src/sat/bsat/satMem.h File Reference

#include <stdio.h>
#include <stdlib.h>

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Typedefs
typedef struct Sat_MmFixed_t_	Sat_MmFixed_t
typedef struct Sat_MmFlex_t_	Sat_MmFlex_t
typedef struct Sat_MmStep_t_	Sat_MmStep_t
Functions
Sat_MmFixed_t *	Sat_MmFixedStart (int nEntrySize)
void	Sat_MmFixedStop (Sat_MmFixed_t *p, int fVerbose)
char *	Sat_MmFixedEntryFetch (Sat_MmFixed_t *p)
void	Sat_MmFixedEntryRecycle (Sat_MmFixed_t *p, char *pEntry)
void	Sat_MmFixedRestart (Sat_MmFixed_t *p)
int	Sat_MmFixedReadMemUsage (Sat_MmFixed_t *p)
Sat_MmFlex_t *	Sat_MmFlexStart ()
void	Sat_MmFlexStop (Sat_MmFlex_t *p, int fVerbose)
char *	Sat_MmFlexEntryFetch (Sat_MmFlex_t *p, int nBytes)
int	Sat_MmFlexReadMemUsage (Sat_MmFlex_t *p)
Sat_MmStep_t *	Sat_MmStepStart (int nSteps)
void	Sat_MmStepStop (Sat_MmStep_t *p, int fVerbose)
char *	Sat_MmStepEntryFetch (Sat_MmStep_t *p, int nBytes)
void	Sat_MmStepEntryRecycle (Sat_MmStep_t *p, char *pEntry, int nBytes)
int	Sat_MmStepReadMemUsage (Sat_MmStep_t *p)

---

Typedef Documentation

typedef struct Sat_MmFixed_t_ Sat_MmFixed_t

CFile****************************************************************

FileName [satMem.h]

PackageName [SAT solver.]

Synopsis [Memory management.]

Author [Alan Mishchenko <alanmi@eecs.berkeley.edu>]

Affiliation [UC Berkeley]

Date [Ver. 1.0. Started - January 1, 2004.]

Revision [

Id

satMem.h,v 1.0 2004/01/01 1:00:00 alanmi Exp

] INCLUDES /// PARAMETERS /// STRUCTURE DEFINITIONS ///

Definition at line 38 of file satMem.h.

typedef struct Sat_MmFlex_t_ Sat_MmFlex_t

Definition at line 39 of file satMem.h.

typedef struct Sat_MmStep_t_ Sat_MmStep_t

Definition at line 40 of file satMem.h.

---

Function Documentation

char* Sat_MmFixedEntryFetch

(

Sat_MmFixed_t *

p

)

Function*************************************************************

Synopsis []

Description []

SideEffects []

SeeAlso []

Definition at line 156 of file satMem.c.

{
    char * pTemp;
    int i;

    // check if there are still free entries
    if ( p->nEntriesUsed == p->nEntriesAlloc )
    { // need to allocate more entries
        assert( p->pEntriesFree == NULL );
        if ( p->nChunks == p->nChunksAlloc )
        {
            p->nChunksAlloc *= 2;
            p->pChunks = REALLOC( char *, p->pChunks, p->nChunksAlloc ); 
        }
        p->pEntriesFree = ALLOC( char, p->nEntrySize * p->nChunkSize );
        p->nMemoryAlloc += p->nEntrySize * p->nChunkSize;
        // transform these entries into a linked list
        pTemp = p->pEntriesFree;
        for ( i = 1; i < p->nChunkSize; i++ )
        {
            *((char **)pTemp) = pTemp + p->nEntrySize;
            pTemp += p->nEntrySize;
        }
        // set the last link
        *((char **)pTemp) = NULL;
        // add the chunk to the chunk storage
        p->pChunks[ p->nChunks++ ] = p->pEntriesFree;
        // add to the number of entries allocated
        p->nEntriesAlloc += p->nChunkSize;
    }
    // incrememt the counter of used entries
    p->nEntriesUsed++;
    if ( p->nEntriesMax < p->nEntriesUsed )
        p->nEntriesMax = p->nEntriesUsed;
    // return the first entry in the free entry list
    pTemp = p->pEntriesFree;
    p->pEntriesFree = *((char **)pTemp);
    return pTemp;
}

void Sat_MmFixedEntryRecycle	(	Sat_MmFixed_t *	p,
		char *	pEntry
	)

Function*************************************************************

Synopsis []

Description []

SideEffects []

SeeAlso []

Definition at line 207 of file satMem.c.

