Mercurial > hg > graal-compiler
diff src/share/vm/gc_implementation/shared/markSweep.hpp @ 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/shared/markSweep.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,245 @@ +/* + * Copyright 1997-2007 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. + * + */ + +class ReferenceProcessor; + +// MarkSweep takes care of global mark-compact garbage collection for a +// GenCollectedHeap using a four-phase pointer forwarding algorithm. All +// generations are assumed to support marking; those that can also support +// compaction. +// +// Class unloading will only occur when a full gc is invoked. + +// If VALIDATE_MARK_SWEEP is defined, the -XX:+ValidateMarkSweep flag will +// be operational, and will provide slow but comprehensive self-checks within +// the GC. This is not enabled by default in product or release builds, +// since the extra call to track_adjusted_pointer() in _adjust_pointer() +// would be too much overhead, and would disturb performance measurement. +// However, debug builds are sometimes way too slow to run GC tests! +#ifdef ASSERT +#define VALIDATE_MARK_SWEEP 1 +#endif +#ifdef VALIDATE_MARK_SWEEP +#define VALIDATE_MARK_SWEEP_ONLY(code) code +#else +#define VALIDATE_MARK_SWEEP_ONLY(code) +#endif + + +// declared at end +class PreservedMark; + +class MarkSweep : AllStatic { + // + // In line closure decls + // + + class FollowRootClosure: public OopsInGenClosure{ + public: + void do_oop(oop* p) { follow_root(p); } + virtual const bool do_nmethods() const { return true; } + }; + + class MarkAndPushClosure: public OopClosure { + public: + void do_oop(oop* p) { mark_and_push(p); } + virtual const bool do_nmethods() const { return true; } + }; + + class FollowStackClosure: public VoidClosure { + public: + void do_void() { follow_stack(); } + }; + + class AdjustPointerClosure: public OopsInGenClosure { + bool _is_root; + public: + AdjustPointerClosure(bool is_root) : _is_root(is_root) {} + void do_oop(oop* p) { _adjust_pointer(p, _is_root); } + }; + + // Used for java/lang/ref handling + class IsAliveClosure: public BoolObjectClosure { + public: + void do_object(oop p) { assert(false, "don't call"); } + bool do_object_b(oop p) { return p->is_gc_marked(); } + }; + + class KeepAliveClosure: public OopClosure { + public: + void do_oop(oop* p); + }; + + // + // Friend decls + // + + friend class AdjustPointerClosure; + friend class KeepAliveClosure; + friend class VM_MarkSweep; + friend void marksweep_init(); + + // + // Vars + // + protected: + // Traversal stack used during phase1 + static GrowableArray<oop>* _marking_stack; + // Stack for live klasses to revisit at end of marking phase + static GrowableArray<Klass*>* _revisit_klass_stack; + + // Space for storing/restoring mark word + static GrowableArray<markOop>* _preserved_mark_stack; + static GrowableArray<oop>* _preserved_oop_stack; + static size_t _preserved_count; + static size_t _preserved_count_max; + static PreservedMark* _preserved_marks; + + // Reference processing (used in ...follow_contents) + static ReferenceProcessor* _ref_processor; + +#ifdef VALIDATE_MARK_SWEEP + static GrowableArray<oop*>* _root_refs_stack; + static GrowableArray<oop> * _live_oops; + static GrowableArray<oop> * _live_oops_moved_to; + static GrowableArray<size_t>* _live_oops_size; + static size_t _live_oops_index; + static size_t _live_oops_index_at_perm; + static GrowableArray<oop*>* _other_refs_stack; + static GrowableArray<oop*>* _adjusted_pointers; + static bool _pointer_tracking; + static bool _root_tracking; + + // The following arrays are saved since the time of the last GC and + // assist in tracking down problems where someone has done an errant + // store into the heap, usually to an oop that wasn't properly + // handleized across a GC. If we crash or otherwise fail before the + // next GC, we can query these arrays to find out the object we had + // intended to do the store to (assuming it is still alive) and the + // offset within that object. Covered under RecordMarkSweepCompaction. + static GrowableArray<HeapWord*> * _cur_gc_live_oops; + static GrowableArray<HeapWord*> * _cur_gc_live_oops_moved_to; + static GrowableArray<size_t>* _cur_gc_live_oops_size; + static GrowableArray<HeapWord*> * _last_gc_live_oops; + static GrowableArray<HeapWord*> * _last_gc_live_oops_moved_to; + static GrowableArray<size_t>* _last_gc_live_oops_size; +#endif + + + // Non public closures + static IsAliveClosure is_alive; + static KeepAliveClosure keep_alive; + + // Class unloading. Update subklass/sibling/implementor links at end of marking phase. + static void follow_weak_klass_links(); + + // Debugging + static void trace(const char* msg) PRODUCT_RETURN; + + public: + // Public closures + static FollowRootClosure follow_root_closure; + static MarkAndPushClosure mark_and_push_closure; + static FollowStackClosure follow_stack_closure; + static AdjustPointerClosure adjust_root_pointer_closure; + static AdjustPointerClosure adjust_pointer_closure; + + // Reference Processing + static ReferenceProcessor* const ref_processor() { return _ref_processor; } + + // Call backs for marking + static void mark_object(oop obj); + static void follow_root(oop* p); // Mark pointer and follow contents. Empty marking + + // stack afterwards. + + static void mark_and_follow(oop* p); // Mark pointer and follow contents. + static void _mark_and_push(oop* p); // Mark pointer and push obj on + // marking stack. + + + static void mark_and_push(oop* p) { // Check mark and maybe push on + // marking stack + // assert(Universe::is_reserved_heap((oop)p), "we should only be traversing objects here"); + oop m = *p; + if (m != NULL && !m->mark()->is_marked()) { + _mark_and_push(p); + } + } + + static void follow_stack(); // Empty marking stack. + + + static void preserve_mark(oop p, markOop mark); // Save the mark word so it can be restored later + static void adjust_marks(); // Adjust the pointers in the preserved marks table + static void restore_marks(); // Restore the marks that we saved in preserve_mark + + static void _adjust_pointer(oop* p, bool isroot); + + static void adjust_root_pointer(oop* p) { _adjust_pointer(p, true); } + static void adjust_pointer(oop* p) { _adjust_pointer(p, false); } + +#ifdef VALIDATE_MARK_SWEEP + static void track_adjusted_pointer(oop* p, oop newobj, bool isroot); + static void check_adjust_pointer(oop* p); // Adjust this pointer + static void track_interior_pointers(oop obj); + static void check_interior_pointers(); + + static void reset_live_oop_tracking(bool at_perm); + static void register_live_oop(oop p, size_t size); + static void validate_live_oop(oop p, size_t size); + static void live_oop_moved_to(HeapWord* q, size_t size, HeapWord* compaction_top); + static void compaction_complete(); + + // Querying operation of RecordMarkSweepCompaction results. + // Finds and prints the current base oop and offset for a word + // within an oop that was live during the last GC. Helpful for + // tracking down heap stomps. + static void print_new_location_of_heap_address(HeapWord* q); +#endif + + // Call backs for class unloading + static void revisit_weak_klass_link(Klass* k); // Update subklass/sibling/implementor links at end of marking. +}; + + +class PreservedMark VALUE_OBJ_CLASS_SPEC { +private: + oop _obj; + markOop _mark; + +public: + void init(oop obj, markOop mark) { + _obj = obj; + _mark = mark; + } + + void adjust_pointer() { + MarkSweep::adjust_pointer(&_obj); + } + + void restore() { + _obj->set_mark(_mark); + } +};