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Java example source code file (psPromotionLAB.cpp)
The psPromotionLAB.cpp Java example source code/* * 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(HeapWord* obj, size_t obj_size) { assert(Universe::heap()->is_in(obj), "Object outside heap"); if (contains(obj)) { HeapWord* object_end = obj + obj_size; assert(object_end == top(), "Not matching last allocation"); set_top(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 */ Other Java examples (source code examples)Here is a short list of links related to this Java psPromotionLAB.cpp source code file: |
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