test/shared2.test

# 2005 January 19
#
# 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: shared2.test,v 1.8 2009/06/05 17:09:12 drh Exp $

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

ifcapable !shared_cache {
  finish_test
  return
}
set ::enable_shared_cache [sqlite3_enable_shared_cache 1]

# Test that if we delete all rows from a table any read-uncommitted 
# cursors are correctly invalidated. Test on both table and index btrees.
do_test shared2-1.1 {
  sqlite3 db1 test.db
  sqlite3 db2 test.db

  # Set up some data. Table "numbers" has 64 rows after this block 
  # is executed.
  execsql {
    BEGIN;
    CREATE TABLE numbers(a PRIMARY KEY, b);
    INSERT INTO numbers(oid) VALUES(NULL);
    INSERT INTO numbers(oid) SELECT NULL FROM numbers;
    INSERT INTO numbers(oid) SELECT NULL FROM numbers;
    INSERT INTO numbers(oid) SELECT NULL FROM numbers;
    INSERT INTO numbers(oid) SELECT NULL FROM numbers;
    INSERT INTO numbers(oid) SELECT NULL FROM numbers;
    INSERT INTO numbers(oid) SELECT NULL FROM numbers;
    UPDATE numbers set a = oid, b = 'abcdefghijklmnopqrstuvwxyz0123456789';
    COMMIT;
  } db1
} {}
do_test shared2-1.2 {
  # Put connection 2 in read-uncommitted mode and start a SELECT on table 
  # 'numbers'. Half way through the SELECT, use connection 1 to delete the
  # contents of this table.
  execsql {
    pragma read_uncommitted = 1;
  } db2
  set count [execsql {SELECT count(*) FROM numbers} db2]
  db2 eval {SELECT a FROM numbers ORDER BY oid} {
    if {$a==32} {
      execsql {
        BEGIN;
        DELETE FROM numbers;
      } db1
    }
  }
  list $a $count
} {32 64}
do_test shared2-1.3 {
  # Same test as 1.2, except scan using the index this time.
  execsql {
    ROLLBACK;
  } db1
  set count [execsql {SELECT count(*) FROM numbers} db2]
  db2 eval {SELECT a, b FROM numbers ORDER BY a} {
    if {$a==32} {
      execsql {
        DELETE FROM numbers;
      } db1
    }
  }
  list $a $count
} {32 64}

#---------------------------------------------------------------------------
# These tests, shared2.2.*, test the outcome when data is added to or 
# removed from a table due to a rollback while a read-uncommitted 
# cursor is scanning it.
#
do_test shared2-2.1 {
  execsql {
    INSERT INTO numbers VALUES(1, 'Medium length text field');
    INSERT INTO numbers VALUES(2, 'Medium length text field');
    INSERT INTO numbers VALUES(3, 'Medium length text field');
    INSERT INTO numbers VALUES(4, 'Medium length text field');
    BEGIN;
    DELETE FROM numbers WHERE (a%2)=0;
  } db1
  set res [list]
  db2 eval {
    SELECT a FROM numbers ORDER BY a;
  } {
    lappend res $a
    if {$a==3} {
      execsql {ROLLBACK} db1
    }
  }
  set res
} {1 3 4}
do_test shared2-2.2 {
  execsql {
    BEGIN;
    INSERT INTO numbers VALUES(5, 'Medium length text field');
    INSERT INTO numbers VALUES(6, 'Medium length text field');
  } db1
  set res [list]
  db2 eval {
    SELECT a FROM numbers ORDER BY a;
  } {
    lappend res $a
    if {$a==5} {
      execsql {ROLLBACK} db1
    }
  }
  set res
} {1 2 3 4 5}

db1 close
db2 close

do_test shared2-3.2 {
  sqlite3_enable_shared_cache 1
} {1}

file delete -force test.db

sqlite3 db test.db
do_test shared2-4.1 {
  execsql {
    CREATE TABLE t0(a, b);
    CREATE TABLE t1(a, b DEFAULT 'hello world');
  }
} {}
db close

sqlite3 db test.db
sqlite3 db2 test.db

do_test shared2-4.2 {
  execsql { SELECT a, b FROM t0 } db
  execsql { INSERT INTO t1(a) VALUES(1) } db2
} {}

do_test shared2-4.3 {
  db2 close
  db close
} {}

# At one point, this was causing a crash.
#
do_test shared2-5.1 {
  sqlite3 db test.db
  sqlite3 db2 test.db
  execsql { CREATE TABLE t2(a, b, c) }
  
  # The following statement would crash when attempting to sqlite3_free()
  # a pointer allocated from a lookaside buffer.
  execsql { CREATE INDEX i1 ON t2(a) } db2
} {}

db close
db2 close

sqlite3_enable_shared_cache $::enable_shared_cache
finish_test