github.com/codingfuture/orig-energi3@v0.8.4/energi/contracts/src/NonReentrant.sol (about)

     1  // Copyright 2019 The Energi Core Authors
     2  // This file is part of Energi Core.
     3  //
     4  // Energi Core is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // Energi Core is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU General Public License
    15  // along with Energi Core. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // Energi Governance system is the fundamental part of Energi Core.
    18  
    19  // NOTE: It's not allowed to change the compiler due to byte-to-byte
    20  //       match requirement.
    21  pragma solidity 0.5.16;
    22  //pragma experimental SMTChecker;
    23  
    24  /**
    25   * A little helper to protect contract from being re-entrant in state
    26   * modifying functions.
    27   */
    28  contract NonReentrant {
    29      uint private entry_guard;
    30  
    31      modifier noReentry {
    32          require(entry_guard == 0, "Reentry");
    33          entry_guard = 1;
    34          _;
    35          entry_guard = 0;
    36      }
    37  }