Vyper has a handy way to secure your contract from reentrancy.
A reentrancy lock can be created on a function with @nonreentrant.
Example Vyper contract with reentrancy lock
# pragma version ^0.4.0
@external
@nonreentrant
def func():
raw_call(msg.sender, b"", value=0)
Example Vyper contract without reentrancy lock
# pragma version ^0.4.0
interface ILock:
def func(): nonpayable
count: public(uint256)
@external
@payable
def __default__():
if self.count < 2:
self.count += 1
extcall ILock(msg.sender).func()
@external
def reset():
self.count = 0
@external
def test_lock(to: address):
extcall ILock(to).func()
