CODEWITHSUNDEEP
scalaplayframework-2.0
lovesh
lovesh

Reputation: 5411

Asynchronous tasks are not done in play framework(scala)

I have some code that i want to run asynchronously in a request. That code has no effect on the response so i run it like this

import scala.concurrent.Future    

Database.forURL(url, driver = driver) withSession {
  implicit session =>
// some db changes
//some code that has effect on response like getting userId
//so run synchronously

// now asynchronous code

import play.api.libs.concurrent.Execution.Implicits.defaultContext

Future {
          println("inside Futute, starting")
          val userAuthTable = TableQuery[Tables.UserAuth]
          println("inside Futute, running")
          // some db operations
          println("inside Futute, done")

} // Future block ends
userId


} // session ends

Here i can see the 2 lines print on the console

inside Futute, starting

and

inside Futute, running

but i dont see

inside Futute, done

Neither the db operations are done. I am able to get userId which is outside Future. When i put those db operations outside the Future, they get executed. But why not inside the Future? And why the first 2 lines get printed on the console. I am using play 2.3.3 and scala 2.11.

Update

My code was in a Postgres Session and somehow Future block gets executed outside of scope of session. So i created 2 sessions, one for executing the db code synchronously and the other for asynchronous code inside the Future. This works correctly

import scala.concurrent.Future    

val userId = Database.forURL(url, driver = driver) withSession {
    implicit session =>
    // some db changes
    //some code that has effect on response like getting userId
    //so run synchronously
} // session ends

// now asynchronous code
import play.api.libs.concurrent.Execution.Implicits.defaultContext

Future {
println("inside Futute, starting")
Database.forURL(url, driver = driver) withSession {
   implicit session =>
      val userAuthTable = TableQuery[Tables.UserAuth]
      println("inside Futute, running")
      // some db operations
   } // session ends
      println("inside Futute, done")
} // Future ends

Thanks to @Ryan and @applicius

Upvotes: 1

Views: 124

Answers (1)

Ryan
Ryan

Reputation: 7257

Add a .recover to the end of your future to make sure an exception isn't being thrown and ignored.

Upvotes: 2

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