os/kernelhwsrv/userlibandfileserver/fileserver/sfile/sf_cache_man.cpp
author sl@SLION-WIN7.fritz.box
Fri, 15 Jun 2012 03:10:57 +0200
changeset 0 bde4ae8d615e
permissions -rw-r--r--
First public contribution.
     1 // Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
     2 // All rights reserved.
     3 // This component and the accompanying materials are made available
     4 // under the terms of the License "Eclipse Public License v1.0"
     5 // which accompanies this distribution, and is available
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
     7 //
     8 // Initial Contributors:
     9 // Nokia Corporation - initial contribution.
    10 //
    11 // Contributors:
    12 //
    13 // Description:
    14 // f32\sfile\sf_cache_man.cpp
    15 // 
    16 //
    17 
    18 /**
    19  @file
    20  @internalTechnology
    21 */
    22 
    23 
    24 #include <e32std.h>
    25 #include <e32std_private.h>
    26 #include "sf_std.h"
    27 #include <e32uid.h>
    28 #include <e32wins.h>
    29 #include <f32file.h>
    30 #include <hal.h>
    31 #include "sf_cache_man.h"
    32 #include "sf_cache_client.h"
    33 #include "sf_file_cache.h"
    34 #include "sf_file_cache_defs.h"
    35 
    36 //#undef __SIMULATE_LOCK_FAILURES__
    37 //#define __RAMDOM_LOCK_FAILURES__
    38 //#define __PSEUDO_RANDOM_FAILURES__		
    39 //#define __LOCK_ENTIRE_CACHELINE__
    40 
    41 #ifdef __RAMDOM_LOCK_FAILURES__	
    42 #include <e32math.h>
    43 #endif
    44 
    45 #define CACHE_NUM_TO_ADDR(n) (iBase + (n << iCacheLineSizeLog2))
    46 #define ADDR_TO_CACHELINE_ADDR(a) ((((a - iBase) >> iCacheLineSizeLog2) << iCacheLineSizeLog2) + iBase)
    47 #define ADDR_TO_INDEX(a) ((a - iBase) >> iCacheLineSizeLog2)
    48 
    49 #if defined(_DEBUG)
    50 	#define __CACHELINE_INVARIANT(aCacheLine)						\
    51 	__ASSERT_DEBUG(												\
    52 		aCacheLine.iDirtySegments <= aCacheLine.iFilledSegments &&	\
    53 		aCacheLine.iFilledSegments <= aCacheLine.iAllocatedSegments,	\
    54 		Fault(EInvalidCacheLine));
    55 
    56 #else
    57 	#define __CACHELINE_INVARIANT(aCacheLine)
    58 #endif
    59 
    60 const TInt KSegmentSize = 4096;
    61 const TInt KSegmentSizeLog2 = 12;
    62 const TInt64 KSegmentSizeMask = MAKE_TINT64(0x7FFFFFFF,0xFFFFF000);
    63 
    64 const TInt KCacheLineSizeLog2 = 17;	// 128K
    65 const TInt KCacheLineSize = (1 << KCacheLineSizeLog2 );
    66 const TInt KCacheLineSizeInSegments = (KCacheLineSize >> KSegmentSizeLog2);
    67 
    68 CCacheManager* CCacheManagerFactory::iCacheManager = NULL;
    69 
    70 
    71 LOCAL_C void Fault(TCacheManagerFault aFault)
    72 //
    73 // Report a fault in the cache manager
    74 //
    75 	{
    76 	User::Panic(_L("FSCACHEMAN"), aFault);
    77 	}
    78 
    79 
    80 /*
    81 Indicates if a number passed in is a power of two
    82 
    83 @param aNum number to be tested
    84 @return Flag to indicate the result of the test
    85 */
    86 LOCAL_C TBool IsPowerOfTwo(TInt aNum)
    87 	{
    88 	return (aNum != 0 && (aNum & -aNum) == aNum);
    89 	}
    90 
    91 
    92 //********************
    93 // CCacheManagerFactory
    94 //********************
    95 void CCacheManagerFactory::CreateL()
    96 	{
    97 	__ASSERT_ALWAYS(iCacheManager == NULL, Fault(ECacheAlreadyCreated));
    98 
    99 	if (TGlobalFileCacheSettings::Enabled())
   100 		{
   101 		iCacheManager = CCacheManager::NewCacheL(TGlobalFileCacheSettings::CacheSize());
   102 		}
   103 	else
   104 		{
   105 		Destroy(); 
   106 		}
   107 	}
   108 
   109 CCacheManager* CCacheManagerFactory::CacheManager()
   110 	{
   111 	return iCacheManager;
   112 	}
   113 
   114 TInt CCacheManagerFactory::Destroy()
   115 	{
   116 	delete iCacheManager;
   117 	iCacheManager = NULL;
   118 	return KErrNone;
   119 	}
   120 
   121 //********************
   122 // CCacheManager
   123 //********************
   124 CCacheManager* CCacheManager::NewCacheL(TInt aCacheSize)
   125 	{
   126 	CCacheManager* cacheManager = new (ELeave) CCacheManager(aCacheSize);
   127 
   128 	CleanupStack::PushL(cacheManager);
   129 	cacheManager->ConstructL();
   130 	CleanupStack::Pop(1, cacheManager);
   131 
   132 	return cacheManager;
   133 	}
   134 
   135 CCacheManager::~CCacheManager()
   136 	{
   137 	CacheLock();
   138 
   139 	iFreeQueue.Close();
   140 	iUsedQueue.Close();
   141 
   142 	delete [] iCacheLines;
   143 
   144 	CacheUnlock();
   145 	iLock.Close();
   146 
   147 	iChunk.Close();
   148 	}
   149 
   150 
   151 CCacheManager::CCacheManager(TUint aCacheSize)
   152 	{
   153 	// Get the page size
   154 	TInt pageSize;
   155 	TInt r = HAL::Get(HAL::EMemoryPageSize, pageSize);
   156 	if (r != KErrNone)
   157 		pageSize = KSegmentSize;
   158 	__ASSERT_ALWAYS(IsPowerOfTwo(pageSize), Fault(EIllegalPageSize));
   159 
   160 	// For the time being we only a support page size of 4K and we assume
   161 	// that page size = segment size, since the extra overhead of supporting 
   162 	// variable page sizes now is non-trivial.
   163 	//
   164 	// If a processor with a different page size needs to be supported 
   165 	// in the future, then we need to either rework this code to be able to
   166 	// devide up pages into smaller segments or analyze the impact of having 
   167 	// a different page size on performance.
