/*
* Copyright (c) 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.
*
*/
/////////////////////////////////////////////////////////////////
// Closures used by ConcurrentMarkSweepGeneration's collector
/////////////////////////////////////////////////////////////////
class ConcurrentMarkSweepGeneration;
class CMSBitMap;
class CMSMarkStack;
class CMSCollector;
class MarkFromRootsClosure;
class Par_MarkFromRootsClosure;
// Decode the oop and call do_oop on it.
#define DO_OOP_WORK_DEFN \
void do_oop(oop obj); \
template <class T> inline void do_oop_work(T* p) { \
T heap_oop = oopDesc::load_heap_oop(p); \
if (!oopDesc::is_null(heap_oop)) { \
oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); \
do_oop(obj); \
} \
}
class MarkRefsIntoClosure: public OopsInGenClosure {
private:
const MemRegion _span;
CMSBitMap* _bitMap;
const bool _should_do_nmethods;
protected:
DO_OOP_WORK_DEFN
public:
MarkRefsIntoClosure(MemRegion span, CMSBitMap* bitMap,
bool should_do_nmethods);
bool should_do_nmethods() { return _should_do_nmethods; }
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { MarkRefsIntoClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { MarkRefsIntoClosure::do_oop_work(p); }
bool do_header() { return true; }
Prefetch::style prefetch_style() {
return Prefetch::do_read;
}
};
// A variant of the above used in certain kinds of CMS
// marking verification.
class MarkRefsIntoVerifyClosure: public OopsInGenClosure {
private:
const MemRegion _span;
CMSBitMap* _verification_bm;
CMSBitMap* _cms_bm;
const bool _should_do_nmethods;
protected:
DO_OOP_WORK_DEFN
public:
MarkRefsIntoVerifyClosure(MemRegion span, CMSBitMap* verification_bm,
CMSBitMap* cms_bm, bool should_do_nmethods);
bool should_do_nmethods() { return _should_do_nmethods; }
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { MarkRefsIntoVerifyClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { MarkRefsIntoVerifyClosure::do_oop_work(p); }
bool do_header() { return true; }
Prefetch::style prefetch_style() {
return Prefetch::do_read;
}
};
// KlassRememberingOopClosure is used when marking of the permanent generation
// is being done. It adds fields to support revisiting of klasses
// for class unloading. _should_remember_klasses should be set to
// indicate if klasses should be remembered. Currently that is whenever
// CMS class unloading is turned on. The _revisit_stack is used
// to save the klasses for later processing.
class KlassRememberingOopClosure : public OopClosure {
protected:
CMSCollector* _collector;
CMSMarkStack* _revisit_stack;
bool const _should_remember_klasses;
public:
void check_remember_klasses() const PRODUCT_RETURN;
virtual const bool should_remember_klasses() const {
check_remember_klasses();
return _should_remember_klasses;
}
virtual void remember_klass(Klass* k);
KlassRememberingOopClosure(CMSCollector* collector,
ReferenceProcessor* rp,
CMSMarkStack* revisit_stack);
};
// Similar to KlassRememberingOopClosure for use when multiple
// GC threads will execute the closure.
class Par_KlassRememberingOopClosure : public KlassRememberingOopClosure {
public:
Par_KlassRememberingOopClosure(CMSCollector* collector,
ReferenceProcessor* rp,
CMSMarkStack* revisit_stack):
KlassRememberingOopClosure(collector, rp, revisit_stack) {}
virtual void remember_klass(Klass* k);
};
// The non-parallel version (the parallel version appears further below).
class PushAndMarkClosure: public KlassRememberingOopClosure {
private:
MemRegion _span;
CMSBitMap* _bit_map;
CMSBitMap* _mod_union_table;
CMSMarkStack* _mark_stack;
bool _concurrent_precleaning;
protected:
DO_OOP_WORK_DEFN
public:
PushAndMarkClosure(CMSCollector* collector,
MemRegion span,
ReferenceProcessor* rp,
CMSBitMap* bit_map,
CMSBitMap* mod_union_table,
CMSMarkStack* mark_stack,
CMSMarkStack* revisit_stack,
bool concurrent_precleaning);
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { PushAndMarkClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { PushAndMarkClosure::do_oop_work(p); }
bool do_header() { return true; }
Prefetch::style prefetch_style() {
return Prefetch::do_read;
}
// In support of class unloading
virtual const bool should_remember_mdo() const {
return false;
// return _should_remember_klasses;
}
virtual void remember_mdo(DataLayout* v);
};
// In the parallel case, the revisit stack, the bit map and the
// reference processor are currently all shared. Access to
// these shared mutable structures must use appropriate
// synchronization (for instance, via CAS). The marking stack
// used in the non-parallel case above is here replaced with
// an OopTaskQueue structure to allow efficient work stealing.
