static Bool AMSSegRegionIsFree(Seg seg, Addr base, Addr limit)
{
AMSSeg amsseg = MustBeA(AMSSeg, seg);
Index baseIndex = PoolIndexOfAddr(SegBase(seg), SegPool(seg), base);
if (amsseg->allocTableInUse) {
Index limitIndex = PoolIndexOfAddr(SegBase(seg), SegPool(seg), limit);
return BTIsResRange(amsseg->allocTable, baseIndex, limitIndex);
} else {
return amsseg->firstFree <= baseIndex;
}
}
/* AMSTStressBufferedSeg -- Stress test for a buffered seg
*
* Test splitting or merging a buffered seg.
*
* .bmerge: A merge is performed when the segment had previously
* been split and the segment above meets the constraints (i.e. empty,
* not already attached to a buffer and similar colour)
*
* .bsplit: Whether or not a merge happpened, a split is performed if
* the limit of the buffered region is also the limit of an arena
* grain, and yet does not correspond to the segment limit, provided
* that the part of the segment above the buffer is all free.
*/
static void AMSTStressBufferedSeg(Seg seg, Buffer buffer)
{
AMSTSeg amstseg;
AMST amst;
Arena arena;
Addr limit;
Buffer segBuf;
AVERT(Seg, seg);
AVERT(Buffer, buffer);
AVER(SegBuffer(&segBuf, seg) && segBuf == buffer);
amstseg = Seg2AMSTSeg(seg);
AVERT(AMSTSeg, amstseg);
limit = BufferLimit(buffer);
arena = PoolArena(SegPool(seg));
amst = PoolAMST(SegPool(seg));
AVERT(AMST, amst);
if (amstseg->next != NULL) {
Seg segHi = AMSTSeg2Seg(amstseg->next);
if (AMSSegIsFree(segHi) && SegGrey(segHi) == SegGrey(seg)) {
/* .bmerge */
Seg mergedSeg;
Res res;
res = SegMerge(&mergedSeg, seg, segHi);
if (ResOK == res) {
amst->bmerges++;
printf("J");
} else {
/* deliberate fails only */
AVER(amst->failSegs);
}
}
}
if (SegLimit(seg) != limit &&
AddrIsArenaGrain(limit, arena) &&
AMSSegRegionIsFree(seg, limit, SegLimit(seg))) {
/* .bsplit */
Seg segLo, segHi;
Res res;
res = SegSplit(&segLo, &segHi, seg, limit);
if (ResOK == res) {
amst->bsplits++;
printf("C");
} else {
/* deliberate fails only */
AVER(amst->failSegs);
}
}
}
static void ArenaFormattedObjectsWalk(Arena arena, FormattedObjectsStepMethod f,
void *p, size_t s)
{
Seg seg;
FormattedObjectsStepClosure c;
AVERT(Arena, arena);
AVER(FUNCHECK(f));
AVER(f == ArenaFormattedObjectsStep);
/* p and s are arbitrary closures. */
/* Know that p is a FormattedObjectsStepClosure */
/* Know that s is 0 */
AVER(p != NULL);
AVER(s == 0);
c = p;
AVERT(FormattedObjectsStepClosure, c);
if (SegFirst(&seg, arena)) {
do {
Pool pool;
pool = SegPool(seg);
if (PoolHasAttr(pool, AttrFMT)) {
ShieldExpose(arena, seg);
PoolWalk(pool, seg, f, p, s);
ShieldCover(arena, seg);
}
} while(SegNext(&seg, arena, seg));
}
}
static Res RootsWalkFix(Pool pool, ScanState ss, Seg seg, Ref *refIO)
{
rootsStepClosure rsc;
Ref ref;
UNUSED(pool);
AVERT(ScanState, ss);
AVER(refIO != NULL);
rsc = ScanState2rootsStepClosure(ss);
AVERT(rootsStepClosure, rsc);
ref = *refIO;
/* If the segment isn't GCable then the ref is not to the heap and */
/* shouldn't be passed to the client. */
AVER(PoolHasAttr(SegPool(seg), AttrGC));
/* Call the client closure - .assume.rootaddr */
rsc->f((mps_addr_t*)refIO, (mps_root_t)rsc->root, rsc->p, rsc->s);
AVER(ref == *refIO); /* can walk object graph - but not modify it */