   168 	__ASSERT_ALWAYS(pageSize == KSegmentSize, Fault(EIllegalPageSize));
   169 
   170 	iCacheLineSize = KCacheLineSize;
   171 	iCacheLineSizeLog2 = KCacheLineSizeLog2;
   172 
   173 	iCacheSize = aCacheSize;
   174 
   175 	iSegmentsPerCacheLine = 1 << (iCacheLineSizeLog2 - KSegmentSizeLog2);
   176 
   177 	iMaxLockedSegments = TGlobalFileCacheSettings::MaxLockedSize() >> KSegmentSizeLog2;
   178 
   179 #ifdef __SIMULATE_LOCK_FAILURES__
   180 	iSimulateLockFailureMode = ETrue;
   181 #endif
   182 	}
   183 
   184 void CCacheManager::ConstructL()
   185 	{
   186 
   187 	// calculate the low-memory threshold below which we fail any attempt to allocate memory
   188 	TMemoryInfoV1Buf meminfo;
   189 	TInt r = UserHal::MemoryInfo(meminfo);
   190 	__ASSERT_ALWAYS(r==KErrNone,Fault(EMemoryInfoFailed));
   191 
   192 	iLowMemoryThreshold = (meminfo().iTotalRamInBytes * TGlobalFileCacheSettings::LowMemoryThreshold()) / 100;
   193 	__CACHE_PRINT4(_L("CACHEMAN: totalRAM %d freeRAM %d KDefaultLowMemoryThresholdPercent %d iLowMemoryThreshold %d"), 
   194 		meminfo().iTotalRamInBytes, meminfo().iFreeRamInBytes, KDefaultLowMemoryThreshold, iLowMemoryThreshold);
   195 	__CACHE_PRINT1(_L("CACHEMAN: iCacheSize %d"), iCacheSize);
   196 	TChunkCreateInfo createInfo;
   197 	createInfo.SetCache(iCacheSize);
   198 	createInfo.SetOwner(EOwnerProcess);
   199 	r = iChunk.Create(createInfo);
   200 	User::LeaveIfError(r);
   201 
   202 	
   203 	TInt mm = UserSvr::HalFunction(EHalGroupKernel, EKernelHalMemModelInfo, 0, 0) & EMemModelTypeMask;
   204 	if (mm < EMemModelTypeFlexible)
   205 		{
   206 		// On memory models before flexible, File System has to register chunks that will be DMA-ed.
   207 		// On flexible memory model, local media is using new physical pinning Kernel interface that
   208 		// doesn't require registration of the chunk.
   209 		UserSvr::RegisterTrustedChunk(iChunk.Handle());
   210 		}
   211 	
   212 
   213 	__ASSERT_ALWAYS(iCacheSize > KSegmentSize, Fault(EIllegalCacheSize));
   214 
   215 	r = iLock.CreateLocal();
   216 	User::LeaveIfError(r);
   217 
   218 	iNumOfCacheLines = iCacheSize >> iCacheLineSizeLog2;
   219 	iBase = Base();
   220 
   221 	iCacheLines = new (ELeave) TCacheLine[iNumOfCacheLines];
   222 
   223 	for (TInt n=0; n<iNumOfCacheLines; n++)
   224 		{
   225 		// coverity[var_decl]
   226 		TCacheLine cacheLine;
   227 		cacheLine.iAddr = CACHE_NUM_TO_ADDR(n);
   228 		cacheLine.iAllocatedSegments = 0;
   229 		cacheLine.iFilledSegments = 0;
   230 		cacheLine.iDirtySegments = 0;
   231 		cacheLine.iLockCount = 0;
   232 		cacheLine.iLockedSegmentStart = 0;
   233 		cacheLine.iLockedSegmentCount = 0;
   234 		cacheLine.iClient = NULL;
   235 		// coverity[uninit_use]
   236 		iCacheLines[n] = cacheLine;
   237 
   238 		r = iFreeQueue.Append(&iCacheLines[n]);
   239 		User::LeaveIfError(r);
   240 		}
   241 
   242 	}
   243 
   244 CCacheClient* CCacheManager::CreateClientL()
   245 	{
   246 	CCacheClient* client = CCacheClient::NewL(*this);
   247 	return client;
   248 	}
   249 
   250 void CCacheManager::RegisterClient(CCacheClient& /*aClient*/)
   251 	{
   252 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
   253 	iStats.iFileCount++;
   254 #endif
   255 	}
   256 
   257 void CCacheManager::DeregisterClient(CCacheClient& /*aClient*/)
   258 	{
   259 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
   260 	iStats.iFileCount--;
   261 #endif
   262 	}
   263 
   264 
   265 void CCacheManager::FreeMemoryChanged(TBool aMemoryLow)
   266 	{
   267 	iMemoryLow = aMemoryLow;
   268 	}
   269 
   270 TBool CCacheManager::TooManyLockedSegments()
   271 	{
   272 	return (iLockedSegmentCount >= iMaxLockedSegments)?(TBool)ETrue:(TBool)EFalse;
   273 	}
   274 
   275 TInt CCacheManager::SegmentSize()
   276 	{
   277 	return KSegmentSize;
   278 	}
   279 
   280 TInt CCacheManager::SegmentSizeLog2()
   281 	{
   282 	return KSegmentSizeLog2;
   283 	}
   284 
   285 TInt64 CCacheManager::SegmentSizeMask()
   286 	{
   287 	return KSegmentSizeMask;
   288 	}
   289 
   290 TInt CCacheManager::CacheLineSize()
   291 	{
   292 	return KCacheLineSize;
   293 	}
   294 
   295 TInt CCacheManager::CacheLineSizeInSegments()
   296 	{
   297 	return KCacheLineSizeInSegments;
   298 	}
   299 
   300 TInt CCacheManager::CacheLineSizeLog2()
   301 	{
   302 	return KCacheLineSizeLog2;
   303 	}
   304 
   305 
   306 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
   307 TFileCacheStats& CCacheManager::Stats()
   308 	{
   309 	iStats.iFreeCount = iFreeQueue.Count();
   310 	iStats.iUsedCount = iUsedQueue.Count();
   311 	iStats.iLockedSegmentCount = iLockedSegmentCount;
   312 	iStats.iFilesOnClosedQueue = TClosedFileUtils::Count();
   313 	__ASSERT_DEBUG(iStats.iFreeCount >= 0, Fault(EInvalidStats));
   314 	__ASSERT_DEBUG(iStats.iUsedCount >= 0, Fault(EInvalidStats));
   315 	__ASSERT_DEBUG(iStats.iLockedSegmentCount >= 0, Fault(EInvalidStats));
   316 	__ASSERT_DEBUG(iStats.iFilesOnClosedQueue >= 0, Fault(EInvalidStats));
   317 	return iStats;
   318 	}
   319 #endif	// #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
   320 
   321 
   322 
   323 void CCacheManager::CacheLock()
   324 	{
   325 	iLock.Wait();
   326 
   327 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
   328 	iManagerLocked = ETrue;
   329 #endif
   330 	}
   331 
   332 void CCacheManager::CacheUnlock()
   333 	{
   334 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
   335 	iManagerLocked = EFalse;
   336 #endif
   337 	iLock.Signal();
   338 	}
   339 
   340 
   341 TInt CCacheManager::AllocateAndLockCacheLine(CCacheClient* aClient, TInt64 aPos, const TCacheLine*& aCacheLine, TInt aSegmentCount)
   342 	{
   343 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidAllocCount));
   344 
   345 	// check for low system memory
   346 	TMemoryInfoV1Buf meminfo;
   347 	TInt r = UserHal::MemoryInfo(meminfo);
   348 	__ASSERT_ALWAYS(r==KErrNone,Fault(EMemoryInfoFailed));
   349 	if (iMemoryLow || (meminfo().iFreeRamInBytes < iLowMemoryThreshold))
   350 		{
   351 		__CACHE_PRINT(_L("CACHEMAN: free RAM below threshold !!!"));
   352 		return KErrNoMemory;
   353 		}
   354 
   355 	CacheLock();
   356 
   357 	__CACHE_PRINT1(_L("CACHEMAN: Allocate %d segments, Lock %d"), aSegmentCount);
   358 	__CACHE_PRINT2(_L("CACHEMAN: iFreeQueue %d iUsedQueue %d"), iFreeQueue.Count(), iUsedQueue.Count());
   359 
   360 #ifdef  __SIMULATE_LOCK_FAILURES__
   361 	if (SimulatedFailure(iAllocFailureCount))
   362 		{
   363 		__CACHE_PRINT(_L("CACHEMAN: simulating allocation failure"));
   364 		CacheUnlock();
   365 		return KErrNoMemory;
   366 		}
   367 #endif
   368 
   369 	// any cachelines free ?
