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emacs/mps/code/poolmv2.c
Gareth Rees aabe4992eb Compile out statistic declarations in non-statistical varieties (at the cost of some syntax checking). 
Add some missing STATISTIC guards where statistics are used.
Add design documentation.
Avoid unnecessary distinction between STATISTIC and STATISTIC_STAT (both result in statements).

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/* poolmv2.c: MANUAL VARIABLE-SIZED TEMPORAL POOL
*
* $Id$
* Copyright (c) 2001-2014 Ravenbrook Limited. See end of file for license.
*
* .purpose: A manual-variable pool designed to take advantage of
* placement according to predicted deathtime.
*
* .design: See <design/poolmvt/>.
*/
#include "mpm.h"
#include "poolmv2.h"
#include "mpscmvt.h"
#include "abq.h"
#include "cbs.h"
#include "failover.h"
#include "freelist.h"
#include "meter.h"
#include "range.h"
SRCID(poolmv2, "$Id$");
/* Signatures */
#define MVTSig ((Sig)0x5193F299) /* SIGnature MVT */
/* Private prototypes */
typedef struct MVTStruct *MVT;
static void MVTVarargs(ArgStruct args[MPS_ARGS_MAX], va_list varargs);
static Res MVTInit(Pool pool, ArgList arg);
static Bool MVTCheck(MVT mvt);
static void MVTFinish(Pool pool);
static Res MVTBufferFill(Addr *baseReturn, Addr *limitReturn,
Pool pool, Buffer buffer, Size minSize);
static void MVTBufferEmpty(Pool pool, Buffer buffer, Addr base, Addr limit);
static void MVTFree(Pool pool, Addr base, Size size);
static Res MVTDescribe(Pool pool, mps_lib_FILE *stream, Count depth);
static Size MVTTotalSize(Pool pool);
static Size MVTFreeSize(Pool pool);
static Res MVTSegAlloc(Seg *segReturn, MVT mvt, Size size);
static void MVTSegFree(MVT mvt, Seg seg);
static Bool MVTReturnSegs(MVT mvt, Range range, Arena arena);
static Res MVTInsert(MVT mvt, Addr base, Addr limit);
static Res MVTDelete(MVT mvt, Addr base, Addr limit);
static void MVTRefillABQIfEmpty(MVT mvt, Size size);
static Res MVTContingencySearch(Addr *baseReturn, Addr *limitReturn,
MVT mvt, Size min);
static Bool MVTCheckFit(Addr base, Addr limit, Size min, Arena arena);
static ABQ MVTABQ(MVT mvt);
static Land MVTFreePrimary(MVT mvt);
static Land MVTFreeSecondary(MVT mvt);
static Land MVTFreeLand(MVT mvt);
/* Types */
typedef struct MVTStruct
{
PoolStruct poolStruct;
CBSStruct cbsStruct; /* The coalescing block structure */
FreelistStruct flStruct; /* The emergency free list structure */
FailoverStruct foStruct; /* The fail-over mechanism */
ABQStruct abqStruct; /* The available block queue */
/* <design/poolmvt/#arch.parameters> */
Size minSize; /* Pool parameter */
Size meanSize; /* Pool parameter */
Size maxSize; /* Pool parameter */
Count fragLimit; /* Pool parameter */
/* <design/poolmvt/#arch.overview.abq.reuse.size> */
Size reuseSize; /* Size at which blocks are recycled */
/* <design/poolmvt/#arch.ap.fill.size> */
Size fillSize; /* Size of pool segments */
/* <design/poolmvt/#arch.contingency> */
Size availLimit; /* Limit on available */
/* <design/poolmvt/#impl.c.free.merge.segment.overflow> */
Bool abqOverflow; /* ABQ dropped some candidates */
/* <design/poolmvt/#arch.ap.no-fit>.* */
Bool splinter; /* Saved splinter */
Addr splinterBase; /* Saved splinter base */
Addr splinterLimit; /* Saved splinter size */
/* pool accounting --- one of these first four is redundant, but
size and available are used to implement fragmentation policy */
Size size; /* size of segs in pool */
Size allocated; /* bytes allocated to mutator */
Size available; /* bytes available for allocation */
Size unavailable; /* bytes lost to fragmentation */
/* pool meters*/
METER_DECL(segAllocs)
METER_DECL(segFrees)
METER_DECL(bufferFills)
METER_DECL(bufferEmpties)
METER_DECL(poolFrees)
METER_DECL(poolSize)
METER_DECL(poolAllocated)
METER_DECL(poolAvailable)
METER_DECL(poolUnavailable)
METER_DECL(poolUtilization)
/* abq meters */
METER_DECL(finds)
METER_DECL(overflows)
METER_DECL(underflows)
METER_DECL(refills)
METER_DECL(refillPushes)
METER_DECL(returns)
/* fragmentation meters */
METER_DECL(perfectFits)
METER_DECL(firstFits)
METER_DECL(secondFits)
METER_DECL(failures)
/* contingency meters */
METER_DECL(emergencyContingencies)
METER_DECL(fragLimitContingencies)
METER_DECL(contingencySearches)
METER_DECL(contingencyHardSearches)
/* splinter meters */
METER_DECL(splinters)
METER_DECL(splintersUsed)
METER_DECL(splintersDropped)
METER_DECL(sawdust)
/* exception meters */
METER_DECL(exceptions)
METER_DECL(exceptionSplinters)
METER_DECL(exceptionReturns)
Sig sig;
} MVTStruct;
DEFINE_POOL_CLASS(MVTPoolClass, this)
{
INHERIT_CLASS(this, AbstractBufferPoolClass);
this->name = "MVT";
this->size = sizeof(MVTStruct);
this->offset = offsetof(MVTStruct, poolStruct);
this->varargs = MVTVarargs;
this->init = MVTInit;
this->finish = MVTFinish;
