SQLite

    drop_all_tables
    set nAlloc4  [lindex [sqlite3_status SQLITE_STATUS_MEMORY_USED 0] 1]
    incr nAlloc4 [lookaside db]
    set nSchema4 [lindex [sqlite3_db_status db SQLITE_DBSTATUS_SCHEMA_USED 0] 1]
    set nFree [expr {$nAlloc1-$nAlloc2}]
    
    # Tests for which the test name ends in an "x" report slightly less
    # memory than is actually freed when all schema items are finalized.
    # This is because memory allocated by virtual table implementations

    # for any reason is not counted as "schema memory".
    #
    # Additionally, in auto-vacuum mode, dropping tables and indexes causes
    # the page-cache to shrink. So the amount of memory freed is always
    # much greater than just that reported by DBSTATUS_SCHEMA_USED in this
    # case.
    #
    if {[string match *x $tn] || $AUTOVACUUM} {
      do_test dbstatus-2.$tn.ax { expr {($nSchema1-$nSchema2)<=$nFree} } 1
    } else {
      do_test dbstatus-2.$tn.a { expr {$nSchema1-$nSchema2} } $nFree
    }
  
    do_test dbstatus-2.$tn.b { list $nAlloc1 $nSchema1 } "$nAlloc3 $nSchema3"
    do_test dbstatus-2.$tn.c { list $nAlloc2 $nSchema2 } "$nAlloc4 $nSchema4"

    # Tests for which the test name ends in an "x" report slightly less
    # memory than is actually freed when all statements are finalized.
    # This is because a small amount of memory allocated by a virtual table
    # implementation using sqlite3_mprintf() is technically considered
    # external and so is not counted as "statement memory".
    #
#puts "$nStmt1 $nFree"
    if {[string match *x $tn]} {
      do_test dbstatus-3.$tn.bx { expr $nStmt1<=$nFree }  {1}
    } else {
      do_test dbstatus-3.$tn.b { expr $nStmt1==$nFree } {1}
    }

    do_test dbstatus-3.$tn.c { list $nAlloc1 $nStmt1 } [list $nAlloc3 $nStmt3]
    do_test dbstatus-3.$tn.d { list $nAlloc2 $nStmt2 } [list $nAlloc4 $nStmt4]
  }
}

finish_test

    # Dirty (at least) one of the pages in the cache.
    do_test ioerr5-1.$locking_mode-$iFail.1 {
      execsql {
        BEGIN EXCLUSIVE;
        INSERT INTO a VALUES(1, 'ABCDEFGHIJKLMNOP');
      }
    } {}

    # Open a read-only cursor on table "a". If the COMMIT below is
    # interrupted by a persistent IO error, the pager will transition to 
    # PAGER_ERROR state. If there are no other read-only cursors open,
    # from there the pager immediately discards all cached data and 
    # switches to PAGER_OPEN state. This read-only cursor stops that
    # from happening, leaving the pager stuck in PAGER_ERROR state.
    #
    set channel [db incrblob -readonly a Name [db last_insert_rowid]]
  
    # Now try to commit the transaction. Cause an IO error to occur
    # within this operation, which moves the pager into the error state.
    #
    set ::sqlite_io_error_persist 1
    set ::sqlite_io_error_pending $iFail
    do_test ioerr5-1.$locking_mode-$iFail.2 {

    # Set a very low soft-limit and then try to compile an SQL statement 
    # from UTF-16 text. To do this, SQLite will need to reclaim memory
    # from the pager that is in error state. Including that associated
    # with the dirty page.
    #
    do_test ioerr5-1.$locking_mode-$iFail.3 {

      sqlite3_soft_heap_limit 1024
      compilesql16 "SELECT 10"

    } {}










    close $channel




    # Ensure that nothing was written to the database while reclaiming
    # memory from the pager in error state.
    #
    do_test ioerr5-1.$locking_mode-$iFail.4 {
      set fd [open test.db]
      fconfigure $fd -translation binary -encoding binary
      set zDatabase2 [read $fd]
      close $fd
      expr {$zDatabase eq $zDatabase2}
    } {1}

    if {$rc eq [list 0 {}]} {
      do_test ioerr5.1-$locking_mode-$iFail.3 {
        execsql { SELECT count(*) FROM a }
      } [expr $nRow+1]
      break
    }
  }