Let's say I have a contract like this:

contract Test{
  uint8 test = 0;
  // getter and setter

and I want to issue it using some python code like:

initial = contract.getTest()
contract.setTest(1, {"from": 0x123123123...})
final = contract.getTest()

since getTest is a call, and setTest is a transaction, this should not be safe code right? Or call are dispatched synchronously with transaction and there is no race condition in this code?

Will getTest always return 1 if I run the above in order?

  • Can you rephrase the question to clarify what you mean by "safe"? Sep 14 '21 at 19:42
  • @PatrickCollins with safe, i mean that there is no race condition in this code... for the example provided, that final will always be 1 Sep 15 '21 at 10:47

To 100% guarantee that this will execute in order, you can wait for a transaction to be mined.

initial = contract.getTest()
set_transaction = contract.setTest(1, {"from": 0x123123123...})
final = contract.getTest()

wait(1) means we are going to wait 1 block for the transaction to finish.

  • since Vitalik said that to be sure that the consensus is reached we need to wait 7/8 blocks, do I need to use tx.wait(7)? Sep 15 '21 at 12:48
  • Yes! You got it! Sep 15 '21 at 22:19
  • 1
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