Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/shared/mutableSpace.cpp @ 266:2214b226b7f0
6724367: par compact could clear less young gen summary data
Reviewed-by: jmasa, apetrusenko
author | jcoomes |
---|---|
date | Fri, 11 Jul 2008 16:11:50 -0700 |
parents | 12eea04c8b06 |
children | 850fdf70db2b |
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/* * Copyright 2001-2007 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/_mutableSpace.cpp.incl" MutableSpace::MutableSpace(): ImmutableSpace(), _top(NULL) { _mangler = new MutableSpaceMangler(this); } MutableSpace::~MutableSpace() { delete _mangler; } void MutableSpace::initialize(MemRegion mr, bool clear_space, bool mangle_space) { HeapWord* bottom = mr.start(); HeapWord* end = mr.end(); assert(Universe::on_page_boundary(bottom) && Universe::on_page_boundary(end), "invalid space boundaries"); set_bottom(bottom); set_end(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(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(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(bool allow_dirty) { 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"); }