SQLite

/*
** 2004 April 6
**
** 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: btree.c,v 1.408 2007/08/22 02:56:43 drh Exp $
**
** This file implements a external (disk-based) database using BTrees.
** See the header comment on "btreeInt.h" for additional information.
** Including a description of file format and an overview of operation.
*/
#include "btreeInt.h"

      pBt->xFreeSchema(pBt->pSchema);
    }
    sqlite3_free(pBt->pSchema);
    sqlite3_free(pBt);
  }

#ifndef SQLITE_OMIT_SHARED_CACHE
  else{
    assert( p->wantToLock==0 );
    assert( p->locked==0 );
    assert( p->sharable );
    if( p->pPrev ) p->pPrev->pNext = p->pNext;
    if( p->pNext ) p->pNext->pPrev = p->pPrev;
  }
#endif

  sqlite3_free(p);
  return SQLITE_OK;
}

#if SQLITE_THREADSAFE && !defined(SQLITE_OMIT_SHARED_CACHE)

#if SQLITE_THREADSAFE && !defined(SQLITE_OMIT_SHARED_CACHE)
/*
** Short-cuts for entering and leaving mutexes on a cursor.
*/
static void cursorLeave(BtCursor *p){
  sqlite3BtreeLeave(p->pBt);
}
static void cursorEnter(BtCursor *pCur){
  sqlite3BtreeEnter(pCur->pBt);
}
#else
# define cursorEnter(X)
# define cursorLeave(X)
#endif /* !SQLITE_OMIT_SHARED_CACHE */

/*

      *pRes = 0;
      return rc;
    }
    do{
      if( sqlite3BtreeIsRootPage(pPage) ){
        *pRes = 1;
        pCur->eState = CURSOR_INVALID;
        cursorLeave(pCur);
        return SQLITE_OK;
      }
      sqlite3BtreeMoveToParent(pCur);
      pPage = pCur->pPage;
    }while( pCur->idx>=pPage->nCell );
    *pRes = 0;
    if( pPage->leafData ){

/*
** 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 1.596 2007/08/22 11:22:04 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_
#include "sqliteLimit.h"


#if defined(SQLITE_TCL) || defined(TCLSH)

** Older versions of SQLite used an optional THREADSAFE macro.
** We support that for legacy
*/
#if !defined(SQLITE_THREADSAFE)
#if defined(THREADSAFE)
# define SQLITE_THREADSAFE THREADSAFE
#else
# define SQLTIE_THREADSAFE 1
#endif
#endif

/*
** These #defines should enable >2GB file support on Posix if the
** underlying operating system supports it.  If the OS lacks
** large file support, or if the OS is windows, these should be no-ops.

/*
** 2003 December 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.
**
*************************************************************************
** Code for testing the the SQLite library in a multithreaded environment.
**
** $Id: test4.c,v 1.20 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#if defined(OS_UNIX) && OS_UNIX==1 && SQLITE_THREADSAFE
#include <stdlib.h>
#include <string.h>
#include <pthread.h>

  i = parse_thread_id(interp, argv[1]);
  if( i<0 ) return TCL_ERROR;
  if( threadset[i].busy ){
    Tcl_AppendResult(interp, "thread ", argv[1], " is already running", 0);
    return TCL_ERROR;
  }
  threadset[i].busy = 1;
  sqliteFree(threadset[i].zFilename);
  threadset[i].zFilename = sqlite3StrDup(argv[2]);
  threadset[i].opnum = 1;
  threadset[i].completed = 0;
  rc = pthread_create(&x, 0, thread_main, &threadset[i]);
  if( rc ){
    Tcl_AppendResult(interp, "failed to create the thread", 0);
    sqliteFree(threadset[i].zFilename);
    threadset[i].busy = 0;
    return TCL_ERROR;
  }
  pthread_detach(x);
  return TCL_OK;
}

** Stop a thread.
*/
static void stop_thread(Thread *p){
  thread_wait(p);
  p->xOp = 0;
  p->opnum++;
  thread_wait(p);
  sqliteFree(p->zArg);
  p->zArg = 0;
  sqliteFree(p->zFilename);
  p->zFilename = 0;
  p->busy = 0;
}

