--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/serial/markSweep.cpp Wed May 13 15:16:06 2015 +0200
@@ -0,0 +1,407 @@
+/*
+ * Copyright (c) 1997, 2015, 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 "compiler/compileBroker.hpp"
+#include "gc/serial/markSweep.inline.hpp"
+#include "gc/shared/collectedHeap.inline.hpp"
+#include "gc/shared/gcTimer.hpp"
+#include "gc/shared/gcTrace.hpp"
+#include "oops/instanceKlass.inline.hpp"
+#include "oops/instanceMirrorKlass.inline.hpp"
+#include "oops/methodData.hpp"
+#include "oops/objArrayKlass.inline.hpp"
+#include "oops/oop.inline.hpp"
+
+uint MarkSweep::_total_invocations = 0;
+
+Stack<oop, mtGC> MarkSweep::_marking_stack;
+Stack<ObjArrayTask, mtGC> MarkSweep::_objarray_stack;
+
+Stack<oop, mtGC> MarkSweep::_preserved_oop_stack;
+Stack<markOop, mtGC> MarkSweep::_preserved_mark_stack;
+size_t MarkSweep::_preserved_count = 0;
+size_t MarkSweep::_preserved_count_max = 0;
+PreservedMark* MarkSweep::_preserved_marks = NULL;
+ReferenceProcessor* MarkSweep::_ref_processor = NULL;
+STWGCTimer* MarkSweep::_gc_timer = NULL;
+SerialOldTracer* MarkSweep::_gc_tracer = NULL;
+
+MarkSweep::FollowRootClosure MarkSweep::follow_root_closure;
+
+void MarkSweep::FollowRootClosure::do_oop(oop* p) { follow_root(p); }
+void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
+
+MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
+CLDToOopClosure MarkSweep::follow_cld_closure(&mark_and_push_closure);
+CLDToOopClosure MarkSweep::adjust_cld_closure(&adjust_pointer_closure);
+
+template <typename T>
+void MarkSweep::MarkAndPushClosure::do_oop_nv(T* p) { mark_and_push(p); }
+void MarkSweep::MarkAndPushClosure::do_oop(oop* p) { do_oop_nv(p); }
+void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { do_oop_nv(p); }
+
+void MarkSweep::follow_class_loader(ClassLoaderData* cld) {
+ MarkSweep::follow_cld_closure.do_cld(cld);
+}
+
+void InstanceKlass::oop_ms_follow_contents(oop obj) {
+ assert(obj != NULL, "can't follow the content of NULL object");
+ MarkSweep::follow_klass(this);
+
+ oop_oop_iterate_oop_maps<true>(obj, &MarkSweep::mark_and_push_closure);
+}
+
+void InstanceMirrorKlass::oop_ms_follow_contents(oop obj) {
+ InstanceKlass::oop_ms_follow_contents(obj);
+
+ // Follow the klass field in the mirror
+ Klass* klass = java_lang_Class::as_Klass(obj);
+ if (klass != NULL) {
+ // An anonymous class doesn't have its own class loader, so the call
+ // to follow_klass will mark and push its java mirror instead of the
+ // class loader. When handling the java mirror for an anonymous class
+ // we need to make sure its class loader data is claimed, this is done
+ // by calling follow_class_loader explicitly. For non-anonymous classes
+ // the call to follow_class_loader is made when the class loader itself
+ // is handled.
+ if (klass->oop_is_instance() && InstanceKlass::cast(klass)->is_anonymous()) {
+ MarkSweep::follow_class_loader(klass->class_loader_data());
+ } else {
+ MarkSweep::follow_klass(klass);
+ }
+ } else {
+ // If klass is NULL then this a mirror for a primitive type.
+ // We don't have to follow them, since they are handled as strong
+ // roots in Universe::oops_do.
