src/share/vm/gc_implementation/g1/g1StringDedupTable.cpp

rev 6141 : [mq]: review_fixes

*** 67,84 ****
      return _length;
    }
  };
  
  //
! // Cache of deduplication table enties. This cache provides fast allocation and
! // reuse of table entries to lower the preasure on the underlaying allocator.
  // But more importantly, it provides fast/deferred freeing of table entries. This
  // is important because freeing of table entries is done during stop-the-world
! // phases and it is not uncommon for large number of String to be freed at once.
  // Tables entries that are freed during these phases are placed onto a freelist in
  // the cache. The deduplication thread, which executes in a concurrent phase, will
! // later reuse or free the underlaying memory for these entries.
  //
  // The cache allows for single-threaded allocations and multi-threaded frees.
  // Allocations are synchronized by StringDedupTable_lock as part of a table
  // modification.
  //
--- 67,84 ----
      return _length;
    }
  };
  
  //
! // Cache of deduplication table entries. This cache provides fast allocation and
! // reuse of table entries to lower the pressure on the underlying allocator.
  // But more importantly, it provides fast/deferred freeing of table entries. This
  // is important because freeing of table entries is done during stop-the-world
! // phases and it is not uncommon for large number of entries to be freed at once.
  // Tables entries that are freed during these phases are placed onto a freelist in
  // the cache. The deduplication thread, which executes in a concurrent phase, will
! // later reuse or free the underlying memory for these entries.
  //
  // The cache allows for single-threaded allocations and multi-threaded frees.
  // Allocations are synchronized by StringDedupTable_lock as part of a table
  // modification.
  //
*** 99,108 ****
--- 99,111 ----
    G1StringDedupEntry* alloc();
  
    // Insert a table entry into the cache freelist.
    void free(G1StringDedupEntry* entry, uint worker_id);
  
+   // Returns current number of entries in the cache.
+   size_t size();
+ 
    // If the cache has grown above the given max size, trim it down
    // and deallocate the memory occupied by trimmed of entries.
    void trim(size_t max_size);
  };
  
*** 131,140 ****
--- 134,151 ----
    entry->set_obj(NULL);
    entry->set_hash(0);
    _lists[worker_id].add(entry);
  }
  
+ size_t G1StringDedupEntryCache::size() {
+   size_t size = 0;
+   for (size_t i = 0; i < _nlists; i++) {
+     size += _lists[i].length();
+   }
+   return size;
+ }
+ 
  void G1StringDedupEntryCache::trim(size_t max_size) {
    size_t cache_size = 0;
    for (size_t i = 0; i < _nlists; i++) {
      G1StringDedupEntryFreeList* list = &_lists[i];
      cache_size += list->length();
*** 543,558 ****
  void G1StringDedupTable::print_statistics(outputStream* st) {
    st->print_cr(
      "   [Table]\n"
      "      [Memory Usage: "G1_STRDEDUP_BYTES_FORMAT_NS"]\n"
      "      [Size: "SIZE_FORMAT", Min: "SIZE_FORMAT", Max: "SIZE_FORMAT"]\n"
!     "      [Entries: "UINTX_FORMAT", Load: "G1_STRDEDUP_PERCENT_FORMAT_NS", Added: "UINTX_FORMAT", Removed: "UINTX_FORMAT"]\n"
      "      [Resize Count: "UINTX_FORMAT", Shrink Threshold: "UINTX_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT_NS"), Grow Threshold: "UINTX_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT_NS")]\n"
      "      [Rehash Count: "UINTX_FORMAT", Rehash Threshold: "UINTX_FORMAT", Hash Seed: 0x%x]\n"
      "      [Age Threshold: "UINTX_FORMAT"]",
!     G1_STRDEDUP_BYTES_PARAM(_table->_size * sizeof(G1StringDedupEntry*) + _table->_entries * sizeof(G1StringDedupEntry)),
      _table->_size, _min_size, _max_size,
!     _table->_entries, (double)_table->_entries / (double)_table->_size * 100.0, _entries_added, _entries_removed,
      _resize_count, _table->_shrink_threshold, _shrink_load_factor * 100.0, _table->_grow_threshold, _grow_load_factor * 100.0,
      _rehash_count, _rehash_threshold, _table->_hash_seed,
      StringDeduplicationAgeThreshold);
  }
--- 554,569 ----
  void G1StringDedupTable::print_statistics(outputStream* st) {
    st->print_cr(
      "   [Table]\n"
      "      [Memory Usage: "G1_STRDEDUP_BYTES_FORMAT_NS"]\n"
      "      [Size: "SIZE_FORMAT", Min: "SIZE_FORMAT", Max: "SIZE_FORMAT"]\n"
!     "      [Entries: "UINTX_FORMAT", Load: "G1_STRDEDUP_PERCENT_FORMAT_NS", Cached: " UINTX_FORMAT ", Added: "UINTX_FORMAT", Removed: "UINTX_FORMAT"]\n"
      "      [Resize Count: "UINTX_FORMAT", Shrink Threshold: "UINTX_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT_NS"), Grow Threshold: "UINTX_FORMAT"("G1_STRDEDUP_PERCENT_FORMAT_NS")]\n"
      "      [Rehash Count: "UINTX_FORMAT", Rehash Threshold: "UINTX_FORMAT", Hash Seed: 0x%x]\n"
      "      [Age Threshold: "UINTX_FORMAT"]",
!     G1_STRDEDUP_BYTES_PARAM(_table->_size * sizeof(G1StringDedupEntry*) + (_table->_entries + _entry_cache->size()) * sizeof(G1StringDedupEntry)),
      _table->_size, _min_size, _max_size,
!     _table->_entries, (double)_table->_entries / (double)_table->_size * 100.0, _entry_cache->size(), _entries_added, _entries_removed,
      _resize_count, _table->_shrink_threshold, _shrink_load_factor * 100.0, _table->_grow_threshold, _grow_load_factor * 100.0,
      _rehash_count, _rehash_threshold, _table->_hash_seed,
      StringDeduplicationAgeThreshold);
  }