Just want to confirm something involving the exper...

# exposed

[Evan R.]

Just want to confirm something involving the experimental coroutine support via newSuspendedTransaction. The documentation states that we shouldn’t share a transaction between multiple threads due to undefined behavior, so are we not allowed to call other suspending functions within a newSuspendedTransaction() block given when the suspended transaction resumes it may resume on another thread?

For example:

newSuspendedTransaction(<http://Dispatchers.IO|Dispatchers.IO>) {
  val result1 = myTable.select { ... }.toList()
  // newSuspendedTransaction suspends here
  callSomeSuspendingFunction()
  // newSuspendedTransaction resumes, possibly in another thread??
  val result2 = myTable.select {...}.toList()
}

Or:

newSuspendedTransaction(<http://Dispatchers.IO|Dispatchers.IO>) {
  coroutineScope {
    repeat(5) { 
      // Should I be using suspendedTransactionAsync here?
      launch { someFunctionThatUpdatesRows() }
    }
  }
}

[tapac]

Not exactly, you should not share Transaction instance between threads what means if you launch 5 parallel jobs which will make some modification within same transaction you could face unpredicitible result.

It's the same as shared state (https://kotlinlang.org/docs/reference/coroutines/shared-mutable-state-and-concurrency.html)

[Evan R.]

Got it, so we just can’t use the same transaction with muiltiple coroutines executing in parallel