SQLite

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.488 2008/08/12 15:21:12 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif

*/
char *sqlite3_temp_directory = 0;

/*
** Initialize SQLite.  
**
** This routine must be called to initialize the memory allocation,
** VFS, and mutex subsystems prior to doing any serious work with
** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
** this routine will be called automatically by key routines such as
** sqlite3_open().  
**
** This routine is a no-op except on its very first call for the process,
** or for the first call after a call to sqlite3_shutdown.
**
** The first thread to call this routine runs the initialization to
** completion.  If subsequent threads call this routine before the first
** thread has finished the initialization process, then the subsequent
** threads must block until the first thread finishes with the initialization.
**
** The first thread might call this routine recursively.  Recursive
** calls to this routine should not block, of course.  Otherwise the
** initialization process would never complete.
**
** Let X be the first thread to enter this routine.  Let Y be some other
** thread.  Then while the initial invocation of this routine by X is
** incomplete, it is required that:
**
**    *  Calls to this routine from Y must block until the outer-most
**       call by X completes.
**
**    *  Recursive calls to this routine from thread X return immediately
**       without blocking.
*/
int sqlite3_initialize(void){
  static int inProgress = 0;        /* Prevent recursion */
  sqlite3_mutex *pMaster;           /* The main static mutex */
  int rc;                           /* Result code */

  /* If SQLite is already completely initialized, then this call
  ** to sqlite3_initialize() should be a no-op.  But the initialization
  ** must be complete.  So isInit must not be set until the very end
  ** of this routine.
  */
  if( sqlite3Config.isInit ) return SQLITE_OK;

  /* Make sure the mutex subsystem is initialized.  If unable to 
  ** initialize the mutex subsystem, return early with the error.
  ** If the system is so sick that we are unable to allocate a mutex,
  ** there is not much SQLite is going to be able to do.
  **
  ** The mutex subsystem must take care of serializing its own
  ** initialization.
  */
  rc = sqlite3MutexInit();
  if( rc ) return rc;


  /* Initialize the malloc() system and the recursive pInitMutex mutex.
  ** This operation is protected by the STATIC_MASTER mutex.  Note that
  ** MutexAlloc() is called for a static mutex prior to initializing the
  ** malloc subsystem - this implies that the allocation of a static
  ** mutex must not require support from the malloc subsystem.
  */
  pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
  sqlite3_mutex_enter(pMaster);
  if( !sqlite3Config.isMallocInit ){
    rc = sqlite3MallocInit();
  }
  if( rc==SQLITE_OK ){
    sqlite3Config.isMallocInit = 1;
    if( !sqlite3Config.pInitMutex ){
      sqlite3Config.pInitMutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
      if( sqlite3Config.bCoreMutex && !sqlite3Config.pInitMutex ){
        rc = SQLITE_NOMEM;
      }
    }
    sqlite3Config.nRefInitMutex++;
  }
  sqlite3_mutex_leave(pMaster);

  /* If unable to initialize the malloc subsystem, then return early.
  ** There is little hope of getting SQLite to run if the malloc
  ** subsystem cannot be initialized.
  */
  if( rc!=SQLITE_OK ){
    return rc;
  }



  /* Do the rest of the initialization under the recursive mutex so
  ** that we will be able to handle recursive calls into
  ** sqlite3_initialize().  The recursive calls normally come through
  ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
  ** recursive calls might also be possible.
  */
  sqlite3_mutex_enter(sqlite3Config.pInitMutex);
  if( sqlite3Config.isInit==0 && inProgress==0 ){




    inProgress = 1;
    rc = sqlite3_os_init();
    inProgress = 0;
    sqlite3Config.isInit = (rc==SQLITE_OK ? 1 : 0);
  }
  sqlite3_mutex_leave(sqlite3Config.pInitMutex);

  /* Go back under the static mutex and clean up the recursive
  ** mutex to prevent a resource leak.
  */
  sqlite3_mutex_enter(pMaster);
  sqlite3Config.nRefInitMutex--;
  if( sqlite3Config.nRefInitMutex<=0 ){
    assert( sqlite3Config.nRefInitMutex==0 );
    sqlite3_mutex_free(sqlite3Config.pInitMutex);
    sqlite3Config.pInitMutex = 0;
  }
  sqlite3_mutex_leave(pMaster);

  /* The following is just a sanity check to make sure SQLite has
  ** been compiled correctly.  It is important to run this code, but
  ** we don't want to run it too often and soak up CPU cycles for no
  ** reason.  So we run it once during initialization.
  */
#ifndef NDEBUG
  /* This section of code's only "output" is via assert() statements. */
  if ( rc==SQLITE_OK ){
    u64 x = (((u64)1)<<63)-1;
    double y;
    assert(sizeof(x)==8);
    assert(sizeof(x)==sizeof(y));

