duke@435: /*
zgu@7074:  * Copyright (c) 2000, 2014, 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"
minqi@5103: #include "memory/allocation.hpp"
minqi@5103: #include "memory/allocation.inline.hpp"
stefank@2314: #include "memory/memRegion.hpp"
stefank@2314: #include "runtime/globals.hpp"
stefank@2314: 
duke@435: // A very simple data structure representing a contigous word-aligned
duke@435: // region of address space.
duke@435: 
duke@435: MemRegion MemRegion::intersection(const MemRegion mr2) const {
duke@435:   MemRegion res;
duke@435:   HeapWord* res_start = MAX2(start(), mr2.start());
duke@435:   HeapWord* res_end   = MIN2(end(),   mr2.end());
duke@435:   if (res_start < res_end) {
duke@435:     res.set_start(res_start);
duke@435:     res.set_end(res_end);
duke@435:   }
duke@435:   return res;
duke@435: }
duke@435: 
duke@435: MemRegion MemRegion::_union(const MemRegion mr2) const {
duke@435:   // If one region is empty, return the other
duke@435:   if (is_empty()) return mr2;
duke@435:   if (mr2.is_empty()) return MemRegion(start(), end());
duke@435: 
duke@435:   // Otherwise, regions must overlap or be adjacent
duke@435:   assert(((start() <= mr2.start()) && (end() >= mr2.start())) ||
duke@435:          ((mr2.start() <= start()) && (mr2.end() >= start())),
duke@435:              "non-adjacent or overlapping regions");
duke@435:   MemRegion res;
duke@435:   HeapWord* res_start = MIN2(start(), mr2.start());
duke@435:   HeapWord* res_end   = MAX2(end(),   mr2.end());
duke@435:   res.set_start(res_start);
duke@435:   res.set_end(res_end);
duke@435:   return res;
duke@435: }
duke@435: 
duke@435: MemRegion MemRegion::minus(const MemRegion mr2) const {
duke@435:   // There seem to be 6 cases:
duke@435:   //                  |this MemRegion|
duke@435:   // |strictly below|
duke@435:   //   |overlap beginning|
duke@435:   //                    |interior|
duke@435:   //                        |overlap ending|
duke@435:   //                                   |strictly above|
duke@435:   //              |completely overlapping|
duke@435:   // We can't deal with an interior case because it would
duke@435:   // produce two disjoint regions as a result.
duke@435:   // We aren't trying to be optimal in the number of tests below,
duke@435:   // but the order is important to distinguish the strictly cases
duke@435:   // from the overlapping cases.
duke@435:   if (mr2.end() <= start()) {
duke@435:     // strictly below
duke@435:     return MemRegion(start(), end());
duke@435:   }
duke@435:   if (mr2.start() <= start() && mr2.end() <= end()) {
duke@435:     // overlap beginning
duke@435:     return MemRegion(mr2.end(), end());
duke@435:   }
duke@435:   if (mr2.start() >= end()) {
duke@435:     // strictly above
duke@435:     return MemRegion(start(), end());
duke@435:   }
duke@435:   if (mr2.start() >= start() && mr2.end() >= end()) {
duke@435:     // overlap ending
duke@435:     return MemRegion(start(), mr2.start());
duke@435:   }
duke@435:   if (mr2.start() <= start() && mr2.end() >= end()) {
duke@435:     // completely overlapping
duke@435:     return MemRegion();
duke@435:   }
duke@435:   if (mr2.start() > start() && mr2.end() < end()) {
duke@435:     // interior
duke@435:     guarantee(false, "MemRegion::minus, but interior");
duke@435:     return MemRegion();
duke@435:   }
duke@435:   ShouldNotReachHere();
duke@435:   return MemRegion();
duke@435: }
minqi@5103: 
coleenp@5614: void* MemRegion::operator new(size_t size) throw() {
zgu@7074:   return (address)AllocateHeap(size, mtGC, CURRENT_PC,
zgu@7074:     AllocFailStrategy::RETURN_NULL);
minqi@5103: }
minqi@5103: 
coleenp@5614: void* MemRegion::operator new [](size_t size) throw() {
zgu@7074:   return (address)AllocateHeap(size, mtGC, CURRENT_PC,
zgu@7074:     AllocFailStrategy::RETURN_NULL);
minqi@5103: }
minqi@5103: void  MemRegion::operator delete(void* p) {
minqi@5103:   FreeHeap(p, mtGC);
minqi@5103: }
minqi@5103: 
minqi@5103: void  MemRegion::operator delete [](void* p) {
minqi@5103:   FreeHeap(p, mtGC);
minqi@5103: }
minqi@5103: