读写锁是以 ReaderWriterLockSlim 对象作为锁管理资源的,不同的 ReaderWriterLockSlim 对象中锁定同一个文件也会被视为不同的锁进行管理,这种差异可能会再次导致文件的并发写入问题,所以 ReaderWriterLockSlim 应尽量定义为只读的静态对象。
多线程同时写入文件
class Program
{
static int writeCount = ;
static int wrongCount = ;
static void Main(string[] args)
{
Test();
}
static void Test()
{
//迭代运行写入内容,由于多个线程同时写入同一个文件将会导致错误
Parallel.For(, , e =>
{
try
{
writeCount++;
var logFilePath = "/test.txt";
var now = DateTime.Now;
var logContent = string.Format("Tid: {0}{1} {2}=>{3}\r\n", Thread.CurrentThread.ManagedThreadId.ToString().PadRight(), now.ToLongDateString(), now.ToLongTimeString(), writeCount); File.AppendAllText(logFilePath, logContent);
}
catch (Exception ex)
{
wrongCount++;
Console.WriteLine("累计失败" + wrongCount + "次");
Console.WriteLine(ex.Message);
throw;
}
}); Console.Read();
}
}
运行结果
只有部分数据写入了文件
多线程使用读写锁同步写入文件
class Program
{
static int writeCount = ;
static int wrongCount = ;
static void Main(string[] args)
{
Test();
}
static ReaderWriterLockSlim writeLock = new ReaderWriterLockSlim();
static void Test()
{
//迭代运行写入内容
Parallel.For(, , e =>
{
try
{
writeLock.EnterWriteLock();
writeCount++;
var logFilePath = "/test.txt";
var now = DateTime.Now;
var logContent = string.Format("Tid: {0}{1} {2}=>{3}\r\n", Thread.CurrentThread.ManagedThreadId.ToString().PadRight(), now.ToLongDateString(), now.ToLongTimeString(), writeCount); File.AppendAllText(logFilePath, logContent);
}
catch (Exception ex)
{
wrongCount++;
Console.WriteLine("累计失败" + wrongCount + "次");
Console.WriteLine(ex.Message);
throw;
}
finally
{
writeLock.ExitWriteLock();
}
}); Console.Read();
}
}
运行成功,数据全部写入文件