// SPDX-License-Identifier: MIT // OpenZeppelin Contracts (last updated v5.0.0) (utils/ReentrancyGuard.sol) pragma solidity ^0.8.20; import {Initializable} from "../proxy/utils/Initializable.sol"; /** * @dev Contract module that helps prevent reentrant calls to a function. * * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier * available, which can be applied to functions to make sure there are no nested * (reentrant) calls to them. * * Note that because there is a single `nonReentrant` guard, functions marked as * `nonReentrant` may not call one another. This can be worked around by making * those functions `private`, and then adding `external` `nonReentrant` entry * points to them. * * TIP: If you would like to learn more about reentrancy and alternative ways * to protect against it, check out our blog post * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul]. */ abstract contract ReentrancyGuardUpgradeable is Initializable { // Booleans are more expensive than uint256 or any type that takes up a full // word because each write operation emits an extra SLOAD to first read the // slot's contents, replace the bits taken up by the boolean, and then write // back. This is the compiler's defense against contract upgrades and // pointer aliasing, and it cannot be disabled. // The values being non-zero value makes deployment a bit more expensive, // but in exchange the refund on every call to nonReentrant will be lower in // amount. Since refunds are capped to a percentage of the total // transaction's gas, it is best to keep them low in cases like this one, to // increase the likelihood of the full refund coming into effect. uint256 private constant NOT_ENTERED = 1; uint256 private constant ENTERED = 2; /// @custom:storage-location erc7201:openzeppelin.storage.ReentrancyGuard struct ReentrancyGuardStorage { uint256 _status; } // keccak256(abi.encode(uint256(keccak256("openzeppelin.storage.ReentrancyGuard")) - 1)) & ~bytes32(uint256(0xff)) bytes32 private constant ReentrancyGuardStorageLocation = 0x9b779b17422d0df92223018b32b4d1fa46e071723d6817e2486d003becc55f00; function _getReentrancyGuardStorage() private pure returns (ReentrancyGuardStorage storage $) { assembly { $.slot := ReentrancyGuardStorageLocation } } /** * @dev Unauthorized reentrant call. */ error ReentrancyGuardReentrantCall(); function __ReentrancyGuard_init() internal onlyInitializing { __ReentrancyGuard_init_unchained(); } function __ReentrancyGuard_init_unchained() internal onlyInitializing { ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage(); $._status = NOT_ENTERED; } /** * @dev Prevents a contract from calling itself, directly or indirectly. * Calling a `nonReentrant` function from another `nonReentrant` * function is not supported. It is possible to prevent this from happening * by making the `nonReentrant` function external, and making it call a * `private` function that does the actual work. */ modifier nonReentrant() { _nonReentrantBefore(); _; _nonReentrantAfter(); } function _nonReentrantBefore() private { ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage(); // On the first call to nonReentrant, _status will be NOT_ENTERED if ($._status == ENTERED) { revert ReentrancyGuardReentrantCall(); } // Any calls to nonReentrant after this point will fail $._status = ENTERED; } function _nonReentrantAfter() private { ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage(); // By storing the original value once again, a refund is triggered (see // https://eips.ethereum.org/EIPS/eip-2200) $._status = NOT_ENTERED; } /** * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a * `nonReentrant` function in the call stack. */ function _reentrancyGuardEntered() internal view returns (bool) { ReentrancyGuardStorage storage $ = _getReentrancyGuardStorage(); return $._status == ENTERED; } }