{
    // decrement the counter of used entries
    p->nEntriesUsed--;
    // add the entry to the linked list of free entries
    *((char **)pEntry) = p->pEntriesFree;
    p->pEntriesFree = pEntry;
}

int Sat_MmFixedReadMemUsage

(

Sat_MmFixed_t *

p

)

Function*************************************************************

Synopsis []

Description []

SideEffects []

SeeAlso []

Definition at line 265 of file satMem.c.

{
    return p->nMemoryAlloc;
}

void Sat_MmFixedRestart

(

Sat_MmFixed_t *

p

)

Function*************************************************************

Synopsis []

Description [Relocates all the memory except the first chunk.]

SideEffects []

SeeAlso []

Definition at line 227 of file satMem.c.

{
    int i;
    char * pTemp;

    // deallocate all chunks except the first one
    for ( i = 1; i < p->nChunks; i++ )
        free( p->pChunks[i] );
    p->nChunks = 1;
    // transform these entries into a linked list
    pTemp = p->pChunks[0];
    for ( i = 1; i < p->nChunkSize; i++ )
    {
        *((char **)pTemp) = pTemp + p->nEntrySize;
        pTemp += p->nEntrySize;
    }
    // set the last link
    *((char **)pTemp) = NULL;
    // set the free entry list
    p->pEntriesFree  = p->pChunks[0];
    // set the correct statistics
    p->nMemoryAlloc  = p->nEntrySize * p->nChunkSize;
    p->nMemoryUsed   = 0;
    p->nEntriesAlloc = p->nChunkSize;
    p->nEntriesUsed  = 0;
}

Sat_MmFixed_t* Sat_MmFixedStart

(

int

nEntrySize

)

GLOBAL VARIABLES /// MACRO DEFINITIONS /// FUNCTION DECLARATIONS ///

FUNCTION DEFINITIONS ///Function*************************************************************

Synopsis [Allocates memory pieces of fixed size.]

Description [The size of the chunk is computed as the minimum of 1024 entries and 64K. Can only work with entry size at least 4 byte long.]

SideEffects []

SeeAlso []

Definition at line 88 of file satMem.c.

{
    Sat_MmFixed_t * p;

    p = ALLOC( Sat_MmFixed_t, 1 );
    memset( p, 0, sizeof(Sat_MmFixed_t) );

    p->nEntrySize    = nEntrySize;
    p->nEntriesAlloc = 0;
    p->nEntriesUsed  = 0;
    p->pEntriesFree  = NULL;

    if ( nEntrySize * (1 << 10) < (1<<16) )
        p->nChunkSize = (1 << 10);
    else
        p->nChunkSize = (1<<16) / nEntrySize;
    if ( p->nChunkSize < 8 )
        p->nChunkSize = 8;

    p->nChunksAlloc  = 64;
    p->nChunks       = 0;
    p->pChunks       = ALLOC( char *, p->nChunksAlloc );

    p->nMemoryUsed   = 0;
    p->nMemoryAlloc  = 0;
    return p;
}

void Sat_MmFixedStop	(	Sat_MmFixed_t *	p,
		int	fVerbose
	)

Function*************************************************************

Synopsis []

Description []

SideEffects []

SeeAlso []

Definition at line 127 of file satMem.c.

