src/aig/mem/mem.c

Go to the documentation of this file.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "mem.h"


struct Mem_Fixed_t_
{
    // information about individual entries
    int           nEntrySize;    // the size of one entry
    int           nEntriesAlloc; // the total number of entries allocated
    int           nEntriesUsed;  // the number of entries in use
    int           nEntriesMax;   // the max number of entries in use
    char *        pEntriesFree;  // the linked list of free entries

    // this is where the memory is stored
    int           nChunkSize;    // the size of one chunk
    int           nChunksAlloc;  // the maximum number of memory chunks 
    int           nChunks;       // the current number of memory chunks 
    char **       pChunks;       // the allocated memory

    // statistics
    int           nMemoryUsed;   // memory used in the allocated entries
    int           nMemoryAlloc;  // memory allocated
};

struct Mem_Flex_t_
{
    // information about individual entries
    int           nEntriesUsed;  // the number of entries allocated
    char *        pCurrent;      // the current pointer to free memory
    char *        pEnd;          // the first entry outside the free memory

    // this is where the memory is stored
    int           nChunkSize;    // the size of one chunk
    int           nChunksAlloc;  // the maximum number of memory chunks 
    int           nChunks;       // the current number of memory chunks 
    char **       pChunks;       // the allocated memory

    // statistics
    int           nMemoryUsed;   // memory used in the allocated entries
    int           nMemoryAlloc;  // memory allocated
};

struct Mem_Step_t_
{
    int             nMems;    // the number of fixed memory managers employed
    Mem_Fixed_t **  pMems;    // memory managers: 2^1 words, 2^2 words, etc
    int             nMapSize; // the size of the memory array
    Mem_Fixed_t **  pMap;     // maps the number of bytes into its memory manager
};

#define ALLOC(type, num)         ((type *) malloc(sizeof(type) * (num)))
#define FREE(obj)                    ((obj) ? (free((char *) (obj)), (obj) = 0) : 0)
#define REALLOC(type, obj, num) \
        ((obj) ? ((type *) realloc((char *)(obj), sizeof(type) * (num))) : \
             ((type *) malloc(sizeof(type) * (num))))


Mem_Fixed_t * Mem_FixedStart( int nEntrySize )
{
    Mem_Fixed_t * p;

    p = ALLOC( Mem_Fixed_t, 1 );
    memset( p, 0, sizeof(Mem_Fixed_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 Mem_FixedStop( Mem_Fixed_t * p, int fVerbose )
{
    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 * Mem_FixedEntryFetch( Mem_Fixed_t * p )
{
    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 Mem_FixedEntryRecycle( Mem_Fixed_t * p, char * pEntry )
{
    // 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;
}

void Mem_FixedRestart( Mem_Fixed_t * p )
{
    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;
}

int Mem_FixedReadMemUsage( Mem_Fixed_t * p )
{
    return p->nMemoryAlloc;
}

int Mem_FixedReadMaxEntriesUsed( Mem_Fixed_t * p )
{
    return p->nEntriesMax;
}



Mem_Flex_t * Mem_FlexStart()
{
    Mem_Flex_t * p;

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

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

    p->nChunkSize    = (1 << 14);
    p->nChunksAlloc  = 64;
    p->nChunks       = 0;
    p->pChunks       = ALLOC( char *, p->nChunksAlloc );

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

void Mem_FlexStop( Mem_Flex_t * p, int fVerbose )
{
    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 * Mem_FlexEntryFetch( Mem_Flex_t * p, int nBytes )
{
    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;
}

void Mem_FlexRestart( Mem_Flex_t * p )
{
    int i;
    if ( p->nChunks == 0 )
        return;
    // deallocate all chunks except the first one
    for ( i = 1; i < p->nChunks; i++ )
        free( p->pChunks[i] );
    p->nChunks  = 1;
    p->nMemoryAlloc = p->nChunkSize;
    // transform these entries into a linked list
    p->pCurrent = p->pChunks[0];
    p->pEnd     = p->pCurrent + p->nChunkSize;
    p->nEntriesUsed = 0;
    p->nMemoryUsed = 0;
}

int Mem_FlexReadMemUsage( Mem_Flex_t * p )
{
    return p->nMemoryUsed;
}





Mem_Step_t * Mem_StepStart( int nSteps )
{
    Mem_Step_t * p;
    int i, k;
    p = ALLOC( Mem_Step_t, 1 );
    memset( p, 0, sizeof(Mem_Step_t) );
    p->nMems = nSteps;
    // start the fixed memory managers
    p->pMems = ALLOC( Mem_Fixed_t *, p->nMems );
    for ( i = 0; i < p->nMems; i++ )
        p->pMems[i] = Mem_FixedStart( (8<<i) );
    // set up the mapping of the required memory size into the corresponding manager
    p->nMapSize = (4<<p->nMems);
    p->pMap = ALLOC( Mem_Fixed_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 Mem_StepStop( Mem_Step_t * p, int fVerbose )
{
    int i;
    for ( i = 0; i < p->nMems; i++ )
        Mem_FixedStop( p->pMems[i], fVerbose );
//    if ( p->pLargeChunks ) 
//    {
//      for ( i = 0; i < p->nLargeChunks; i++ )
//          free( p->pLargeChunks[i] );
//      free( p->pLargeChunks );
//    }
    free( p->pMems );
    free( p->pMap );
    free( p );
}

char * Mem_StepEntryFetch( Mem_Step_t * p, int nBytes )
{
    if ( nBytes == 0 )
        return NULL;
    if ( nBytes > p->nMapSize )
    {
//        printf( "Allocating %d bytes.\n", nBytes );
/*
        if ( p->nLargeChunks == p->nLargeChunksAlloc )
        {
            if ( p->nLargeChunksAlloc == 0 )
                p->nLargeChunksAlloc = 5;
            p->nLargeChunksAlloc *= 2;
            p->pLargeChunks = REALLOC( char *, p->pLargeChunks, p->nLargeChunksAlloc ); 
        }
        p->pLargeChunks[ p->nLargeChunks++ ] = ALLOC( char, nBytes );
        return p->pLargeChunks[ p->nLargeChunks - 1 ];
*/
        return ALLOC( char, nBytes );
    }
    return Mem_FixedEntryFetch( p->pMap[nBytes] );
}


void Mem_StepEntryRecycle( Mem_Step_t * p, char * pEntry, int nBytes )
{
    if ( nBytes == 0 )
        return;
    if ( nBytes > p->nMapSize )
    {
        free( pEntry );
        return;
    }
    Mem_FixedEntryRecycle( p->pMap[nBytes], pEntry );
}

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

---