# 2007 December 20

#

# 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: tkt2854.test,v 1.3 2008/07/12 14:52:21 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]

# Open 3 database connections. Connection "db" and "db2" share a cache.

# Connection "db3" has its own cache.

#

do_test tkt2854-1.1 {

  sqlite3 db test.db

  sqlite3 db2 test.db

  # This is taken from shared.test.  The Windows VFS expands 

  # ./test.db (and test.db) to be the same thing so the path

  # matches and they share a cache.  By changing the case 

  # for Windows platform, we get around this and get a separate

  # connection.

  if {$::tcl_platform(platform)=="unix"} {

    sqlite3 db3 ./test.db

  } else {

    sqlite3 db3 TEST.DB

  }

  db eval {

    CREATE TABLE abc(a, b, c);

  }

} {}

# Check that an exclusive lock cannot be obtained if some other 

# shared-cache connection has a read-lock on a table.

#

do_test tkt2854-1.2 {

  execsql { 

    BEGIN;

    SELECT * FROM abc;

  } db2

} {}

do_test tkt2854-1.3 {

  catchsql { BEGIN EXCLUSIVE } db

} {1 {database is locked}}

do_test tkt2854-1.4 {

  execsql { SELECT * FROM abc } db3

} {}

do_test tkt2854-1.5 {

  catchsql { INSERT INTO abc VALUES(1, 2, 3) } db3

} {1 {database is locked}}

do_test tkt2854-1.6 {

  execsql { COMMIT } db2

} {}

# Check that an exclusive lock prevents other shared-cache users from

# starting a transaction.

#

do_test tkt2854-1.7 {

  set ::DB2 [sqlite3_connection_pointer db2]

  set ::STMT1 [sqlite3_prepare $DB2 "SELECT * FROM abc" -1 TAIL]

  set ::STMT2 [sqlite3_prepare $DB2 "BEGIN EXCLUSIVE" -1 TAIL]

  set ::STMT3 [sqlite3_prepare $DB2 "BEGIN IMMEDIATE" -1 TAIL]

  set ::STMT4 [sqlite3_prepare $DB2 "BEGIN" -1 TAIL]

  set ::STMT5 [sqlite3_prepare $DB2 "COMMIT" -1 TAIL]

  execsql { BEGIN EXCLUSIVE } db

} {}

do_test tkt2854-1.8 {

  catchsql { BEGIN EXCLUSIVE } db2

} {1 {database schema is locked: main}}

do_test tkt2854-1.9 {

  catchsql { BEGIN IMMEDIATE } db2

} {1 {database schema is locked: main}}

do_test tkt2854-1.10 {

  # This fails because the schema of main cannot be verified.

  catchsql { BEGIN } db2

} {1 {database schema is locked: main}}

# Check that an exclusive lock prevents other shared-cache users from

# reading the database. Use stored statements so that the error occurs

# at the b-tree level, not the schema level.

#

do_test tkt2854-1.11 {

  list [sqlite3_step $::STMT1] [sqlite3_finalize $::STMT1]

} {SQLITE_ERROR SQLITE_LOCKED}

do_test tkt2854-1.12 {

  list [sqlite3_step $::STMT2] [sqlite3_finalize $::STMT2]

} {SQLITE_BUSY SQLITE_BUSY}

do_test tkt2854-1.13 {

  list [sqlite3_step $::STMT3] [sqlite3_finalize $::STMT3]

} {SQLITE_BUSY SQLITE_BUSY}

do_test tkt2854-1.14 {

  # A regular "BEGIN" doesn't touch any databases. So it succeeds.

  list [sqlite3_step $::STMT4] [sqlite3_finalize $::STMT4]

} {SQLITE_DONE SQLITE_OK}

do_test tkt2854-1.15 {

  # As does a COMMIT.

  list [sqlite3_step $::STMT5] [sqlite3_finalize $::STMT5]

} {SQLITE_DONE SQLITE_OK}

# Try to read the database using connection "db3" (which does not share

# a cache with "db"). The database should be locked.

do_test tkt2854-1.16 {

  catchsql { SELECT * FROM abc } db3

} {1 {database is locked}}

do_test tkt2854-1.17 {

  execsql { COMMIT } db

} {}

do_test tkt2854-1.18 {

  execsql { SELECT * FROM abc } db2

} {}

# Check that if an attempt to obtain an exclusive lock fails because an

# attached db cannot be locked, the internal exclusive flag used by

# shared-cache users is correctly cleared.

do_test tkt2854-1.19 {

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

  sqlite3 db4 test2.db

  execsql { CREATE TABLE def(d, e, f) } db4

  execsql { ATTACH 'test2.db' AS aux } db

} {}

do_test tkt2854-1.20 {

  execsql {BEGIN IMMEDIATE} db4

  catchsql {BEGIN EXCLUSIVE} db

} {1 {database is locked}}

do_test tkt2854-1.21 {

  execsql {SELECT * FROM abc} db2

} {}

db close

db2 close

db3 close

db4 close

sqlite3_enable_shared_cache $::enable_shared_cache

finish_test