{
    int i;
    if ( p == NULL )
        return;
    if ( fVerbose )
    {
        printf( "Fixed memory manager: Entry = %5d. Chunk = %5d. Chunks used = %5d.\n",
            p->nEntrySize, p->nChunkSize, p->nChunks );
        printf( "   Entries used = %8d. Entries peak = %8d. Memory used = %8d. Memory alloc = %8d.\n",
            p->nEntriesUsed, p->nEntriesMax, p->nEntrySize * p->nEntriesUsed, p->nMemoryAlloc );
    }
    for ( i = 0; i < p->nChunks; i++ )
        free( p->pChunks[i] );
    free( p->pChunks );
    free( p );
}

char* Sat_MmFlexEntryFetch	(	Sat_MmFlex_t *	p,
		int	nBytes
	)

Function*************************************************************

Synopsis []

Description []

SideEffects []

SeeAlso []

Definition at line 344 of file satMem.c.

{
    char * pTemp;
    // check if there are still free entries
    if ( p->pCurrent == NULL || p->pCurrent + nBytes > p->pEnd )
    { // need to allocate more entries
        if ( p->nChunks == p->nChunksAlloc )
        {
            p->nChunksAlloc *= 2;
            p->pChunks = REALLOC( char *, p->pChunks, p->nChunksAlloc ); 
        }
        if ( nBytes > p->nChunkSize )
        {
            // resize the chunk size if more memory is requested than it can give
            // (ideally, this should never happen)
            p->nChunkSize = 2 * nBytes;
        }
        p->pCurrent = ALLOC( char, p->nChunkSize );
        p->pEnd     = p->pCurrent + p->nChunkSize;
        p->nMemoryAlloc += p->nChunkSize;
        // add the chunk to the chunk storage
        p->pChunks[ p->nChunks++ ] = p->pCurrent;
    }
    assert( p->pCurrent + nBytes <= p->pEnd );
    // increment the counter of used entries
    p->nEntriesUsed++;
    // keep track of the memory used
    p->nMemoryUsed += nBytes;
    // return the next entry
    pTemp = p->pCurrent;
    p->pCurrent += nBytes;
    return pTemp;
}

int Sat_MmFlexReadMemUsage

(

Sat_MmFlex_t *

p

)

Function*************************************************************

Synopsis []

Description []

SideEffects []

SeeAlso []

Definition at line 389 of file satMem.c.

{
    return p->nMemoryAlloc;
}

Sat_MmFlex_t* Sat_MmFlexStart

(

)

Function*************************************************************

Synopsis [Allocates entries of flexible size.]

Description [Can only work with entry size at least 4 byte long.]

SideEffects []

SeeAlso []

Definition at line 283 of file satMem.c.

{
    Sat_MmFlex_t * p;

    p = ALLOC( Sat_MmFlex_t, 1 );
    memset( p, 0, sizeof(Sat_MmFlex_t) );

    p->nEntriesUsed  = 0;
    p->pCurrent      = NULL;
    p->pEnd          = NULL;

    p->nChunkSize    = (1 << 12);
    p->nChunksAlloc  = 64;
    p->nChunks       = 0;
    p->pChunks       = ALLOC( char *, p->nChunksAlloc );

    p->nMemoryUsed   = 0;
    p->nMemoryAlloc  = 0;
    return p;
}

void Sat_MmFlexStop	(	Sat_MmFlex_t *	p,
		int	fVerbose
	)

Function*************************************************************

Synopsis []

Description []

SideEffects []

SeeAlso []

Definition at line 315 of file satMem.c.

{
    int i;
    if ( p == NULL )
        return;
    if ( fVerbose )
    {
        printf( "Flexible memory manager: Chunk size = %d. Chunks used = %d.\n",
            p->nChunkSize, p->nChunks );
        printf( "   Entries used = %d. Memory used = %d. Memory alloc = %d.\n",
            p->nEntriesUsed, p->nMemoryUsed, p->nMemoryAlloc );
    }
    for ( i = 0; i < p->nChunks; i++ )
        free( p->pChunks[i] );
    free( p->pChunks );
    free( p );
}

char* Sat_MmStepEntryFetch	(	Sat_MmStep_t *	p,
		int	nBytes
	)

Function*************************************************************

Synopsis [Creates the entry.]

