1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/shared/mutableSpace.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,271 @@
1.4 +/*
1.5 + * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "utilities/macros.hpp"
1.30 +#if INCLUDE_ALL_GCS
1.31 +#include "gc_implementation/shared/mutableSpace.hpp"
1.32 +#include "gc_implementation/shared/spaceDecorator.hpp"
1.33 +#include "oops/oop.inline.hpp"
1.34 +#include "runtime/safepoint.hpp"
1.35 +#include "runtime/thread.hpp"
1.36 +#endif // INCLUDE_ALL_GCS
1.37 +
1.38 +PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
1.39 +
1.40 +MutableSpace::MutableSpace(size_t alignment): ImmutableSpace(), _top(NULL), _alignment(alignment) {
1.41 + assert(MutableSpace::alignment() >= 0 &&
1.42 + MutableSpace::alignment() % os::vm_page_size() == 0,
1.43 + "Space should be aligned");
1.44 + _mangler = new MutableSpaceMangler(this);
1.45 +}
1.46 +
1.47 +MutableSpace::~MutableSpace() {
1.48 + delete _mangler;
1.49 +}
1.50 +
1.51 +void MutableSpace::numa_setup_pages(MemRegion mr, bool clear_space) {
1.52 + if (!mr.is_empty()) {
1.53 + size_t page_size = UseLargePages ? alignment() : os::vm_page_size();
1.54 + HeapWord *start = (HeapWord*)round_to((intptr_t) mr.start(), page_size);
1.55 + HeapWord *end = (HeapWord*)round_down((intptr_t) mr.end(), page_size);
1.56 + if (end > start) {
1.57 + size_t size = pointer_delta(end, start, sizeof(char));
1.58 + if (clear_space) {
1.59 + // Prefer page reallocation to migration.
1.60 + os::free_memory((char*)start, size, page_size);
1.61 + }
1.62 + os::numa_make_global((char*)start, size);
1.63 + }
1.64 + }
1.65 +}
1.66 +
1.67 +void MutableSpace::pretouch_pages(MemRegion mr) {
1.68 + for (volatile char *p = (char*)mr.start(); p < (char*)mr.end(); p += os::vm_page_size()) {
1.69 + char t = *p; *p = t;
1.70 + }
1.71 +}
1.72 +
1.73 +void MutableSpace::initialize(MemRegion mr,
1.74 + bool clear_space,
1.75 + bool mangle_space,
1.76 + bool setup_pages) {
1.77 +
1.78 + assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
1.79 + "invalid space boundaries");
1.80 +
1.81 + if (setup_pages && (UseNUMA || AlwaysPreTouch)) {
1.82 + // The space may move left and right or expand/shrink.
1.83 + // We'd like to enforce the desired page placement.
1.84 + MemRegion head, tail;
1.85 + if (last_setup_region().is_empty()) {
1.86 + // If it's the first initialization don't limit the amount of work.
1.87 + head = mr;
1.88 + tail = MemRegion(mr.end(), mr.end());
1.89 + } else {
1.90 + // Is there an intersection with the address space?
1.91 + MemRegion intersection = last_setup_region().intersection(mr);
1.92 + if (intersection.is_empty()) {
1.93 + intersection = MemRegion(mr.end(), mr.end());
1.94 + }
1.95 + // All the sizes below are in words.
1.96 + size_t head_size = 0, tail_size = 0;
1.97 + if (mr.start() <= intersection.start()) {
1.98 + head_size = pointer_delta(intersection.start(), mr.start());
1.99 + }
1.100 + if(intersection.end() <= mr.end()) {
1.101 + tail_size = pointer_delta(mr.end(), intersection.end());
1.102 + }
1.103 + // Limit the amount of page manipulation if necessary.
1.104 + if (NUMASpaceResizeRate > 0 && !AlwaysPreTouch) {
1.105 + const size_t change_size = head_size + tail_size;
1.106 + const float setup_rate_words = NUMASpaceResizeRate >> LogBytesPerWord;
1.107 + head_size = MIN2((size_t)(setup_rate_words * head_size / change_size),
1.108 + head_size);
1.109 + tail_size = MIN2((size_t)(setup_rate_words * tail_size / change_size),
1.110 + tail_size);
1.111 + }
1.112 + head = MemRegion(intersection.start() - head_size, intersection.start());
1.113 + tail = MemRegion(intersection.end(), intersection.end() + tail_size);
1.114 + }
1.115 + assert(mr.contains(head) && mr.contains(tail), "Sanity");
1.116 +
1.117 + if (UseNUMA) {
1.118 + numa_setup_pages(head, clear_space);
1.119 + numa_setup_pages(tail, clear_space);
1.120 + }
1.121 +
1.122 + if (AlwaysPreTouch) {
1.123 + pretouch_pages(head);
1.124 + pretouch_pages(tail);
1.125 + }
1.126 +
1.127 + // Remember where we stopped so that we can continue later.
1.128 + set_last_setup_region(MemRegion(head.start(), tail.end()));
1.129 + }
1.130 +
1.131 + set_bottom(mr.start());
1.132 + set_end(mr.end());
1.133 +
1.134 + if (clear_space) {
1.135 + clear(mangle_space);
1.136 + }
1.137 +}
1.138 +
1.139 +void MutableSpace::clear(bool mangle_space) {
1.140 + set_top(bottom());
1.141 + if (ZapUnusedHeapArea && mangle_space) {
1.142 + mangle_unused_area();
1.143 + }
1.144 +}
1.145 +
1.146 +#ifndef PRODUCT
1.147 +void MutableSpace::check_mangled_unused_area(HeapWord* limit) {
1.148 + mangler()->check_mangled_unused_area(limit);
1.149 +}
1.150 +
1.151 +void MutableSpace::check_mangled_unused_area_complete() {
1.152 + mangler()->check_mangled_unused_area_complete();
1.153 +}
1.154 +
1.155 +// Mangle only the unused space that has not previously
1.156 +// been mangled and that has not been allocated since being
1.157 +// mangled.
