Exemplo n.º 1
0
/* MVFFFreeSegs -- Free segments from given range
 *
 * Given a free range, attempts to find entire segments within
 * it, and returns them to the arena, updating total size counter.
 *
 * This is usually called immediately after MVFFAddToFreeList.
 * It is not combined with MVFFAddToFreeList because the latter
 * is also called when new segments are added under MVFFAlloc.
 */
static void MVFFFreeSegs(MVFF mvff, Addr base, Addr limit)
{
  Seg seg = NULL;       /* suppress "may be used uninitialized" */
  Arena arena;
  Bool b;
  Addr segLimit;  /* limit of the current segment when iterating */
  Addr segBase;   /* base of the current segment when iterating */
  Res res;

  AVERT(MVFF, mvff);
  AVER(base < limit);
  /* Could profitably AVER that the given range is free, */
  /* but the CBS doesn't provide that facility. */

  if (AddrOffset(base, limit) < mvff->minSegSize)
    return; /* not large enough for entire segments */

  arena = PoolArena(MVFF2Pool(mvff));
  b = SegOfAddr(&seg, arena, base);
  AVER(b);

  segBase = SegBase(seg);
  segLimit = SegLimit(seg);

  while(segLimit <= limit) { /* segment ends in range */
    if (segBase >= base) { /* segment starts in range */
      /* Must remove from free list first, in case free list */
      /* is using inline data structures. */
      res = CBSDelete(CBSOfMVFF(mvff), segBase, segLimit);
      AVER(res == ResOK);
      mvff->free -= AddrOffset(segBase, segLimit);
      mvff->total -= AddrOffset(segBase, segLimit);
      SegFree(seg);
    }

    /* Avoid calling SegNext if the next segment would fail */
    /* the loop test, mainly because there might not be a */
    /* next segment. */
    if (segLimit == limit) /* segment ends at end of range */
      break;

    b = SegNext(&seg, arena, segBase);
    AVER(b);
    segBase = SegBase(seg);
    segLimit = SegLimit(seg);
  }

  return;
}
Exemplo n.º 2
0
/* MVFFFreeSegs -- Free segments from given range
 *
 * Given a free range, attempts to find entire segments within
 * it, and returns them to the arena, updating total size counter.
 *
 * This is usually called immediately after MVFFAddToFreeList.
 * It is not combined with MVFFAddToFreeList because the latter
 * is also called when new segments are added under MVFFAlloc.
 */
static void MVFFFreeSegs(MVFF mvff, Addr base, Addr limit)
{
  Seg seg = NULL;       /* suppress "may be used uninitialized" */
  Arena arena;
  Bool b;
  Addr segLimit;  /* limit of the current segment when iterating */
  Addr segBase;   /* base of the current segment when iterating */
  Res res;

  AVERT(MVFF, mvff);
  AVER(base < limit);
  /* Could profitably AVER that the given range is free, */
  /* but the CBS doesn't provide that facility. */

  if (AddrOffset(base, limit) < mvff->minSegSize)
    return; /* not large enough for entire segments */

  arena = PoolArena(MVFF2Pool(mvff));
  b = SegOfAddr(&seg, arena, base);
  AVER(b);

  segBase = SegBase(seg);
  segLimit = SegLimit(seg);

  while(segLimit <= limit) { /* segment ends in range */
    if (segBase >= base) { /* segment starts in range */
      RangeStruct range, oldRange;
      RangeInit(&range, segBase, segLimit);

      res = CBSDelete(&oldRange, CBSOfMVFF(mvff), &range);
      if (res == ResOK) {
        mvff->free -= RangeSize(&range);
      } else if (ResIsAllocFailure(res)) {
        /* CBS ran out of memory for splay nodes, which must mean that
         * there were fragments on both sides: see
         * <design/cbs/#function.cbs.delete.fail>. Handle this by
         * deleting the whole of oldRange (which requires no
         * allocation) and re-inserting the fragments. */
        RangeStruct oldRange2;
        res = CBSDelete(&oldRange2, CBSOfMVFF(mvff), &oldRange);
        AVER(res == ResOK);
        AVER(RangesEqual(&oldRange2, &oldRange));
        mvff->free -= RangeSize(&oldRange);
        AVER(RangeBase(&oldRange) != segBase);
        {
          Addr leftBase = RangeBase(&oldRange);
          Addr leftLimit = segBase;
          res = MVFFAddToFreeList(&leftBase, &leftLimit, mvff);
        }
        AVER(RangeLimit(&oldRange) != segLimit);
        {
          Addr rightBase = segLimit;
          Addr rightLimit = RangeLimit(&oldRange);
          res = MVFFAddToFreeList(&rightBase, &rightLimit, mvff);
        }
      } else if (res == ResFAIL) {
        /* Not found in the CBS: must be found in the Freelist. */
        res = FreelistDelete(&oldRange, FreelistOfMVFF(mvff), &range);
        AVER(res == ResOK);
        mvff->free -= RangeSize(&range);
      }

      AVER(res == ResOK);
      AVER(RangesNest(&oldRange, &range));

      /* Can't free the segment earlier, because if it was on the
       * Freelist rather than the CBS then it likely contains data
       * that needs to be read in order to update the Freelist. */
      SegFree(seg);
      mvff->total -= RangeSize(&range);
    }

