** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.429 2008/04/17 20:59:38 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*
................................................................................
static void pager_unlock(Pager *pPager){
  if( !pPager->exclusiveMode ){
    if( !MEMDB ){
      int rc = osUnlock(pPager->fd, NO_LOCK);
      if( rc ) pPager->errCode = rc;
      pPager->dbSize = -1;
      IOTRACE(("UNLOCK %p\n", pPager))












      /* If Pager.errCode is set, the contents of the pager cache cannot be
      ** trusted. Now that the pager file is unlocked, the contents of the
      ** cache can be discarded and the error code safely cleared.
      */
      if( pPager->errCode ){
        if( rc==SQLITE_OK ) pPager->errCode = SQLITE_OK;
        pager_reset(pPager);
        if( pPager->stmtOpen ){
          sqlite3OsClose(pPager->stfd);
          sqlite3BitvecDestroy(pPager->pInStmt);
          pPager->pInStmt = 0;
        }
        if( pPager->journalOpen ){
          sqlite3OsClose(pPager->jfd);
          pPager->journalOpen = 0;
          sqlite3BitvecDestroy(pPager->pInJournal);
          pPager->pInJournal = 0;
        }
        pPager->stmtOpen = 0;
        pPager->stmtInUse = 0;
        pPager->journalOff = 0;
        pPager->journalStarted = 0;
        pPager->stmtAutoopen = 0;
        pPager->origDbSize = 0;
      }
................................................................................
      pPager->pNext->pPrev = pPager->pPrev;
    }
    sqlite3_mutex_leave(mutex);
  }
#endif

  disable_simulated_io_errors();

  pPager->errCode = 0;
  pPager->exclusiveMode = 0;
  pager_reset(pPager);
  pagerUnlockAndRollback(pPager);
  enable_simulated_io_errors();

  PAGERTRACE2("CLOSE %d\n", PAGERID(pPager));
  IOTRACE(("CLOSE %p\n", pPager))
  if( pPager->journalOpen ){
    sqlite3OsClose(pPager->jfd);
  }
  sqlite3BitvecDestroy(pPager->pInJournal);
  if( pPager->stmtOpen ){
................................................................................
          if( rc!=SQLITE_OK ){
            pager_unlock(pPager);
            return pager_error(pPager, rc);
          }
          pPager->state = PAGER_EXCLUSIVE;
        }
 
        /* Open the journal for reading only.  Return SQLITE_BUSY if
        ** we are unable to open the journal file. 
        **
        ** The journal file does not need to be locked itself.  The
        ** journal file is never open unless the main database file holds
        ** a write lock, so there is never any chance of two or more
        ** processes opening the journal at the same time.
        **
        ** Open the journal for read/write access. This is because in 
        ** exclusive-access mode the file descriptor will be kept open and
        ** possibly used for a transaction later on. On some systems, the
        ** OsTruncate() call used in exclusive-access mode also requires
        ** a read/write file handle.
        */
        if( !isHot ){
          int res = sqlite3OsAccess(pVfs,pPager->zJournal,SQLITE_ACCESS_EXISTS);
          if( res==1 ){
            int fout = 0;
            int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
            assert( !pPager->tempFile );
            rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);
            assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
            if( fout&SQLITE_OPEN_READONLY ){
              rc = SQLITE_BUSY;
              sqlite3OsClose(pPager->jfd);
            }




          }else{


            rc = (res==0?SQLITE_BUSY:SQLITE_IOERR_NOMEM);
          }
        }
        if( rc!=SQLITE_OK ){
          pager_unlock(pPager);
          switch( rc ){
            case SQLITE_NOMEM:
            case SQLITE_IOERR_UNLOCK:

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.430 2008/04/19 20:34:19 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*
................................................................................
static void pager_unlock(Pager *pPager){
  if( !pPager->exclusiveMode ){
    if( !MEMDB ){
      int rc = osUnlock(pPager->fd, NO_LOCK);
      if( rc ) pPager->errCode = rc;
      pPager->dbSize = -1;
      IOTRACE(("UNLOCK %p\n", pPager))

      /* Always close the journal file when dropping the database lock.
      ** Otherwise, another connection with journal_mode=delete might
      ** delete the file out from under us.
      */
      if( pPager->journalOpen ){
        sqlite3OsClose(pPager->jfd);
        pPager->journalOpen = 0;
        sqlite3BitvecDestroy(pPager->pInJournal);
        pPager->pInJournal = 0;
      }