this->free = MVTFree;
this->bufferFill = MVTBufferFill;
this->bufferEmpty = MVTBufferEmpty;
this->totalSize = MVTTotalSize;
this->freeSize = MVTFreeSize;
this->describe = MVTDescribe;
AVERT(PoolClass, this);
}
/* Macros */
#define PoolMVT(pool) PARENT(MVTStruct, poolStruct, pool)
#define MVTPool(mvt) (&(mvt)->poolStruct)
/* Accessors */
static ABQ MVTABQ(MVT mvt)
{
return &mvt->abqStruct;
}
static Land MVTFreePrimary(MVT mvt)
{
return CBSLand(&mvt->cbsStruct);
}
static Land MVTFreeSecondary(MVT mvt)
{
return FreelistLand(&mvt->flStruct);
}
static Land MVTFreeLand(MVT mvt)
{
return FailoverLand(&mvt->foStruct);
}
/* Methods */
/* MVTVarargs -- decode obsolete varargs */
static void MVTVarargs(ArgStruct args[MPS_ARGS_MAX], va_list varargs)
{
args[0].key = MPS_KEY_MIN_SIZE;
args[0].val.size = va_arg(varargs, Size);
args[1].key = MPS_KEY_MEAN_SIZE;
args[1].val.size = va_arg(varargs, Size);
args[2].key = MPS_KEY_MAX_SIZE;
args[2].val.size = va_arg(varargs, Size);
args[3].key = MPS_KEY_MVT_RESERVE_DEPTH;
args[3].val.count = va_arg(varargs, Count);
/* Divide the old "percentage" argument by 100, fixing job003319. */
args[4].key = MPS_KEY_MVT_FRAG_LIMIT;
args[4].val.d = (double)va_arg(varargs, Count) / 100.0;
args[5].key = MPS_KEY_ARGS_END;
AVERT(ArgList, args);
}
/* MVTInit -- initialize an MVT pool
*
* Parameters are:
* minSize, meanSize, maxSize, reserveDepth, fragLimit
*/
ARG_DEFINE_KEY(MVT_MIN_SIZE, Size);
ARG_DEFINE_KEY(MVT_MEAN_SIZE, Size);
ARG_DEFINE_KEY(MVT_MAX_SIZE, Size);
ARG_DEFINE_KEY(MVT_RESERVE_DEPTH, Count);
ARG_DEFINE_KEY(MVT_FRAG_LIMIT, double);
static Res MVTInit(Pool pool, ArgList args)
{
Arena arena;
Size align = MVT_ALIGN_DEFAULT;
Size minSize = MVT_MIN_SIZE_DEFAULT;
Size meanSize = MVT_MEAN_SIZE_DEFAULT;
Size maxSize = MVT_MAX_SIZE_DEFAULT;
Count reserveDepth = MVT_RESERVE_DEPTH_DEFAULT;
Count fragLimit = MVT_FRAG_LIMIT_DEFAULT;
Size reuseSize, fillSize;
Count abqDepth;
MVT mvt;
Res res;
ArgStruct arg;
AVERT(Pool, pool);
mvt = PoolMVT(pool);
/* can't AVERT mvt, yet */
arena = PoolArena(pool);
AVERT(Arena, arena);
if (ArgPick(&arg, args, MPS_KEY_ALIGN))
align = arg.val.align;
if (ArgPick(&arg, args, MPS_KEY_MIN_SIZE))
minSize = arg.val.size;
if (ArgPick(&arg, args, MPS_KEY_MEAN_SIZE))
meanSize = arg.val.size;
if (ArgPick(&arg, args, MPS_KEY_MAX_SIZE))
maxSize = arg.val.size;
if (ArgPick(&arg, args, MPS_KEY_MVT_RESERVE_DEPTH))
reserveDepth = arg.val.count;
if (ArgPick(&arg, args, MPS_KEY_MVT_FRAG_LIMIT)) {
/* pending complete fix for job003319 */
AVER(0 <= arg.val.d);
AVER(arg.val.d <= 1);
fragLimit = (Count)(arg.val.d * 100);
}
AVERT(Align, align);
/* This restriction on the alignment is necessary because of the use
of a Freelist to store the free address ranges in low-memory
situations. See <design/freelist/#impl.grain.align>. */
AVER(AlignIsAligned(align, FreelistMinimumAlignment));
AVER(align <= ArenaGrainSize(arena));
AVER(0 < minSize);
AVER(minSize <= meanSize);
AVER(meanSize <= maxSize);
AVER(reserveDepth > 0);
AVER(fragLimit <= 100);
/* TODO: More sanity checks possible? */
/* see <design/poolmvt/#arch.parameters> */
fillSize = SizeArenaGrains(maxSize, arena);
/* see <design/poolmvt/#arch.fragmentation.internal> */
reuseSize = 2 * fillSize;
abqDepth = (reserveDepth * meanSize + reuseSize - 1) / reuseSize;
/* keep the abq from being useless */
if (abqDepth < 3)
abqDepth = 3;
res = LandInit(MVTFreePrimary(mvt), CBSFastLandClassGet(), arena, align, mvt,
mps_args_none);
if (res != ResOK)
goto failFreePrimaryInit;
res = LandInit(MVTFreeSecondary(mvt), FreelistLandClassGet(), arena, align,
mvt, mps_args_none);
if (res != ResOK)
goto failFreeSecondaryInit;
MPS_ARGS_BEGIN(foArgs) {
MPS_ARGS_ADD(foArgs, FailoverPrimary, MVTFreePrimary(mvt));
MPS_ARGS_ADD(foArgs, FailoverSecondary, MVTFreeSecondary(mvt));
res = LandInit(MVTFreeLand(mvt), FailoverLandClassGet(), arena, align, mvt,
foArgs);
} MPS_ARGS_END(foArgs);
if (res != ResOK)
goto failFreeLandInit;
res = ABQInit(arena, MVTABQ(mvt), (void *)mvt, abqDepth, sizeof(RangeStruct));
if (res != ResOK)
goto failABQInit;
pool->alignment = align;
mvt->reuseSize = reuseSize;
mvt->fillSize = fillSize;
mvt->abqOverflow = FALSE;
mvt->minSize = minSize;
mvt->meanSize = meanSize;
mvt->maxSize = maxSize;
mvt->fragLimit = fragLimit;
mvt->splinter = FALSE;
mvt->splinterBase = (Addr)0;
mvt->splinterLimit = (Addr)0;
/* accounting */
mvt->size = 0;
mvt->allocated = 0;
mvt->available = 0;
mvt->availLimit = 0;
mvt->unavailable = 0;
/* meters*/
METER_INIT(mvt->segAllocs, "segment allocations", (void *)mvt);
METER_INIT(mvt->segFrees, "segment frees", (void *)mvt);
METER_INIT(mvt->bufferFills, "buffer fills", (void *)mvt);
METER_INIT(mvt->bufferEmpties, "buffer empties", (void *)mvt);
METER_INIT(mvt->poolFrees, "pool frees", (void *)mvt);