/*
** Usage:  thread_halt ID
**

  if( i<0 ) return TCL_ERROR;
  if( !threadset[i].busy ){
    Tcl_AppendResult(interp, "no such thread", 0);
    return TCL_ERROR;
  }
  thread_wait(&threadset[i]);
  threadset[i].xOp = do_compile;
  sqliteFree(threadset[i].zArg);
  threadset[i].zArg = sqlite3StrDup(argv[2]);
  threadset[i].opnum++;
  return TCL_OK;
}

/*
** This procedure runs in the thread to step the virtual machine.

  if( i<0 ) return TCL_ERROR;
  if( !threadset[i].busy ){
    Tcl_AppendResult(interp, "no such thread", 0);
    return TCL_ERROR;
  }
  thread_wait(&threadset[i]);
  threadset[i].xOp = do_finalize;
  sqliteFree(threadset[i].zArg);
  threadset[i].zArg = 0;
  threadset[i].opnum++;
  return TCL_OK;
}

/*
** Usage: thread_swap ID ID

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the client/server version of the SQLite library.
** Derived from test4.c.
**
** $Id: test7.c,v 1.7 2007/08/21 10:44:16 drh Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"

/*
** This test only works on UNIX with a SQLITE_THREADSAFE build that includes
** the SQLITE_SERVER option.

  i = parse_client_id(interp, argv[1]);
  if( i<0 ) return TCL_ERROR;
  if( threadset[i].busy ){
    Tcl_AppendResult(interp, "thread ", argv[1], " is already running", 0);
    return TCL_ERROR;
  }
  threadset[i].busy = 1;
  sqliteFree(threadset[i].zFilename);
  threadset[i].zFilename = sqlite3StrDup(argv[2]);
  threadset[i].opnum = 1;
  threadset[i].completed = 0;
  rc = pthread_create(&x, 0, client_main, &threadset[i]);
  if( rc ){
    Tcl_AppendResult(interp, "failed to create the thread", 0);
    sqliteFree(threadset[i].zFilename);
    threadset[i].busy = 0;
    return TCL_ERROR;
  }
  pthread_detach(x);
  sqlite3_server_start();
  return TCL_OK;
}

** Stop a thread.
*/
static void stop_thread(Thread *p){
  client_wait(p);
  p->xOp = 0;
  p->opnum++;
  client_wait(p);
  sqliteFree(p->zArg);
  p->zArg = 0;
  sqliteFree(p->zFilename);
  p->zFilename = 0;
  p->busy = 0;
}

/*
** Usage:  client_halt ID
**

  if( i<0 ) return TCL_ERROR;
  if( !threadset[i].busy ){
    Tcl_AppendResult(interp, "no such thread", 0);
    return TCL_ERROR;
  }
  client_wait(&threadset[i]);
  threadset[i].xOp = do_compile;
  sqliteFree(threadset[i].zArg);
  threadset[i].zArg = sqlite3StrDup(argv[2]);
  threadset[i].opnum++;
  return TCL_OK;
}

/*
** This procedure runs in the thread to step the virtual machine.

  if( i<0 ) return TCL_ERROR;
  if( !threadset[i].busy ){
    Tcl_AppendResult(interp, "no such thread", 0);
    return TCL_ERROR;
  }
  client_wait(&threadset[i]);
  threadset[i].xOp = do_finalize;
  sqliteFree(threadset[i].zArg);
  threadset[i].zArg = 0;
  threadset[i].opnum++;
  return TCL_OK;
}

/*
** This procedure runs in the thread to reset a virtual machine.

  if( i<0 ) return TCL_ERROR;
  if( !threadset[i].busy ){
    Tcl_AppendResult(interp, "no such thread", 0);
    return TCL_ERROR;
  }
  client_wait(&threadset[i]);
  threadset[i].xOp = do_reset;
  sqliteFree(threadset[i].zArg);
  threadset[i].zArg = 0;
  threadset[i].opnum++;
  return TCL_OK;
}

/*
** Usage: client_swap ID ID