class Par_PushAndMarkClosure: public Par_KlassRememberingOopClosure {
private:
MemRegion _span;
CMSBitMap* _bit_map;
OopTaskQueue* _work_queue;
protected:
DO_OOP_WORK_DEFN
public:
Par_PushAndMarkClosure(CMSCollector* collector,
MemRegion span,
ReferenceProcessor* rp,
CMSBitMap* bit_map,
OopTaskQueue* work_queue,
CMSMarkStack* revisit_stack);
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { Par_PushAndMarkClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { Par_PushAndMarkClosure::do_oop_work(p); }
bool do_header() { return true; }
Prefetch::style prefetch_style() {
return Prefetch::do_read;
}
// In support of class unloading
virtual const bool should_remember_mdo() const {
return false;
// return _should_remember_klasses;
}
virtual void remember_mdo(DataLayout* v);
};
// The non-parallel version (the parallel version appears further below).
class MarkRefsIntoAndScanClosure: public OopsInGenClosure {
private:
MemRegion _span;
CMSBitMap* _bit_map;
CMSMarkStack* _mark_stack;
PushAndMarkClosure _pushAndMarkClosure;
CMSCollector* _collector;
Mutex* _freelistLock;
bool _yield;
// Whether closure is being used for concurrent precleaning
bool _concurrent_precleaning;
protected:
DO_OOP_WORK_DEFN
public:
MarkRefsIntoAndScanClosure(MemRegion span,
ReferenceProcessor* rp,
CMSBitMap* bit_map,
CMSBitMap* mod_union_table,
CMSMarkStack* mark_stack,
CMSMarkStack* revisit_stack,
CMSCollector* collector,
bool should_yield,
bool concurrent_precleaning);
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { MarkRefsIntoAndScanClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { MarkRefsIntoAndScanClosure::do_oop_work(p); }
bool do_header() { return true; }
Prefetch::style prefetch_style() {
return Prefetch::do_read;
}
void set_freelistLock(Mutex* m) {
_freelistLock = m;
}
virtual const bool should_remember_klasses() const {
return _pushAndMarkClosure.should_remember_klasses();
}
virtual void remember_klass(Klass* k) {
_pushAndMarkClosure.remember_klass(k);
}
private:
inline void do_yield_check();
void do_yield_work();
bool take_from_overflow_list();
};
// Tn this, the parallel avatar of MarkRefsIntoAndScanClosure, the revisit
// stack and the bitMap are shared, so access needs to be suitably
// sycnhronized. An OopTaskQueue structure, supporting efficient
// workstealing, replaces a CMSMarkStack for storing grey objects.
class Par_MarkRefsIntoAndScanClosure: public OopsInGenClosure {
private:
MemRegion _span;
CMSBitMap* _bit_map;
OopTaskQueue* _work_queue;
const uint _low_water_mark;
Par_PushAndMarkClosure _par_pushAndMarkClosure;
protected:
DO_OOP_WORK_DEFN
public:
Par_MarkRefsIntoAndScanClosure(CMSCollector* collector,
MemRegion span,
ReferenceProcessor* rp,
CMSBitMap* bit_map,
OopTaskQueue* work_queue,
CMSMarkStack* revisit_stack);
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { Par_MarkRefsIntoAndScanClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { Par_MarkRefsIntoAndScanClosure::do_oop_work(p); }
bool do_header() { return true; }
virtual const bool do_nmethods() const { return true; }
// When ScanMarkedObjectsAgainClosure is used,
// it passes [Par_]MarkRefsIntoAndScanClosure to oop_oop_iterate(),
// and this delegation is used.
virtual const bool should_remember_klasses() const {
return _par_pushAndMarkClosure.should_remember_klasses();
}
// See comment on should_remember_klasses() above.
virtual void remember_klass(Klass* k) {
_par_pushAndMarkClosure.remember_klass(k);
}
Prefetch::style prefetch_style() {
return Prefetch::do_read;
}
void trim_queue(uint size);
};
// This closure is used during the concurrent marking phase
// following the first checkpoint. Its use is buried in
// the closure MarkFromRootsClosure.