   370 	TInt freeCacheLines = iFreeQueue.Count();
   371 	TCacheLine* cacheLine = NULL;
   372 	if (freeCacheLines == 0 && !StealCacheLine(aClient))
   373 		{
   374 		CacheUnlock();
   375 		return KErrNotFound;
   376 		}
   377 
   378 	cacheLine = iFreeQueue[0];
   379 
   380 	__CACHELINE_INVARIANT((*cacheLine));
   381 	__ASSERT_DEBUG( cacheLine->iAllocatedSegments == 0, Fault(EInvalidAllocCount));
   382 	__ASSERT_DEBUG( cacheLine->iFilledSegments == 0, Fault(EInvalidFillCount));
   383 	__ASSERT_DEBUG( cacheLine->iDirtySegments == 0, Fault(EInvalidFillCount));
   384 	__ASSERT_DEBUG( cacheLine->iLockCount == 0, Fault(EInvalidLockCount));
   385 	__ASSERT_DEBUG( cacheLine->iLockedSegmentStart == 0, Fault(EInvalidLockedPageStart));
   386 	__ASSERT_DEBUG( cacheLine->iLockedSegmentCount == 0, Fault(EInvalidLockedPageCount));
   387 	__ASSERT_DEBUG( cacheLine->iClient == NULL, Fault(EInvalidClient));
   388 
   389 	TUint8* addr = cacheLine->iAddr;
   390 
   391 	// Commit it
   392 	r = Commit(addr, aSegmentCount);
   393 	if (r != KErrNone)
   394 		{
   395 		CacheUnlock();
   396 		return r;
   397 		}
   398 	cacheLine->iAllocatedSegments = (TUint8) (aSegmentCount);
   399 	cacheLine->iLockedSegmentStart = 0;
   400 	cacheLine->iLockedSegmentCount = (TUint8) aSegmentCount;
   401 
   402 	// Add to used queue
   403 	r = iUsedQueue.InsertInAddressOrder(cacheLine);
   404 	if (r != KErrNone)
   405 		{
   406 		Decommit(addr, aSegmentCount);
   407 		CacheUnlock();
   408 		return r;
   409 		}
   410 
   411 	cacheLine->iClient = aClient;
   412 	cacheLine->iPos = aPos;
   413 
   414 	// Remove from free queue
   415 	iFreeQueue.Remove(0);
   416 
   417 	// RChunk will lock segments initially unless explicitly unlocked
   418 
   419 	cacheLine->iLockCount++;
   420 	
   421 	__CACHE_PRINT2(_L("CACHEMAN: LockCount for %08X is %d"), cacheLine->iAddr, cacheLine->iLockCount);
   422 
   423 	CacheUnlock();
   424 
   425 	aCacheLine = cacheLine;
   426 	return r;
   427 
   428 	}
   429 
   430 /**
   431 CCacheManager::ExtendCacheLine()
   432 
   433 Attempts to extend the length of an existing cacheline by committing extra segments
   434 The cacheline must be owned and locked already.
   435 
   436 @param aCacheLine A reference to a locked, owned cacheline
   437 @param aSegmentCount The new length of the cacheline (including the existing segments)
   438 					 This must be greater then the existing length.
   439 
   440 @return KErrNone if successful
   441 		or other system wide error code.
   442 */
   443 TInt CCacheManager::ExtendCacheLine(CCacheClient* aClient, const TCacheLine& aCacheLine, TInt aSegmentCount)
   444 	{
   445 	CacheLock();
   446 
   447 	__ASSERT_DEBUG(aSegmentCount > 0, Fault(EInvalidSegmentCount));
   448 
   449 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   450 	__CACHELINE_INVARIANT((cacheLine));
   451 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidSegmentCount));
   452 	__ASSERT_DEBUG(aSegmentCount > cacheLine.iAllocatedSegments, Fault(EInvalidSegmentCount));
   453 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(EInvalidLockCount));	// must be locked already
   454 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EExtendingUnownedCacheline));
   455 
   456 	// ensure all pages in cachline are locked
   457 	__ASSERT_DEBUG(cacheLine.iLockedSegmentStart == 0, Fault(EInvalidLockRange));
   458 	__ASSERT_DEBUG(cacheLine.iLockedSegmentCount == cacheLine.iAllocatedSegments, Fault(EInvalidLockRange));
   459 
   460 	__CACHE_PRINT2(_L("CACHEMAN: ExtendCacheLine(%08X, %d)"), cacheLine.iAddr, aSegmentCount);
   461 
   462 	// Commit the new segments
   463 	TUint8* addrNewSegment = cacheLine.iAddr + (cacheLine.iAllocatedSegments << KSegmentSizeLog2);
   464 	TInt segmentCountNew = aSegmentCount - cacheLine.iAllocatedSegments;
   465 
   466 	TInt r = Commit(addrNewSegment, segmentCountNew);
   467 	if (r == KErrNone)
   468 		{
   469 		cacheLine.iAllocatedSegments = cacheLine.iLockedSegmentCount = (TUint8) aSegmentCount;
   470 		}
   471 	
   472 
   473 	CacheUnlock();
   474 	return r;
   475 	}
   476 
   477 /**
   478 CCacheManager::ReUseCacheLine()
   479 
   480 Attempts to lock and then extend or shrink an already owned cacheline, ready for re-use.
   481 If successful the cacheline is returned locked and all segments are marked as empty.
   482 The cacheline must initially be unlocked.
   483 
   484 @param aCacheLine A reference to an unlocked cacheline
   485 @param aSegmentCount The new length of the cacheline;
   486 					 this may be greater or less than the existing length.
