# 2007 April 6

#

# 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 this script is database locks.

#

# $Id: lock4.test,v 1.8 2008/03/14 08:57:42 danielk1977 Exp $

set testdir [file dirname $argv0]

source $testdir/tester.tcl

# Initialize the test.db database so that it is non-empty

#

do_test lock4-1.1 {

  db eval {

     PRAGMA auto_vacuum=OFF;

     CREATE TABLE t1(x);

  }

  file delete -force test2.db test2.db-journal

  sqlite3 db2 test2.db

  db2 eval {

     PRAGMA auto_vacuum=OFF;

     CREATE TABLE t2(x)

  }

  db2 close

  list [file size test.db] [file size test2.db]

} {2048 2048}

# Create a script to drive a separate process that will

#

#     1.  Create a second database test2.db

#     2.  Get an exclusive lock on test2.db

#     3.  Add an entry to test.db in table t1, waiting as necessary.

#     4.  Commit the change to test2.db.

#

# Meanwhile, this process will:

# 

#     A.  Get an exclusive lock on test.db

#     B.  Attempt to read from test2.db but get an SQLITE_BUSY error.

#     C.  Commit the changes to test.db thus alloing the other process

#         to continue.

#

do_test lock4-1.2 {

  # Create a script for the second process to run.

  #

  set out [open test2-script.tcl w]

  puts $out "set sqlite_pending_byte [set sqlite_pending_byte]"

  puts $out {

     sqlite3 db2 test2.db

     db2 eval {

        BEGIN;

        INSERT INTO t2 VALUES(2);

     }

     sqlite3 db test.db

     db timeout 1000000

     db eval {

        INSERT INTO t1 VALUES(2);

     }

     db close

     db2 eval COMMIT

     exit

  }

  close $out

  # Begin a transaction on test.db.

  db eval {

     BEGIN EXCLUSIVE;

     INSERT INTO t1 VALUES(1);

  }

  # Kick off the second process.

  exec [info nameofexec] ./test2-script.tcl &

  # Wait until the second process has started its transaction on test2.db.

  while {![file exists test2.db-journal]} {

    after 10

  }

  # Try to write to test2.db. We are locked out.

  sqlite3 db2 test2.db

  catchsql {

    INSERT INTO t2 VALUES(1)

  } db2

} {1 {database is locked}}

do_test lock4-1.3 {

  db eval {

     COMMIT;

  }

  while {[file exists test2.db-journal]} {

    after 10

  }

  # The other process has committed its transaction on test2.db by 

  # deleting the journal file. But it might retain the lock for a 

  # fraction longer 

  #

  db2 eval {

     SELECT * FROM t2

  }

} {2}

do_test lock4-999.1 {

  rename db2 {}

} {}

finish_test