SQLite

      CREATE TABLE t3(a INTEGER PRIMARY KEY, b);
      WITH s(i) AS ( VALUES(1) UNION ALL SELECT i+1 FROM s WHERE i<100) 
      INSERT INTO t3 SELECT NULL, randomblob(400) FROM s;

      CREATE TABLE t4(a INTEGER PRIMARY KEY, b);


    }
    set {} {}
  } {}

  do_test 7.$tn.2 {
    sql2 {
      BEGIN CONCURRENT;

    csql2 { COMMIT } 
  } {1 {database is locked}}

  do_test 7.$tn.6 {
    csql3 { COMMIT } 
  } {1 {database is locked}}


  csql2 ROLLBACK
  csql3 ROLLBACK

  # The following test works with $tn==1 (sql2 and sql3 use separate 
  # processes), but is quite slow. So only run it with $tn==2 (all
  # connections in the same process).
  #
  if {$tn==2} {
    do_test 7.$tn.7 {
      for {set i 1} {$i < 10000} {incr i} {
        sql3 { 
          PRAGMA wal_checkpoint;
          BEGIN CONCURRENT;
          SELECT * FROM t3;
          INSERT INTO t4 VALUES(1, 2);
        }

        sql1 {
          UPDATE t2 SET b = randomblob(400) WHERE rowid <= $i;
          UPDATE t3 SET b = randomblob(400) WHERE rowid = 1;
        }

        if {[csql3 COMMIT]!={1 {database is locked}}} {
          error "Failed at i=$i"
        }
        csql3 ROLLBACK
      }
    } {}
  }

}

finish_test