SQLite

/*
** 2008 July 24
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** $Id: mem6.c,v 1.2 2008/07/24 10:11:28 danielk1977 Exp $
*/

#ifdef SQLITE_ENABLE_MEMSYS6

/*
** Maximum size of any allocation is ((1<<LOGMAX)*Mem6Chunk.nAtom). Since
** Mem6Chunk.nAtom is always at least 8, this is not really a practical

  return pChunk;
}

struct Mem6Global {
  sqlite3_mem_methods parent;     /* Used to allocate chunks */
  int nChunkSize;                 /* Size of each chunk, in bytes. */
  int nMinAlloc;                  /* Minimum allowed allocation size */

  sqlite3_mutex *mutex;

  /* This data structure will be fixed... */
  Mem6Chunk *pChunk;              /* Singly linked list of all memory chunks */
} mem6;


static void mem6Enter(void){
  sqlite3_mutex_enter(mem6.mutex);
}

static void mem6Leave(void){
  sqlite3_mutex_leave(mem6.mutex);
}

/*
** The argument is a pointer that may or may not have been allocated from
** one of the Mem6Chunk objects managed within mem6. If it is, return
** a pointer to the owner chunk. If not, return 0.
*/
static Mem6Chunk *findChunk(u8 *p){
  Mem6Chunk *pChunk;

  for( pp=&mem6.pChunk; *pp!=pChunk; pp = &(*pp)->pNext );
  *pp = (*pp)->pNext;
  mem6.parent.xFree(pChunk);
}

static void *memsys6Malloc(int nByte){
  Mem6Chunk *pChunk;
  void *p = 0;

  mem6Enter();
  if( nByte>=mem6.nChunkSize/3 ){
    p = mem6.parent.xMalloc(nByte);
  }else{
    for(pChunk=mem6.pChunk; !p && pChunk; pChunk=pChunk->pNext){
      p = chunkMalloc(pChunk, nByte);


    }
  
    if( !p ){
      p = mem6.parent.xMalloc(mem6.nChunkSize);
      if( p ){
        pChunk = chunkInit((u8 *)p, mem6.nChunkSize, mem6.nMinAlloc);
        pChunk->pNext = mem6.pChunk;
        mem6.pChunk = pChunk;
        p = chunkMalloc(pChunk, nByte);
        assert(p);
      }
    }
  }
  mem6Leave();

  return p;
}

static int memsys6Size(void *p){
  Mem6Chunk *pChunk;
  int iSize;
  mem6Enter();
  pChunk = findChunk(p);
  iSize = (pChunk ? chunkSize(pChunk, p) : mem6.parent.xSize(p));
  mem6Leave();
  return iSize;
}

static void memsys6Free(void *p){
  Mem6Chunk *pChunk;

  mem6Enter();
  pChunk = findChunk(p);
  if( pChunk ){
    chunkFree(pChunk, p);
    if( chunkIsEmpty(pChunk) ){
      freeChunk(pChunk);
    }
  }else{
    mem6.parent.xFree(p);
  }
  mem6Leave();
}

static void *memsys6Realloc(void *p, int nByte){

  void *p2;

  if( p && nByte<=memsys6Size(p) ){


    p2 = p;
  }else{
    p2 = memsys6Malloc(nByte);
    if( p && p2 ){

      memcpy(p2, p, memsys6Size(p));
      memsys6Free(p);
    }
  }

  return p2;
}


static int memsys6Roundup(int n){
  int iFullSz;
  for(iFullSz=mem6.nMinAlloc; iFullSz<n; iFullSz *= 2);
  return iFullSz;
}

static int memsys6Init(void *pCtx){
  u8 bMemstat = sqlite3Config.bMemstat;
  mem6.parent = *sqlite3MemGetDefault();
  mem6.nChunkSize = (1<<16);
  mem6.nMinAlloc = 16;
  mem6.pChunk = 0;

  if( !bMemstat ){
    mem6.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MEM);
  }

  /* Initialize the parent allocator. */
#ifdef SQLITE_MEMDEBUG
  sqlite3Config.bMemstat = 1;
#endif
  mem6.parent.xInit(mem6.parent.pAppData);
#ifdef SQLITE_MEMDEBUG
  sqlite3Config.bMemstat = bMemstat;
#endif

  return SQLITE_OK;
}

static void memsys6Shutdown(void *pCtx){
}

# 2008 June 21
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# $Id: permutations.test,v 1.15 2008/07/24 10:11:29 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Argument processing.
#
set ::testmode [lindex $argv 0]

  } -shutdown {
    catch {db close}
    sqlite3_shutdown
    install_mutex_counters 0
  }
}

run_tests "memsys6" -description {
  Run tests using the allocator in mem6.c.


} -initialize {
  catch {db close}
  sqlite3_reset_auto_extension
  sqlite3_shutdown
  sqlite3_config_chunkalloc
  install_malloc_faultsim 1 
  sqlite3_initialize
  autoinstall_test_functions
} -shutdown {
  catch {db close}
  sqlite3_reset_auto_extension
  sqlite3_shutdown
  sqlite3_config_heap 0 0
  install_malloc_faultsim 1 
  sqlite3_initialize
}

# run_tests "crash_safe_append" -description {
#   Run crash.test with persistent journals on a SAFE_APPEND file-system.
# } -initialize {
#   rename crashsql sa_crashsql
#   proc crashsql {args} {
#     set options [lrange $args 0 [expr {[llength $args]-2}]]