test/crash5.test

# 2007 Aug 13
#
# 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 tests aspects of recovery from a malloc() failure
# in a CREATE INDEX statement.
#
# $Id: crash5.test,v 1.3 2008/07/12 14:52:20 drh Exp $

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

# Only run these tests if memory debugging is turned on.
#
ifcapable !memdebug||!crashtest||!memorymanage {
   puts "Skipping crash5 tests: not compiled with -DSQLITE_MEMDEBUG..."
   finish_test
   return
}

db close

for {set ii 0} {$ii < 10} {incr ii} {
  for {set jj 50} {$jj < 100} {incr jj} {

    # Set up the database so that it is an auto-vacuum database 
    # containing a single table (root page 3) with a single row. 
    # The row has an overflow page (page 4).
    forcedelete test.db test.db-journal
    sqlite3 db test.db
    set c [string repeat 3 1500]
    db eval {
      pragma auto_vacuum = 1;
      CREATE TABLE t1(a, b, c);
      INSERT INTO t1 VALUES('1111111111', '2222222222', $c);
    }
    db close

    do_test crash5-$ii.$jj.1 {
      crashsql -delay 1 -file test.db-journal -seed $ii -tclbody [join [list \
        [list set iFail $jj] {
        sqlite3_crashparams 0 [file join [get_pwd] test.db-journal]
      
        # Begin a transaction and evaluate a "CREATE INDEX" statement
        # with the iFail'th malloc() set to fail. This operation will
        # have to move the current contents of page 4 (the overflow
        # page) to make room for the new root page. The bug is that
        # if malloc() fails at a particular point in sqlite3PagerMovepage(),
        # sqlite mistakenly thinks that the page being moved (page 4) has 
        # been safely synced into the journal. If the page is written
        # to later in the transaction, it may be written out to the database
        # before the relevant part of the journal has been synced.
        #
        db eval BEGIN
        sqlite3_memdebug_fail $iFail -repeat 0
        catch {db eval { CREATE UNIQUE INDEX i1 ON t1(a); }} msg
        # puts "$n $msg ac=[sqlite3_get_autocommit db]"
      
        # If the transaction is still active (it may not be if the malloc()
        # failure occurred in the OS layer), write to the database. Make sure
        # page 4 is among those written.
        #
        if {![sqlite3_get_autocommit db]} {
          db eval {
            DELETE FROM t1;  -- This will put page 4 on the free list.
            INSERT INTO t1 VALUES('111111111', '2222222222', '33333333');
            INSERT INTO t1 SELECT * FROM t1;                     -- 2
            INSERT INTO t1 SELECT * FROM t1;                     -- 4
            INSERT INTO t1 SELECT * FROM t1;                     -- 8
            INSERT INTO t1 SELECT * FROM t1;                     -- 16
            INSERT INTO t1 SELECT * FROM t1;                     -- 32
            INSERT INTO t1 SELECT * FROM t1 WHERE rowid%2;       -- 48
          }
        }
        
        # If the right malloc() failed during the 'CREATE INDEX' above and
        # the transaction was not rolled back, then the sqlite cache now 
        # has a dirty page 4 that it incorrectly believes is already safely
        # in the synced part of the journal file. When 
        # sqlite3_release_memory() is called sqlite tries to free memory
        # by writing page 4 out to the db file. If it crashes later on,
        # before syncing the journal... Corruption!
        #
        sqlite3_crashparams 1 [file join [get_pwd] test.db-journal]
        sqlite3_release_memory 8092
      }]] {}
      expr 1
    } {1}
  
    sqlite3 db test.db
    do_test crash5-$ii.$jj.2 {
      db eval {pragma integrity_check}
    } {ok}
    do_test crash5-$ii.$jj.3 {
      db eval {SELECT * FROM t1}
    } [list 1111111111 2222222222 $::c]
    db close
  }
}


finish_test