METER_INIT(mvt->poolSize, "pool size", (void *)mvt);
METER_INIT(mvt->poolAllocated, "pool allocated", (void *)mvt);
METER_INIT(mvt->poolAvailable, "pool available", (void *)mvt);
METER_INIT(mvt->poolUnavailable, "pool unavailable", (void *)mvt);
METER_INIT(mvt->poolUtilization, "pool utilization", (void *)mvt);
METER_INIT(mvt->finds, "ABQ finds", (void *)mvt);
METER_INIT(mvt->overflows, "ABQ overflows", (void *)mvt);
METER_INIT(mvt->underflows, "ABQ underflows", (void *)mvt);
METER_INIT(mvt->refills, "ABQ refills", (void *)mvt);
METER_INIT(mvt->refillPushes, "ABQ refill pushes", (void *)mvt);
METER_INIT(mvt->returns, "ABQ returns", (void *)mvt);
METER_INIT(mvt->perfectFits, "perfect fits", (void *)mvt);
METER_INIT(mvt->firstFits, "first fits", (void *)mvt);
METER_INIT(mvt->secondFits, "second fits", (void *)mvt);
METER_INIT(mvt->failures, "failures", (void *)mvt);
METER_INIT(mvt->emergencyContingencies, "emergency contingencies",
(void *)mvt);
METER_INIT(mvt->fragLimitContingencies,
"fragmentation limit contingencies", (void *)mvt);
METER_INIT(mvt->contingencySearches, "contingency searches", (void *)mvt);
METER_INIT(mvt->contingencyHardSearches,
"contingency hard searches", (void *)mvt);
METER_INIT(mvt->splinters, "splinters", (void *)mvt);
METER_INIT(mvt->splintersUsed, "splinters used", (void *)mvt);
METER_INIT(mvt->splintersDropped, "splinters dropped", (void *)mvt);
METER_INIT(mvt->sawdust, "sawdust", (void *)mvt);
METER_INIT(mvt->exceptions, "exceptions", (void *)mvt);
METER_INIT(mvt->exceptionSplinters, "exception splinters", (void *)mvt);
METER_INIT(mvt->exceptionReturns, "exception returns", (void *)mvt);
mvt->sig = MVTSig;
AVERT(MVT, mvt);
EVENT6(PoolInitMVT, pool, minSize, meanSize, maxSize,
reserveDepth, fragLimit);
return ResOK;
failABQInit:
LandFinish(MVTFreeLand(mvt));
failFreeLandInit:
LandFinish(MVTFreeSecondary(mvt));
failFreeSecondaryInit:
LandFinish(MVTFreePrimary(mvt));
failFreePrimaryInit:
AVER(res != ResOK);
return res;
}
/* MVTCheck -- validate an MVT Pool */
ATTRIBUTE_UNUSED
static Bool MVTCheck(MVT mvt)
{
CHECKS(MVT, mvt);
CHECKD(Pool, MVTPool(mvt));
CHECKL(MVTPool(mvt)->class == MVTPoolClassGet());
CHECKD(CBS, &mvt->cbsStruct);
CHECKD(ABQ, &mvt->abqStruct);
CHECKD(Freelist, &mvt->flStruct);
CHECKD(Failover, &mvt->foStruct);
CHECKL(mvt->reuseSize >= 2 * mvt->fillSize);
CHECKL(mvt->fillSize >= mvt->maxSize);
CHECKL(mvt->maxSize >= mvt->meanSize);
CHECKL(mvt->meanSize >= mvt->minSize);
CHECKL(mvt->minSize > 0);
CHECKL(mvt->fragLimit <= 100);
CHECKL(mvt->availLimit == mvt->size * mvt->fragLimit / 100);
CHECKL(BoolCheck(mvt->abqOverflow));
CHECKL(BoolCheck(mvt->splinter));
if (mvt->splinter) {
CHECKL(AddrOffset(mvt->splinterBase, mvt->splinterLimit) >=
mvt->minSize);
CHECKL(mvt->splinterBase < mvt->splinterLimit);
}
CHECKL(mvt->size == mvt->allocated + mvt->available +
mvt->unavailable);
/* --- could check that sum of segment sizes == mvt->size */
/* --- check meters? */
return TRUE;
}
/* MVTFinish -- finish an MVT pool
*/
static void MVTFinish(Pool pool)
{
MVT mvt;
Arena arena;
Ring ring;
Ring node, nextNode;
AVERT(Pool, pool);
mvt = PoolMVT(pool);
AVERT(MVT, mvt);
arena = PoolArena(pool);
AVERT(Arena, arena);
mvt->sig = SigInvalid;
/* Free the segments in the pool */
ring = PoolSegRing(pool);
RING_FOR(node, ring, nextNode) {
/* We mustn't call MVTSegFree, because we don't know whether or not
* there was any fragmented (unavailable) space in this segment,
* and so we can't keep the accounting correct. */
SegFree(SegOfPoolRing(node));
}
/* Finish the ABQ, Failover, Freelist and CBS structures */
ABQFinish(arena, MVTABQ(mvt));
LandFinish(MVTFreeLand(mvt));
LandFinish(MVTFreeSecondary(mvt));
LandFinish(MVTFreePrimary(mvt));
}
/* SURELY(expr) -- evaluate expr and AVER that the result is true */
#define SURELY(expr) \
BEGIN \
Bool _b = (expr); \
AVER(_b); \
UNUSED(_b); \
END
/* MUST(expr) -- evaluate expr and AVER that the result is ResOK */
#define MUST(expr) \
BEGIN \
Res _res = (expr); \
AVER(_res == ResOK); \
UNUSED(_res); \
END
/* MVTNoteFill -- record that a buffer fill has occurred */
static void MVTNoteFill(MVT mvt, Addr base, Addr limit, Size minSize) {
mvt->available -= AddrOffset(base, limit);
mvt->allocated += AddrOffset(base, limit);
AVER(mvt->size == mvt->allocated + mvt->available + mvt->unavailable);
METER_ACC(mvt->poolUtilization, mvt->allocated * 100 / mvt->size);
METER_ACC(mvt->poolUnavailable, mvt->unavailable);
METER_ACC(mvt->poolAvailable, mvt->available);
METER_ACC(mvt->poolAllocated, mvt->allocated);
METER_ACC(mvt->poolSize, mvt->size);
METER_ACC(mvt->bufferFills, AddrOffset(base, limit));
AVER(AddrOffset(base, limit) >= minSize);
}
/* MVTOversizeFill -- try to fill a request for a large object
*
* When a request exceeds mvt->fillSize, we allocate it on a segment of
* its own.
