run solidity code after every x amount of time

Question

I am creating a dev application in which after for example every 5 minutes would like to run some code from my erc20 token's smart contract. How can I call that function after every 5 minutes in solidity?

Answer 1

There's no native delay (sleep, or anything that waits some amount of time) function in Solidity (or in EVM bytecode in general).

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Each solidity function is executed as a part of a transaction.

So you can set the timer on your off-chain app, sending a transaction each 5 minutes. Mind that there's a delay between sending a transaction from your app and actually publishing the block (by a miner) that contains the transaction.

Example in JS:

function sendTx() {
   myContract.methods.myFunction().send();
};

setInterval('sendTx', 5 * 1000 * 60);

You can also validate the delay in Solidity and perform an action only if 5 minutes passed since the last action.

pragma solidity ^0.8;

contract MyContract {
    uint256 lastRun;

    function myFunction() external {
        require(block.timestamp - lastRun > 5 minutes, 'Need to wait 5 minutes');

        // TODO perform the action

        lastRun = block.timestamp;
    }
}