      /* If Pager.errCode is set, the contents of the pager cache cannot be
      ** trusted. Now that the pager file is unlocked, the contents of the
      ** cache can be discarded and the error code safely cleared.
      */
      if( pPager->errCode ){
        if( rc==SQLITE_OK ) pPager->errCode = SQLITE_OK;
        pager_reset(pPager);
        if( pPager->stmtOpen ){
          sqlite3OsClose(pPager->stfd);
          sqlite3BitvecDestroy(pPager->pInStmt);
          pPager->pInStmt = 0;
        }






        pPager->stmtOpen = 0;
        pPager->stmtInUse = 0;
        pPager->journalOff = 0;
        pPager->journalStarted = 0;
        pPager->stmtAutoopen = 0;
        pPager->origDbSize = 0;
      }
................................................................................
      pPager->pNext->pPrev = pPager->pPrev;
    }
    sqlite3_mutex_leave(mutex);
  }
#endif

  disable_simulated_io_errors();
  sqlite3FaultBenign(-1, 1);
  pPager->errCode = 0;
  pPager->exclusiveMode = 0;
  pager_reset(pPager);
  pagerUnlockAndRollback(pPager);
  enable_simulated_io_errors();
  sqlite3FaultBenign(-1, 0);
  PAGERTRACE2("CLOSE %d\n", PAGERID(pPager));
  IOTRACE(("CLOSE %p\n", pPager))
  if( pPager->journalOpen ){
    sqlite3OsClose(pPager->jfd);
  }
  sqlite3BitvecDestroy(pPager->pInJournal);
  if( pPager->stmtOpen ){
................................................................................
          if( rc!=SQLITE_OK ){
            pager_unlock(pPager);
            return pager_error(pPager, rc);
          }
          pPager->state = PAGER_EXCLUSIVE;
        }
 








        /* Open the journal for read/write access. This is because in 
        ** exclusive-access mode the file descriptor will be kept open and
        ** possibly used for a transaction later on. On some systems, the
        ** OsTruncate() call used in exclusive-access mode also requires
        ** a read/write file handle.
        */
        if( !isHot && pPager->journalOpen==0 ){
          int res = sqlite3OsAccess(pVfs,pPager->zJournal,SQLITE_ACCESS_EXISTS);
          if( res==1 ){
            int fout = 0;
            int f = SQLITE_OPEN_READWRITE|SQLITE_OPEN_MAIN_JOURNAL;
            assert( !pPager->tempFile );
            rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, f, &fout);
            assert( rc!=SQLITE_OK || pPager->jfd->pMethods );
            if( fout&SQLITE_OPEN_READONLY ){
              rc = SQLITE_BUSY;
              sqlite3OsClose(pPager->jfd);
            }
          }else if( res==0 ){
            /* If the journal does not exist, that means some other process
            ** has already rolled it back */
            rc = SQLITE_BUSY;
          }else{
            /* If sqlite3OsAccess() returns a negative value, that means it
            ** failed a memory allocation */
            rc = SQLITE_IOERR_NOMEM;
          }
        }
        if( rc!=SQLITE_OK ){
          pager_unlock(pPager);
          switch( rc ){
            case SQLITE_NOMEM:
            case SQLITE_IOERR_UNLOCK:

# 2008 April 17
#
# 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 implements regression tests for SQLite library. The focus
# of these tests is the journal mode pragma.
#
# $Id: jrnlmode.test,v 1.1 2008/04/19 20:34:19 drh Exp $

