var db;
(function() {
"use strict";
const conn = MongoRunner.runMongod();
assert.neq(null, conn, "mongod failed to start.");
db = conn.getDB("test");

const t = db.foo;
t.drop();

const N = 10000;

var bulk = t.initializeUnorderedBulkOp();
for (let i = 0; i < N; i++) {
    bulk.insert({_id: i, x: 1});
}
assert.commandWorked(bulk.execute());

const join = startParallelShell(
    "while( db.foo.findOne( { _id : 0 } ).x == 1 ); db.foo.createIndex( { x : 1 } );");

assert.commandWorked(t.update({
    $where: function() {
        sleep(1);
        return true;
    }
},
                              {$set: {x: 5}},
                              false,
                              true));

join();

assert.eq(N, t.find({x: 5}).count());

MongoRunner.stopMongod(conn);
})();