SQLite

  u8 noReadlock;              /* Do not bother to obtain readlocks */
  u8 noSync;                  /* Do not sync the journal if true */
  u8 fullSync;                /* Do extra syncs of the journal for robustness */
  u8 sync_flags;              /* One of SYNC_NORMAL or SYNC_FULL */
  u8 tempFile;                /* zFilename is a temporary file */
  u8 readOnly;                /* True for a read-only database */
  u8 memDb;                   /* True to inhibit all file I/O */


  /* The following block contains those class members that are dynamically
  ** modified during normal operations. The other variables in this structure
  ** are either constant throughout the lifetime of the pager, or else
  ** used to store configuration parameters that affect the way the pager 
  ** operates.
  **

** an open journal-file, then the next time a shared-lock is obtained
** on the pager file (by this or any other process), it will be
** treated as a hot-journal and rolled back.
*/
static void pager_unlock(Pager *pPager){
  if( !pPager->exclusiveMode ){
    int rc = SQLITE_OK;          /* Return code */
    int iDc = isOpen(pPager->fd)?sqlite3OsDeviceCharacteristics(pPager->fd):0;

    /* 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.
    */
    assert( (PAGER_JOURNALMODE_MEMORY   & 5)!=1 );
    assert( (PAGER_JOURNALMODE_OFF      & 5)!=1 );
    assert( (PAGER_JOURNALMODE_WAL      & 5)!=1 );
    assert( (PAGER_JOURNALMODE_DELETE   & 5)!=1 );
    assert( (PAGER_JOURNALMODE_TRUNCATE & 5)==1 );
    assert( (PAGER_JOURNALMODE_PERSIST  & 5)==1 );
    if( 0==(iDc & SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN)
     || 1!=(pPager->journalMode & 5)
    ){
      sqlite3OsClose(pPager->jfd);
    }

    sqlite3BitvecDestroy(pPager->pInJournal);
    pPager->pInJournal = 0;
    releaseAllSavepoints(pPager);

int sqlite3PagerClose(Pager *pPager){
  u8 *pTmp = (u8 *)pPager->pTmpSpace;

  disable_simulated_io_errors();
  sqlite3BeginBenignMalloc();
  pPager->errCode = 0;
  pPager->exclusiveMode = 0;

#ifndef SQLITE_OMIT_WAL
  sqlite3WalClose(pPager->pWal,
    (pPager->noSync ? 0 : pPager->sync_flags), 
    pPager->pageSize, pTmp
  );
  pPager->pWal = 0;
#endif

    }
    pagerUnlockAndRollback(pPager);
  }
  sqlite3EndBenignMalloc();
  enable_simulated_io_errors();
  PAGERTRACE(("CLOSE %d\n", PAGERID(pPager)));
  IOTRACE(("CLOSE %p\n", pPager))
  sqlite3OsClose(pPager->jfd);
  sqlite3OsClose(pPager->fd);
  sqlite3PageFree(pTmp);
  sqlite3PcacheClose(pPager->pPCache);

#ifdef SQLITE_HAS_CODEC
  if( pPager->xCodecFree ) pPager->xCodecFree(pPager->pCodec);
#endif

        );
#ifdef SQLITE_ENABLE_ATOMIC_WRITE
      rc = sqlite3JournalOpen(
          pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
      );
#else
      rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);




#endif
    }
    assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );
  }


  /* Write the first journal header to the journal file and open 

  }
}
proc faultsim_save_and_close {} {
  faultsim_save
  catch { db close }
  return ""
}
proc faultsim_restore_and_reopen {{dbfile test.db}} {
  catch { db close }
  foreach f [glob -nocomplain test.db*] { file delete -force $f }
  foreach f2 [glob -nocomplain sv_test.db*] {
    set f [string range $f2 3 end]
    file copy -force $f2 $f
  }
  sqlite3 db $dbfile
  sqlite3_extended_result_codes db 1
  sqlite3_db_config_lookaside db 0 0 0
}

proc faultsim_integrity_check {{db db}} {
  set ic [$db eval { PRAGMA integrity_check }]
  if {$ic != "ok"} { error "Integrity check: $ic" }
}

proc faultsim_delete_and_reopen {{file test.db}} {
  catch { db close }
  foreach f [glob -nocomplain test.db*] { file delete -force $f }
  sqlite3 db $file
}


# The following procs are used as [do_one_faultsim_test] callbacks when 
# injecting OOM faults into test cases.
#
proc oom_injectstart {nRepeat iFail} {

#               xAccess() call to check for the presence of any master 
#               journal file is made).
#
# pager1.4.3.*: Test that the contents of a hot-journal are ignored if the
#               page-size or sector-size in the journal header appear to
#               be invalid (too large, too small or not a power of 2).
# 
# pager1.4.4.*: Test hot-journal rollback of journal file with a master
#               journal pointer generated in various "PRAGMA synchronous"
#               modes.
#
# pager1.4.5.*: Test that hot-journal rollback stops if it encounters a
#               journal-record for which the checksum fails.
# 
do_test pager1.4.1.1 {
  faultsim_delete_and_reopen
  execsql { 
    CREATE TABLE x(y, z);
    INSERT INTO x VALUES(1, 2);
  }
  set fd [open test.db-journal w]

  do_test pager1.4.3.$tn {
    faultsim_restore_and_reopen
    hexio_write test.db-journal $ofst [format %.8x $value]
    execsql { SELECT * FROM t1 }
  } $result
}
db close