return ResOK;
}
void PoolBlacken(Pool pool, TraceSet traceSet, Seg seg)
{
AVERT(Pool, pool);
AVERT(TraceSet, traceSet);
AVERT(Seg, seg);
AVER(SegPool(seg) == pool);
Method(Pool, pool, blacken)(pool, traceSet, seg);
}
Res PoolWhiten(Pool pool, Trace trace, Seg seg)
{
AVERT(Pool, pool);
AVERT(Trace, trace);
AVERT(Seg, seg);
AVER(PoolArena(pool) == trace->arena);
AVER(SegPool(seg) == pool);
return Method(Pool, pool, whiten)(pool, trace, seg);
}
void PoolGrey(Pool pool, Trace trace, Seg seg)
{
AVERT(Pool, pool);
AVERT(Trace, trace);
AVERT(Seg, seg);
AVER(pool->arena == trace->arena);
AVER(SegPool(seg) == pool);
Method(Pool, pool, grey)(pool, trace, seg);
}
Res PoolAddrObject(Addr *pReturn, Pool pool, Seg seg, Addr addr)
{
AVER(pReturn != NULL);
AVERT(Pool, pool);
AVERT(Seg, seg);
AVER(pool == SegPool(seg));
AVER(SegBase(seg) <= addr);
AVER(addr < SegLimit(seg));
return Method(Pool, pool, addrObject)(pReturn, pool, seg, addr);
}
void BufferReassignSeg(Buffer buffer, Seg seg)
{
AVERT(Buffer, buffer);
AVERT(Seg, seg);
AVER(!BufferIsReset(buffer));
AVER(BufferBase(buffer) >= SegBase(seg));
AVER(BufferLimit(buffer) <= SegLimit(seg));
AVER(BufferPool(buffer) == SegPool(seg));
Method(Buffer, buffer, reassignSeg)(buffer, seg);
}
Res PoolFix(Pool pool, ScanState ss, Seg seg, Addr *refIO)
{
AVERT_CRITICAL(Pool, pool);
AVERT_CRITICAL(ScanState, ss);
AVERT_CRITICAL(Seg, seg);
AVER_CRITICAL(pool == SegPool(seg));
AVER_CRITICAL(refIO != NULL);
/* Should only be fixing references to white segments. */
AVER_CRITICAL(TraceSetInter(SegWhite(seg), ss->traces) != TraceSetEMPTY);
return pool->fix(pool, ss, seg, refIO);
}
/* AMSUnallocateRange -- set a range to be unallocated
*
* Used as a means of overriding the behaviour of AMSBufferFill.
* The code is similar to amsSegBufferEmpty.
*/
static void AMSUnallocateRange(AMS ams, Seg seg, Addr base, Addr limit)
{
AMSSeg amsseg;
Index baseIndex, limitIndex;
Count unallocatedGrains;
/* parameters checked by caller */
amsseg = Seg2AMSSeg(seg);
baseIndex = PoolIndexOfAddr(SegBase(seg), SegPool(seg), base);
limitIndex = PoolIndexOfAddr(SegBase(seg), SegPool(seg), limit);
if (amsseg->allocTableInUse) {
/* check that it's allocated */
AVER(BTIsSetRange(amsseg->allocTable, baseIndex, limitIndex));
BTResRange(amsseg->allocTable, baseIndex, limitIndex);
} else {
/* check that it's allocated */
AVER(limitIndex <= amsseg->firstFree);
if (limitIndex == amsseg->firstFree) /* is it at the end? */ {
amsseg->firstFree = baseIndex;
} else { /* start using allocTable */
amsseg->allocTableInUse = TRUE;
BTSetRange(amsseg->allocTable, 0, amsseg->firstFree);
if (amsseg->firstFree < amsseg->grains)
BTResRange(amsseg->allocTable, amsseg->firstFree, amsseg->grains);
BTResRange(amsseg->allocTable, baseIndex, limitIndex);
}
}
unallocatedGrains = limitIndex - baseIndex;
AVER(amsseg->bufferedGrains >= unallocatedGrains);
amsseg->freeGrains += unallocatedGrains;
amsseg->bufferedGrains -= unallocatedGrains;
PoolGenAccountForEmpty(ams->pgen, 0,
PoolGrainsSize(AMSPool(ams), unallocatedGrains),
FALSE);
}
/* AMSAllocateRange -- set a range to be allocated
*
* Used as a means of overriding the behaviour of AMSBufferFill.