*/
static Res MVTOversizeFill(Addr *baseReturn,
Addr *limitReturn,
MVT mvt,
Size minSize)
{
Res res;
Seg seg;
Addr base, limit;
Size alignedSize;
alignedSize = SizeArenaGrains(minSize, PoolArena(MVTPool(mvt)));
res = MVTSegAlloc(&seg, mvt, alignedSize);
if (res != ResOK)
return res;
/* Just exactly fill the buffer so that only this allocation comes from
the segment. */
base = SegBase(seg);
limit = AddrAdd(SegBase(seg), minSize);
/* The rest of the segment was lost to fragmentation, so transfer it
* to the unavailable total. (We deliberately lose these fragments
* now so as to avoid the more severe fragmentation that we believe
* would result if we used these for allocation. See
* design.mps.poolmvt.arch.fragmentation.internal and
* design.mps.poolmvt.anal.policy.size.)
*/
mvt->available -= alignedSize - minSize;
mvt->unavailable += alignedSize - minSize;
METER_ACC(mvt->exceptions, minSize);
METER_ACC(mvt->exceptionSplinters, alignedSize - minSize);
MVTNoteFill(mvt, base, limit, minSize);
*baseReturn = base;
*limitReturn = limit;
return ResOK;
}
/* MVTSplinterFill -- try to fill a request from the splinter */
static Bool MVTSplinterFill(Addr *baseReturn, Addr *limitReturn,
MVT mvt, Size minSize)
{
Addr base, limit;
if (!mvt->splinter ||
AddrOffset(mvt->splinterBase, mvt->splinterLimit) < minSize)
return FALSE;
base = mvt->splinterBase;
limit = mvt->splinterLimit;
mvt->splinter = FALSE;
METER_ACC(mvt->splintersUsed, AddrOffset(base, limit));
MVTNoteFill(mvt, base, limit, minSize);
*baseReturn = base;
*limitReturn = limit;
return TRUE;
}
/* MVTOneSegOnly -- restrict a buffer fill to a single segment
*
* After a block has been found, this is applied so that the block
* used to fill the buffer does not span multiple segments. (This
* makes it more likely that when we free the objects that were
* allocated from the block, that this will free the whole segment,
* and so we'll be able to return the segment to the arena. A block
* that spanned two segments would keep both segments allocated,
* possibly unnecessarily.)
*/
static void MVTOneSegOnly(Addr *baseIO, Addr *limitIO, MVT mvt, Size minSize)
{
Addr base, limit, segLimit;
Seg seg;
Arena arena;
base = *baseIO;
limit = *limitIO;
arena = PoolArena(MVTPool(mvt));
SURELY(SegOfAddr(&seg, arena, base));
segLimit = SegLimit(seg);
if (limit <= segLimit) {
/* perfect fit */
METER_ACC(mvt->perfectFits, AddrOffset(base, limit));
} else if (AddrOffset(base, segLimit) >= minSize) {
/* fit in 1st segment */
limit = segLimit;
METER_ACC(mvt->firstFits, AddrOffset(base, limit));
} else {
/* fit in 2nd segment */
base = segLimit;
SURELY(SegOfAddr(&seg, arena, base));
segLimit = SegLimit(seg);
if (limit > segLimit)
limit = segLimit;
METER_ACC(mvt->secondFits, AddrOffset(base, limit));
}
*baseIO = base;
*limitIO = limit;
}
/* MVTABQFill -- try to fill a request from the available block queue */
static Bool MVTABQFill(Addr *baseReturn, Addr *limitReturn,
MVT mvt, Size minSize)
{
Addr base, limit;
RangeStruct range;
Res res;
MVTRefillABQIfEmpty(mvt, minSize);
if (!ABQPeek(MVTABQ(mvt), &range))
return FALSE;
/* Check that the range was stored and retrieved correctly by the ABQ. */
AVERT(Range, &range);
base = RangeBase(&range);
limit = RangeLimit(&range);
MVTOneSegOnly(&base, &limit, mvt, minSize);
METER_ACC(mvt->finds, minSize);
res = MVTDelete(mvt, base, limit);
if (res != ResOK) {
return FALSE;
}
MVTNoteFill(mvt, base, limit, minSize);
*baseReturn = base;
*limitReturn = limit;
return TRUE;
}
/* MVTContingencyFill -- try to fill a request from the free lists */
static Bool MVTContingencyFill(Addr *baseReturn, Addr *limitReturn,
MVT mvt, Size minSize)
{
Res res;
Addr base, limit;
if (!MVTContingencySearch(&base, &limit, mvt, minSize))
return FALSE;
MVTOneSegOnly(&base, &limit, mvt, minSize);
res = MVTDelete(mvt, base, limit);
if (res != ResOK)
return FALSE;
MVTNoteFill(mvt, base, limit, minSize);
*baseReturn = base;
*limitReturn = limit;
return TRUE;
}
/* MVTSegFill -- try to fill a request with a new segment */
static Res MVTSegFill(Addr *baseReturn, Addr *limitReturn,
MVT mvt, Size fillSize,
