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Fix flush count overflow and underflow in sacempty

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 Change: 21602
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This commit is contained in:
Pekka Pirinen 2001-02-08 16:47:49 +00:00
parent f4b44686b9
commit 9ef9d8ec06
1 changed files with 24 additions and 23 deletions
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47
mps/src/sac.c
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@ -1,18 +1,18 @@
/* impl.h.sac: SEGREGATED ALLOCATION CACHES
/* impl.c.sac: SEGREGATED ALLOCATION CACHES
*
* $HopeName: MMsrc!sac.c(MM_epcore_brisling.5) $
* $HopeName: MMsrc!sac.c(trunk.2) $
* Copyright (C) 1999 Harlequin Limited. All rights reserved.
*/
#include "mpm.h"
#include "sac.h"
SRCID(sac, "$HopeName: MMsrc!sac.c(MM_epcore_brisling.5) $");
SRCID(sac, "$HopeName: MMsrc!sac.c(trunk.2) $");
/* SACCheck -- check function for SACs */
static Bool SACFreeListBlockCheck(SACFreeListBlock fb)
static Bool sacFreeListBlockCheck(SACFreeListBlock fb)
{
Count j;
Addr cb;
@ -46,7 +46,7 @@ static Bool SACCheck(SAC sac)
for (j = sac->middleIndex + 1, i = 0;
j <= sac->classesCount; ++j, i += 2) {
CHECKL(prevSize < sac->esacStruct.freelists[i].size);
b = SACFreeListBlockCheck(&(sac->esacStruct.freelists[i]));
b = sacFreeListBlockCheck(&(sac->esacStruct.freelists[i]));
if (!b) return b;
prevSize = sac->esacStruct.freelists[i].size;
}
@ -59,20 +59,20 @@ static Bool SACCheck(SAC sac)
prevSize = sac->esacStruct.middle;
for (j = sac->middleIndex, i = 1; j > 0; --j, i += 2) {
CHECKL(prevSize > sac->esacStruct.freelists[i].size);
b = SACFreeListBlockCheck(&(sac->esacStruct.freelists[i]));
b = sacFreeListBlockCheck(&(sac->esacStruct.freelists[i]));
if (!b) return b;
prevSize = sac->esacStruct.freelists[i].size;
}
/* check smallest class */
CHECKL(sac->esacStruct.freelists[i].size == 0);
b = SACFreeListBlockCheck(&(sac->esacStruct.freelists[i]));
b = sacFreeListBlockCheck(&(sac->esacStruct.freelists[i]));
return b;
}
/* SACSize -- calculate size of a SAC structure */
/* sacSize -- calculate size of a SAC structure */
static Size SACSize(Index middleIndex, Count classesCount)
static Size sacSize(Index middleIndex, Count classesCount)
{
Index indexMax; /* max index for the freelist */
SACStruct dummy;
@ -134,7 +134,7 @@ Res SACCreate(SAC *sacReturn, Pool pool, Count classesCount,
middleIndex = i + 1; /* there must exist another class at i+1 */
/* Allocate SAC */
res = ControlAlloc(&p, PoolArena(pool), SACSize(middleIndex, classesCount),
res = ControlAlloc(&p, PoolArena(pool), sacSize(middleIndex, classesCount),
FALSE);
if(res != ResOK)
goto failSACAlloc;
@ -187,17 +187,17 @@ void SACDestroy(SAC sac)
SACFlush(sac);
sac->sig = SigInvalid;
ControlFree(PoolArena(sac->pool), sac,
SACSize(sac->middleIndex, sac->classesCount));
sacSize(sac->middleIndex, sac->classesCount));
}
/* SACFind -- find the index corresponding to size
/* sacFind -- find the index corresponding to size
*
* This function replicates the loop in MPS_SAC_ALLOC_FAST, only with
* added checks.
*/
static void SACFind(Index *iReturn, Size *blockSizeReturn,
static void sacFind(Index *iReturn, Size *blockSizeReturn,
SAC sac, Size size)
{
Index i, j;
@ -240,7 +240,7 @@ Res SACFill(Addr *p_o, SAC sac, Size size, Bool hasReservoirPermit)
AVER(size != 0);
AVER(BoolCheck(hasReservoirPermit));
SACFind(&i, &blockSize, sac, size);
sacFind(&i, &blockSize, sac, size);
/* Check it's empty (in the future, there will be other cases). */
AVER(sac->esacStruct.freelists[i].count == 0);
@ -273,12 +273,12 @@ Res SACFill(Addr *p_o, SAC sac, Size size, Bool hasReservoirPermit)
}
/* SACClassFlush -- discard elements from the cache for a given class
/* sacClassFlush -- discard elements from the cache for a given class
*
* blockCount says how many elements to discard.
*/
static void SACClassFlush(SAC sac, Index i, Size blockSize,
static void sacClassFlush(SAC sac, Index i, Size blockSize,
Count blockCount)
{
Addr cb, fl;
@ -307,7 +307,7 @@ void SACEmpty(SAC sac, Addr p, Size size)
AVER(PoolHasAddr(sac->pool, p));
AVER(size > 0);
SACFind(&i, &blockSize, sac, size);
sacFind(&i, &blockSize, sac, size);
/* Check it's full (in the future, there will be other cases). */
AVER(sac->esacStruct.freelists[i].count
== sac->esacStruct.freelists[i].countMax);
@ -320,9 +320,10 @@ void SACEmpty(SAC sac, Addr p, Size size)
Count blockCount;
/* Flush 2/3 of the cache for this class. */
/* @@@@ Needs an overflow check */
blockCount = sac->esacStruct.freelists[i].count * 2 / 3;
SACClassFlush(sac, i, blockSize, (blockCount > 0) ? blockCount : 1);
/* Computed as count - count/3, so that the rounding works out right. */
blockCount = sac->esacStruct.freelists[i].count;
blockCount -= sac->esacStruct.freelists[i].count / 3;
sacClassFlush(sac, i, blockSize, (blockCount > 0) ? blockCount : 1);
/* Leave the current one in the cache. */
sac->esacStruct.freelists[i].count += 1;
/* @@@@ ignoring shields for now */
@ -346,18 +347,18 @@ void SACFlush(SAC sac)
for (j = sac->middleIndex + 1, i = 0;
j < sac->classesCount; ++j, i += 2) {
SACClassFlush(sac, i, sac->esacStruct.freelists[i].size,
sacClassFlush(sac, i, sac->esacStruct.freelists[i].size,
sac->esacStruct.freelists[i].count);
AVER(sac->esacStruct.freelists[i].blocks == NULL);
}
/* no need to flush overlarge, there's nothing there */
prevSize = sac->esacStruct.middle;
for (j = sac->middleIndex, i = 1; j > 0; --j, i += 2) {
SACClassFlush(sac, i, prevSize, sac->esacStruct.freelists[i].count);
sacClassFlush(sac, i, prevSize, sac->esacStruct.freelists[i].count);
AVER(sac->esacStruct.freelists[i].blocks == NULL);
prevSize = sac->esacStruct.freelists[i].size;
}
/* flush smallest class */
SACClassFlush(sac, i, prevSize, sac->esacStruct.freelists[i].count);
sacClassFlush(sac, i, prevSize, sac->esacStruct.freelists[i].count);
AVER(sac->esacStruct.freelists[i].blocks == NULL);
}