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

ifcapable {!pager_pragmas} {
  finish_test
  return
}

#----------------------------------------------------------------------
# Test cases jrnlmode-1.X test the PRAGMA logic.
#
do_test jrnlmode-1.0 {
  execsql {
    PRAGMA journal_mode;
    PRAGMA main.journal_mode;
    PRAGMA temp.journal_mode;
  } 
} [list delete delete delete]
do_test jrnlmode-1.1 {
  execsql {
    PRAGMA journal_mode = persist;
  } 
} {persist}
do_test jrnlmode-1.2 {
  execsql {
    PRAGMA journal_mode;
    PRAGMA main.journal_mode;
    PRAGMA temp.journal_mode;
  } 
} [list persist persist persist]
do_test jrnlmode-1.4 {
  execsql {
    PRAGMA journal_mode = off;
  } 
} {off}
do_test jrnlmode-1.5 {
  execsql {
    PRAGMA journal_mode;
    PRAGMA main.journal_mode;
    PRAGMA temp.journal_mode;
  } 
} {off off off}
do_test jrnlmode-1.6 {
  execsql {
    PRAGMA journal_mode = delete;
  } 
} {delete}
do_test jrnlmode-1.7 {
  execsql {
    PRAGMA journal_mode;
    PRAGMA main.journal_mode;
    PRAGMA temp.journal_mode;
  } 
} {delete delete delete}
do_test jrnlmode-1.8 {
  execsql {
    PRAGMA journal_mode = off;
    PRAGMA journal_mode = invalid;
  } 
} {off off}
ifcapable attach {
  do_test jrnlmode-1.9 {
    execsql {
      PRAGMA journal_mode = persist;
      ATTACH ':memory:' as aux1;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA aux1.journal_mode;
    }
  } {persist persist}
  do_test jrnlmode-1.10 {
    execsql {
      PRAGMA main.journal_mode = off;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA temp.journal_mode;
      PRAGMA aux1.journal_mode;
    }
  } {off persist persist}
  do_test jrnlmode-1.11 {
    execsql {
      PRAGMA journal_mode;
    }
  } {persist}
  do_test jrnlmode-1.12 {
    execsql {
      ATTACH ':memory:' as aux2;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA aux1.journal_mode;
      PRAGMA aux2.journal_mode;
    }
  } {off persist persist}
  do_test jrnlmode-1.11 {
    execsql {
      PRAGMA aux1.journal_mode = delete;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA aux1.journal_mode;
      PRAGMA aux2.journal_mode;
    }
  } {off delete persist}
  do_test jrnlmode-1.12 {
    execsql {
      PRAGMA journal_mode = delete;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA temp.journal_mode;
      PRAGMA aux1.journal_mode;
      PRAGMA aux2.journal_mode;
    }
  } {delete delete delete delete}
  do_test jrnlmode-1.13 {
    execsql {
      ATTACH ':memory:' as aux3;
    }
    execsql {
      PRAGMA main.journal_mode;
      PRAGMA temp.journal_mode;
      PRAGMA aux1.journal_mode;
      PRAGMA aux2.journal_mode;
      PRAGMA aux3.journal_mode;
    }
  } {delete delete delete delete delete}
  
  do_test jrnlmode-1.99 {
    execsql {
      DETACH aux1;
      DETACH aux2;
      DETACH aux3;
    }
  } {}
}


finish_test

# 2007 March 26
#
# 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 runs the tests in the file ioerr.test with 
# persistent journal mode enabled.
#
# $Id: jrnlmode2.test,v 1.1 2008/04/19 20:34:19 drh Exp $

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

ifcapable {!pager_pragmas} {
  finish_test
  return
}

rename finish_test really_finish_test2
proc finish_test {} {}
set ISQUICK 1

rename sqlite3 real_sqlite3
proc sqlite3 {args} {
  set r [eval "real_sqlite3 $args"]
  if { [llength $args] == 2 } {
    [lindex $args 0] eval {PRAGMA journal_mode = persist}
  }
  set r
}

rename do_test really_do_test
proc do_test {args} {
  set sc [concat really_do_test "jrlnmode2-[lindex $args 0]" \
      [lrange $args 1 end]]
  eval $sc
}

source $testdir/vacuum.test
source $testdir/rollback.test
source $testdir/select1.test
source $testdir/select2.test
source $testdir/trans.test


rename sqlite3 ""
rename real_sqlite3 sqlite3
rename finish_test ""
rename really_finish_test2 finish_test
rename do_test ""
rename really_do_test do_test
finish_test

# 2007 March 26
#
# 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 runs the tests in the file ioerr.test with 
# persistent journal mode enabled.
#
# $Id: jrnlmode3.test,v 1.1 2008/04/19 20:34:19 drh Exp $

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

ifcapable {!pager_pragmas} {
  finish_test
  return
}

rename finish_test really_finish_test2
proc finish_test {} {}
set ISQUICK 1

rename sqlite3 real_sqlite3
proc sqlite3 {args} {
  set r [eval "real_sqlite3 $args"]
  if { [llength $args] == 2 } {
    [lindex $args 0] eval {PRAGMA journal_mode = persist}
  }
  set r
}

rename do_test really_do_test
proc do_test {args} {
  set sc [concat really_do_test "jrlnmode2-[lindex $args 0]" \
      [lrange $args 1 end]]
  eval $sc
}

source $testdir/malloc.test
source $testdir/ioerr.test


rename sqlite3 ""
rename real_sqlite3 sqlite3
rename finish_test ""
rename really_finish_test2 finish_test
rename do_test ""
rename really_do_test do_test
finish_test

#    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 runs all tests.
#
# $Id: quick.test,v 1.77 2008/04/11 14:56:53 drh Exp $

proc lshift {lvar} {
  upvar $lvar l
  set ret [lindex $l 0]
  set l [lrange $l 1 end]
  return $ret
}
................................................................................
  crash6.test
  crash7.test
  exclusive3.test
  fts3.test
  fuzz.test
  fuzz_malloc.test
  in2.test

  loadext.test
  mallocAll.test
  malloc.test
  malloc2.test
  malloc3.test
  malloc4.test
  memleak.test

