[SPARK-36717] Wrong order of variable initialization may lead to incorrect behavior

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.1.2
• Fix Version/s: 3.1.3, 3.0.4, 3.2.1, 3.3.0
• Component/s: Spark Core

Language

scala

• Assignee: Jianmeng Li
• Reporter: Jianmeng Li
• Created: 10/Sep/21 12:05
• Updated: 10/Jan/22 23:52
• Resolved: 08/Oct/21 12:13

Description

Incorrect order of variable initialization may lead to incorrect behavior, Related code: TorrentBroadcast.scala , TorrentBroadCast will get wrong checksumEnabled value after initialization, this may not be what we need, we can move L94 front of setConf(SparkEnv.get.conf) to avoid this.

Supplement:

Snippet 1:

class Broadcast {
  def setConf(): Unit = {
    checksumEnabled = true
  }
  setConf()
  var checksumEnabled = false
}

println(new Broadcast().checksumEnabled)

output:

false

Snippet 2:

class Broadcast {
  var checksumEnabled = false
  def setConf(): Unit = {
    checksumEnabled = true
  }
  setConf()
}

println(new Broadcast().checksumEnabled)

output: 

true

Issue Links

• links to: [Github] Pull Request #33957 (daugraph)