Res SegAlloc(Seg *segReturn, SegClass klass, LocusPref pref,
Size size, Pool pool, ArgList args)
{
Res res;
Arena arena;
Seg seg;
Addr base;
void *p;
AVER(segReturn != NULL);
AVERT(SegClass, klass);
AVERT(LocusPref, pref);
AVER(size > (Size)0);
AVERT(Pool, pool);
arena = PoolArena(pool);
AVERT(Arena, arena);
AVER(SizeIsArenaGrains(size, arena));
/* allocate the memory from the arena */
res = ArenaAlloc(&base, pref, size, pool);
if (res != ResOK)
goto failArena;
/* allocate the segment object from the control pool */
res = ControlAlloc(&p, arena, klass->size);
if (res != ResOK)
goto failControl;
seg = p;
res = SegInit(seg, klass, pool, base, size, args);
if (res != ResOK)
goto failInit;
EVENT5(SegAlloc, arena, seg, SegBase(seg), size, pool);
*segReturn = seg;
return ResOK;
failInit:
ControlFree(arena, seg, klass->size);
failControl:
ArenaFree(base, size, pool);
failArena:
EVENT3(SegAllocFail, arena, size, pool);
return res;
}
static Res SegAbsInit(Seg seg, Pool pool, Addr base, Size size, ArgList args)
{
Arena arena;
Addr addr, limit;
Tract tract;
AVER(seg != NULL);
AVERT(Pool, pool);
arena = PoolArena(pool);
AVER(AddrIsArenaGrain(base, arena));
AVER(SizeIsArenaGrains(size, arena));
AVERT(ArgList, args);
NextMethod(Inst, Seg, init)(CouldBeA(Inst, seg));
limit = AddrAdd(base, size);
seg->limit = limit;
seg->rankSet = RankSetEMPTY;
seg->white = TraceSetEMPTY;
seg->nailed = TraceSetEMPTY;
seg->grey = TraceSetEMPTY;
seg->pm = AccessSetEMPTY;
seg->sm = AccessSetEMPTY;
seg->defer = WB_DEFER_INIT;
seg->depth = 0;
seg->queued = FALSE;
seg->firstTract = NULL;
RingInit(SegPoolRing(seg));
TRACT_FOR(tract, addr, arena, base, limit) {
AVERT(Tract, tract);
AVER(TractP(tract) == NULL);
AVER(!TractHasSeg(tract));
AVER(TractPool(tract) == pool);
AVER(TractWhite(tract) == TraceSetEMPTY);
TRACT_SET_SEG(tract, seg);
if (addr == base) {
AVER(seg->firstTract == NULL);
seg->firstTract = tract;
}
AVER(seg->firstTract != NULL);
}
Bool MFSCheck(MFS mfs)
{
Arena arena;
CHECKS(MFS, mfs);
CHECKC(MFSPool, mfs);
CHECKD(Pool, MFSPool(mfs));
CHECKC(MFSPool, mfs);
CHECKL(mfs->unitSize >= UNIT_MIN);
CHECKL(mfs->extendBy >= UNIT_MIN);
CHECKL(BoolCheck(mfs->extendSelf));
arena = PoolArena(MFSPool(mfs));
CHECKL(SizeIsArenaGrains(mfs->extendBy, arena));
CHECKL(SizeAlignUp(mfs->unroundedUnitSize, PoolAlignment(MFSPool(mfs))) ==
mfs->unitSize);
if(mfs->tractList != NULL) {
CHECKD_NOSIG(Tract, mfs->tractList);
}
CHECKL(mfs->free <= mfs->total);
CHECKL((mfs->total - mfs->free) % mfs->unitSize == 0);
return TRUE;
}
/* 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;
}
