Leaked source code of windows server 2003
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423 lines
15 KiB

// Ruler
// 1 2 3 4 5 6 7 8
//345678901234567890123456789012345678901234567890123456789012345678901234567890
/********************************************************************/
/* */
/* The standard layout. */
/* */
/* The standard layout for 'cpp' files in this code is as */
/* follows: */
/* */
/* 1. Include files. */
/* 2. Constants local to the class. */
/* 3. Data structures local to the class. */
/* 4. Data initializations. */
/* 5. Static functions. */
/* 6. Class functions. */
/* */
/* The constructor is typically the first function, class */
/* member functions appear in alphabetical order with the */
/* destructor appearing at the end of the file. Any section */
/* or function this is not required is simply omitted. */
/* */
/********************************************************************/
#include "InterfacePCH.hpp"
#include "Assembly.hpp"
#include "Prefetch.hpp"
#include "Spinlock.hpp"
#include "ZoneHeap.hpp"
/********************************************************************/
/* */
/* Constants local to the class. */
/* */
/* The constants supplied here try to make the layout of the */
/* the caches easier to understand and update. */
/* */
/********************************************************************/
CONST SBIT32 AlignmentMask = (sizeof(double)-1);
CONST SBIT32 FindCacheSize = 2048;
CONST SBIT32 FindCacheThreshold = 0;
CONST SBIT32 FindSize = 1024;
CONST SBIT32 Stride1 = 1024;
CONST SBIT32 Stride2 = 1024;
CONST SBIT32 ZonePageSize = 4096;
/********************************************************************/
/* */
/* The description of the heap. */
/* */
/* A heap is a collection of fixed sized allocation caches. */
/* An allocation cache consists of an allocation size, the */
/* number of pre-built allocations to cache, a chunk size and */
/* a parent page size which is sub-divided to create elements */
/* for this cache. A heap consists of two arrays of caches. */
/* Each of these arrays has a stride (i.e. 'Stride1' and */
/* 'Stride2') which is typically the smallest common factor of */
/* all the allocation sizes in the array. */
/* */
/********************************************************************/
STATIC ROCKALL::CACHE_DETAILS Caches1[] =
{
//
// Bucket Size Of Bucket Parent
// Size Cache Chunks Page Size
//
{ 4096, 8, 65536, 65536 },
{ 0,0,0,0 }
};
STATIC ROCKALL::CACHE_DETAILS Caches2[] =
{
//
// Bucket Size Of Bucket Parent
// Size Cache Chunks Page Size
//
{ 5120, 4, 65536, 65536 },
{ 6144, 4, 65536, 65536 },
{ 7168, 4, 65536, 65536 },
{ 8192, 8, 65536, 65536 },
{ 9216, 0, 65536, 65536 },
{ 10240, 0, 65536, 65536 },
{ 12288, 0, 65536, 65536 },
{ 16384, 2, 65536, 65536 },
{ 21504, 0, 65536, 65536 },
{ 32768, 0, 65536, 65536 },
{ 65536, 0, 65536, 65536 },
{ 65536, 0, 65536, 65536 },
{ 0,0,0,0 }
};
/********************************************************************/
/* */
/* The description bit vectors. */
/* */
/* All heaps keep track of allocations using bit vectors. An */
/* allocation requires 2 bits to keep track of its state. The */
/* following array supplies the size of the available bit */
/* vectors measured in 32 bit words. */
/* */
/********************************************************************/
STATIC int NewPageSizes[] = { 2,0 };
/********************************************************************/
/* */
/* Static data structures. */
/* */
/* The static data structures are initialized and prepared for */
/* use here. */
/* */
/********************************************************************/
STATIC PREFETCH Prefetch;
/********************************************************************/
/* */
/* Class constructor. */
/* */
/* The overall structure and layout of the heap is controlled */
/* by the various constants and calls made in this function. */
/* There is a significant amount of flexibility available to */
/* a heap which can lead to them having dramatically different */
/* properties. */
/* */
/********************************************************************/
ZONE_HEAP::ZONE_HEAP
(
int MaxFreeSpace,
bool Recycle,
bool SingleImage,
bool ThreadSafe
) :
//
// Call the constructors for the contained classes.
//
ROCKALL
(
Caches1,
Caches2,
FindCacheSize,
FindCacheThreshold,
FindSize,
MaxFreeSpace,
NewPageSizes,
Recycle,
SingleImage,
Stride1,
Stride2,
ThreadSafe
)
{
AUTO ZONE NewZone = { NULL,NULL };
//
// Setup the heap structures.
//
MaxSize = ZonePageSize;
ThreadLocks = ThreadSafe;
Zone = NewZone;
}
/********************************************************************/
/* */
/* Delete all allocations. */
/* */
/* Delete all the heap allocations and return all the space */
/* back to the operating system. */
/* */
/********************************************************************/
void ZONE_HEAP::DeleteAll( bool Recycle )
{
AUTO ZONE Update = { NULL,NULL };
//
// Delete all outstanding allocations.