   487 
   488 @return KErrNone if successful
   489 		or other system wide error code.
   490 */
   491 TInt CCacheManager::ReAllocateAndLockCacheLine(CCacheClient* aClient, TInt64 aPos, const TCacheLine& aCacheLine, TInt aSegmentCount)
   492 	{
   493 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   494 	__CACHELINE_INVARIANT((cacheLine));
   495 
   496 	__ASSERT_DEBUG(aSegmentCount > 0, Fault(EInvalidSegmentCount));
   497 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidSegmentCount));
   498 
   499 	__CACHE_PRINT2(_L("CACHEMAN: ReUseCacheLine(%08X, %d)"), cacheLine.iAddr, aSegmentCount);
   500 
   501 	TInt r;
   502 	// old cacheline same size or bigger ?
   503 	if (cacheLine.iAllocatedSegments >= aSegmentCount)
   504 		{
   505 		r = LockCacheLine(aClient, aCacheLine, 0, aSegmentCount);
   506 		if (r!= KErrNone)
   507 			return r;
   508 		if (cacheLine.iAllocatedSegments > aSegmentCount)
   509 			{
   510 			cacheLine.iFilledSegments = (TUint8) aSegmentCount;
   511 			RemoveEmptySegments(aClient, aCacheLine);
   512 			}
   513 		}
   514 	// old cacheline smaller
   515 	else 
   516 		{
   517 		r = LockCacheLine(aClient, aCacheLine, 0, cacheLine.iAllocatedSegments);
   518 		if (r != KErrNone)
   519 			return r;
   520 		r = ExtendCacheLine(aClient, aCacheLine, aSegmentCount);
   521 		if (r != KErrNone)
   522 			{
   523 			UnlockCacheLine(aClient, aCacheLine);
   524 			return r;
   525 			}
   526 		}
   527 	cacheLine.iFilledSegments = 0;
   528 	cacheLine.iPos = aPos;
   529 
   530 	return KErrNone;
   531 	}
   532 
   533 
   534 /**
   535 CCacheManager::LockCacheLine()
   536 
   537 @return KErrNone on success
   538 */
   539 TInt CCacheManager::LockCacheLine(
   540 	CCacheClient* aClient, 
   541 	const TCacheLine& aCacheLine,
   542 	TInt aLockedPageStart,
   543 	TInt aLockedPageCount)
   544 	{
   545 	CacheLock();
   546 
   547 
   548 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   549 	__CACHELINE_INVARIANT((cacheLine));
   550 	
   551 	// has the cacheline been stolen ?
   552 	if (cacheLine.iClient != aClient)
   553 		{
   554 		__CACHE_PRINT(_L("CCacheManager::LockCacheLine(), Cacheline Stolen !\n"));
   555 		CacheUnlock();
   556 		return KErrNotFound;
   557 		}
   558 	
   559 	// validate lock range
   560 	__ASSERT_DEBUG(aLockedPageStart >= 0, Fault(EInvalidLockRange));
   561 	__ASSERT_DEBUG(aLockedPageStart + aLockedPageCount <= cacheLine.iAllocatedSegments, Fault(EInvalidLockRange));
   562 	__ASSERT_DEBUG(aLockedPageCount <= iSegmentsPerCacheLine, Fault(EInvalidLockRange));
   563 	// if already locked, don't allow lock range to grow down or up (to simplify code)
   564 	__ASSERT_DEBUG(cacheLine.iLockCount == 0 || 
   565 			aLockedPageStart >= cacheLine.iLockedSegmentStart, 
   566 		Fault(EInvalidLockRange));
   567 	__ASSERT_DEBUG(cacheLine.iLockCount == 0 || 
   568 		aLockedPageStart + aLockedPageCount <= cacheLine.iLockedSegmentStart + cacheLine.iLockedSegmentCount, 
   569 		Fault(EInvalidLockRange));
   570 	
   571 	__CACHE_PRINT1(_L("CACHEMAN: LockCacheLine(%08X, %d)"), cacheLine.iAddr);
   572 
   573 	if (InUse(aCacheLine))
   574 		{
   575 		__CACHE_PRINT(_L("CCacheManager::LockCacheLine(), Cacheline in use !\n"));
   576 		CacheUnlock();
   577 		return KErrInUse;
   578 		}
   579 
   580 	TInt lockErr = KErrNone;
   581 	
   582 	// increment the lock count
   583 	// if not already locked, lock requested segments
   584 	if (cacheLine.iLockCount++ == 0)
   585 		{
   586 #ifdef __LOCK_ENTIRE_CACHELINE__
   587 		lockErr = Lock(cacheLine.iAddr, cacheLine.iAllocatedSegments);
   588 #else
   589 		__ASSERT_DEBUG(cacheLine.iDirtySegments == 0, Fault(ELockingAndAlreadyDirty));
   590 		lockErr = Lock(	cacheLine.iAddr + (aLockedPageStart<<KSegmentSizeLog2), aLockedPageCount);
   591 #endif
   592 
   593 		if (lockErr == KErrNone)
   594 			{
   595 			cacheLine.iLockedSegmentStart = (TUint8) aLockedPageStart;
   596 			cacheLine.iLockedSegmentCount = (TUint8) aLockedPageCount;
   597 			}
   598 		else	// if (lockErr != KErrNone)
   599 			{
   600 			__CACHE_PRINT2(_L("CACHEMAN: LockCacheLine(%08X) failure %d"), cacheLine.iAddr, lockErr);
   601 			cacheLine.iLockCount--;
   602 			// NB a lock failure implies segment is decomitted
   603 			FreeCacheLine(cacheLine);
   604 			}
   605 		}
   606 	// if already locked (because cacheline is dirty) ensure lock range 
   607 	// isn't growing (this isn't allowed to keep the code simpler) 
   608 	else
   609 		{
   610 		__ASSERT_DEBUG(cacheLine.iLockedSegmentStart == 0, Fault(EInvalidLockRange));
   611 		__ASSERT_DEBUG(cacheLine.iLockedSegmentCount >= aLockedPageStart + aLockedPageCount, Fault(EInvalidLockRange));
   612 		}
