github.com/samgwo/go-ethereum@v1.8.2-0.20180302101319-49bcb5fbd55e/internal/ethapi/addrlock.go (about)

     1  // Copyright 2017 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser 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  // The go-ethereum library 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 Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package ethapi
    18  
    19  import (
    20  	"sync"
    21  
    22  	"github.com/ethereum/go-ethereum/common"
    23  )
    24  
    25  type AddrLocker struct {
    26  	mu    sync.Mutex
    27  	locks map[common.Address]*sync.Mutex
    28  }
    29  
    30  // lock returns the lock of the given address.
    31  func (l *AddrLocker) lock(address common.Address) *sync.Mutex {
    32  	l.mu.Lock()
    33  	defer l.mu.Unlock()
    34  	if l.locks == nil {
    35  		l.locks = make(map[common.Address]*sync.Mutex)
    36  	}
    37  	if _, ok := l.locks[address]; !ok {
    38  		l.locks[address] = new(sync.Mutex)
    39  	}
    40  	return l.locks[address]
    41  }
    42  
    43  // LockAddr locks an account's mutex. This is used to prevent another tx getting the
    44  // same nonce until the lock is released. The mutex prevents the (an identical nonce) from
    45  // being read again during the time that the first transaction is being signed.
    46  func (l *AddrLocker) LockAddr(address common.Address) {
    47  	l.lock(address).Lock()
    48  }
    49  
    50  // UnlockAddr unlocks the mutex of the given account.
    51  func (l *AddrLocker) UnlockAddr(address common.Address) {
    52  	l.lock(address).Unlock()
    53  }