#    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 runs all tests.
#
# $Id: quick.test,v 1.78 2008/04/19 20:34:19 drh Exp $

proc lshift {lvar} {
  upvar $lvar l
  set ret [lindex $l 0]
  set l [lrange $l 1 end]
  return $ret
}
................................................................................
  crash6.test
  crash7.test
  exclusive3.test
  fts3.test
  fuzz.test
  fuzz_malloc.test
  in2.test
  jrnlmode3.test
  loadext.test
  mallocAll.test
  malloc.test
  malloc2.test
  malloc3.test
  malloc4.test
  memleak.test

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is database locks.
#
# $Id: trans.test,v 1.37 2007/09/12 17:01:45 danielk1977 Exp $


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


# Create several tables to work with.
................................................................................
    BEGIN;
    CREATE TABLE t3 AS SELECT * FROM t2;
    DELETE FROM t2;
  }
  sqlite_abort
}
close $fd
file copy -force test.db test.db-bu1
do_test trans-8.1 {
  catch {exec [info nameofexec] test.tcl}
  file copy -force test.db test.db-bu2
  file copy -force test.db-journal test.db-bu2-journal
  execsql {SELECT md5sum(x,y,z) FROM t2}
} $checksum
do_test trans-8.2 {
  execsql {SELECT md5sum(type,name,tbl_name,rootpage,sql) FROM sqlite_master}
} $checksum2
integrity_check trans-8.3






















# In the following sequence of tests, compute the MD5 sum of the content
# of a table, make lots of modifications to that table, then do a rollback.
# Verify that after the rollback, the MD5 checksum is unchanged.
#
do_test trans-9.1 {
  execsql {

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is database locks.
#
# $Id: trans.test,v 1.38 2008/04/19 20:34:19 drh Exp $


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


# Create several tables to work with.
................................................................................
    BEGIN;
    CREATE TABLE t3 AS SELECT * FROM t2;
    DELETE FROM t2;
  }
  sqlite_abort
}
close $fd

do_test trans-8.1 {
  catch {exec [info nameofexec] test.tcl}


  execsql {SELECT md5sum(x,y,z) FROM t2}
} $checksum
do_test trans-8.2 {
  execsql {SELECT md5sum(type,name,tbl_name,rootpage,sql) FROM sqlite_master}
} $checksum2
integrity_check trans-8.3
set fd [open test.tcl w]
puts $fd {
  sqlite3 db test.db
  db eval {
    PRAGMA journal_mode=persist;
    PRAGMA default_cache_size=20;
    BEGIN;
    CREATE TABLE t3 AS SELECT * FROM t2;
    DELETE FROM t2;
  }
  sqlite_abort
}
close $fd
do_test trans-8.4 {
  catch {exec [info nameofexec] test.tcl}
  execsql {SELECT md5sum(x,y,z) FROM t2}
} $checksum
do_test trans-8.5 {
  execsql {SELECT md5sum(type,name,tbl_name,rootpage,sql) FROM sqlite_master}
} $checksum2
integrity_check trans-8.6

# In the following sequence of tests, compute the MD5 sum of the content
# of a table, make lots of modifications to that table, then do a rollback.
# Verify that after the rollback, the MD5 checksum is unchanged.
#
do_test trans-9.1 {
  execsql {

#    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 runs all tests.
#
# $Id: veryquick.test,v 1.2 2008/04/10 13:33:18 drh Exp $

proc lshift {lvar} {
  upvar $lvar l
  set ret [lindex $l 0]
  set l [lrange $l 1 end]
  return $ret
}
................................................................................
  fts3.test
  fuzz.test
  fuzz_malloc.test
  in2.test
  interrupt.test
  ioerr.test
  ioerr2.test

  loadext.test
  mallocAll.test
  malloc.test
  malloc2.test
  malloc3.test
  malloc4.test
  malloc5.test

#    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 runs all tests.
#
# $Id: veryquick.test,v 1.3 2008/04/19 20:34:19 drh Exp $

proc lshift {lvar} {
  upvar $lvar l
  set ret [lindex $l 0]
  set l [lrange $l 1 end]
  return $ret
}
................................................................................
  fts3.test
  fuzz.test
  fuzz_malloc.test
  in2.test
  interrupt.test
  ioerr.test
  ioerr2.test
  jrnlmode3.test
  loadext.test
  mallocAll.test
  malloc.test
  malloc2.test
  malloc3.test
  malloc4.test
  malloc5.test