   613 
   614 	CacheUnlock();
   615 	return lockErr;
   616 	}
   617 
   618 /**
   619 UnlockCacheLine()
   620 */
   621 TBool CCacheManager::UnlockCacheLine(CCacheClient* aClient, const TCacheLine& aCacheLine)
   622 	{
   623 	CacheLock();
   624 
   625 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   626 	__CACHELINE_INVARIANT((cacheLine));
   627 	
   628 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(EInvalidLockCount));
   629 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EUnlockingUnownedCacheline));
   630 
   631 	
   632 	__CACHE_PRINT2(_L("CACHEMAN: UnlockCacheLine(%08X, %d)"), cacheLine.iAddr, cacheLine.iAllocatedSegments);
   633 
   634 
   635 	// decrement the lock count
   636 	TBool success = ETrue;
   637 
   638 	if (cacheLine.iLockCount > 1)
   639 		{
   640 		cacheLine.iLockCount--;
   641 		}
   642 	else
   643 		{
   644 		if (cacheLine.iDirtySegments == 0)
   645 			{
   646 			cacheLine.iLockCount--;
   647 #ifdef __LOCK_ENTIRE_CACHELINE__
   648 			Unlock(cacheLine.iAddr, cacheLine.iAllocatedSegments);
   649 #else
   650 			Unlock(
   651 				cacheLine.iAddr + (cacheLine.iLockedSegmentStart<<KSegmentSizeLog2), 
   652 				cacheLine.iLockedSegmentCount);
   653 #endif
   654 
   655 			cacheLine.iLockedSegmentStart = cacheLine.iLockedSegmentCount = 0;
   656 			}
   657 		else
   658 			{
   659 			__CACHE_PRINT(_L("CACHEMAN: UnlockCacheLine - not unlocking segment dirty"));
   660 			success = EFalse;
   661 			}
   662 		}
   663 
   664 	CacheUnlock();
   665 
   666 	return success;
   667 	}
   668 
   669 
   670 
   671 TBool CCacheManager::StealCacheLine(CCacheClient* aClient)
   672 	{
   673 	__ASSERT_DEBUG(iManagerLocked, Fault(EManagerNotLocked));
   674 
   675 	TInt usedQueueSize = iUsedQueue.Count();
   676 
   677 	#define INC_INDEX(x) (x++, x = (x >= usedQueueSize ? 0 : x))
   678 
   679 	__CACHE_PRINT2(_L("CACHEMAN: StealCacheLine, iNextCacheLineToSteal %d used count %d"), iNextCacheLineToSteal, iUsedQueue.Count());
   680 
   681 	TInt iInitIndex = iNextCacheLineToSteal;
   682 
   683 	// Loop through all used cachelines, starting at the last stolen 
   684 	// cacheline index + 1 and ending when we find a suitable cacheline 
   685 	// to steal or we have looped back to the start
   686 	for (INC_INDEX(iNextCacheLineToSteal);
   687 		iNextCacheLineToSteal != iInitIndex; 
   688 		INC_INDEX(iNextCacheLineToSteal))
   689 		{
   690 		TCacheLine& cacheLine = *iUsedQueue[iNextCacheLineToSteal];
   691 		if (cacheLine.iLockCount == 0 && cacheLine.iClient != aClient)
   692 			{
   693 			__CACHE_PRINT3(_L("CACHEMAN: StealCacheLine, stealing %d from %08X to %08X"), 
   694 				  iNextCacheLineToSteal, cacheLine.iClient, aClient);
   695 			FreeCacheLine(cacheLine);
   696 			return ETrue;
   697 			}
   698 		}
   699 	return EFalse;
   700 	}
   701 
   702 
   703 TBool CCacheManager::FreeCacheLine(CCacheClient* aClient, const TCacheLine& aCacheLine)
   704 	{
   705 	CacheLock();
   706 
   707 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   708 	__CACHELINE_INVARIANT((cacheLine));
   709 
   710 	// Has the cacheline been stolen ? (Assume success if it has)
   711 	if (cacheLine.iClient != aClient)
   712 		{
   713 		__CACHE_PRINT(_L("CCacheManager::FreeCacheLine(), Cacheline Stolen !!!!\n"));
   714 		CacheUnlock();
   715 		return ETrue;		
   716 		}
   717 	
   718 	// Is the cacheline locked ?
   719 	if (cacheLine.iLockCount > 0)
   720 		{
   721 		__CACHE_PRINT(_L("CCacheManager::FreeCacheLine(), attempt to free locked cacheline\n"));
   722 		CacheUnlock();
   723 		return EFalse;
   724 		}
   725 
   726 	FreeCacheLine(cacheLine);
   727 
   728 	CacheUnlock();
   729 	return ETrue;
   730 	}
   731 
   732 TInt CCacheManager::LockCount(CCacheClient* aClient, const TCacheLine& aCacheLine)
   733 	{
   734 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   735 	__CACHELINE_INVARIANT((cacheLine));
   736 	
   737 	// cacheline stolen ?
   738 	if (cacheLine.iClient != aClient)
   739 		return 0;
   740 
   741 	return cacheLine.iLockCount;
   742 	}
   743 
   744 TInt CCacheManager::FillCount(CCacheClient* aClient, const TCacheLine& aCacheLine)
   745 	{
   746 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   747 	__CACHELINE_INVARIANT((cacheLine));
   748 	
   749 	// cacheline stolen ?
   750 	if (cacheLine.iClient != aClient)
   751 		return 0;
   752 
   753 	return cacheLine.iFilledSegments;
   754 	}
   755 
   756 TInt CCacheManager::DirtyCount(CCacheClient* aClient, const TCacheLine& aCacheLine)
   757 	{
   758 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   759 	__CACHELINE_INVARIANT((cacheLine));
   760 
   761 	// cacheline stolen ?