+ assert(java_lang_Class::is_primitive(obj), "Sanity check");
+ }
+
+ oop_oop_iterate_statics<true>(obj, &MarkSweep::mark_and_push_closure);
+}
+
+void InstanceClassLoaderKlass::oop_ms_follow_contents(oop obj) {
+ InstanceKlass::oop_ms_follow_contents(obj);
+
+ ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data(obj);
+
+ // We must NULL check here, since the class loader
+ // can be found before the loader data has been set up.
+ if(loader_data != NULL) {
+ MarkSweep::follow_class_loader(loader_data);
+ }
+}
+
+template <class T>
+static void oop_ms_follow_contents_specialized(InstanceRefKlass* klass, oop obj) {
+ T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
+ T heap_oop = oopDesc::load_heap_oop(referent_addr);
+ debug_only(
+ if(TraceReferenceGC && PrintGCDetails) {
+ gclog_or_tty->print_cr("InstanceRefKlass::oop_ms_follow_contents_specialized " PTR_FORMAT, p2i(obj));
+ }
+ )
+ if (!oopDesc::is_null(heap_oop)) {
+ oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
+ if (!referent->is_gc_marked() &&
+ MarkSweep::ref_processor()->discover_reference(obj, klass->reference_type())) {
+ // reference was discovered, referent will be traversed later
+ klass->InstanceKlass::oop_ms_follow_contents(obj);
+ debug_only(
+ if(TraceReferenceGC && PrintGCDetails) {
+ gclog_or_tty->print_cr(" Non NULL enqueued " PTR_FORMAT, p2i(obj));
+ }
+ )
+ return;
+ } else {
+ // treat referent as normal oop
+ debug_only(
+ if(TraceReferenceGC && PrintGCDetails) {
+ gclog_or_tty->print_cr(" Non NULL normal " PTR_FORMAT, p2i(obj));
+ }
+ )
+ MarkSweep::mark_and_push(referent_addr);
+ }
+ }
+ T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
+ // Treat discovered as normal oop, if ref is not "active",
+ // i.e. if next is non-NULL.
+ T next_oop = oopDesc::load_heap_oop(next_addr);
+ if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active"
+ T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
+ debug_only(
+ if(TraceReferenceGC && PrintGCDetails) {
+ gclog_or_tty->print_cr(" Process discovered as normal "
+ PTR_FORMAT, p2i(discovered_addr));
+ }
+ )
+ MarkSweep::mark_and_push(discovered_addr);
+ }
+ // treat next as normal oop. next is a link in the reference queue.
+ debug_only(
+ if(TraceReferenceGC && PrintGCDetails) {
+ gclog_or_tty->print_cr(" Process next as normal " PTR_FORMAT, p2i(next_addr));
+ }
+ )
+ MarkSweep::mark_and_push(next_addr);
+ klass->InstanceKlass::oop_ms_follow_contents(obj);
+}
+
+void InstanceRefKlass::oop_ms_follow_contents(oop obj) {
+ if (UseCompressedOops) {
+ oop_ms_follow_contents_specialized<narrowOop>(this, obj);
+ } else {
+ oop_ms_follow_contents_specialized<oop>(this, obj);
+ }
+}
+
+template <class T>
+static void oop_ms_follow_contents_specialized(oop obj, int index) {
+ objArrayOop a = objArrayOop(obj);
+ const size_t len = size_t(a->length());
+ const size_t beg_index = size_t(index);
+ assert(beg_index < len || len == 0, "index too large");
+
+ const size_t stride = MIN2(len - beg_index, ObjArrayMarkingStride);
+ const size_t end_index = beg_index + stride;
+ T* const base = (T*)a->base();
+ T* const beg = base + beg_index;
+ T* const end = base + end_index;
+
+ // Push the non-NULL elements of the next stride on the marking stack.
+ for (T* e = beg; e < end; e++) {
+ MarkSweep::mark_and_push<T>(e);
+ }
+
+ if (end_index < len) {
+ MarkSweep::push_objarray(a, end_index); // Push the continuation.
