dalvik/vm/alloc/CardTable.h

   1 /*
   2  * Copyright (C) 2010 The Android Open Source Project
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 /*
  18  * Maintain a card table from the the write barrier. All writes of
  19  * non-NULL values to heap addresses should go through an entry in
  20  * WriteBarrier, and from there to here.
  21  */
  22
  23 #ifndef DALVIK_ALLOC_CARDTABLE_H_
  24 #define DALVIK_ALLOC_CARDTABLE_H_
  25
  26 #define GC_CARD_SHIFT 7
  27 #define GC_CARD_SIZE (1 << GC_CARD_SHIFT)
  28 #define GC_CARD_CLEAN 0
  29 #define GC_CARD_DIRTY 0x70
  30
  31 /*
  32  * Initializes the card table; must be called before any other
  33  * dvmCardTable*() functions.
  34  */
  35 bool dvmCardTableStartup(size_t heapMaximumSize, size_t growthLimit);
  36
  37 /*
  38  * Tears down the entire CardTable structure.
  39  */
  40 void dvmCardTableShutdown(void);
  41
  42 /*
  43  * Resets all of the bytes in the card table to clean.
  44  */
  45 void dvmClearCardTable(void);
  46
  47 /*
  48  * Returns the address of the relevent byte in the card table, given
  49  * an address on the heap.
  50  */
  51 u1 *dvmCardFromAddr(const void *addr);
  52
  53 /*
  54  * Returns the first address in the heap which maps to this card.
  55  */
  56 void *dvmAddrFromCard(const u1 *card);
  57
  58 /*
  59  * Returns true if addr points to a valid card.
  60  */
  61 bool dvmIsValidCard(const u1 *card);
  62
  63 /*
  64  * Set the card associated with the given address to GC_CARD_DIRTY.
  65  */
  66 void dvmMarkCard(const void *addr);
  67
  68 /*
  69  * Verifies that all gray objects are on a dirty card.
  70  */
  71 void dvmVerifyCardTable(void);
  72
  73 #endif  // DALVIK_ALLOC_CARDTABLE_H_