   762 	if (cacheLine.iClient != aClient)
   763 		return 0;
   764 
   765 	return cacheLine.iDirtySegments;
   766 	}
   767 
   768 TBool CCacheManager::InUse(const TCacheLine& aCacheLine)
   769 	{
   770 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   771 	__CACHELINE_INVARIANT((cacheLine));
   772 
   773 	// busy if lock count >= 1 and there are no dirty segments
   774 	// or   if lock count >= 2 and there are dirty segments
   775 	return (cacheLine.iLockCount - 
   776 		   (cacheLine.iDirtySegments?1:0)) > 0 ? (TBool)ETrue : (TBool)EFalse;
   777 	}
   778 
   779 void CCacheManager::SetFilled(CCacheClient* aClient, const TCacheLine& aCacheLine,  TInt aSegmentCount)
   780 	{
   781 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   782 	__CACHELINE_INVARIANT((cacheLine));
   783 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidSegmentCount));
   784 	__ASSERT_DEBUG(aSegmentCount <= cacheLine.iAllocatedSegments , Fault(EInvalidDirtyCount));
   785 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(ESetFilledNotLocked));
   786 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EExtendingUnownedCacheline));
   787 
   788 	
   789 	cacheLine.iFilledSegments = Max(cacheLine.iFilledSegments, (TUint8) aSegmentCount);
   790 
   791 	__ASSERT_DEBUG(cacheLine.iFilledSegments >= cacheLine.iDirtySegments , Fault(EInvalidDirtyCount));
   792 	}
   793 
   794 void CCacheManager::SetDirty(CCacheClient* aClient, const TCacheLine& aCacheLine,  TInt aSegmentCount)
   795 	{
   796 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   797 	__CACHELINE_INVARIANT((cacheLine));
   798 	__ASSERT_DEBUG(aSegmentCount <= iSegmentsPerCacheLine, Fault(EInvalidSegmentCount));
   799 	__ASSERT_DEBUG(aSegmentCount <= cacheLine.iAllocatedSegments , Fault(EInvalidDirtyCount));
   800 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(ESetDirtyNotLocked));
   801 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EExtendingUnownedCacheline));
   802 
   803 	// ensure that lock range is valid - we insist on dirty
   804 	// cachelines having all dirty pages locked up to the the last dirty page
   805 	__ASSERT_DEBUG(cacheLine.iLockedSegmentStart == 0, Fault(ESetDirtyInvalidLockRange));
   806 	__ASSERT_DEBUG(cacheLine.iLockedSegmentCount >= aSegmentCount, Fault(ESetDirtyInvalidLockRange));
   807 	
   808 	cacheLine.iFilledSegments = Max(cacheLine.iFilledSegments, (TUint8) aSegmentCount);
   809 	cacheLine.iDirtySegments = Max(cacheLine.iDirtySegments, (TUint8) aSegmentCount);
   810 
   811 	__ASSERT_DEBUG(cacheLine.iFilledSegments >= cacheLine.iDirtySegments , Fault(EInvalidDirtyCount));
   812 	}
   813 
   814 void CCacheManager::ClearDirty(CCacheClient* aClient, const TCacheLine& aCacheLine)
   815 	{
   816 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   817 	__CACHELINE_INVARIANT((cacheLine));
   818 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(EClearDirtyNotLocked));
   819 	__ASSERT_ALWAYS(cacheLine.iClient == aClient, Fault(EExtendingUnownedCacheline));
   820 
   821 	TInt dirtySegments = cacheLine.iDirtySegments;
   822 	cacheLine.iDirtySegments = 0;
   823 	SetFilled(aClient, cacheLine, dirtySegments);
   824 	UnlockCacheLine(aClient, cacheLine);
   825 	}
   826 
   827 
   828 void CCacheManager::RemoveEmptySegments(CCacheClient* aClient, const TCacheLine& aCacheLine)
   829 	{
   830 	CacheLock();
   831 
   832 	TCacheLine& cacheLine = const_cast<TCacheLine&>(aCacheLine);
   833 	__CACHELINE_INVARIANT((cacheLine));
   834 
   835 	// has the cacheline been stolen ?
   836 	if (cacheLine.iClient != aClient)
   837 		{
   838 		__CACHE_PRINT(_L("CCacheManager::RemoveEmptySegments((), Cacheline Stolen ! !!!\n"));
   839 		CacheUnlock();
   840 		return;
   841 		}
   842 		
   843 	__ASSERT_DEBUG(cacheLine.iLockCount > 0, Fault(ERemovingEmptyUnlocked));
   844 
   845 	// Unlock any locked segments past the last filled segment
   846 	TInt filledSegmentCount = cacheLine.iFilledSegments;
   847 	TInt firstSegmentToUnlock;
   848 	TInt segmentsToUnlock;
   849 #ifdef __LOCK_ENTIRE_CACHELINE__
   850 	firstSegmentToUnlock = filledSegmentCount;
   851 	segmentsToUnlock = cacheLine.iAllocatedSegments - filledSegmentCount;
   852 #else
   853 	TInt firstLockedSegment = cacheLine.iLockedSegmentStart;
   854 	if (firstLockedSegment <= filledSegmentCount)
   855 		{
   856 		firstSegmentToUnlock = filledSegmentCount;
   857 		segmentsToUnlock = firstLockedSegment + cacheLine.iLockedSegmentCount - filledSegmentCount;
   858 		}
   859 	else
   860 		{
   861 		firstSegmentToUnlock = firstLockedSegment;
   862 		segmentsToUnlock = cacheLine.iLockedSegmentCount;
   863 		}
   864 #endif
   865 	TUint8* addrFirstSegmentToUnlock = 
   866 		cacheLine.iAddr + (firstSegmentToUnlock << KSegmentSizeLog2);
   867 	if (segmentsToUnlock > 0)
   868 		{
   869 		Unlock(addrFirstSegmentToUnlock, segmentsToUnlock);
   870 		cacheLine.iLockedSegmentCount = 
   871 			(TUint8) (cacheLine.iLockedSegmentCount - segmentsToUnlock);
   872 		}
   873 
   874 	// Decommit any segments past the last filled segment
   875 	Decommit(
   876 		cacheLine.iAddr + (filledSegmentCount << KSegmentSizeLog2), 
   877 		cacheLine.iAllocatedSegments - filledSegmentCount);
   878 	cacheLine.iAllocatedSegments = (TUint8) filledSegmentCount;
   879 
   880 	CacheUnlock();
   881 	}