+ }
+}
+
+void ObjArrayKlass::oop_ms_follow_contents(oop obj) {
+ assert (obj->is_array(), "obj must be array");
+ MarkSweep::follow_klass(this);
+ if (UseCompressedOops) {
+ oop_ms_follow_contents_specialized<narrowOop>(obj, 0);
+ } else {
+ oop_ms_follow_contents_specialized<oop>(obj, 0);
+ }
+}
+
+void TypeArrayKlass::oop_ms_follow_contents(oop obj) {
+ assert(obj->is_typeArray(),"must be a type array");
+ // Performance tweak: We skip iterating over the klass pointer since we
+ // know that Universe::TypeArrayKlass never moves.
+}
+
+void MarkSweep::follow_array(objArrayOop array, int index) {
+ if (UseCompressedOops) {
+ oop_ms_follow_contents_specialized<narrowOop>(array, index);
+ } else {
+ oop_ms_follow_contents_specialized<oop>(array, index);
+ }
+}
+
+void MarkSweep::follow_stack() {
+ do {
+ while (!_marking_stack.is_empty()) {
+ oop obj = _marking_stack.pop();
+ assert (obj->is_gc_marked(), "p must be marked");
+ follow_object(obj);
+ }
+ // Process ObjArrays one at a time to avoid marking stack bloat.
+ if (!_objarray_stack.is_empty()) {
+ ObjArrayTask task = _objarray_stack.pop();
+ follow_array(objArrayOop(task.obj()), task.index());
+ }
+ } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty());
+}
+
+MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
+
+void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
+
+void PreservedMark::adjust_pointer() {
+ MarkSweep::adjust_pointer(&_obj);
+}
+
+void PreservedMark::restore() {
+ _obj->set_mark(_mark);
+}
+
+// We preserve the mark which should be replaced at the end and the location
+// that it will go. Note that the object that this markOop belongs to isn't
+// currently at that address but it will be after phase4
+void MarkSweep::preserve_mark(oop obj, markOop mark) {
+ // We try to store preserved marks in the to space of the new generation since
+ // this is storage which should be available. Most of the time this should be
+ // sufficient space for the marks we need to preserve but if it isn't we fall
+ // back to using Stacks to keep track of the overflow.
+ if (_preserved_count < _preserved_count_max) {
+ _preserved_marks[_preserved_count++].init(obj, mark);
+ } else {
+ _preserved_mark_stack.push(mark);
+ _preserved_oop_stack.push(obj);
+ }
+}
+
+MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure;
+
+template <typename T>
+void MarkSweep::AdjustPointerClosure::do_oop_nv(T* p) { adjust_pointer(p); }
+void MarkSweep::AdjustPointerClosure::do_oop(oop* p) { do_oop_nv(p); }
+void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { do_oop_nv(p); }
+
+void MarkSweep::adjust_marks() {
+ assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),
+ "inconsistent preserved oop stacks");
+
+ // adjust the oops we saved earlier
+ for (size_t i = 0; i < _preserved_count; i++) {
+ _preserved_marks[i].adjust_pointer();
+ }
+
+ // deal with the overflow stack
+ StackIterator<oop, mtGC> iter(_preserved_oop_stack);
+ while (!iter.is_empty()) {
+ oop* p = iter.next_addr();
+ adjust_pointer(p);
+ }
+}
+
+void MarkSweep::restore_marks() {
+ assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(),
+ "inconsistent preserved oop stacks");
+ if (PrintGC && Verbose) {
+ gclog_or_tty->print_cr("Restoring " SIZE_FORMAT " marks",
+ _preserved_count + _preserved_oop_stack.size());
+ }
+
+ // restore the marks we saved earlier
+ for (size_t i = 0; i < _preserved_count; i++) {
+ _preserved_marks[i].restore();
+ }
+
+ // deal with the overflow