Description []

SideEffects []

SeeAlso []

Definition at line 474 of file satMem.c.

{
    if ( nBytes == 0 )
        return NULL;
    if ( nBytes > p->nMapSize )
    {
//        printf( "Allocating %d bytes.\n", nBytes );
        return ALLOC( char, nBytes );
    }
    return Sat_MmFixedEntryFetch( p->pMap[nBytes] );
}

void Sat_MmStepEntryRecycle	(	Sat_MmStep_t *	p,
		char *	pEntry,
		int	nBytes
	)

Function*************************************************************

Synopsis [Recycles the entry.]

Description []

SideEffects []

SeeAlso []

Definition at line 498 of file satMem.c.

{
    if ( nBytes == 0 )
        return;
    if ( nBytes > p->nMapSize )
    {
        free( pEntry );
        return;
    }
    Sat_MmFixedEntryRecycle( p->pMap[nBytes], pEntry );
}

int Sat_MmStepReadMemUsage

(

Sat_MmStep_t *

p

)

Function*************************************************************

Synopsis []

Description []

SideEffects []

SeeAlso []

Definition at line 521 of file satMem.c.

{
    int i, nMemTotal = 0;
    for ( i = 0; i < p->nMems; i++ )
        nMemTotal += p->pMems[i]->nMemoryAlloc;
    return nMemTotal;
}

Sat_MmStep_t* Sat_MmStepStart

(

int

nSteps

)

Function*************************************************************

Synopsis [Starts the hierarchical memory manager.]

Description [This manager can allocate entries of any size. Iternally they are mapped into the entries with the number of bytes equal to the power of 2. The smallest entry size is 8 bytes. The next one is 16 bytes etc. So, if the user requests 6 bytes, he gets 8 byte entry. If we asks for 25 bytes, he gets 32 byte entry etc. The input parameters "nSteps" says how many fixed memory managers are employed internally. Calling this procedure with nSteps equal to 10 results in 10 hierarchically arranged internal memory managers, which can allocate up to 4096 (1Kb) entries. Requests for larger entries are handed over to malloc() and then free()ed.]

SideEffects []

SeeAlso []

Definition at line 418 of file satMem.c.

{
    Sat_MmStep_t * p;
    int i, k;
    p = ALLOC( Sat_MmStep_t, 1 );
    p->nMems = nSteps;
    // start the fixed memory managers
    p->pMems = ALLOC( Sat_MmFixed_t *, p->nMems );
    for ( i = 0; i < p->nMems; i++ )
        p->pMems[i] = Sat_MmFixedStart( (8<<i) );
    // set up the mapping of the required memory size into the corresponding manager
    p->nMapSize = (4<<p->nMems);
    p->pMap = ALLOC( Sat_MmFixed_t *, p->nMapSize+1 );
    p->pMap[0] = NULL;
    for ( k = 1; k <= 4; k++ )
        p->pMap[k] = p->pMems[0];
    for ( i = 0; i < p->nMems; i++ )
        for ( k = (4<<i)+1; k <= (8<<i); k++ )
            p->pMap[k] = p->pMems[i];
//for ( i = 1; i < 100; i ++ )
//printf( "%10d: size = %10d\n", i, p->pMap[i]->nEntrySize );
    return p;
}

void Sat_MmStepStop	(	Sat_MmStep_t *	p,
		int	fVerbose
	)

Function*************************************************************

Synopsis [Stops the memory manager.]

Description []

SideEffects []

SeeAlso []

Definition at line 453 of file satMem.c.

{
    int i;
    for ( i = 0; i < p->nMems; i++ )
        Sat_MmFixedStop( p->pMems[i], fVerbose );
    free( p->pMems );
    free( p->pMap );
    free( p );
}