github.com/MetalBlockchain/subnet-evm@v0.4.9/internal/ethapi/addrlock.go (about)

     1  // (c) 2019-2020, Ava Labs, Inc.
     2  //
     3  // This file is a derived work, based on the go-ethereum library whose original
     4  // notices appear below.
     5  //
     6  // It is distributed under a license compatible with the licensing terms of the
     7  // original code from which it is derived.
     8  //
     9  // Much love to the original authors for their work.
    10  // **********
    11  // Copyright 2017 The go-ethereum Authors
    12  // This file is part of the go-ethereum library.
    13  //
    14  // The go-ethereum library is free software: you can redistribute it and/or modify
    15  // it under the terms of the GNU Lesser General Public License as published by
    16  // the Free Software Foundation, either version 3 of the License, or
    17  // (at your option) any later version.
    18  //
    19  // The go-ethereum library is distributed in the hope that it will be useful,
    20  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    21  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    22  // GNU Lesser General Public License for more details.
    23  //
    24  // You should have received a copy of the GNU Lesser General Public License
    25  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    26  
    27  package ethapi
    28  
    29  import (
    30  	"sync"
    31  
    32  	"github.com/ethereum/go-ethereum/common"
    33  )
    34  
    35  type AddrLocker struct {
    36  	mu    sync.Mutex
    37  	locks map[common.Address]*sync.Mutex
    38  }
    39  
    40  // lock returns the lock of the given address.
    41  func (l *AddrLocker) lock(address common.Address) *sync.Mutex {
    42  	l.mu.Lock()
    43  	defer l.mu.Unlock()
    44  	if l.locks == nil {
    45  		l.locks = make(map[common.Address]*sync.Mutex)
    46  	}
    47  	if _, ok := l.locks[address]; !ok {
    48  		l.locks[address] = new(sync.Mutex)
    49  	}
    50  	return l.locks[address]
    51  }
    52  
    53  // LockAddr locks an account's mutex. This is used to prevent another tx getting the
    54  // same nonce until the lock is released. The mutex prevents the (an identical nonce) from
    55  // being read again during the time that the first transaction is being signed.
    56  func (l *AddrLocker) LockAddr(address common.Address) {
    57  	l.lock(address).Lock()
    58  }
    59  
    60  // UnlockAddr unlocks the mutex of the given account.
    61  func (l *AddrLocker) UnlockAddr(address common.Address) {
    62  	l.lock(address).Unlock()
    63  }