/*
** Undo the effects of sqlite3_initialize().  Must not be called while
** there are outstanding database connections or memory allocations or
** while any part of SQLite is otherwise in use in any thread.  This
** routine is not threadsafe.  Not by a long shot.
*/
int sqlite3_shutdown(void){


  sqlite3Config.isMallocInit = 0;
  if( sqlite3Config.isInit ){
    sqlite3_os_end();
  }
  if( sqlite3Config.m.xShutdown ){
    sqlite3MallocEnd();
  }

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.753 2008/08/12 15:21:12 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Include the configuration header output by 'configure' if we're using the
** autoconf-based build

  int nScratch;                     /* Number of scratch buffers */
  void *pPage;                      /* Page cache memory */
  int szPage;                       /* Size of each page in pPage[] */
  int nPage;                        /* Number of pages in pPage[] */
  int isInit;                       /* True after initialization has finished */
  int isMallocInit;                 /* True after malloc is initialized */
  sqlite3_mutex *pInitMutex;        /* Mutex used by sqlite3_initialize() */
  int nRefInitMutex;                /* Number of users of pInitMutex */
  int nSmall;                       /* alloc size threshold used by mem6.c */
  int mxParserStack;                /* maximum depth of the parser stack */
};

/*
** Assuming zIn points to the first byte of a UTF-8 character,
** advance zIn to point to the first byte of the next UTF-8 character.

#ifndef SQLITE_MUTEX_NOOP
  sqlite3_mutex_methods *sqlite3DefaultMutex(void);
  sqlite3_mutex *sqlite3MutexAlloc(int);
  int sqlite3MutexInit(void);
  int sqlite3MutexEnd(void);
#endif


int sqlite3StatusValue(int);
void sqlite3StatusAdd(int, int);
void sqlite3StatusSet(int, int);

int sqlite3IsNaN(double);

void sqlite3VXPrintf(StrAccum*, int, const char*, va_list);

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
** This module implements the sqlite3_status() interface and related
** functionality.
**
** $Id: status.c,v 1.8 2008/08/12 15:21:12 drh Exp $
*/
#include "sqliteInt.h"

/*
** Variables in which to record status information.
*/
static struct {
  int nowValue[9];         /* Current value */
  int mxValue[9];          /* Maximum value */
} sqlite3Stat;










/*
** Return the current value of a status parameter.
*/
int sqlite3StatusValue(int op){
  assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
  return sqlite3Stat.nowValue[op];
}

# 2008 June 18
#
# 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.
#
#***********************************************************************
#
# This file contains tests of the memory allocation subsystem
#
# $Id: memsubsys1.test,v 1.9 2008/08/12 15:21:12 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
sqlite3_reset_auto_extension

# This procedure constructs a new database in test.db.  It fills
# this database with many small records (enough to force multiple

    db eval {DELETE FROM t2}
  }
  do_test $testname.1 {
    db eval {SELECT count(*) FROM t1}
  } 8192
  integrity_check $testname.2
}

# Reset all of the highwater marks.
#
proc reset_highwater_marks {} {
  sqlite3_status SQLITE_STATUS_MEMORY_USED 1
  sqlite3_status SQLITE_STATUS_MALLOC_SIZE 1
  sqlite3_status SQLITE_STATUS_PAGECACHE_USED 1
  sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 1
  sqlite3_status SQLITE_STATUS_PAGECACHE_SIZE 1
  sqlite3_status SQLITE_STATUS_SCRATCH_USED 1
  sqlite3_status SQLITE_STATUS_SCRATCH_OVERFLOW 1
  sqlite3_status SQLITE_STATUS_SCRATCH_SIZE 1
  sqlite3_status SQLITE_STATUS_PARSER_STACK 1
}

# Test 1:  Both PAGECACHE and SCRATCH are shut down.
#
db close
sqlite3_shutdown
sqlite3_config_lookaside 0 0
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-1 {PRAGMA page_size=1024}
do_test memsubsys1-1.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 0
do_test memsubsys1-1.4 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 0
set max_pagecache [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2]
#show_memstats

# Test 2:  Activate PAGECACHE with 20 pages
#
db close
sqlite3_shutdown
sqlite3_config_pagecache 1024 20
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-2 {PRAGMA page_size=1024}
#show_memstats
do_test memsubsys1-2.3 {
  set pg_ovfl [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2]
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
  expr {$pg_used*1024 + $pg_ovfl}
} $max_pagecache

