Mercurial > hg > truffle
diff src/share/vm/gc_implementation/parallelScavenge/psPromotionLAB.cpp @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
---|---|
date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | ba764ed4b6f2 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/parallelScavenge/psPromotionLAB.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,162 @@ +/* + * Copyright 2002-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +#include "incls/_precompiled.incl" +#include "incls/_psPromotionLAB.cpp.incl" + +const size_t PSPromotionLAB::filler_header_size = align_object_size(typeArrayOopDesc::header_size(T_INT)); + +// 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); + + // 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 */