Assembly ReenterancyGaurd

noRenter.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;


abstract contract NoReEnter {
    uint8 internal mutex;
    bytes32 constant internal ERROR_STATE_LOCKED = 0x07b2e09e00000000000000000000000000000000000000000000000000000000;
    
    error StateLocked();

    function _auth() private view returns(bool unlocked) {
        assembly {
            let _mutex := sload(mutex.slot)
            if iszero(eq(_mutex, 0x00)) {
                mstore(0x00, ERROR_STATE_LOCKED)
                revert(0x00, 0x04) 
            }
             unlocked := 0x01
        }   
    }

    function toggle(uint8 locked) internal  {
        assembly {
            
            if eq(locked, 0x0) {
                sstore(mutex.slot, 0x01)

            }
            if eq(locked, 0x01) {
                sstore(mutex.slot, 0x00)
                
            }
            
        }


    }

    modifier reenterancyGaurd {
        if (_auth()) {
            toggle(1);
             _;
            toggle(0);
        }
       
    }

}