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8027553: Change the in_cset_fast_test functionality to use the G1BiasedArray abstraction

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Instead of using a manually managed array for the in_cset_fast_test array, use a G1BiasedArray instance.

Reviewed-by: brutisso, mgerdin
This commit is contained in:
Thomas Schatzl 2014-04-16 10:55:26 +02:00
parent f8088df0b4
commit aa00878260
3 changed files with 20 additions and 57 deletions
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46
hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp
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@ -28,6 +28,7 @@
#include "gc_implementation/g1/concurrentMark.hpp"
#include "gc_implementation/g1/evacuationInfo.hpp"
#include "gc_implementation/g1/g1AllocRegion.hpp"
#include "gc_implementation/g1/g1BiasedArray.hpp"
#include "gc_implementation/g1/g1HRPrinter.hpp"
#include "gc_implementation/g1/g1MonitoringSupport.hpp"
#include "gc_implementation/g1/g1RemSet.hpp"
@ -197,6 +198,16 @@ public:
bool do_object_b(oop p);
};
// Instances of this class are used for quick tests on whether a reference points
// into the collection set. Each of the array's elements denotes whether the
// corresponding region is in the collection set.
class G1FastCSetBiasedMappedArray : public G1BiasedMappedArray<bool> {
protected:
bool default_value() const { return false; }
public:
void clear() { G1BiasedMappedArray<bool>::clear(); }
};
class RefineCardTableEntryClosure;
class G1CollectedHeap : public SharedHeap {
@ -353,26 +364,10 @@ private:
// than the current allocation region.
size_t _summary_bytes_used;
// This is used for a quick test on whether a reference points into
// the collection set or not. Basically, we have an array, with one
// byte per region, and that byte denotes whether the corresponding
// region is in the collection set or not. The entry corresponding
// the bottom of the heap, i.e., region 0, is pointed to by
// _in_cset_fast_test_base. The _in_cset_fast_test field has been
// biased so that it actually points to address 0 of the address
// space, to make the test as fast as possible (we can simply shift
// the address to address into it, instead of having to subtract the
// bottom of the heap from the address before shifting it; basically
// it works in the same way the card table works).
bool* _in_cset_fast_test;
// The allocated array used for the fast test on whether a reference
// points into the collection set or not. This field is also used to
// free the array.
bool* _in_cset_fast_test_base;
// The length of the _in_cset_fast_test_base array.
uint _in_cset_fast_test_length;
// This array is used for a quick test on whether a reference points into
// the collection set or not. Each of the array's elements denotes whether the
// corresponding region is in the collection set or not.
G1FastCSetBiasedMappedArray _in_cset_fast_test;
volatile unsigned _gc_time_stamp;
@ -695,12 +690,7 @@ public:
// We register a region with the fast "in collection set" test. We
// simply set to true the array slot corresponding to this region.
void register_region_with_in_cset_fast_test(HeapRegion* r) {
assert(_in_cset_fast_test_base != NULL, "sanity");
assert(r->in_collection_set(), "invariant");
uint index = r->hrs_index();
assert(index < _in_cset_fast_test_length, "invariant");
assert(!_in_cset_fast_test_base[index], "invariant");
_in_cset_fast_test_base[index] = true;
_in_cset_fast_test.set_by_index(r->hrs_index(), true);
}
// This is a fast test on whether a reference points into the
@ -709,9 +699,7 @@ public:
inline bool in_cset_fast_test(oop obj);
void clear_cset_fast_test() {
assert(_in_cset_fast_test_base != NULL, "sanity");
memset(_in_cset_fast_test_base, false,
(size_t) _in_cset_fast_test_length * sizeof(bool));
_in_cset_fast_test.clear();
}
// This is called at the start of either a concurrent cycle or a Full