1.158 +void MutableSpace::mangle_unused_area() {
1.159 + mangler()->mangle_unused_area();
1.160 +}
1.161 +
1.162 +void MutableSpace::mangle_unused_area_complete() {
1.163 + mangler()->mangle_unused_area_complete();
1.164 +}
1.165 +
1.166 +void MutableSpace::mangle_region(MemRegion mr) {
1.167 + SpaceMangler::mangle_region(mr);
1.168 +}
1.169 +
1.170 +void MutableSpace::set_top_for_allocations(HeapWord* v) {
1.171 + mangler()->set_top_for_allocations(v);
1.172 +}
1.173 +
1.174 +void MutableSpace::set_top_for_allocations() {
1.175 + mangler()->set_top_for_allocations(top());
1.176 +}
1.177 +#endif
1.178 +
1.179 +// This version requires locking. */
1.180 +HeapWord* MutableSpace::allocate(size_t size) {
1.181 + assert(Heap_lock->owned_by_self() ||
1.182 + (SafepointSynchronize::is_at_safepoint() &&
1.183 + Thread::current()->is_VM_thread()),
1.184 + "not locked");
1.185 + HeapWord* obj = top();
1.186 + if (pointer_delta(end(), obj) >= size) {
1.187 + HeapWord* new_top = obj + size;
1.188 + set_top(new_top);
1.189 + assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
1.190 + "checking alignment");
1.191 + return obj;
1.192 + } else {
1.193 + return NULL;
1.194 + }
1.195 +}
1.196 +
1.197 +// This version is lock-free.
1.198 +HeapWord* MutableSpace::cas_allocate(size_t size) {
1.199 + do {
1.200 + HeapWord* obj = top();
1.201 + if (pointer_delta(end(), obj) >= size) {
1.202 + HeapWord* new_top = obj + size;
1.203 + HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
1.204 + // result can be one of two:
1.205 + // the old top value: the exchange succeeded
1.206 + // otherwise: the new value of the top is returned.
1.207 + if (result != obj) {
1.208 + continue; // another thread beat us to the allocation, try again
1.209 + }
1.210 + assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
1.211 + "checking alignment");
1.212 + return obj;
1.213 + } else {
1.214 + return NULL;
1.215 + }
1.216 + } while (true);
1.217 +}
1.218 +
1.219 +// Try to deallocate previous allocation. Returns true upon success.
1.220 +bool MutableSpace::cas_deallocate(HeapWord *obj, size_t size) {
1.221 + HeapWord* expected_top = obj + size;
1.222 + return (HeapWord*)Atomic::cmpxchg_ptr(obj, top_addr(), expected_top) == expected_top;
1.223 +}
1.224 +
1.225 +void MutableSpace::oop_iterate(ExtendedOopClosure* cl) {
1.226 + HeapWord* obj_addr = bottom();
1.227 + HeapWord* t = top();
1.228 + // Could call objects iterate, but this is easier.
1.229 + while (obj_addr < t) {
1.230 + obj_addr += oop(obj_addr)->oop_iterate(cl);
1.231 + }
1.232 +}
1.233 +
1.234 +void MutableSpace::oop_iterate_no_header(OopClosure* cl) {
1.235 + HeapWord* obj_addr = bottom();
1.236 + HeapWord* t = top();
1.237 + // Could call objects iterate, but this is easier.
1.238 + while (obj_addr < t) {
1.239 + obj_addr += oop(obj_addr)->oop_iterate_no_header(cl);
1.240 + }
1.241 +}
1.242 +
1.243 +void MutableSpace::object_iterate(ObjectClosure* cl) {
1.244 + HeapWord* p = bottom();
1.245 + while (p < top()) {
1.246 + cl->do_object(oop(p));
1.247 + p += oop(p)->size();
1.248 + }
1.249 +}
1.250 +
1.251 +void MutableSpace::print_short() const { print_short_on(tty); }
1.252 +void MutableSpace::print_short_on( outputStream* st) const {
1.253 + st->print(" space " SIZE_FORMAT "K, %d%% used", capacity_in_bytes() / K,
1.254 + (int) ((double) used_in_bytes() * 100 / capacity_in_bytes()));
1.255 +}
1.256 +
1.257 +void MutableSpace::print() const { print_on(tty); }
1.258 +void MutableSpace::print_on(outputStream* st) const {
1.259 + MutableSpace::print_short_on(st);
1.260 + st->print_cr(" [" INTPTR_FORMAT "," INTPTR_FORMAT "," INTPTR_FORMAT ")",
1.261 + bottom(), top(), end());
1.262 +}
1.263 +
1.264 +void MutableSpace::verify() {
1.265 + HeapWord* p = bottom();
1.266 + HeapWord* t = top();
1.267 + HeapWord* prev_p = NULL;
1.268 + while (p < t) {
1.269 + oop(p)->verify();
1.270 + prev_p = p;
1.271 + p += oop(p)->size();
1.272 + }
1.273 + guarantee(p == top(), "end of last object must match end of space");
1.274 +}
