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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* published by the Free Software Foundation.
*
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef SHARE_GC_SHARED_PRESERVEDMARKS_HPP
#define SHARE_GC_SHARED_PRESERVEDMARKS_HPP
#include "memory/allocation.hpp"
#include "memory/padded.hpp"
#include "oops/oop.hpp"
#include "utilities/stack.hpp"
class WorkerTask;
class PreservedMarksSet;
class WorkerThreads;
class PreservedMarks {
private:
class OopAndMarkWord {
private:
oop _o;
markWord _m;
public:
OopAndMarkWord(oop obj, markWord m) : _o(obj), _m(m) { }
oop get_oop() {
return _o; }
inline void set_mark()
const;
void set_oop(oop obj) { _o = obj; }
};
typedef Stack<OopAndMarkWord, mtGC> OopAndMarkWordStack;
OopAndMarkWordStack _stack;
inline bool should_preserve_mark(oop obj, markWord m)
const;
public:
size_t size()
const {
return _stack.size(); }
inline void push_if_necessary(oop obj, markWord m);
inline void push_always(oop obj, markWord m);
// Iterate over the stack, restore all preserved marks, and
// reclaim the memory taken up by the stack segments.
void restore();
// Iterate over the stack, adjust all preserved marks according
// to their forwarding location stored in the mark.
void adjust_during_full_gc();
void restore_and_increment(
volatile size_t*
const _total_size_addr);
// Assert the stack is empty and has no cached segments.
void assert_empty() PRODUCT_RETURN;
inline PreservedMarks();
~PreservedMarks() { assert_empty(); }
};
class PreservedMarksSet :
public CHeapObj<mtGC> {
private:
// true -> _stacks will be allocated in the C heap
// false -> _stacks will be allocated in the resource arena
const bool _in_c_heap;
// Number of stacks we have allocated (typically, one stack per GC worker).
// This should be >= 1 if the stacks have been initialized,
// or == 0 if they have not.
uint _num;
// Stack array (typically, one stack per GC worker) of length _num.
// This should be != NULL if the stacks have been initialized,
// or == NULL if they have not.
Padded<PreservedMarks>* _stacks;
public:
uint num()
const {
return _num; }
// Return the i'th stack.
PreservedMarks* get(uint i = 0)
const {
assert(_num > 0 && _stacks != NULL,
"stacks should have been initialized");
assert(i < _num,
"pre-condition");
return (_stacks + i);
}
// Allocate stack array.
void init(uint num);
// Iterate over all stacks, restore all preserved marks, and reclaim
// the memory taken up by the stack segments using the given WorkerThreads. If the WorkerThreads
// is NULL, perform the work serially in the current thread.
void restore(WorkerThreads* workers);
WorkerTask* create_task();
// Reclaim stack array.
void reclaim();
// Assert all the stacks are empty and have no cached segments.
void assert_empty() PRODUCT_RETURN;
PreservedMarksSet(
bool in_c_heap)
: _in_c_heap(in_c_heap), _num(0), _stacks(NULL) { }
~PreservedMarksSet() {
assert(_stacks == NULL && _num == 0,
"stacks should have been reclaimed");
}
};
#endif // SHARE_GC_SHARED_PRESERVEDMARKS_HPP
