src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp
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rev 6802 : imported patch refactor-heapregionseq
rev 6805 : imported patch commit-uncommit-within-heap
rev 6806 : imported patch mikael-suggestions
rev 6807 : imported patch bengt-suggestions
@@ -23,10 +23,11 @@
*/
#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_HPP
+#include "gc_implementation/g1/g1RegionToSpaceMapper.hpp"
#include "memory/memRegion.hpp"
#include "runtime/virtualspace.hpp"
#include "utilities/globalDefinitions.hpp"
// The CollectedHeap type requires subtypes to implement a method
@@ -104,10 +105,15 @@
// Same as above, but does not have any of the possible side effects
// discussed above.
inline HeapWord* block_start_const(const void* addr) const;
};
+class G1BlockOffsetSharedArrayMappingChangedListener : public G1MappingChangedListener {
+ public:
+ virtual void on_commit(uint start_idx, size_t num_regions);
+};
+
// This implementation of "G1BlockOffsetTable" divides the covered region
// into "N"-word subregions (where "N" = 2^"LogN". An array with an entry
// for each such subregion indicates how far back one must go to find the
// start of the chunk that includes the first word of the subregion.
//
@@ -123,94 +129,57 @@
friend class G1BlockOffsetArray;
friend class G1BlockOffsetArrayContigSpace;
friend class VMStructs;
private:
+ G1BlockOffsetSharedArrayMappingChangedListener _listener;
// The reserved region covered by the shared array.
MemRegion _reserved;
// End of the current committed region.
HeapWord* _end;
// Array for keeping offsets for retrieving object start fast given an
// address.
- VirtualSpace _vs;
u_char* _offset_array; // byte array keeping backwards offsets
- void check_index(size_t index, const char* msg) const {
- assert(index < _vs.committed_size(),
- err_msg("%s - "
- "index: " SIZE_FORMAT ", _vs.committed_size: " SIZE_FORMAT,
- msg, index, _vs.committed_size()));
- }
-
void check_offset(size_t offset, const char* msg) const {
assert(offset <= N_words,
err_msg("%s - "
"offset: " SIZE_FORMAT", N_words: %u",
msg, offset, (uint)N_words));
}
// Bounds checking accessors:
// For performance these have to devolve to array accesses in product builds.
- u_char offset_array(size_t index) const {
- check_index(index, "index out of range");
- return _offset_array[index];
- }
+ inline u_char offset_array(size_t index) const;
void set_offset_array(HeapWord* left, HeapWord* right, u_char offset);
- void set_offset_array(size_t index, u_char offset) {
- check_index(index, "index out of range");
- check_offset(offset, "offset too large");
+ void set_offset_array_raw(size_t index, u_char offset) {
_offset_array[index] = offset;
}
- void set_offset_array(size_t index, HeapWord* high, HeapWord* low) {
- check_index(index, "index out of range");
- assert(high >= low, "addresses out of order");
- check_offset(pointer_delta(high, low), "offset too large");
- _offset_array[index] = (u_char) pointer_delta(high, low);
- }
-
- void set_offset_array(size_t left, size_t right, u_char offset) {
- check_index(right, "right index out of range");
- assert(left <= right, "indexes out of order");
- size_t num_cards = right - left + 1;
- if (UseMemSetInBOT) {
- memset(&_offset_array[left], offset, num_cards);
- } else {
- size_t i = left;
- const size_t end = i + num_cards;
- for (; i < end; i++) {
- _offset_array[i] = offset;
- }
- }
- }
+ inline void set_offset_array(size_t index, u_char offset);
- void check_offset_array(size_t index, HeapWord* high, HeapWord* low) const {
- check_index(index, "index out of range");
- assert(high >= low, "addresses out of order");
- check_offset(pointer_delta(high, low), "offset too large");
- assert(_offset_array[index] == pointer_delta(high, low), "Wrong offset");
- }
+ inline void set_offset_array(size_t index, HeapWord* high, HeapWord* low);
+
+ inline void set_offset_array(size_t left, size_t right, u_char offset);
+
+ inline void check_offset_array(size_t index, HeapWord* high, HeapWord* low) const;
bool is_card_boundary(HeapWord* p) const;
+public:
+
// Return the number of slots needed for an offset array
// that covers mem_region_words words.
- // We always add an extra slot because if an object
- // ends on a card boundary we put a 0 in the next
- // offset array slot, so we want that slot always
- // to be reserved.
-
- size_t compute_size(size_t mem_region_words) {
- size_t number_of_slots = (mem_region_words / N_words) + 1;
- return ReservedSpace::page_align_size_up(number_of_slots);
+ static size_t compute_size(size_t mem_region_words) {
+ size_t number_of_slots = (mem_region_words / N_words);
+ return ReservedSpace::allocation_align_size_up(number_of_slots);
}
-public:
enum SomePublicConstants {
LogN = 9,
LogN_words = LogN - LogHeapWordSize,
N_bytes = 1 << LogN,
N_words = 1 << LogN_words
@@ -220,25 +189,25 @@
// "base + init_word_size". In the future, the table may be expanded
// (see "resize" below) up to the size of "_reserved" (which must be at
// least "init_word_size".) The contents of the initial table are
// undefined; it is the responsibility of the constituent
// G1BlockOffsetTable(s) to initialize cards.
- G1BlockOffsetSharedArray(MemRegion reserved, size_t init_word_size);
-
- // Notes a change in the committed size of the region covered by the
- // table. The "new_word_size" may not be larger than the size of the
- // reserved region this table covers.
- void resize(size_t new_word_size);
+ G1BlockOffsetSharedArray(MemRegion heap, G1RegionToSpaceMapper* storage);
void set_bottom(HeapWord* new_bottom);
// Return the appropriate index into "_offset_array" for "p".
inline size_t index_for(const void* p) const;
+ inline size_t index_for_raw(const void* p) const;
// Return the address indicating the start of the region corresponding to
// "index" in "_offset_array".
inline HeapWord* address_for_index(size_t index) const;
+ // Variant of address_for_index that does not check the index for validity.
+ inline HeapWord* address_for_index_raw(size_t index) const {
+ return _reserved.start() + (index << LogN_words);
+ }
};
// And here is the G1BlockOffsetTable subtype that uses the array.
class G1BlockOffsetArray: public G1BlockOffsetTable {
@@ -474,22 +443,28 @@
void alloc_block_work1(HeapWord* blk_start, HeapWord* blk_end) {
alloc_block_work2(&_next_offset_threshold, &_next_offset_index,
blk_start, blk_end);
}
+ // Variant of zero_bottom_entry that does not check for availability of the
+ // memory first.
+ void zero_bottom_entry_raw();
+ // Variant of initialize_threshold that does not check for availability of the
+ // memory first.
+ HeapWord* initialize_threshold_raw();
// Zero out the entry for _bottom (offset will be zero).
void zero_bottom_entry();
public:
G1BlockOffsetArrayContigSpace(G1BlockOffsetSharedArray* array, MemRegion mr);
// Initialize the threshold to reflect the first boundary after the
// bottom of the covered region.
HeapWord* initialize_threshold();
void reset_bot() {
- zero_bottom_entry();
- initialize_threshold();
+ zero_bottom_entry_raw();
+ initialize_threshold_raw();
}
// Return the next threshold, the point at which the table should be
// updated.
HeapWord* threshold() const { return _next_offset_threshold; }