Size minSize)
{
Res res;
Seg seg;
Addr base, limit;
res = MVTSegAlloc(&seg, mvt, fillSize);
if (res != ResOK)
return res;
base = SegBase(seg);
limit = SegLimit(seg);
MVTNoteFill(mvt, base, limit, minSize);
*baseReturn = base;
*limitReturn = limit;
return ResOK;
}
/* MVTBufferFill -- refill an allocation buffer from an MVT pool
*
* See <design/poolmvt/#impl.c.ap.fill>
*/
static Res MVTBufferFill(Addr *baseReturn, Addr *limitReturn,
Pool pool, Buffer buffer, Size minSize)
{
MVT mvt;
Res res;
AVER(baseReturn != NULL);
AVER(limitReturn != NULL);
AVERT(Pool, pool);
mvt = PoolMVT(pool);
AVERT(MVT, mvt);
AVERT(Buffer, buffer);
AVER(BufferIsReset(buffer));
AVER(minSize > 0);
AVER(SizeIsAligned(minSize, pool->alignment));
/* Allocate oversize blocks exactly, directly from the arena.
<design/poolmvt/#arch.ap.no-fit.oversize> */
if (minSize > mvt->fillSize) {
return MVTOversizeFill(baseReturn, limitReturn, mvt,
minSize);
}
/* Use any splinter, if available.
<design/poolmvt/#arch.ap.no-fit.return> */
if (MVTSplinterFill(baseReturn, limitReturn, mvt, minSize))
return ResOK;
/* Attempt to retrieve a free block from the ABQ. */
if (MVTABQFill(baseReturn, limitReturn, mvt, minSize))
return ResOK;
METER_ACC(mvt->underflows, minSize);
/* If fragmentation is acceptable, attempt to find a free block from
the free lists. <design/poolmvt/#arch.contingency.fragmentation-limit> */
if (mvt->available >= mvt->availLimit) {
METER_ACC(mvt->fragLimitContingencies, minSize);
if (MVTContingencyFill(baseReturn, limitReturn, mvt, minSize))
return ResOK;
}
/* Attempt to request a block from the arena.
<design/poolmvt/#impl.c.free.merge.segment> */
res = MVTSegFill(baseReturn, limitReturn,
mvt, mvt->fillSize, minSize);
if (res == ResOK)
return ResOK;
/* Things are looking pretty desperate. Try the contingencies again,
disregarding fragmentation limits. */
if (ResIsAllocFailure(res)) {
METER_ACC(mvt->emergencyContingencies, minSize);
if (MVTContingencyFill(baseReturn, limitReturn, mvt, minSize))
return ResOK;
}
METER_ACC(mvt->failures, minSize);
AVER(res != ResOK);
return res;
}
/* MVTDeleteOverlapping -- ABQIterate callback used by MVTInsert and
* MVTDelete. It receives a Range in its closure argument, and sets
* *deleteReturn to TRUE for ranges in the ABQ that overlap with it,
* and FALSE for ranges that do not.
*/
static Bool MVTDeleteOverlapping(Bool *deleteReturn, void *element,
void *closure)
{
Range oldRange, newRange;
AVER(deleteReturn != NULL);
AVER(element != NULL);
AVER(closure != NULL);
oldRange = element;
newRange = closure;
*deleteReturn = RangesOverlap(oldRange, newRange);
return TRUE;
}
/* MVTReserve -- add a range to the available range queue, and if the
* queue is full, return segments to the arena. Return TRUE if it
* succeeded in adding the range to the queue, FALSE if the queue
* overflowed.
*/
static Bool MVTReserve(MVT mvt, Range range)
{
AVERT(MVT, mvt);
AVERT(Range, range);
AVER(RangeSize(range) >= mvt->reuseSize);
/* See <design/poolmvt/#impl.c.free.merge> */
if (!ABQPush(MVTABQ(mvt), range)) {
Arena arena = PoolArena(MVTPool(mvt));
RangeStruct oldRange;
/* We just failed to push, so the ABQ must be full, and so surely
* the peek will succeed. */
SURELY(ABQPeek(MVTABQ(mvt), &oldRange));
AVERT(Range, &oldRange);
if (!MVTReturnSegs(mvt, &oldRange, arena))
goto overflow;
METER_ACC(mvt->returns, RangeSize(&oldRange));
if (!ABQPush(MVTABQ(mvt), range))
goto overflow;
}
return TRUE;
overflow:
mvt->abqOverflow = TRUE;
METER_ACC(mvt->overflows, RangeSize(range));
return FALSE;
}
/* MVTInsert -- insert an address range into the free lists and update
* the ABQ accordingly.
*/
static Res MVTInsert(MVT mvt, Addr base, Addr limit)
{
Res res;
RangeStruct range, newRange;
AVERT(MVT, mvt);
AVER(base < limit);
RangeInit(&range, base, limit);
res = LandInsert(&newRange, MVTFreeLand(mvt), &range);
if (res != ResOK)
return res;
if (RangeSize(&newRange) >= mvt->reuseSize) {
/* The new range is big enough that it might have been coalesced
* with ranges on the ABQ, so ensure that the corresponding ranges
* are coalesced on the ABQ.