//
ROCKALL::DeleteAll( Recycle );
//
// Delete the stale zone pointers.
//
WriteZone( & Update );
}
/********************************************************************/
/* */
/* Multiple memory allocations. */
/* */
/* We allocate by advancing a pinter down an array. This */
/* is very fast but means that it can not be deleted except */
/* by destroying the entire heap. */
/* */
/********************************************************************/
bool ZONE_HEAP::MultipleNew
(
int *Actual,
void *Array[],
int Requested,
int Size,
int *Space,
bool Zero
)
{
//
// We simply call 'New' to create each element
// for a zone heap.
//
for ( (*Actual)=0;(*Actual) < Requested;(*Actual) ++ )
{
REGISTER VOID **Current = & Array[ (*Actual) ];
//
// Create an allocation.
//
(*Current) = (ZONE_HEAP::New( Size,Space,Zero ));
//
// Exit if there is no more space.
//
if ( (*Current) == NULL )
{ return false; }
}
return true;
}
/********************************************************************/
/* */
/* Memory allocation. */
/* */
/* We allocate by advancing a pinter down an array. This */
/* is very fast but means that it can not be deleted except */
/* by destroying the entire heap. */
/* */
/********************************************************************/
void *ZONE_HEAP::New( int Size,int *Space,bool Zero )
{
//
// We would really hope that nobody would ask
// for a negative amount of memory but just to
// be sure we verify that this is not the case.
//
if ( Size >= 0 )
{
AUTO SBIT32 NewSize = ((Size + AlignmentMask) & ~AlignmentMask);
AUTO ZONE Original;
AUTO ZONE Update;
//
// We would hope to create the allocation on the
// first try but there is a possibility that it
// may take serveral tries.
do
{
//
// Extract a copy of the current zone pointers
// into local variables.
//
Original = Zone;
Update = Original;
//
// We need to ensure that there is enough space
// in the zone for the current allocation.
//
if
(
(Update.Start == NULL)
||
((Update.Start += NewSize) > Update.End)
)
{
//
// We do not have enough space. If the size
// seems reasonable then get a new block from
// Rockall. If not just pass the request along
// to Rockall.
//
if ( NewSize <= (MaxSize / 2) )
{
STATIC SPINLOCK Spinlock;
//
// We need to create a new zone page
// so claim a lock.
//
Spinlock.ClaimLock();
//
// We may find that the zone has
// already been updated. If so
// just exit.
//
if ( Update.End == Zone.End )
{
//
// Try to allocate a new zone
// block.
//
Update.Start = ((CHAR*) ROCKALL::New( MaxSize ));
//
// Verify we were able to create
// a new zone page.
//
if ( Update.Start != NULL )
{ Update.End = (Update.Start + MaxSize); }
else
{ Update.End = NULL; }
//
// Update the zone.
//
WriteZone( & Update );
}
//
// Release the lock.
//
Spinlock.ReleaseLock();
//
// If we were unable to get more
// space then exit.
//
if ( Update.Start == NULL )
{ return NULL; }
}
else
{ return (ROCKALL::New( Size,Space,Zero )); }
}
}
while ( ! UpdateZone( & Original,& Update ) );
//
// Prefetch the first cache line of
// the allocation if we are running
// a Pentium III or better.
//
Prefetch.L1( ((CHAR*) Original.Start),1 );
//
// If the caller wants to know the real
// size them we supply it.
//
if ( Space != NULL )
{ (*Space) = NewSize; }
//
// If we need to zero the allocation
// we do it here.
//
if ( Zero )
{ ZeroMemory( Original.Start,NewSize ); }
//
// Exit and return the address.
//
return (Original.Start);
}
else
{ return NULL; }
}
/********************************************************************/
/* */
/* Update the zone. */
/* */
/* Ww update the zone when we do an allocation. We do this */
/* atomically if there are multiple threads. */
/* */
/********************************************************************/
bool ZONE_HEAP::UpdateZone( ZONE *Original,ZONE *Update )
{
//
// Do we need to allow for multiple threads. If
// so we need to do the update atomically. If
// not then a simple assignment is fine.
//
if ( ThreadLocks )
{
REGISTER SBIT64 FinalValue =
(
ASSEMBLY::AtomicCompareExchange64
(
((SBIT64*) & Zone),
(*((SBIT64*) Update)),
(*((SBIT64*) Original))
)
);
return (FinalValue == (*((SBIT64*) Original)));
}
else
{
Zone = (*Update);
return True;
}
}
/********************************************************************/
/* */
/* Class destructor. */
/* */
/* Destory the heap. */
/* */
/********************************************************************/
ZONE_HEAP::~ZONE_HEAP( VOID )
{ /* void */ }