Lock

source code // tests

Lock provides a reentrancy mutex. Contracts that inherit from Lock will have the lock modifier available, any subcall resulting from a call to a locked method will revert if it attempts to call any other locked method on the same contract.

Note that reentrant calls to methods that are not protected by the lock modifier will still succeed.

Interface

Data

• bool unlocked: lock status

Modifiers

lock():

reverts if unlocked is true, and sets it to false for the duration of the call to the wrapped method.

Example

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity ^0.8.6;

import {Lock} from "dappsys-v2/lock.sol";

contract Locked is Lock {
    uint public value = 0;

    function badSet(uint v) external lock {
        doSet(v);
    }

    function doBadSet(uint v) internal lock {
        value = v;
    }

    function goodSet(uint v) external lock {
        doGoodSet(v);
    }

    function doGoodSet(uint v) internal {
        value = v;
    }
}

contract Test {
    function go() external {
        Locked locked = new Locked();

        // this call will work since `doGoodSet` is not protected by the lock
        locked.goodSet(10);

        // this will always revert since `unlocked` is `false` during the inner call to `doBadSet`
        locked.badSet(10);
    }
}