   882 
   883 
   884 void CCacheManager::FreeCacheLine(TCacheLine& aCacheLine)
   885 	{
   886 	__ASSERT_DEBUG(iManagerLocked, Fault(EManagerNotLocked));
   887 	aCacheLine.iClient = NULL;
   888 	__ASSERT_ALWAYS( (aCacheLine.iLockCount == 0), Fault(EFreeingLockedCacheLine));
   889 	__ASSERT_ALWAYS( (aCacheLine.iDirtySegments == 0), Fault(EFreeingDirtyCacheLine));
   890 
   891 	Decommit(aCacheLine.iAddr, aCacheLine.iAllocatedSegments);
   892 	aCacheLine.iAllocatedSegments = 0;
   893 	aCacheLine.iFilledSegments = 0;
   894 	aCacheLine.iLockedSegmentStart = 0;
   895 	aCacheLine.iLockedSegmentCount = 0;
   896 
   897 	// Remove from used queue
   898 	TInt index = iUsedQueue.FindInAddressOrder(&aCacheLine);
   899 	__ASSERT_ALWAYS(index != KErrNotFound, Fault(ESegmentNotFound));
   900 	iUsedQueue.Remove(index);
   901 
   902 	// put back on free queue
   903 //	TInt r = iFreeQueue.Append(&aCacheLine);
   904 	TInt r = iFreeQueue.InsertInAddressOrder(&aCacheLine);
   905 	__ASSERT_ALWAYS(r == KErrNone, Fault(EAppendToFreeQueueFailed));
   906 
   907 	__CACHE_PRINT2(_L("CACHEMAN: FreeCacheLine, iFreeQueue %d iUsedQueue %d"), iFreeQueue.Count(), iUsedQueue.Count());
   908 	}
   909 
   910 
   911 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
   912 void CCacheManager::DumpCacheLine(TCacheLine& aCacheLine)
   913 	{
   914 	RDebug::Print(_L("CACHEMAN: Cacheline client %08X addr %08X pos %d alloc %d filled %d dirty %d lock %d \tData: %02X %02X %02X %02X %02X %02X %02X %02X "), 
   915 		aCacheLine.iClient,
   916 		aCacheLine.iAddr,
   917 		I64LOW(aCacheLine.iPos),
   918 
   919 		aCacheLine.iAllocatedSegments,
   920 		aCacheLine.iFilledSegments,
   921 		aCacheLine.iDirtySegments,
   922 		aCacheLine.iLockCount,
   923 
   924 		aCacheLine.iAddr[0], 
   925 		aCacheLine.iAddr[1], 
   926 		aCacheLine.iAddr[2], 
   927 		aCacheLine.iAddr[3], 
   928 		aCacheLine.iAddr[4], 
   929 		aCacheLine.iAddr[5], 
   930 		aCacheLine.iAddr[6], 
   931 		aCacheLine.iAddr[7]
   932 		);
   933 	}
   934 
   935 void CCacheManager::DumpCache()
   936 	{
   937 	CacheLock();
   938 	
   939 	RPointerArray<CCacheClient> clients;
   940 
   941 	RDebug::Print(_L("**** CACHEMAN: CacheLines ****\n"));
   942 	TInt usedQueueSize = iUsedQueue.Count();
   943 	TInt n;
   944 	for (n=0; n<usedQueueSize; n++)
   945 		{
   946 		TCacheLine& cacheLine = *iUsedQueue[n];
   947 		DumpCacheLine(cacheLine);
   948 
   949 		clients.InsertInAddressOrder(cacheLine.iClient);
   950 		}
   951 
   952 	TInt clientCount = clients.Count();
   953 
   954 	for (n=0; n<clientCount; n++)
   955 		{
   956 		RDebug::Print(_L("**** CACHEMAN: CacheClient #%d ****\n"), n);
   957 		clients[n]->DumpCache();
   958 		}
   959 
   960 	clients.Close();
   961 
   962 	CacheUnlock();
   963 	}
   964 #endif
   965 
   966 
   967 
   968 
   969 TUint8* CCacheManager::Base()
   970 	{
   971 	return iChunk.Base();
   972 	}
   973 
   974 
   975 TInt CCacheManager::Lock(TUint8* const aAddr, TInt aSegmentCount)
   976 	{
   977 	TInt r = iChunk.Lock(aAddr-iBase, aSegmentCount << KSegmentSizeLog2);
   978 //RDebug::Print(_L("RChunk::Lock(%08X, %d) %d"), aAddr-iBase, aSegmentCount << KSegmentSizeLog2, r);
   979 	__ASSERT_DEBUG(r == KErrNone || r == KErrNoMemory || r == KErrNotFound, Fault(EUnexpectedLockFailure));
   980 
   981 	__CACHE_PRINT3(_L("CACHEMAN: LOCK %08X %d %d"), aAddr, aSegmentCount, r);
   982 
   983 #ifdef  __SIMULATE_LOCK_FAILURES__
   984 	if (SimulatedFailure(iLockFailureCount))
   985 		{
   986 		__CACHE_PRINT(_L("CACHEMAN: simulating lock failure"));
   987 		r = KErrNotFound;
   988 		}
   989 #endif
   990 
   991 	if (r == KErrNone)
   992 		{
   993 		iLockedSegmentCount+= aSegmentCount;
   994 		}
   995 	else
   996 		{
   997 		__CACHE_PRINT(_L("CACHEMAN: LOCK FAILED"));
   998 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
   999 		iStats.iLockFailureCount++;
  1000 #endif
  1001 		}
  1002 
  1003 	return r;
  1004 	}
  1005 
  1006 TInt CCacheManager::Unlock(TUint8* const aAddr, TInt aSegmentCount)
  1007 	{
  1008 	TInt r = iChunk.Unlock(aAddr-iBase, aSegmentCount << KSegmentSizeLog2);
  1009 //RDebug::Print(_L("RChunk::Unlock(%08X, %d) %d"), aAddr-iBase, aSegmentCount << KSegmentSizeLog2, r);
  1010 
  1011 	__CACHE_PRINT3(_L("CACHEMAN: UNLOCK %08X %d %d"), aAddr, aSegmentCount, r);
  1012 	if (r == KErrNone)
  1013 		{
  1014 		iLockedSegmentCount-= aSegmentCount;
  1015 		}
  1016 	else
  1017 		{
  1018 		__CACHE_PRINT(_L("CACHEMAN: UNLOCK FAILED"));
  1019 		}
  1020 
  1021 	return r;
  1022 	}
  1023 
  1024 TInt CCacheManager::Commit(TUint8* const aAddr, TInt aSegmentCount)
  1025 	{
  1026 #ifdef  __SIMULATE_LOCK_FAILURES__
  1027 	if (SimulatedFailure(iCommitFailureCount))
  1028 		{
  1029 		__CACHE_PRINT(_L("CACHEMAN: simulating commit failure "));
  1030 		return KErrNoMemory;
  1031 		}
  1032 #endif
  1033 
  1034 	TInt r = iChunk.Commit(aAddr-iBase, aSegmentCount << KSegmentSizeLog2);
  1035 //RDebug::Print(_L("RChunk::Commit(%08X, %d) %d, "), aAddr-iBase, aSegmentCount << KSegmentSizeLog2, r);
  1036 	
  1037 	__CACHE_PRINT3(_L("CACHEMAN: COMMIT: %08X %d %d, "), aAddr, aSegmentCount, r);
  1038 	if (r == KErrNone)
  1039 		{
  1040 		iLockedSegmentCount+= aSegmentCount;
  1041 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
