jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/shared/mutableSpace.cpp@da91efe96a93 (annotated)

src/share/vm/gc_implementation/shared/mutableSpace.cpp@da91efe96a93 (annotated)

src/share/vm/gc_implementation/shared/mutableSpace.cpp

Sat, 01 Sep 2012 13:25:18 -0400

author: coleenp
date: Sat, 01 Sep 2012 13:25:18 -0400
changeset 4037: da91efe96a93
parent 3711: b632e80fc9dc
child 4542: db9981fd3124
permissions: -rw-r--r--

6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>

 /*
  * Copyright (c) 2001, 2012, 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"
 #ifndef SERIALGC
 #include "gc_implementation/shared/mutableSpace.hpp"
 #include "gc_implementation/shared/spaceDecorator.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/safepoint.hpp"
 #include "runtime/thread.hpp"
 #endif
 MutableSpace::MutableSpace(size_t alignment): ImmutableSpace(), _top(NULL), _alignment(alignment) {
   assert(MutableSpace::alignment() >= 0 &&
          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 = (HeapWord*)round_to((intptr_t) mr.start(), page_size);
     HeapWord *end =  (HeapWord*)round_down((intptr_t) 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) {
   for (volatile char *p = (char*)mr.start(); p < (char*)mr.end(); p += os::vm_page_size()) {
     char t = *p; *p = t;
   }
 }
 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((intptr_t)obj) && is_object_aligned((intptr_t)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((intptr_t)obj) && is_object_aligned((intptr_t)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(ExtendedOopClosure* 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(cl);
   }
 }
 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 ")",
                  bottom(), top(), 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");
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/shared/mutableSpace.cpp@da91efe96a93 (annotated)

src/share/vm/gc_implementation/shared/mutableSpace.cpp