# 2004 September 2

 #

 # 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 testing the callback-free C/C++ API and in

 # particular the behavior of sqlite3_step() when trying to commit

 # with lock contention.

 #

 # $Id: capi3b.test,v 1.4 2007/08/10 19:46:14 drh Exp $

 #

 set testdir [file dirname $argv0]

 source $testdir/tester.tcl

 # These tests depend on the pager holding changes in cache

 # until it is time to commit.  But that won't happen if the

 # soft-heap-limit is set too low.  So disable the soft heap limit

 # for the duration of this test.

 #

 sqlite3_soft_heap_limit 0

 set DB [sqlite3_connection_pointer db]

 sqlite3 db2 test.db

 set DB2 [sqlite3_connection_pointer db2]

 # Create some data in the database

 #

 do_test capi3b-1.1 {

   execsql {

     CREATE TABLE t1(x);

     INSERT INTO t1 VALUES(1);

     INSERT INTO t1 VALUES(2);

     SELECT * FROM t1

   }

 } {1 2}

 # Make sure the second database connection can see the data

 #

 do_test capi3b-1.2 {

   execsql {

     SELECT * FROM t1

   } db2

 } {1 2}

 # First database connection acquires a shared lock

 #

 do_test capi3b-1.3 {

   execsql {

     BEGIN;

     SELECT * FROM t1;

   }

 } {1 2}

 # Second database connection tries to write.  The sqlite3_step()

 # function returns SQLITE_BUSY because it cannot commit.

 #

 do_test capi3b-1.4 {

   set VM [sqlite3_prepare $DB2 {INSERT INTO t1 VALUES(3)} -1 TAIL]

   sqlite3_step $VM

 } SQLITE_BUSY

 # The sqlite3_step call can be repeated multiple times.

 #

 do_test capi3b-1.5.1 {

   sqlite3_step $VM

 } SQLITE_BUSY

 do_test capi3b-1.5.2 {

   sqlite3_step $VM

 } SQLITE_BUSY

 # The first connection closes its transaction.  This allows the second

 # connections sqlite3_step to succeed.

 #

 do_test capi3b-1.6 {

   execsql COMMIT

   sqlite3_step $VM

 } SQLITE_DONE

 do_test capi3b-1.7 {

   sqlite3_finalize $VM

 } SQLITE_OK

 do_test capi3b-1.8 {

   execsql {SELECT * FROM t1} db2

 } {1 2 3}

 do_test capi3b-1.9 {

   execsql {SELECT * FROM t1}

 } {1 2 3}

 # Start doing a SELECT with one connection.  This gets a SHARED lock.

 # Then do an INSERT with the other connection.  The INSERT should

 # not be able to complete until the SELECT finishes.

 #

 do_test capi3b-2.1 {

   set VM1 [sqlite3_prepare $DB {SELECT * FROM t1} -1 TAIL]

   sqlite3_step $VM1

 } SQLITE_ROW

 do_test capi3b-2.2 {

   sqlite3_column_text $VM1 0

 } 1

 do_test capi3b-2.3 {

   set VM2 [sqlite3_prepare $DB2 {INSERT INTO t1 VALUES(4)} -1 TAIL]

   sqlite3_step $VM2

 } SQLITE_BUSY

 do_test capi3b-2.4 {

   sqlite3_step $VM1

 } SQLITE_ROW

 do_test capi3b-2.5 {

   sqlite3_column_text $VM1 0

 } 2

 do_test capi3b-2.6 {

   sqlite3_step $VM2

 } SQLITE_BUSY

 do_test capi3b-2.7 {

   sqlite3_step $VM1

 } SQLITE_ROW

 do_test capi3b-2.8 {

   sqlite3_column_text $VM1 0

 } 3

 do_test capi3b-2.9 {

   sqlite3_step $VM2

 } SQLITE_BUSY

 do_test capi3b-2.10 {

   sqlite3_step $VM1

 } SQLITE_DONE

 do_test capi3b-2.11 {

   sqlite3_step $VM2

 } SQLITE_DONE

 do_test capi3b-2.12 {

   sqlite3_finalize $VM1

   sqlite3_finalize $VM2

   execsql {SELECT * FROM t1}

 } {1 2 3 4}

 catch {db2 close}

 sqlite3_soft_heap_limit $soft_limit

 finish_test