  1042 		iStats.iAllocatedSegmentCount+= aSegmentCount;
  1043 #endif
  1044 		}
  1045 	else
  1046 		{
  1047 		__CACHE_PRINT(_L("CACHEMAN: COMMIT FAILED"));
  1048 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
  1049 		iStats.iCommitFailureCount++;
  1050 #endif
  1051 		}
  1052 
  1053 
  1054 	__ASSERT_DEBUG(r == KErrNone || r == KErrNoMemory, Fault(EUnexpectedCommitFailure));
  1055 
  1056 	return r;
  1057 	}
  1058 
  1059 TInt CCacheManager::Decommit(TUint8* const aAddr, TInt aSegmentCount)
  1060 	{
  1061 	TInt r = iChunk.Decommit(aAddr-iBase, aSegmentCount << KSegmentSizeLog2);
  1062 //RDebug::Print(_L("RChunk::Decommit(%08X, %d), %d"), aAddr-iBase, aSegmentCount << KSegmentSizeLog2, r);
  1063 
  1064 	__CACHE_PRINT3(_L("CACHEMAN: DECOMMIT: %08X %d %d, "), aAddr, aSegmentCount, r);
  1065 	if (r == KErrNone)
  1066 		{
  1067 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
  1068 		iStats.iAllocatedSegmentCount-= aSegmentCount;
  1069 #endif
  1070 		}
  1071 	else
  1072 		{
  1073 		__CACHE_PRINT(_L("CACHEMAN: DECOMMIT FAILED"));
  1074 		}
  1075 
  1076 	return r;
  1077 	}
  1078 
  1079 #if defined(_DEBUG) || defined(_DEBUG_RELEASE)
  1080 
  1081 void CCacheManager::SimulateLockFailureMode(TBool aEnable)
  1082 	{
  1083 	iSimulateLockFailureMode = aEnable;
  1084 __CACHE_PRINT1(_L("CACHEMAN: SimulateLockFailureMode: %d, "), iSimulateLockFailureMode);
  1085 	}
  1086 
  1087 void CCacheManager::AllocateMaxSegments(TBool aEnable)
  1088 	{
  1089 	iAllocateMaxSegments = aEnable;
  1090 __CACHE_PRINT1(_L("CACHEMAN: iAllocateMaxSegments: %d, "), iAllocateMaxSegments);
  1091 	}
  1092 
  1093 TBool CCacheManager::AllocateMaxSegments()
  1094 	{
  1095 	return iAllocateMaxSegments;
  1096 	}
  1097 
  1098 void CCacheManager::SimulateWriteFailure()
  1099 	{
  1100 	iSimulateWriteFailure = ETrue;
  1101 	}
  1102 
  1103 TBool CCacheManager::SimulateWriteFailureEnabled()
  1104 	{
  1105 	TBool b = iSimulateWriteFailure;
  1106 	iSimulateWriteFailure = EFalse;
  1107 	return b;
  1108 	}
  1109 
  1110 TBool CCacheManager::SimulatedFailure(TInt& aFailureCount)
  1111 	{
  1112 #ifdef  __SIMULATE_LOCK_FAILURES__
  1113 	if (iSimulateLockFailureMode)
  1114 		{
  1115 #if defined  (__RAMDOM_LOCK_FAILURES__)
  1116 		static TInt FailCount = 15;
  1117 		if (++aFailureCount >= FailCount)
  1118 #elif defined (__PSEUDO_RANDOM_FAILURES__)
  1119 		const TInt FailCounts[] = {15,2,0,21,1,12,24};
  1120 		const TInt FailCountSize = sizeof(FailCounts) / sizeof(TInt);
  1121 		static TInt FailCountIndex = 0; 
  1122 		if (++aFailureCount >= FailCounts[FailCountIndex])
  1123 #else
  1124 		const TInt KFailCount = 15;
  1125 		if (++aFailureCount >= KFailCount)
  1126 #endif
  1127 			{
  1128 			aFailureCount = 0;
  1129 #if defined (__RAMDOM_LOCK_FAILURES__)
  1130 			FailCount = Math::Random() & 0x1F;
  1131 			__CACHE_PRINT1(_L("FailCount %d"), FailCount);
  1132 #endif
  1133 
  1134 #if defined (__PSEUDO_RANDOM_FAILURES__)
  1135 			FailCountIndex = (FailCountIndex +1) % FailCountSize ;
  1136 			__CACHE_PRINT1(_L("FailCount %d"), FailCounts[FailCountIndex]);
  1137 #endif
  1138 
  1139 			return ETrue;
  1140 			}
  1141 		}
  1142 #endif
  1143 	return EFalse;
  1144 	}
  1145 #endif	// defined(_DEBUG) || defined(_DEBUG_RELEASE)
  1146 
  1147 //************************************
  1148 // TGlobalFileCacheSettings
  1149 //************************************
  1150 
  1151 //TGlobalCacheFlags TGlobalFileCacheSettings::iFlags = TGlobalCacheFlags(ECacheEnabled);
  1152 TInt32 TGlobalFileCacheSettings::iCacheSize	= KDefaultGlobalCacheSize << KByteToByteShift;
  1153 TInt32 TGlobalFileCacheSettings::iMaxLockedSize	= KDefaultGlobalCacheMaxLockedSize << KByteToByteShift;
  1154 TInt32 TGlobalFileCacheSettings::iLowMemoryThreshold = KDefaultLowMemoryThreshold;
  1155 TBool TGlobalFileCacheSettings::iEnabled	= KDefaultGlobalCacheEnabled; 
  1156 
  1157 _LIT8(KLitSectionNameFileCache,"FileCache");
  1158 
  1159 void TGlobalFileCacheSettings::ReadPropertiesFile()
  1160 	{
  1161 	F32Properties::GetBool(KLitSectionNameFileCache, _L8("GlobalCacheEnabled"), iEnabled);
  1162 	
  1163 	// Get size of cache in kilobytes
  1164 	TInt32 cacheSizeInKBytes;
  1165 	if (F32Properties::GetInt(KLitSectionNameFileCache, _L8("GlobalCacheSize"), cacheSizeInKBytes))
  1166 		iCacheSize = cacheSizeInKBytes << KByteToByteShift;
  1167 
  1168 	// Get maximum amount of locked data i.e data unavailable for paging
  1169 	TInt32 maxLockedSize;
  1170 	if (F32Properties::GetInt(KLitSectionNameFileCache, _L8("GlobalCacheMaxLockedSize"), maxLockedSize))
  1171 		iMaxLockedSize = maxLockedSize << KByteToByteShift;
  1172 
  1173 	// Get low memory threshold
  1174 	TInt32 lowMemoryThreshold;
  1175 	if (F32Properties::GetInt(KLitSectionNameFileCache, _L8("LowMemoryThreshold"), lowMemoryThreshold))
  1176 		iLowMemoryThreshold = lowMemoryThreshold;
  1177 
  1178 	}
  1179 
  1180 
  1181 TBool TGlobalFileCacheSettings::Enabled()
  1182 	{
  1183 	return iEnabled;
  1184 	}
  1185 
  1186 TInt TGlobalFileCacheSettings::CacheSize()
  1187 	{
  1188 	return iCacheSize;
  1189 	}
  1190 TInt TGlobalFileCacheSettings::MaxLockedSize()
  1191 	{
  1192 	return iMaxLockedSize;
  1193 	}
  1194 
  1195 TInt TGlobalFileCacheSettings::LowMemoryThreshold()
  1196 	{
  1197 	return iLowMemoryThreshold;
  1198 	}