Files
openzeppelin-contracts/contracts/utils/ReentrancyGuard.sol
Santiago Palladino 7ac0502c50 Rename to @openzeppelin/contracts-ethereum-package (#54)
* Change import path from zos-lib to upgrades in all contracts

* Update readme with new naming

* Update package and deps names

* Change path to initializable in AST of networks.jsons

* Migrate manifest version

* Use new oz file locations

* Rename in ERC20Migrator comments

* Update SDK install instructions in README

* Update gitignore to use new session file name

* trigger CI

* Fixes to readme and package version

* Use 2.5.0 release of OpenZeppelin SDK
2019-07-20 13:37:41 -03:00

37 lines
1.2 KiB
Solidity

pragma solidity ^0.5.2;
import "@openzeppelin/upgrades/contracts/Initializable.sol";
/**
* @title Helps contracts guard against reentrancy attacks.
* @author Remco Bloemen <remco@2π.com>, Eenae <alexey@mixbytes.io>
* @dev If you mark a function `nonReentrant`, you should also
* mark it `external`.
*/
contract ReentrancyGuard is Initializable {
/// @dev counter to allow mutex lock with only one SSTORE operation
uint256 private _guardCounter;
function initialize() public initializer {
// The counter starts at one to prevent changing it from zero to a non-zero
// value, which is a more expensive operation.
_guardCounter = 1;
}
/**
* @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 make it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
_guardCounter += 1;
uint256 localCounter = _guardCounter;
_;
require(localCounter == _guardCounter);
}
uint256[50] private ______gap;
}