class PushOrMarkClosure: public KlassRememberingOopClosure {
private:
MemRegion _span;
CMSBitMap* _bitMap;
CMSMarkStack* _markStack;
HeapWord* const _finger;
MarkFromRootsClosure* const
_parent;
protected:
DO_OOP_WORK_DEFN
public:
PushOrMarkClosure(CMSCollector* cms_collector,
MemRegion span,
CMSBitMap* bitMap,
CMSMarkStack* markStack,
CMSMarkStack* revisitStack,
HeapWord* finger,
MarkFromRootsClosure* parent);
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { PushOrMarkClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { PushOrMarkClosure::do_oop_work(p); }
// In support of class unloading
virtual const bool should_remember_mdo() const {
return false;
// return _should_remember_klasses;
}
virtual void remember_mdo(DataLayout* v);
// Deal with a stack overflow condition
void handle_stack_overflow(HeapWord* lost);
private:
inline void do_yield_check();
};
// A parallel (MT) version of the above.
// This closure is used during the concurrent marking phase
// following the first checkpoint. Its use is buried in
// the closure Par_MarkFromRootsClosure.
class Par_PushOrMarkClosure: public Par_KlassRememberingOopClosure {
private:
MemRegion _whole_span;
MemRegion _span; // local chunk
CMSBitMap* _bit_map;
OopTaskQueue* _work_queue;
CMSMarkStack* _overflow_stack;
HeapWord* const _finger;
HeapWord** const _global_finger_addr;
Par_MarkFromRootsClosure* const
_parent;
protected:
DO_OOP_WORK_DEFN
public:
Par_PushOrMarkClosure(CMSCollector* cms_collector,
MemRegion span,
CMSBitMap* bit_map,
OopTaskQueue* work_queue,
CMSMarkStack* mark_stack,
CMSMarkStack* revisit_stack,
HeapWord* finger,
HeapWord** global_finger_addr,
Par_MarkFromRootsClosure* parent);
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { Par_PushOrMarkClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { Par_PushOrMarkClosure::do_oop_work(p); }
// In support of class unloading
virtual const bool should_remember_mdo() const {
return false;
// return _should_remember_klasses;
}
virtual void remember_mdo(DataLayout* v);
// Deal with a stack overflow condition
void handle_stack_overflow(HeapWord* lost);
private:
inline void do_yield_check();
};
// For objects in CMS generation, this closure marks
// given objects (transitively) as being reachable/live.
// This is currently used during the (weak) reference object
// processing phase of the CMS final checkpoint step, as
// well as during the concurrent precleaning of the discovered
// reference lists.
class CMSKeepAliveClosure: public KlassRememberingOopClosure {
private:
const MemRegion _span;
CMSMarkStack* _mark_stack;
CMSBitMap* _bit_map;
bool _concurrent_precleaning;
protected:
DO_OOP_WORK_DEFN
public:
CMSKeepAliveClosure(CMSCollector* collector, MemRegion span,
CMSBitMap* bit_map, CMSMarkStack* mark_stack,
CMSMarkStack* revisit_stack, bool cpc);
bool concurrent_precleaning() const { return _concurrent_precleaning; }
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { CMSKeepAliveClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { CMSKeepAliveClosure::do_oop_work(p); }
};
class CMSInnerParMarkAndPushClosure: public Par_KlassRememberingOopClosure {
private:
MemRegion _span;
OopTaskQueue* _work_queue;
CMSBitMap* _bit_map;
protected:
DO_OOP_WORK_DEFN
public:
CMSInnerParMarkAndPushClosure(CMSCollector* collector,
MemRegion span, CMSBitMap* bit_map,
CMSMarkStack* revisit_stack,
OopTaskQueue* work_queue);
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { CMSInnerParMarkAndPushClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { CMSInnerParMarkAndPushClosure::do_oop_work(p); }
};
// A parallel (MT) version of the above, used when
// reference processing is parallel; the only difference
// is in the do_oop method.
class CMSParKeepAliveClosure: public Par_KlassRememberingOopClosure {
private:
MemRegion _span;
OopTaskQueue* _work_queue;
CMSBitMap* _bit_map;
CMSInnerParMarkAndPushClosure
_mark_and_push;
const uint _low_water_mark;
void trim_queue(uint max);
protected:
DO_OOP_WORK_DEFN
public:
CMSParKeepAliveClosure(CMSCollector* collector, MemRegion span,
CMSBitMap* bit_map, CMSMarkStack* revisit_stack,
OopTaskQueue* work_queue);
virtual void do_oop(oop* p);
virtual void do_oop(narrowOop* p);
inline void do_oop_nv(oop* p) { CMSParKeepAliveClosure::do_oop_work(p); }
inline void do_oop_nv(narrowOop* p) { CMSParKeepAliveClosure::do_oop_work(p); }
};