    /* Avoid calling SegNext if the next segment would fail */
    /* the loop test, mainly because there might not be a */
    /* next segment. */
    if (segLimit == limit) /* segment ends at end of range */
      break;

    b = SegFindAboveAddr(&seg, arena, segBase);
    AVER(b);
    segBase = SegBase(seg);
    segLimit = SegLimit(seg);
  }

  return;
}
Exemplo n.º 3
0
static void allocate(FBMState state, Addr base, Addr limit)
{
  Res res;
  Index ib, il;                  /* Indexed for base and limit */
  Bool isFree;
  RangeStruct range, oldRange;
  Addr outerBase, outerLimit;    /* interval containing [ib, il) */

  ib = indexOfAddr(state, base);
  il = indexOfAddr(state, limit);

  isFree = BTIsResRange(state->allocTable, ib, il);

  NAllocateTried++;

  if (isFree) {
    Size left, right, total;       /* Sizes of block and two fragments */

    outerBase =
      addrOfIndex(state, lastEdge(state->allocTable, ArraySize, ib));
    outerLimit =
      addrOfIndex(state, nextEdge(state->allocTable, ArraySize, il - 1));

    left = AddrOffset(outerBase, base);
    right = AddrOffset(limit, outerLimit);
    total = AddrOffset(outerBase, outerLimit);

    /* TODO: check these values */
    UNUSED(left);
    UNUSED(right);
    UNUSED(total);
  } else {
    outerBase = outerLimit = NULL;
  }

  RangeInit(&range, base, limit);
  switch (state->type) {
  case FBMTypeCBS:
    res = CBSDelete(&oldRange, state->the.cbs, &range);
    break;
  case FBMTypeFreelist:
    res = FreelistDelete(&oldRange, state->the.fl, &range);
    break;
  default:
    fail();
    return;
  }

  if (verbose) {
    printf("allocate: [%p,%p) -- %s\n",
           (void *)base, (void *)limit, isFree ? "succeed" : "fail");
    describe(state);
  }

  if (!isFree) {
    die_expect((mps_res_t)res, MPS_RES_FAIL,
               "Succeeded in deleting allocated block");
  } else { /* isFree */
    die_expect((mps_res_t)res, MPS_RES_OK,
               "failed to delete free block");
    Insist(RangeBase(&oldRange) == outerBase);
    Insist(RangeLimit(&oldRange) == outerLimit);
    NAllocateSucceeded++;
    BTSetRange(state->allocTable, ib, il);
  }
}
Exemplo n.º 4
0
static void allocate(CBS cbs, Addr block, BT allocTable,
                     Addr base, Addr limit)
{
  Res res;
  Index ib, il;                  /* Indexed for base and limit */
  Bool isFree;

  ib = indexOfAddr(block, base);
  il = indexOfAddr(block, limit);

  isFree = BTIsResRange(allocTable, ib, il);
 
  /*
  printf("allocate: [%p, %p) -- %s\n",
         base, limit, isFree ? "succeed" : "fail");
  */

  NAllocateTried++;

  if (isFree) {
    Addr outerBase, outerLimit;    /* interval containing [ib, il) */
    Size left, right, total;       /* Sizes of block and two fragments */

    outerBase =
      addrOfIndex(block, lastEdge(allocTable, ArraySize, ib));
    outerLimit =
      addrOfIndex(block, nextEdge(allocTable, ArraySize, il - 1));

    left = AddrOffset(outerBase, base);
    right = AddrOffset(limit, outerLimit);
    total = AddrOffset(outerBase, outerLimit);

    /* based on detailed knowledge of CBS behaviour */
    checkExpectations();
    if (total >= MinSize && left < MinSize && right < MinSize) {
      if (left == (Size)0 && right == (Size)0) {
        expectCallback(&CallbackDelete, total, (Addr)0, (Addr)0);
      } else if (left >= right) {
        expectCallback(&CallbackDelete, total, outerBase, base);
      } else {
        expectCallback(&CallbackDelete, total, limit, outerLimit);
      }
    } else if (left >= MinSize && right >= MinSize) {
      if (left >= right) {
        expectCallback(&CallbackShrink, total, outerBase, base);
        expectCallback(&CallbackNew, (Size)0, limit, outerLimit);
      } else {
        expectCallback(&CallbackNew, (Size)0, outerBase, base);
        expectCallback(&CallbackShrink, total, limit, outerLimit);
      }
    } else if (total >= MinSize) {
      if (left >= right) {
        Insist(left >= MinSize);
        Insist(right < MinSize);
        expectCallback(&CallbackShrink, total, outerBase, base);
      } else {
        Insist(left < MinSize);
        Insist(right >= MinSize);
        expectCallback(&CallbackShrink, total, limit, outerLimit);
      }
    }
  }

  res = CBSDelete(cbs, base, limit);

  if (!isFree) {
    die_expect((mps_res_t)res, MPS_RES_FAIL,
               "Succeeded in deleting allocated block");
  } else { /* isFree */
    die_expect((mps_res_t)res, MPS_RES_OK,
               "failed to delete free block");
    NAllocateSucceeded++;
    BTSetRange(allocTable, ib, il);
    checkExpectations();
  }
}