* The code is similar to AMSUnallocateRange.
*/
static void AMSAllocateRange(AMS ams, Seg seg, Addr base, Addr limit)
{
AMSSeg amsseg;
Index baseIndex, limitIndex;
Count allocatedGrains;
/* parameters checked by caller */
amsseg = Seg2AMSSeg(seg);
baseIndex = PoolIndexOfAddr(SegBase(seg), SegPool(seg), base);
limitIndex = PoolIndexOfAddr(SegBase(seg), SegPool(seg), limit);
if (amsseg->allocTableInUse) {
/* check that it's not allocated */
AVER(BTIsResRange(amsseg->allocTable, baseIndex, limitIndex));
BTSetRange(amsseg->allocTable, baseIndex, limitIndex);
} else {
/* check that it's not allocated */
AVER(baseIndex >= amsseg->firstFree);
if (baseIndex == amsseg->firstFree) /* is it at the end? */ {
amsseg->firstFree = limitIndex;
} else { /* start using allocTable */
amsseg->allocTableInUse = TRUE;
BTSetRange(amsseg->allocTable, 0, amsseg->firstFree);
if (amsseg->firstFree < amsseg->grains)
BTResRange(amsseg->allocTable, amsseg->firstFree, amsseg->grains);
BTSetRange(amsseg->allocTable, baseIndex, limitIndex);
}
}
allocatedGrains = limitIndex - baseIndex;
AVER(amsseg->freeGrains >= allocatedGrains);
amsseg->freeGrains -= allocatedGrains;
amsseg->bufferedGrains += allocatedGrains;
PoolGenAccountForFill(ams->pgen, AddrOffset(base, limit));
}
void PoolReclaim(Pool pool, Trace trace, Seg seg)
{
AVERT_CRITICAL(Pool, pool);
AVERT_CRITICAL(Trace, trace);
AVERT_CRITICAL(Seg, seg);
AVER_CRITICAL(pool->arena == trace->arena);
AVER_CRITICAL(SegPool(seg) == pool);
/* There shouldn't be any grey things left for this trace. */
AVER_CRITICAL(!TraceSetIsMember(SegGrey(seg), trace));
/* Should only be reclaiming segments which are still white. */
AVER_CRITICAL(TraceSetIsMember(SegWhite(seg), trace));
Method(Pool, pool, reclaim)(pool, trace, seg);
}
Res PoolFixEmergency(Pool pool, ScanState ss, Seg seg, Addr *refIO)
{
Res res;
AVERT_CRITICAL(Pool, pool);
AVERT_CRITICAL(ScanState, ss);
AVERT_CRITICAL(Seg, seg);
AVER_CRITICAL(pool == SegPool(seg));
AVER_CRITICAL(refIO != NULL);
/* Should only be fixing references to white segments. */
AVER_CRITICAL(TraceSetInter(SegWhite(seg), ss->traces) != TraceSetEMPTY);
res = Method(Pool, pool, fixEmergency)(pool, ss, seg, refIO);
AVER_CRITICAL(res == ResOK);
return res;
}
static void MVFFFinish(Pool pool)
{
MVFF mvff;
Arena arena;
Seg seg;
Ring ring, node, nextNode;
AVERT(Pool, pool);
mvff = Pool2MVFF(pool);
AVERT(MVFF, mvff);
ring = PoolSegRing(pool);
RING_FOR(node, ring, nextNode) {
seg = SegOfPoolRing(node);
AVER(SegPool(seg) == pool);
SegFree(seg);
}
static Res amstSegSplit(Seg seg, Seg segHi,
Addr base, Addr mid, Addr limit)
{
AMST amst;
AMSTSeg amstseg, amstsegHi;
Res res;
AVERT(Seg, seg);
AVER(segHi != NULL); /* can't check fully, it's not initialized */
amstseg = Seg2AMSTSeg(seg);
amstsegHi = Seg2AMSTSeg(segHi);
AVERT(AMSTSeg, amstseg);
amst = PoolAMST(SegPool(seg));
