/*++

Copyright (c) 1990  Microsoft Corporation

Module Name:

    cachedat.c

Abstract:

    This module implements the Memory Management based cache management
    routines for the common Cache subsystem.

Author:

    Tom Miller      [TomM]      4-May-1990

Revision History:

--*/

#include "cc.h"


//  Global SharedCacheMap lists and resource to synchronize access to it.



extern KSPIN_LOCK CcMasterSpinLock;
LIST_ENTRY CcCleanSharedCacheMapList;
SHARED_CACHE_MAP_LIST_CURSOR CcDirtySharedCacheMapList;
SHARED_CACHE_MAP_LIST_CURSOR CcLazyWriterCursor;


//  Worker thread structures:

//      A spinlock to synchronize all three lists.
//      A count of the number of worker threads Cc will use
//      A count of the number of worker threads Cc in use
//      A listhead for preinitialized executive work items for Cc use.
//      A listhead for an express queue of WORK_QUEUE_ENTRYs
//      A listhead for a regular queue of WORK_QUEUE_ENTRYs
//      A listhead for a post-tick queue of WORK_QUEUE_ENTRYs

//    A flag indicating if we are throttling the queue to a single thread


extern KSPIN_LOCK CcWorkQueueSpinlock;
ULONG CcNumberWorkerThreads = 0;
ULONG CcNumberActiveWorkerThreads = 0;
LIST_ENTRY CcIdleWorkerThreadList;
LIST_ENTRY CcExpressWorkQueue;
LIST_ENTRY CcRegularWorkQueue;
LIST_ENTRY CcPostTickWorkQueue;

BOOLEAN CcQueueThrottle = FALSE;


//  Store the current idle delay and target time to clean all.  We must calculate
//  the idle delay in terms of clock ticks for the lazy writer timeout.


ULONG CcIdleDelayTick;
LARGE_INTEGER CcNoDelay;
LARGE_INTEGER CcFirstDelay = {(ULONG)-(3*LAZY_WRITER_IDLE_DELAY), -1};
LARGE_INTEGER CcIdleDelay = {(ULONG)-LAZY_WRITER_IDLE_DELAY, -1};
LARGE_INTEGER CcCollisionDelay = {(ULONG)-LAZY_WRITER_COLLISION_DELAY, -1};
LARGE_INTEGER CcTargetCleanDelay = {(ULONG)-(LONG)(LAZY_WRITER_IDLE_DELAY * (LAZY_WRITER_MAX_AGE_TARGET + 1)), -1};


//  Spinlock for controlling access to Vacb and related global structures,
//  and a counter indicating how many Vcbs are active.


extern KSPIN_LOCK CcVacbSpinLock;
ULONG CcNumberVacbs;


//  Pointer to the global Vacb vector.


PVACB CcVacbs;
PVACB CcBeyondVacbs;
LIST_ENTRY CcVacbLru;
ULONG CcMaxVacbLevelsSeen = 1;
ULONG CcVacbLevelEntries = 0;
PVACB *CcVacbLevelFreeList = NULL;
ULONG CcVacbLevelWithBcbsEntries = 0;
PVACB *CcVacbLevelWithBcbsFreeList = NULL;


//  Deferred write list and respective Thresholds


extern KSPIN_LOCK CcDeferredWriteSpinLock;
LIST_ENTRY CcDeferredWrites;
ULONG CcDirtyPageThreshold;
ULONG CcDirtyPageTarget;
ULONG CcPagesYetToWrite;
ULONG CcPagesWrittenLastTime = 0;
ULONG CcDirtyPagesLastScan = 0;
ULONG CcAvailablePagesThreshold = 100;
ULONG CcTotalDirtyPages = 0;


//  Captured system size


MM_SYSTEMSIZE CcCapturedSystemSize;


//  Number of outstanding aggresive zeroers in the system.  Used
//  to throttle the activity.


LONG CcAggressiveZeroCount;
LONG CcAggressiveZeroThreshold;


//  Tuning options du Jour


ULONG CcTune = 0;


//  Global structure controlling lazy writer algorithms


LAZY_WRITER LazyWriter;

NPAGED_LOOKASIDE_LIST CcTwilightLookasideList;

#ifdef CCDBG

LONG CcDebugTraceLevel = 0;
LONG CcDebugTraceIndent = 0;

#ifdef CCDBG_LOCK
extern KSPIN_LOCK CcDebugTraceLock;
#endif //  def CCDBG_LOCK

#endif


//  Global list of pinned Bcbs which may be examined for debug purposes


#if DBG

ULONG CcBcbCount;
LIST_ENTRY CcBcbList;
extern KSPIN_LOCK CcBcbSpinLock;

#endif


//  Throw away miss counter.


ULONG CcThrowAway;


//  Performance Counters


ULONG CcFastReadNoWait;
ULONG CcFastReadWait;
ULONG CcFastReadResourceMiss;
ULONG CcFastReadNotPossible;

ULONG CcFastMdlReadNoWait;
ULONG CcFastMdlReadWait;
ULONG CcFastMdlReadResourceMiss;
ULONG CcFastMdlReadNotPossible;

ULONG CcMapDataNoWait;
ULONG CcMapDataWait;
ULONG CcMapDataNoWaitMiss;
ULONG CcMapDataWaitMiss;

ULONG CcPinMappedDataCount;

ULONG CcPinReadNoWait;
ULONG CcPinReadWait;
ULONG CcPinReadNoWaitMiss;
ULONG CcPinReadWaitMiss;

ULONG CcCopyReadNoWait;
ULONG CcCopyReadWait;
ULONG CcCopyReadNoWaitMiss;
ULONG CcCopyReadWaitMiss;

ULONG CcMdlReadNoWait;
ULONG CcMdlReadWait;
ULONG CcMdlReadNoWaitMiss;
ULONG CcMdlReadWaitMiss;

ULONG CcReadAheadIos;

ULONG CcLazyWriteHotSpots;
ULONG CcLazyWriteIos;
ULONG CcLazyWritePages;
ULONG CcDataFlushes;
ULONG CcDataPages;

PULONG CcMissCounter = &CcThrowAway;