static void segBufAttach(Buffer buffer, Addr base, Addr limit,
Addr init, Size size)
{
SegBuf segbuf = MustBeA(SegBuf, buffer);
Seg seg = NULL; /* suppress "may be used uninitialized" */
Arena arena;
Bool found;
/* Other parameters are consistency checked in BufferAttach */
UNUSED(init);
UNUSED(size);
arena = BufferArena(buffer);
found = SegOfAddr(&seg, arena, base);
AVER(found);
AVER(segbuf->seg == NULL);
AVER(!SegHasBuffer(seg));
AVER(SegBase(seg) <= base);
AVER(limit <= SegLimit(seg));
/* attach the buffer to the segment */
SegSetBuffer(seg, buffer);
segbuf->seg = seg;
AVERT(SegBuf, segbuf);
}
void ArenaRestoreProtection(Globals globals)
{
Ring node, next;
Arena arena;
arena = GlobalsArena(globals);
RING_FOR(node, GlobalsRememberedSummaryRing(globals), next) {
RememberedSummaryBlock block =
RING_ELT(RememberedSummaryBlock, globalRing, node);
size_t i;
for(i = 0; i < RememberedSummaryBLOCK; ++ i) {
Seg seg;
Bool b;
if(block->the[i].base == (Addr)0) {
AVER(block->the[i].summary == RefSetUNIV);
continue;
}
b = SegOfAddr(&seg, arena, block->the[i].base);
if(b && SegBase(seg) == block->the[i].base) {
AVER(IsA(GCSeg, seg));
SegSetSummary(seg, block->the[i].summary);
} else {
/* Either seg has gone or moved, both of which are */
/* client errors. */
NOTREACHED;
}
}
}
/* 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;
}
/* LDReset -- reset a dependency to empty
*
* .reset.sync: This does not need to be synchronized with LDAge
* because if the epoch advances after it is read the dependency
* will simply include movement for more time than necessary.
*/
void LDReset(mps_ld_t ld, Arena arena)
{
Bool b;
Seg seg;
AVER(ld != NULL);
AVERT(Arena, arena);
b = SegOfAddr(&seg, arena, (Addr)ld);
if (b)
ShieldExpose(arena, seg); /* .ld.access */
ld->_epoch = arena->epoch;
ld->_rs = RefSetEMPTY;
if (b)
ShieldCover(arena, seg);
}
/* 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;
}
/* AMSTBufferFill -- the pool class buffer fill method
*
* Calls next method - but possibly splits or merges the chosen
* segment.
*
* .merge: A merge is performed when the next method returns the
* entire segment, this segment had previously been split from the
* segment below, and the segment below is appropriately similar
* (i.e. not already attached to a buffer and similarly coloured)
*
* .split: If we're not merging, a split is performed if the next method
* returns the entire segment, and yet lower half of the segment would
* meet the request.
*/
static Res AMSTBufferFill(Addr *baseReturn, Addr *limitReturn,
Pool pool, Buffer buffer, Size size)
{
Addr base, limit;
Arena arena;
AMS ams;
AMST amst;
Bool b;
Seg seg;
AMSTSeg amstseg;
Res res;
AVERT(Pool, pool);
AVER(baseReturn != NULL);
AVER(limitReturn != NULL);
/* other parameters are checked by next method */
arena = PoolArena(pool);
ams = PoolAMS(pool);
amst = PoolAMST(pool);
/* call next method */
res = NextMethod(Pool, AMSTPool, bufferFill)(&base, &limit, pool, buffer, size);
if (res != ResOK)
return res;
b = SegOfAddr(&seg, arena, base);
AVER(b);
amstseg = Seg2AMSTSeg(seg);
if (SegLimit(seg) == limit && SegBase(seg) == base) {
if (amstseg->prev != NULL) {
Seg segLo = AMSTSeg2Seg(amstseg->prev);
if (!SegHasBuffer(segLo) &&
SegGrey(segLo) == SegGrey(seg) &&
SegWhite(segLo) == SegWhite(seg)) {
/* .merge */
Seg mergedSeg;
Res mres;
AMSUnallocateRange(ams, seg, base, limit);
mres = SegMerge(&mergedSeg, segLo, seg);
if (ResOK == mres) { /* successful merge */
AMSAllocateRange(ams, mergedSeg, base, limit);
/* leave range as-is */
} else { /* failed to merge */
AVER(amst->failSegs); /* deliberate fails only */
AMSAllocateRange(ams, seg, base, limit);
}
}
} else {
Size half = SegSize(seg) / 2;
if (half >= size && SizeIsArenaGrains(half, arena)) {
/* .split */
Addr mid = AddrAdd(base, half);
Seg segLo, segHi;
Res sres;
AMSUnallocateRange(ams, seg, mid, limit);
sres = SegSplit(&segLo, &segHi, seg, mid);
if (ResOK == sres) { /* successful split */
limit = mid; /* range is lower segment */
} else { /* failed to split */
AVER(amst->failSegs); /* deliberate fails only */
AMSAllocateRange(ams, seg, mid, limit);
}
}
}
}
*baseReturn = base;
*limitReturn = limit;
return ResOK;
}