*/
ABQIterate(MVTABQ(mvt), MVTDeleteOverlapping, &newRange);
(void)MVTReserve(mvt, &newRange);
}
return ResOK;
}
/* MVTDelete -- delete an address range from the free lists, and
* update the ABQ accordingly.
*/
static Res MVTDelete(MVT mvt, Addr base, Addr limit)
{
RangeStruct range, rangeOld, rangeLeft, rangeRight;
Res res;
AVERT(MVT, mvt);
AVER(base < limit);
RangeInit(&range, base, limit);
res = LandDelete(&rangeOld, MVTFreeLand(mvt), &range);
if (res != ResOK)
return res;
AVER(RangesNest(&rangeOld, &range));
/* If the old address range was larger than the reuse size, then it
* might be on the ABQ, so ensure it is removed.
*/
if (RangeSize(&rangeOld) >= mvt->reuseSize)
ABQIterate(MVTABQ(mvt), MVTDeleteOverlapping, &rangeOld);
/* There might be fragments at the left or the right of the deleted
* range, and either might be big enough to go back on the ABQ.
*/
RangeInit(&rangeLeft, RangeBase(&rangeOld), base);
if (RangeSize(&rangeLeft) >= mvt->reuseSize)
(void)MVTReserve(mvt, &rangeLeft);
RangeInit(&rangeRight, limit, RangeLimit(&rangeOld));
if (RangeSize(&rangeRight) >= mvt->reuseSize)
(void)MVTReserve(mvt, &rangeRight);
return ResOK;
}
/* MVTBufferEmpty -- return an unusable portion of a buffer to the MVT
* pool
*
* See <design/poolmvt/#impl.c.ap.empty>
*/
static void MVTBufferEmpty(Pool pool, Buffer buffer,
Addr base, Addr limit)
{
MVT mvt;
Size size;
Res res;
AVERT(Pool, pool);
mvt = PoolMVT(pool);
AVERT(MVT, mvt);
AVERT(Buffer, buffer);
AVER(BufferIsReady(buffer));
AVER(base <= limit);
size = AddrOffset(base, limit);
if (size == 0)
return;
mvt->available += size;
mvt->allocated -= size;
AVER(mvt->size == mvt->allocated + mvt->available +
mvt->unavailable);
METER_ACC(mvt->poolUtilization, mvt->allocated * 100 / mvt->size);
METER_ACC(mvt->poolUnavailable, mvt->unavailable);
METER_ACC(mvt->poolAvailable, mvt->available);
METER_ACC(mvt->poolAllocated, mvt->allocated);
METER_ACC(mvt->poolSize, mvt->size);
METER_ACC(mvt->bufferEmpties, size);
/* <design/poolmvt/#arch.ap.no-fit.splinter> */
if (size < mvt->minSize) {
res = MVTInsert(mvt, base, limit);
AVER(res == ResOK);
METER_ACC(mvt->sawdust, size);
return;
}
METER_ACC(mvt->splinters, size);
/* <design/poolmvt/#arch.ap.no-fit.return> */
if (mvt->splinter) {
Size oldSize = AddrOffset(mvt->splinterBase, mvt->splinterLimit);
/* Old better, drop new */
if (size < oldSize) {
res = MVTInsert(mvt, base, limit);
AVER(res == ResOK);
METER_ACC(mvt->splintersDropped, size);
return;
} else {
/* New better, drop old */
res = MVTInsert(mvt, mvt->splinterBase, mvt->splinterLimit);
AVER(res == ResOK);
METER_ACC(mvt->splintersDropped, oldSize);
}
}
mvt->splinter = TRUE;
mvt->splinterBase = base;
mvt->splinterLimit = limit;
}
/* MVTFree -- free a block (previously allocated from a buffer) that
* is no longer in use
*
* see <design/poolmvt/#impl.c.free>
*/
static void MVTFree(Pool pool, Addr base, Size size)
{
MVT mvt;
Addr limit;
AVERT(Pool, pool);
mvt = PoolMVT(pool);
AVERT(MVT, mvt);
AVER(base != (Addr)0);
AVER(size > 0);
/* We know the buffer observes pool->alignment */
size = SizeAlignUp(size, pool->alignment);
limit = AddrAdd(base, size);
METER_ACC(mvt->poolFrees, size);
mvt->available += size;
mvt->allocated -= size;
AVER(mvt->size == mvt->allocated + mvt->available + mvt->unavailable);
METER_ACC(mvt->poolUtilization, mvt->allocated * 100 / mvt->size);
METER_ACC(mvt->poolUnavailable, mvt->unavailable);
METER_ACC(mvt->poolAvailable, mvt->available);
METER_ACC(mvt->poolAllocated, mvt->allocated);
METER_ACC(mvt->poolSize, mvt->size);
/* <design/poolmvt/#arch.ap.no-fit.oversize.policy> */
/* Return exceptional blocks directly to arena */
if (size > mvt->fillSize) {
Seg seg;
SURELY(SegOfAddr(&seg, PoolArena(pool), base));
AVER(base == SegBase(seg));
AVER(limit <= SegLimit(seg));
mvt->available += SegSize(seg) - size;
mvt->unavailable -= SegSize(seg) - size;
AVER(mvt->size == mvt->allocated + mvt->available +
mvt->unavailable);
METER_ACC(mvt->exceptionReturns, SegSize(seg));
MVTSegFree(mvt, seg);
return;
}
MUST(MVTInsert(mvt, base, limit));
}
/* MVTTotalSize -- total memory allocated from the arena */
static Size MVTTotalSize(Pool pool)
{
MVT mvt;
AVERT(Pool, pool);
mvt = PoolMVT(pool);
AVERT(MVT, mvt);
return mvt->size;
}
/* MVTFreeSize -- free memory (unused by client program) */
static Size MVTFreeSize(Pool pool)
{
MVT mvt;
AVERT(Pool, pool);
mvt = PoolMVT(pool);
AVERT(MVT, mvt);
return mvt->available + mvt->unavailable;
}
/* MVTDescribe -- describe an MVT pool */
static Res MVTDescribe(Pool pool, mps_lib_FILE *stream, Count depth)
{
Res res;
MVT mvt;
if (!TESTT(Pool, pool))
return ResFAIL;
mvt = PoolMVT(pool);
if (!TESTT(MVT, mvt))
return ResFAIL;
if (stream == NULL)
return ResFAIL;
res = WriteF(stream, depth,