+ while (!_preserved_oop_stack.is_empty()) {
+ oop obj = _preserved_oop_stack.pop();
+ markOop mark = _preserved_mark_stack.pop();
+ obj->set_mark(mark);
+ }
+}
+
+MarkSweep::IsAliveClosure MarkSweep::is_alive;
+
+bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }
+
+MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
+
+void MarkSweep::KeepAliveClosure::do_oop(oop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
+void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
+
+void marksweep_init() {
+ MarkSweep::_gc_timer = new (ResourceObj::C_HEAP, mtGC) STWGCTimer();
+ MarkSweep::_gc_tracer = new (ResourceObj::C_HEAP, mtGC) SerialOldTracer();
+}
+
+int InstanceKlass::oop_ms_adjust_pointers(oop obj) {
+ int size = size_helper();
+ oop_oop_iterate_oop_maps<true>(obj, &MarkSweep::adjust_pointer_closure);
+ return size;
+}
+
+int InstanceMirrorKlass::oop_ms_adjust_pointers(oop obj) {
+ int size = oop_size(obj);
+ InstanceKlass::oop_ms_adjust_pointers(obj);
+
+ oop_oop_iterate_statics<true>(obj, &MarkSweep::adjust_pointer_closure);
+ return size;
+}
+
+int InstanceClassLoaderKlass::oop_ms_adjust_pointers(oop obj) {
+ return InstanceKlass::oop_ms_adjust_pointers(obj);
+}
+
+#ifdef ASSERT
+template <class T> static void trace_reference_gc(const char *s, oop obj,
+ T* referent_addr,
+ T* next_addr,
+ T* discovered_addr) {
+ if(TraceReferenceGC && PrintGCDetails) {
+ gclog_or_tty->print_cr("%s obj " PTR_FORMAT, s, p2i(obj));
+ gclog_or_tty->print_cr(" referent_addr/* " PTR_FORMAT " / "
+ PTR_FORMAT, p2i(referent_addr),
+ p2i(referent_addr ?
+ (address)oopDesc::load_decode_heap_oop(referent_addr) : NULL));
+ gclog_or_tty->print_cr(" next_addr/* " PTR_FORMAT " / "
+ PTR_FORMAT, p2i(next_addr),
+ p2i(next_addr ? (address)oopDesc::load_decode_heap_oop(next_addr) : NULL));
+ gclog_or_tty->print_cr(" discovered_addr/* " PTR_FORMAT " / "
+ PTR_FORMAT, p2i(discovered_addr),
+ p2i(discovered_addr ?
+ (address)oopDesc::load_decode_heap_oop(discovered_addr) : NULL));
+ }
+}
+#endif
+
+template <class T> void static adjust_object_specialized(oop obj) {
+ T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
+ MarkSweep::adjust_pointer(referent_addr);
+ T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
+ MarkSweep::adjust_pointer(next_addr);
+ T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
+ MarkSweep::adjust_pointer(discovered_addr);
+ debug_only(trace_reference_gc("InstanceRefKlass::oop_ms_adjust_pointers", obj,
+ referent_addr, next_addr, discovered_addr);)
+}
+
+int InstanceRefKlass::oop_ms_adjust_pointers(oop obj) {
+ int size = size_helper();
+ InstanceKlass::oop_ms_adjust_pointers(obj);
+
+ if (UseCompressedOops) {
+ adjust_object_specialized<narrowOop>(obj);
+ } else {
+ adjust_object_specialized<oop>(obj);
+ }
+ return size;
+}
+
+int ObjArrayKlass::oop_ms_adjust_pointers(oop obj) {
+ assert(obj->is_objArray(), "obj must be obj array");
+ objArrayOop a = objArrayOop(obj);
+ // Get size before changing pointers.
+ // Don't call size() or oop_size() since that is a virtual call.
+ int size = a->object_size();
+ oop_oop_iterate_elements<true>(a, &MarkSweep::adjust_pointer_closure);
+ return size;
+}
+
+int TypeArrayKlass::oop_ms_adjust_pointers(oop obj) {
+ assert(obj->is_typeArray(), "must be a type array");
+ typeArrayOop t = typeArrayOop(obj);
+ // Performance tweak: We skip iterating over the klass pointer since we
+ // know that Universe::TypeArrayKlass never moves.
+ return t->object_size();
+}