# Set up a VFS that snapshots the file-system just before a master journal
# file is deleted to commit a multi-file transaction. Specifically, the
# file-system is saved just before the xDelete() call to remove the 
# master journal file from the file-system.
#
testvfs tv -default 1
tv script copy_on_mj_delete
set ::mj_filename_length 0
proc copy_on_mj_delete {method filename args} {
  if {[string match *mj* [file tail $filename]]} { 
    set ::mj_filename_length [string length $filename]
    faultsim_save 
  }
  return SQLITE_OK
}

set pwd [pwd]
foreach {tn1 tcl} {
  1 { set prefix "test.db" }
  2 { 
    # This test depends on the underlying VFS being able to open paths
    # 512 bytes in length. The idea is to create a hot-journal file that
    # contains a master-journal pointer so large that it could contain
    # a valid page record (if the file page-size is 512 bytes). So as to
    # make sure SQLite doesn't get confused by this.
    #
    set nPadding [expr 511 - $::mj_filename_length]

    # We cannot just create a really long database file name to open, as
    # Linux limits a single component of a path to 255 bytes by default
    # (and presumably other systems have limits too). So create a directory
    # hierarchy to work in.
    #
    set dirname "d123456789012345678901234567890/"
    set nDir [expr $nPadding / 32]
    if { $nDir } {
      set p [string repeat $dirname $nDir]
      file mkdir $p
      cd $p
    }

    set padding [string repeat x [expr $nPadding %32]]
    set prefix "test.db${padding}"
  }
} {
  eval $tcl
  foreach {tn2 sql} {
    o { 
      PRAGMA main.synchronous=OFF;
      PRAGMA aux.synchronous=OFF;
    }
    o512 { 
      PRAGMA main.synchronous=OFF;
      PRAGMA aux.synchronous=OFF;
      PRAGMA main.page_size = 512;
      PRAGMA aux.page_size = 512;
    }
    n { 
      PRAGMA main.synchronous=NORMAL;
      PRAGMA aux.synchronous=NORMAL;
    }
    f { 
      PRAGMA main.synchronous=FULL;
      PRAGMA aux.synchronous=FULL;
    }
  } {

    set tn "${tn1}.${tn2}"
  
    # Set up a connection to have two databases, test.db (main) and 
    # test.db2 (aux). Then run a multi-file transaction on them. The
    # VFS will snapshot the file-system just before the master-journal
    # file is deleted to commit the transaction.
    #
    tv filter xDelete
    do_test pager1-4.4.$tn.1 {
      faultsim_delete_and_reopen $prefix
      execsql "
        ATTACH '${prefix}2' AS aux;
        $sql
        CREATE TABLE a(x);
        CREATE TABLE aux.b(x);
        INSERT INTO a VALUES('double-you');
        INSERT INTO a VALUES('why');
        INSERT INTO a VALUES('zed');
        INSERT INTO b VALUES('won');
        INSERT INTO b VALUES('too');
        INSERT INTO b VALUES('free');
      "
      execsql {
        BEGIN;
          INSERT INTO a SELECT * FROM b WHERE rowid<=3;
          INSERT INTO b SELECT * FROM a WHERE rowid<=3;
        COMMIT;
      }
    } {}
    tv filter {}
    
    # Check that the transaction was committed successfully.
    #
    do_execsql_test pager1-4.4.$tn.2 {
      SELECT * FROM a
    } {double-you why zed won too free}
    do_execsql_test pager1-4.4.$tn.3 {
      SELECT * FROM b
    } {won too free double-you why zed}
    
    # Restore the file-system and reopen the databases. Check that it now
    # appears that the transaction was not committed (because the file-system
    # was restored to the state where it had not been).
    #
    do_test pager1-4.4.$tn.4 {
      faultsim_restore_and_reopen $prefix
      execsql "ATTACH '${prefix}2' AS aux"
    } {}
    do_execsql_test pager1-4.4.$tn.5 {SELECT * FROM a} {double-you why zed}
    do_execsql_test pager1-4.4.$tn.6 {SELECT * FROM b} {won too free}
    
    # Restore the file-system again. This time, before reopening the databases,
    # delete the master-journal file from the file-system. It now appears that
    # the transaction was committed (no master-journal file == no rollback).
    #
    do_test pager1-4.4.$tn.7 {
      faultsim_restore_and_reopen $prefix
      foreach f [glob ${prefix}-mj*] { file delete -force $f }
      execsql "ATTACH '${prefix}2' AS aux"
    } {}
    do_execsql_test pager1-4.4.$tn.8 {
      SELECT * FROM a
    } {double-you why zed won too free}
    do_execsql_test pager1-4.4.$tn.9 {
      SELECT * FROM b
    } {won too free double-you why zed}
  }

  cd $pwd
}
db close
tv delete

#-------------------------------------------------------------------------
# The following tests deal with multi-file commits.
#
# pager1-5.1.*: The case where a multi-file cannot be committed because
#               another connection is holding a SHARED lock on one of the
#               files. After the SHARED lock is removed, the COMMIT succeeds.
#
# pager1-5.2.*: Multi-file commits with journal_mode=memory.
#
# pager1-5.3.*: Multi-file commits with journal_mode=memory.
#
# pager1-5.4.*: Check that with synchronous=normal, the master-journal file
#               name is added to a journal file immediately after the last
#               journal record. But with synchronous=full, extra unused space
#               is allocated between the last journal record and the 
#               master-journal file name so that the master-journal file
#               name does not lie on the same sector as the last journal file
#               record.
#
# pager1-5.5.*: Check that in journal_mode=PERSIST mode, a journal file is
#               truncated to zero bytes when a multi-file transaction is 
#               committed (instead of the first couple of bytes being zeroed).
#
#
do_test pager1-5.1.1 {
  faultsim_delete_and_reopen
  execsql {
    ATTACH 'test.db2' AS aux;
    CREATE TABLE t1(a, b);
    CREATE TABLE aux.t2(a, b);