke@435: void MutableSpace::print_on(outputStream* st) const {
duke@435:   MutableSpace::print_short_on(st);
duke@435:   st->print_cr(" [" INTPTR_FORMAT "," INTPTR_FORMAT "," INTPTR_FORMAT ")",
duke@435:                  bottom(), top(), end());
duke@435: }
duke@435: 
brutisso@3711: void MutableSpace::verify() {
duke@435:   HeapWord* p = bottom();
duke@435:   HeapWord* t = top();
duke@435:   HeapWord* prev_p = NULL;
duke@435:   while (p < t) {
duke@435:     oop(p)->verify();
duke@435:     prev_p = p;
duke@435:     p += oop(p)->size();
duke@435:   }
duke@435:   guarantee(p == top(), "end of last object must match end of space");
duke@435: }