"MVT $P {\n", (WriteFP)mvt,
" minSize: $U\n", (WriteFU)mvt->minSize,
" meanSize: $U\n", (WriteFU)mvt->meanSize,
" maxSize: $U\n", (WriteFU)mvt->maxSize,
" fragLimit: $U\n", (WriteFU)mvt->fragLimit,
" reuseSize: $U\n", (WriteFU)mvt->reuseSize,
" fillSize: $U\n", (WriteFU)mvt->fillSize,
" availLimit: $U\n", (WriteFU)mvt->availLimit,
" abqOverflow: $S\n", WriteFYesNo(mvt->abqOverflow),
" splinter: $S\n", WriteFYesNo(mvt->splinter),
" splinterBase: $A\n", (WriteFA)mvt->splinterBase,
" splinterLimit: $A\n", (WriteFU)mvt->splinterLimit,
" size: $U\n", (WriteFU)mvt->size,
" allocated: $U\n", (WriteFU)mvt->allocated,
" available: $U\n", (WriteFU)mvt->available,
" unavailable: $U\n", (WriteFU)mvt->unavailable,
NULL);
if (res != ResOK)
return res;
res = LandDescribe(MVTFreePrimary(mvt), stream, depth + 2);
if (res != ResOK)
return res;
res = LandDescribe(MVTFreeSecondary(mvt), stream, depth + 2);
if (res != ResOK)
return res;
res = LandDescribe(MVTFreeLand(mvt), stream, depth + 2);
if (res != ResOK)
return res;
res = ABQDescribe(MVTABQ(mvt), (ABQDescribeElement)RangeDescribe, stream,
depth + 2);
if (res != ResOK)
return res;
METER_WRITE(mvt->segAllocs, stream, depth + 2);
METER_WRITE(mvt->segFrees, stream, depth + 2);
METER_WRITE(mvt->bufferFills, stream, depth + 2);
METER_WRITE(mvt->bufferEmpties, stream, depth + 2);
METER_WRITE(mvt->poolFrees, stream, depth + 2);
METER_WRITE(mvt->poolSize, stream, depth + 2);
METER_WRITE(mvt->poolAllocated, stream, depth + 2);
METER_WRITE(mvt->poolAvailable, stream, depth + 2);
METER_WRITE(mvt->poolUnavailable, stream, depth + 2);
METER_WRITE(mvt->poolUtilization, stream, depth + 2);
METER_WRITE(mvt->finds, stream, depth + 2);
METER_WRITE(mvt->overflows, stream, depth + 2);
METER_WRITE(mvt->underflows, stream, depth + 2);
METER_WRITE(mvt->refills, stream, depth + 2);
METER_WRITE(mvt->refillPushes, stream, depth + 2);
METER_WRITE(mvt->returns, stream, depth + 2);
METER_WRITE(mvt->perfectFits, stream, depth + 2);
METER_WRITE(mvt->firstFits, stream, depth + 2);
METER_WRITE(mvt->secondFits, stream, depth + 2);
METER_WRITE(mvt->failures, stream, depth + 2);
METER_WRITE(mvt->emergencyContingencies, stream, depth + 2);
METER_WRITE(mvt->fragLimitContingencies, stream, depth + 2);
METER_WRITE(mvt->contingencySearches, stream, depth + 2);
METER_WRITE(mvt->contingencyHardSearches, stream, depth + 2);
METER_WRITE(mvt->splinters, stream, depth + 2);
METER_WRITE(mvt->splintersUsed, stream, depth + 2);
METER_WRITE(mvt->splintersDropped, stream, depth + 2);
METER_WRITE(mvt->sawdust, stream, depth + 2);
METER_WRITE(mvt->exceptions, stream, depth + 2);
METER_WRITE(mvt->exceptionSplinters, stream, depth + 2);
METER_WRITE(mvt->exceptionReturns, stream, depth + 2);
res = WriteF(stream, depth, "} MVT $P\n", (WriteFP)mvt, NULL);
return res;
}
/* Pool Interface */
/* PoolClassMVT -- the Pool (sub-)Class for an MVT pool */
PoolClass PoolClassMVT(void)
{
return MVTPoolClassGet();
}
/* MPS Interface */
/* mps_class_mvt -- the class of an mvt pool */
mps_pool_class_t mps_class_mvt(void)
{
return (mps_pool_class_t)(PoolClassMVT());
}
/* Internal methods */
/* MVTSegAlloc -- encapsulates SegAlloc with associated accounting and
* metering
*/
static Res MVTSegAlloc(Seg *segReturn, MVT mvt, Size size)
{
Res res = SegAlloc(segReturn, SegClassGet(), LocusPrefDefault(), size,
MVTPool(mvt), argsNone);
if (res == ResOK) {
Size segSize = SegSize(*segReturn);
/* see <design/poolmvt/#arch.fragmentation.internal> */
AVER(segSize >= mvt->fillSize);
mvt->size += segSize;
mvt->available += segSize;
mvt->availLimit = mvt->size * mvt->fragLimit / 100;
AVER(mvt->size == mvt->allocated + mvt->available + mvt->unavailable);
METER_ACC(mvt->segAllocs, segSize);
}
return res;
}
/* MVTSegFree -- encapsulates SegFree with associated accounting and
* metering
*/
static void MVTSegFree(MVT mvt, Seg seg)
{
Size size;
size = SegSize(seg);
AVER(mvt->available >= size);
mvt->available -= size;
mvt->size -= size;
mvt->availLimit = mvt->size * mvt->fragLimit / 100;
AVER(mvt->size == mvt->allocated + mvt->available + mvt->unavailable);
SegFree(seg);
METER_ACC(mvt->segFrees, size);
}
/* MVTReturnSegs -- return (interior) segments of a range to the arena */
static Bool MVTReturnSegs(MVT mvt, Range range, Arena arena)
{
Addr base, limit;
Bool success = FALSE;
base = RangeBase(range);
limit = RangeLimit(range);
while (base < limit) {
Seg seg;
Addr segBase, segLimit;
SURELY(SegOfAddr(&seg, arena, base));
segBase = SegBase(seg);
segLimit = SegLimit(seg);
if (base <= segBase && limit >= segLimit) {
MUST(MVTDelete(mvt, segBase, segLimit));
MVTSegFree(mvt, seg);
success = TRUE;
}
base = segLimit;
}
return success;
}
/* MVTRefillABQIfEmpty -- refill the ABQ from the free lists if it is
* empty.