# Test 3:  Activate PAGECACHE with 20 pages but use the wrong page size
# so that PAGECACHE is not used.
#
db close
sqlite3_shutdown
sqlite3_config_pagecache 512 20
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-3.1 {PRAGMA page_size=1024}
#show_memstats
do_test memsubsys1-3.1.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 0
do_test memsubsys1-3.1.4 {
  set overflow [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2]
} $max_pagecache
do_test memsubsys1-3.1.5 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 0
db close
sqlite3_shutdown
sqlite3_config_pagecache 2048 20
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-3.2 {PRAGMA page_size=2048}
#show_memstats
do_test memsubsys1-3.2.3 {
  db eval {PRAGMA page_size}
} 2048
do_test memsubsys1-3.2.4 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 19
do_test memsubsys1-3.2.5 {
  set s_used [lindex [sqlite3_status SQLITE_STATUS_SCRATCH_USED 0] 2]
} 0

# Test 4:  Activate both PAGECACHE and SCRATCH.
#
db close
sqlite3_shutdown
sqlite3_config_pagecache 1024 50
sqlite3_config_scratch 6000 2
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-4 {PRAGMA page_size=1024}
#show_memstats
do_test memsubsys1-4.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 49
do_test memsubsys1-4.4 {
  set pg_ovfl [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 0] 2]

# such that the SCRATCH allocations are too small.
#
db close
sqlite3_shutdown
sqlite3_config_pagecache 4096 24
sqlite3_config_scratch 6000 2
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-5 {PRAGMA page_size=4096}
#show_memstats
do_test memsubsys1-5.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 23
do_test memsubsys1-5.4 {
  set maxreq [lindex [sqlite3_status SQLITE_STATUS_MALLOC_SIZE 0] 2]

# Make it so that SCRATCH is large enough
#
db close
sqlite3_shutdown
sqlite3_config_pagecache 4096 24
sqlite3_config_scratch 25000 1
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-6 {PRAGMA page_size=4096}
#show_memstats
do_test memsubsys1-6.3 {
  set pg_used [lindex [sqlite3_status SQLITE_STATUS_PAGECACHE_USED 0] 2]
} 23
do_test memsubsys1-6.4 {
  set maxreq [lindex [sqlite3_status SQLITE_STATUS_MALLOC_SIZE 0] 2]

# that maximum allocation size is small.
#
db close
sqlite3_shutdown
sqlite3_config_pagecache 4096 24
sqlite3_config_scratch 25000 1
sqlite3_initialize
reset_highwater_marks
build_test_db memsubsys1-7 {
  PRAGMA page_size=4096;
  PRAGMA cache_size=10;
  PRAGMA temp_cache_size=10;
}
#show_memstats
do_test memsubsys1-7.3 {

# 2008 June 18
#
# 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.
#
#***********************************************************************
#
# This file contains tests of the memory allocation subsystem.
#
# $Id: memsubsys2.test,v 1.2 2008/08/12 15:21:12 drh Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
sqlite3_reset_auto_extension

# This procedure constructs a new database in test.db.  It fills
# this database with many small records (enough to force multiple

    db eval {DELETE FROM t2}
  }
  do_test $testname.1 {
    db eval {SELECT count(*) FROM t1}
  } 8192
  integrity_check $testname.2
}

# Reset all of the highwater marks.
#
proc reset_highwater_marks {} {
  sqlite3_status SQLITE_STATUS_MEMORY_USED 1
  sqlite3_status SQLITE_STATUS_MALLOC_SIZE 1
  sqlite3_status SQLITE_STATUS_PAGECACHE_USED 1
  sqlite3_status SQLITE_STATUS_PAGECACHE_OVERFLOW 1
  sqlite3_status SQLITE_STATUS_PAGECACHE_SIZE 1
  sqlite3_status SQLITE_STATUS_SCRATCH_USED 1
  sqlite3_status SQLITE_STATUS_SCRATCH_OVERFLOW 1
  sqlite3_status SQLITE_STATUS_SCRATCH_SIZE 1
  sqlite3_status SQLITE_STATUS_PARSER_STACK 1
}

# Test 1:  Verify that calling sqlite3_malloc(0) returns a NULL
# pointer.
#
set highwater [sqlite3_memory_highwater 0]
do_test memsubsys2-1.1 {
  sqlite3_malloc 0

# Test 3: Verify that turning of memstatus disables the statistics
# tracking.
#
db close
sqlite3_shutdown
sqlite3_config_memstatus 0
sqlite3_initialize
reset_highwater_marks
set highwater [sqlite3_memory_highwater 0]
do_test memsubsys2-3.1 {
  set highwater
} {0}
do_test memsubsys2-3.2 {
  sqlite3_malloc 0
} {0}

# Test 4: Verify that turning on memstatus reenables the statistics
# tracking.
#
sqlite3_shutdown
sqlite3_config_memstatus 1
sqlite3_initialize
reset_highwater_marks
set highwater [sqlite3_memory_highwater 0]
do_test memsubsys2-4.1 {
  set highwater
} {0}
do_test memsubsys2-4.2 {
  sqlite3_malloc 0
} {0}