InitializableReentrancyGuard Code Style Findings

IRG-01C: Inefficient Data Type

Description:

As indicated in the latest version of OpenZeppelin, the re-entrancy guard has been updated to instead utilize a uint256 variable given that a bool is significantly more expensive to utilize due to the underlying unpadding and re-padding operations the EVM conducts.

Example:

Copy
42modifier nonReentrant() {
43    // On the first call to nonReentrant, _notEntered will be true
44    require(_notEntered, "ReentrancyGuard: reentrant call");
45
46    // Any calls to nonReentrant after this point will fail
47    _notEntered = false;
48
49    _;
50
51    // By storing the original value once again, a refund is triggered (see
52    // https://eips.ethereum.org/EIPS/eip-2200)
53    _notEntered = true;
54}

Recommendation:

We advise the data type to be changed to uint256 and the values signalling "not entered" and "entered" to become 1 and 2 respectively.

Alleviation:

The uint256 data type was utilized across the codebase thus greatly optimizing the gas cost of the contract.