/* Split the superclass fields via direct next-method call */
res = NextMethod(Seg, AMSTSeg, split)(seg, segHi, base, mid, limit);
if (res != ResOK)
goto failSuper;
if (AMSTFailOperation(amst)) {
amst->badSplits++;
printf("B");
goto failDeliberate;
}
/* Full initialization for segHi. */
amstsegHi->next = amstseg->next;
amstsegHi->prev = amstseg;
amstsegHi->sig = AMSTSegSig;
amstseg->next = amstsegHi;
AVERT(AMSTSeg, amstseg);
AVERT(AMSTSeg, amstsegHi);
amst->splits++;
printf("S");
return ResOK;
failDeliberate:
/* Call the anti-method. (see .fail) */
res = NextMethod(Seg, AMSTSeg, merge)(seg, segHi, base, mid, limit);
AVER(res == ResOK);
res = ResFAIL;
failSuper:
AVERT(AMSTSeg, amstseg);
return res;
}
/* amstSegMerge -- AMSTSeg merge method
*
* .fail: Test proper handling of the most complex failure cases
* by deliberately detecting failure sometimes after calling the
* next method. We handle the error by calling the anti-method.
* This isn't strictly safe <design/poolams#.split-merge.fail>.
* But we assume here that we won't run out of memory when calling the
* anti-method.
*/
static Res amstSegMerge(Seg seg, Seg segHi,
Addr base, Addr mid, Addr limit)
{
AMST amst;
AMSTSeg amstseg, amstsegHi;
Res res;
AVERT(Seg, seg);
AVERT(Seg, segHi);
amstseg = Seg2AMSTSeg(seg);
amstsegHi = Seg2AMSTSeg(segHi);
AVERT(AMSTSeg, amstseg);
AVERT(AMSTSeg, amstsegHi);
amst = PoolAMST(SegPool(seg));
/* Merge the superclass fields via direct next-method call */
res = NextMethod(Seg, AMSTSeg, merge)(seg, segHi, base, mid, limit);
if (res != ResOK)
goto failSuper;
if (AMSTFailOperation(amst)) {
amst->badMerges++;
printf("D");
goto failDeliberate;
}
amstseg->next = amstsegHi->next;
amstsegHi->sig = SigInvalid;
AVERT(AMSTSeg, amstseg);
amst->merges++;
printf("M");
return ResOK;
failDeliberate:
/* Call the anti-method (see .fail) */
res = NextMethod(Seg, AMSTSeg, split)(seg, segHi, base, mid, limit);
AVER(res == ResOK);
res = ResFAIL;
failSuper:
AVERT(AMSTSeg, amstseg);
AVERT(AMSTSeg, amstsegHi);
return res;
}
static void MVFFFinish(Pool pool)
{
MVFF mvff;
Arena arena;
Seg seg;
Ring ring, node, nextNode;
AVERT(Pool, pool);
mvff = Pool2MVFF(pool);
AVERT(MVFF, mvff);
/* Do this first, because the free list can use the segs in an emergency. */
CBSFinish(CBSOfMVFF(mvff));
ring = PoolSegRing(pool);
RING_FOR(node, ring, nextNode) {
seg = SegOfPoolRing(node);
AVER(SegPool(seg) == pool);
SegFree(seg);
}
Res PoolScan(Bool *totalReturn, ScanState ss, Pool pool, Seg seg)
{
AVER(totalReturn != NULL);
AVERT(ScanState, ss);
AVERT(Pool, pool);
AVERT(Seg, seg);
AVER(ss->arena == pool->arena);
/* The segment must belong to the pool. */
AVER(pool == SegPool(seg));
/* We check that either ss->rank is in the segment's
* ranks, or that ss->rank is exact. The check is more complicated if
* we actually have multiple ranks in a seg.
