Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2002, 2010, 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_implementation/parallelScavenge/parallelScavengeHeap.hpp"

 #include "gc_implementation/parallelScavenge/psPromotionLAB.hpp"

 #include "gc_implementation/shared/mutableSpace.hpp"

 #include "oops/oop.inline.hpp"

 size_t PSPromotionLAB::filler_header_size;

 // This is the shared initialization code. It sets up the basic pointers,

 // and allows enough extra space for a filler object. We call a virtual

 // method, "lab_is_valid()" to handle the different asserts the old/young

 // labs require.

 void PSPromotionLAB::initialize(MemRegion lab) {

   assert(lab_is_valid(lab), "Sanity");

   HeapWord* bottom = lab.start();

   HeapWord* end    = lab.end();

   set_bottom(bottom);

   set_end(end);

   set_top(bottom);

   // Initialize after VM starts up because header_size depends on compressed

   // oops.

   filler_header_size = align_object_size(typeArrayOopDesc::header_size(T_INT));

   // We can be initialized to a zero size!

   if (free() > 0) {

     if (ZapUnusedHeapArea) {

       debug_only(Copy::fill_to_words(top(), free()/HeapWordSize, badHeapWord));

     }

     // NOTE! We need to allow space for a filler object.

     assert(lab.word_size() >= filler_header_size, "lab is too small");

     end = end - filler_header_size;

     set_end(end);

     _state = needs_flush;

   } else {

     _state = zero_size;

   }

   assert(this->top() <= this->end(), "pointers out of order");

 }

 // Fill all remaining lab space with an unreachable object.

 // The goal is to leave a contiguous parseable span of objects.

 void PSPromotionLAB::flush() {

   assert(_state != flushed, "Attempt to flush PLAB twice");

   assert(top() <= end(), "pointers out of order");

   // If we were initialized to a zero sized lab, there is

   // nothing to flush

   if (_state == zero_size)

     return;

   // PLAB's never allocate the last aligned_header_size

   // so they can always fill with an array.

   HeapWord* tlab_end = end() + filler_header_size;

   typeArrayOop filler_oop = (typeArrayOop) top();

   filler_oop->set_mark(markOopDesc::prototype());

   filler_oop->set_klass(Universe::intArrayKlassObj());

   const size_t array_length =

     pointer_delta(tlab_end, top()) - typeArrayOopDesc::header_size(T_INT);

   assert( (array_length * (HeapWordSize/sizeof(jint))) < (size_t)max_jint, "array too big in PSPromotionLAB");

   filler_oop->set_length((int)(array_length * (HeapWordSize/sizeof(jint))));

 #ifdef ASSERT

   // Note that we actually DO NOT want to use the aligned header size!

   HeapWord* elt_words = ((HeapWord*)filler_oop) + typeArrayOopDesc::header_size(T_INT);

   Copy::fill_to_words(elt_words, array_length, 0xDEAABABE);

 #endif

   set_bottom(NULL);

   set_end(NULL);

   set_top(NULL);

   _state = flushed;

 }

 bool PSPromotionLAB::unallocate_object(oop obj) {

   assert(Universe::heap()->is_in(obj), "Object outside heap");

   if (contains(obj)) {

     HeapWord* object_end = (HeapWord*)obj + obj->size();

     assert(object_end <= top(), "Object crosses promotion LAB boundary");

     if (object_end == top()) {

       set_top((HeapWord*)obj);

       return true;

     }

   }

   return false;

 }

 // Fill all remaining lab space with an unreachable object.

 // The goal is to leave a contiguous parseable span of objects.

 void PSOldPromotionLAB::flush() {

   assert(_state != flushed, "Attempt to flush PLAB twice");

   assert(top() <= end(), "pointers out of order");

   if (_state == zero_size)

     return;

   HeapWord* obj = top();

   PSPromotionLAB::flush();

   assert(_start_array != NULL, "Sanity");

   _start_array->allocate_block(obj);

 }

 #ifdef ASSERT

 bool PSYoungPromotionLAB::lab_is_valid(MemRegion lab) {

   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();

   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");

   MutableSpace* to_space = heap->young_gen()->to_space();

   MemRegion used = to_space->used_region();

   if (used.contains(lab)) {

     return true;

   }

   return false;

 }

 bool PSOldPromotionLAB::lab_is_valid(MemRegion lab) {

   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();

   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");

   assert(_start_array->covered_region().contains(lab), "Sanity");

   PSOldGen* old_gen = heap->old_gen();

   MemRegion used = old_gen->object_space()->used_region();

   if (used.contains(lab)) {

     return true;

   }

   return false;

 }

 #endif /* ASSERT */