# 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