*/
static Bool MVTRefillVisitor(Land land, Range range,
void *closure)
{
MVT mvt;
AVERT(Land, land);
mvt = closure;
AVERT(MVT, mvt);
if (RangeSize(range) < mvt->reuseSize)
return TRUE;
METER_ACC(mvt->refillPushes, ABQDepth(MVTABQ(mvt)));
return MVTReserve(mvt, range);
}
static void MVTRefillABQIfEmpty(MVT mvt, Size size)
{
AVERT(MVT, mvt);
AVER(size > 0);
/* If there have never been any overflows from the ABQ back to the
* free lists, then there cannot be any blocks in the free lists
* that are worth adding to the ABQ. So as an optimization, we don't
* bother to look.
*/
if (mvt->abqOverflow && ABQIsEmpty(MVTABQ(mvt))) {
mvt->abqOverflow = FALSE;
METER_ACC(mvt->refills, size);
/* The iteration stops if the ABQ overflows, so may finish or not. */
(void)LandIterate(MVTFreeLand(mvt), MVTRefillVisitor, mvt);
}
}
/* MVTContingencySearch -- search free lists for a block of a given size */
typedef struct MVTContigencyClosureStruct
{
MVT mvt;
RangeStruct range;
Arena arena;
Size min;
/* meters */
Count steps;
Count hardSteps;
} MVTContigencyClosureStruct, *MVTContigencyClosure;
static Bool MVTContingencyVisitor(Land land, Range range,
void *closure)
{
MVT mvt;
Size size;
Addr base, limit;
MVTContigencyClosure cl;
AVERT(Land, land);
AVERT(Range, range);
AVER(closure != NULL);
cl = closure;
mvt = cl->mvt;
AVERT(MVT, mvt);
base = RangeBase(range);
limit = RangeLimit(range);
size = RangeSize(range);
cl->steps++;
if (size < cl->min)
return TRUE;
/* verify that min will fit when seg-aligned */
if (size >= 2 * cl->min) {
RangeInit(&cl->range, base, limit);
return FALSE;
}
/* do it the hard way */
cl->hardSteps++;
if (MVTCheckFit(base, limit, cl->min, cl->arena)) {
RangeInit(&cl->range, base, limit);
return FALSE;
}
/* keep looking */
return TRUE;
}
static Bool MVTContingencySearch(Addr *baseReturn, Addr *limitReturn,
MVT mvt, Size min)
{
MVTContigencyClosureStruct cls;
cls.mvt = mvt;
cls.arena = PoolArena(MVTPool(mvt));
cls.min = min;
cls.steps = 0;
cls.hardSteps = 0;
if (LandIterate(MVTFreeLand(mvt), MVTContingencyVisitor, &cls))
return FALSE;
AVER(RangeSize(&cls.range) >= min);
METER_ACC(mvt->contingencySearches, cls.steps);
if (cls.hardSteps) {
METER_ACC(mvt->contingencyHardSearches, cls.hardSteps);
}
*baseReturn = RangeBase(&cls.range);
*limitReturn = RangeLimit(&cls.range);
return TRUE;
}
/* MVTCheckFit -- verify that segment-aligned block of size min can
* fit in a candidate address range.
*/
static Bool MVTCheckFit(Addr base, Addr limit, Size min, Arena arena)
{
Seg seg;
Addr segLimit;
SURELY(SegOfAddr(&seg, arena, base));
segLimit = SegLimit(seg);
if (limit <= segLimit) {
if (AddrOffset(base, limit) >= min)
return TRUE;
}
if (AddrOffset(base, segLimit) >= min)
return TRUE;
base = segLimit;
SURELY(SegOfAddr(&seg, arena, base));
segLimit = SegLimit(seg);
if (AddrOffset(base, limit < segLimit ? limit : segLimit) >= min)
return TRUE;
return FALSE;
}
/* Return the CBS of an MVT pool for the benefit of fotest.c. */
extern Land _mps_mvt_cbs(Pool);
Land _mps_mvt_cbs(Pool pool) {
MVT mvt;
AVERT(Pool, pool);
mvt = PoolMVT(pool);
AVERT(MVT, mvt);
return MVTFreePrimary(mvt);
}
/* C. COPYRIGHT AND LICENSE
*
* Copyright (C) 2001-2014 Ravenbrook Limited <http://www.ravenbrook.com/>.
* All rights reserved. This is an open source license. Contact
* Ravenbrook for commercial licensing options.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Redistributions in any form must be accompanied by information on how
* to obtain complete source code for this software and any accompanying
* software that uses this software. The source code must either be
* included in the distribution or be available for no more than the cost
* of distribution plus a nominal fee, and must be freely redistributable
* under reasonable conditions. For an executable file, complete source
* code means the source code for all modules it contains. It does not
* include source code for modules or files that typically accompany the
* major components of the operating system on which the executable file
* runs.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
* PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
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