github.com/jdgcs/sqlite3@v1.12.1-0.20210908114423-bc5f96e4dd51/testdata/tcl/sharedlock.test (about)

     1  # 2009 July 2
     2  #
     3  # The author disclaims copyright to this source code.  In place of
     4  # a legal notice, here is a blessing:
     5  #
     6  #    May you do good and not evil.
     7  #    May you find forgiveness for yourself and forgive others.
     8  #    May you share freely, never taking more than you give.
     9  #
    10  #***********************************************************************
    11  #
    12  # $Id: sharedlock.test,v 1.1 2009/07/02 17:21:58 danielk1977 Exp $
    13  
    14  set testdir [file dirname $argv0]
    15  source $testdir/tester.tcl
    16  set testprefix sharedlock
    17  db close
    18  
    19  ifcapable !shared_cache {
    20    finish_test
    21    return
    22  }
    23  
    24  set ::enable_shared_cache [sqlite3_enable_shared_cache 1]
    25  sqlite3 db  test.db
    26  sqlite3 db2 test.db
    27  
    28  do_test sharedlock-1.1 {
    29    execsql {
    30      CREATE TABLE t1(a, b);
    31      INSERT INTO t1 VALUES(1, 'one');
    32      INSERT INTO t1 VALUES(2, 'two');
    33    }
    34  } {}
    35  
    36  do_test sharedlock-1.2 {
    37    set res [list]
    38    db eval { SELECT * FROM t1 ORDER BY rowid } {
    39      lappend res $a $b
    40      if {$a == 1} { catch { db  eval "INSERT INTO t1 VALUES(3, 'three')" } }
    41  
    42      # This should fail. Connection [db] has a read-lock on t1, which should
    43      # prevent connection [db2] from obtaining the write-lock it needs to
    44      # modify t1. At one point there was a bug causing the previous INSERT
    45      # to drop the read-lock belonging to [db].
    46      if {$a == 2} { catch { db2 eval "INSERT INTO t1 VALUES(4, 'four')"  } }
    47    }
    48    set res
    49  } {1 one 2 two 3 three}
    50  
    51  
    52  #-------------------------------------------------------------------------
    53  # Test that a write-lock is taken on a table when its entire contents
    54  # are deleted using the OP_Clear optimization.
    55  #
    56  foreach {tn delete_sql} {
    57    1 { DELETE FROM t2 WHERE 1 }
    58    2 { DELETE FROM t2 }
    59  } {
    60    do_execsql_test 2.1 {
    61      DROP TABLE IF EXISTS t2;
    62      CREATE TABLE t2(x, y);
    63      INSERT INTO t2 VALUES(1, 2);
    64      INSERT INTO t2 VALUES(3, 4);
    65    }
    66  
    67    do_test 2.2 { execsql { SELECT * FROM t2 } db2 } {1 2 3 4}
    68  
    69    do_execsql_test 2.3 " BEGIN; $delete_sql; "
    70  
    71    do_test 2.4 { 
    72      catchsql { SELECT * FROM t2 } db2 
    73    } {1 {database table is locked: t2}}
    74  
    75    do_execsql_test 2.5 COMMIT
    76  }
    77  
    78  
    79  db close
    80  db2 close
    81  sqlite3_enable_shared_cache $::enable_shared_cache
    82  finish_test