duke@435: /*
stefank@2314:  * Copyright (c) 2002, 2010, 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: #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
stefank@2314: #include "gc_implementation/parallelScavenge/psPromotionLAB.hpp"
stefank@2314: #include "gc_implementation/shared/mutableSpace.hpp"
stefank@2314: #include "oops/oop.inline.hpp"
duke@435: 
coleenp@548: size_t PSPromotionLAB::filler_header_size;
duke@435: 
duke@435: // This is the shared initialization code. It sets up the basic pointers,
duke@435: // and allows enough extra space for a filler object. We call a virtual
duke@435: // method, "lab_is_valid()" to handle the different asserts the old/young
duke@435: // labs require.
duke@435: void PSPromotionLAB::initialize(MemRegion lab) {
duke@435:   assert(lab_is_valid(lab), "Sanity");
duke@435: 
duke@435:   HeapWord* bottom = lab.start();
duke@435:   HeapWord* end    = lab.end();
duke@435: 
duke@435:   set_bottom(bottom);
duke@435:   set_end(end);
duke@435:   set_top(bottom);
duke@435: 
coleenp@548:   // Initialize after VM starts up because header_size depends on compressed
coleenp@548:   // oops.
coleenp@548:   filler_header_size = align_object_size(typeArrayOopDesc::header_size(T_INT));
coleenp@548: 
duke@435:   // We can be initialized to a zero size!
duke@435:   if (free() > 0) {
duke@435:     if (ZapUnusedHeapArea) {
duke@435:       debug_only(Copy::fill_to_words(top(), free()/HeapWordSize, badHeapWord));
duke@435:     }
duke@435: 
duke@435:     // NOTE! We need to allow space for a filler object.
duke@435:     assert(lab.word_size() >= filler_header_size, "lab is too small");
duke@435:     end = end - filler_header_size;
duke@435:     set_end(end);
duke@435: 
duke@435:     _state = needs_flush;
duke@435:   } else {
duke@435:     _state = zero_size;
duke@435:   }
duke@435: 
duke@435:   assert(this->top() <= this->end(), "pointers out of order");
duke@435: }
duke@435: 
duke@435: // Fill all remaining lab space with an unreachable object.
duke@435: // The goal is to leave a contiguous parseable span of objects.
duke@435: void PSPromotionLAB::flush() {
duke@435:   assert(_state != flushed, "Attempt to flush PLAB twice");
duke@435:   assert(top() <= end(), "pointers out of order");
duke@435: 
duke@435:   // If we were initialized to a zero sized lab, there is
duke@435:   // nothing to flush
duke@435:   if (_state == zero_size)
duke@435:     return;
duke@435: 
duke@435:   // PLAB's never allocate the last aligned_header_size
duke@435:   // so they can always fill with an array.
duke@435:   HeapWord* tlab_end = end() + filler_header_size;
duke@435:   typeArrayOop filler_oop = (typeArrayOop) top();
duke@435:   filler_oop->set_mark(markOopDesc::prototype());
duke@435:   filler_oop->set_klass(Universe::intArrayKlassObj());
duke@435:   const size_t array_length =
duke@435:     pointer_delta(tlab_end, top()) - typeArrayOopDesc::header_size(T_INT);
duke@435:   assert( (array_length * (HeapWordSize/sizeof(jint))) < (size_t)max_jint, "array too big in PSPromotionLAB");
duke@435:   filler_oop->set_length((int)(array_length * (HeapWordSize/sizeof(jint))));
duke@435: 
duke@435: #ifdef ASSERT
duke@435:   // Note that we actually DO NOT want to use the aligned header size!
duke@435:   HeapWord* elt_words = ((HeapWord*)filler_oop) + typeArrayOopDesc::header_size(T_INT);
duke@435:   Copy::fill_to_words(elt_words, array_length, 0xDEAABABE);
duke@435: #endif
duke@435: 
duke@435:   set_bottom(NULL);
duke@435:   set_end(NULL);
duke@435:   set_top(NULL);
duke@435: 
duke@435:   _state = flushed;
duke@435: }
duke@435: 
stefank@3181: bool PSPromotionLAB::unallocate_object(HeapWord* obj, size_t obj_size) {
duke@435:   assert(Universe::heap()->is_in(obj), "Object outside heap");
duke@435: 
duke@435:   if (contains(obj)) {
stefank@3181:     HeapWord* object_end = obj + obj_size;
stefank@3181:     assert(object_end == top(), "Not matching last allocation");
duke@435: 
stefank@3181:     set_top(obj);
stefank@3181:     return true;
duke@435:   }
duke@435: 
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: // Fill all remaining lab space with an unreachable object.
duke@435: // The goal is to leave a contiguous parseable span of objects.
duke@435: void PSOldPromotionLAB::flush() {
duke@435:   assert(_state != flushed, "Attempt to flush PLAB twice");
duke@435:   assert(top() <= end(), "pointers out of order");
duke@435: 
duke@435:   if (_state == zero_size)
duke@435:     return;
duke@435: 
duke@435:   HeapWord* obj = top();
duke@435: 
duke@435:   PSPromotionLAB::flush();
duke@435: 
duke@435:   assert(_start_array != NULL, "Sanity");
duke@435: 
duke@435:   _start_array->allocate_block(obj);
duke@435: }
duke@435: 
duke@435: #ifdef ASSERT
duke@435: 
duke@435: bool PSYoungPromotionLAB::lab_is_valid(MemRegion lab) {
duke@435:   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435:   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435: 
duke@435:   MutableSpace* to_space = heap->young_gen()->to_space();
duke@435:   MemRegion used = to_space->used_region();
duke@435:   if (used.contains(lab)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: bool PSOldPromotionLAB::lab_is_valid(MemRegion lab) {
duke@435:   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435:   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435:   assert(_start_array->covered_region().contains(lab), "Sanity");
duke@435: 
duke@435:   PSOldGen* old_gen = heap->old_gen();
duke@435:   MemRegion used = old_gen->object_space()->used_region();
duke@435: 
duke@435:   if (used.contains(lab)) {
duke@435:     return true;
duke@435:   }
duke@435: 
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: #endif /* ASSERT */