Creating many classes instances in parallel

Question

Hello,

My scenario is the following :
I have a server app that creates entitty collections and transforms those into DTO (data transport objects - WCF).
List<CustomerDTO> custDto = new List<CustomerDTO>
foreach (CustomerEntity cust in custEntities)
  custDto.Add(cust.ToDto());
This consists of only creating an object (DTO) and filling its properties with the entity properties.
Can I expect some performace improvements on a multicore machine by using parallel extension ?
One important thing is that the order should remain the same since it is the result of an ORDER BY.

Thanks

---

philippe

Answer 1

Philippe,

At a guess I would say no, but it does depend on

1) how complex the projection is

2) how many cores you have.

Since this a server app Im guessing you will be potentially taking advantage of multiple cores at a more coarse grain level.

Bottom line is try it...

Answer 2

Philippe,

At a guess I would say no, but it does depend on

1) how complex the projection is

2) how many cores you have.

Since this a server app Im guessing you will be potentially taking advantage of multiple cores at a more coarse grain level.

Bottom line is try it...

Thanks for your answer.
1) it can be complex since dto's contains child tables
2) it's a 8 core server running vmware and each machine of my cluster is only allocated 1 processor.

Is it possible while using multithreading to keep the dto list in the same order as the entity list ?

---

philippe

Answer 3

You can use PLINQ to maintain the ordering, e.g.

List<CustomerDto> custDto = custEntities.AsParallel().AsOrdered().Select(cust => cust.ToDto()).ToList();

Without knowing what ToDto does, it's hard to say whether this will scale well or not, but you can certainly try it out and see.  Note that if a lot of object allocation is being done, as it appears it may be, you might also try enabling the server GC in the configuration file for your application, e.g.

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <runtime>
    <gcServer enabled="true"/>
  </runtime>
</configuration>