* See <code/trace.c#scan.conservative> */
AVER(ss->rank == RankEXACT || RankSetIsMember(SegRankSet(seg), ss->rank));
/* Should only scan segments which contain grey objects. */
AVER(TraceSetInter(SegGrey(seg), ss->traces) != TraceSetEMPTY);
return Method(Pool, pool, scan)(totalReturn, ss, pool, seg);
}
void SegFree(Seg seg)
{
Arena arena;
Pool pool;
Addr base;
Size size, structSize;
AVERT(Seg, seg);
pool = SegPool(seg);
AVERT(Pool, pool);
arena = PoolArena(pool);
AVERT(Arena, arena);
base = SegBase(seg);
size = SegSize(seg);
structSize = ClassOfPoly(Seg, seg)->size;
SegFinish(seg);
ControlFree(arena, seg, structSize);
ArenaFree(base, size, pool);
EVENT2(SegFree, arena, seg);
}
static Res ArenaRootsWalk(Globals arenaGlobals, mps_roots_stepper_t f,
void *p, size_t s)
{
Arena arena;
rootsStepClosureStruct rscStruct;
rootsStepClosure rsc = &rscStruct;
Trace trace;
ScanState ss;
Rank rank;
Res res;
Seg seg;
AVERT(Globals, arenaGlobals);
AVER(FUNCHECK(f));
/* p and s are arbitrary client-provided closure data. */
arena = GlobalsArena(arenaGlobals);
/* Scan all the roots with a minimal trace. Invoke the scanner with a */
/* rootsStepClosure, which is a subclass of ScanState and contains the */
/* client-provided closure. Supply a special fix method in order to */
/* call the client closure. This fix method must perform no tracing */
/* operations of its own. */
res = TraceCreate(&trace, arena, TraceStartWhyWALK);
/* Have to fail if no trace available. Unlikely due to .assume.parked. */
if (res != ResOK)
return res;
/* ArenaRootsWalk only passes references to GCable pools to the client. */
/* NOTE: I'm not sure why this is. RB 2012-07-24 */
if (SegFirst(&seg, arena)) {
do {
if (PoolHasAttr(SegPool(seg), AttrGC)) {
res = TraceAddWhite(trace, seg);
AVER(res == ResOK);
}
} while (SegNext(&seg, arena, seg));
}
/* Make the roots grey so that they are scanned */
res = RootsIterate(arenaGlobals, rootWalkGrey, trace);
/* Make this trace look like any other trace. */
arena->flippedTraces = TraceSetAdd(arena->flippedTraces, trace);
rootsStepClosureInit(rsc, arenaGlobals, trace, RootsWalkFix, f, p, s);
ss = rootsStepClosure2ScanState(rsc);
for(rank = RankAMBIG; rank < RankLIMIT; ++rank) {
ss->rank = rank;
AVERT(ScanState, ss);
res = RootsIterate(arenaGlobals, rootWalk, (void *)ss);
if (res != ResOK)
break;
}
/* Turn segments black again. */
if (SegFirst(&seg, arena)) {
do {
if (PoolHasAttr(SegPool(seg), AttrGC)) {
SegSetGrey(seg, TraceSetDel(SegGrey(seg), trace));
SegSetWhite(seg, TraceSetDel(SegWhite(seg), trace));
}
} while (SegNext(&seg, arena, seg));
}
rootsStepClosureFinish(rsc);
/* Make this trace look like any other finished trace. */
trace->state = TraceFINISHED;
TraceDestroy(trace);
AVER(!ArenaEmergency(arena)); /* There was no allocation. */
return res;
}
