当多个线程在同一个对象上请求锁时,CLR是否保证将按照请求的顺序获取锁?
我写了一个测试,看看这是不是真的,它似乎表明是的,但我不确定这是否是确定的.
class LockSequence
{
private static readonly object _lock = new object();
private static DateTime _dueTime;
public static void Test()
{
var states = new List<State>();
_dueTime = DateTime.Now.AddSeconds(5);
for (int i = 0; i < 10; i++)
{
var state = new State {Index = i};
ThreadPool.QueueUserWorkItem(Go, state);
states.Add(state);
Thread.Sleep(100);
}
states.ForEach(s => s.Sync.WaitOne());
states.ForEach(s => s.Sync.Close());
}
private static void Go(object state)
{
var s = (State) state;
Console.WriteLine("Go entered: " + s.Index);
lock (_lock)
{
Console.WriteLine("{0,2} got lock", s.Index);
if (_dueTime > DateTime.Now)
{
var time = _dueTime - DateTime.Now;
Console.WriteLine("{0,2} sleeping for {1} ticks", s.Index, time.Ticks);
Thread.Sleep(time);
}
Console.WriteLine("{0,2} exiting lock", s.Index);
}
s.Sync.Set();
}
private class State
{
public int Index;
public readonly ManualResetEvent Sync = new ManualResetEvent(false);
}
}
输出:
进入:0
0有锁
0睡眠49979998滴答声
GO输入:1
进入:2
进入:3
进入:4
开始:5
开始:6
进入:7
Go Enter:8
Go Enter:9
0退出锁定
%1已锁定
1个5001刻度的睡眠时间
%1正在退出锁定
我有锁
2睡5001刻度
2出口锁
3.有锁
3.睡5001个蜱虫
3出口锁
4.我有锁
4.睡5001只蜱
4出口锁
5.我有锁
5.睡5001只蜱
5退出锁定
6个被锁定
6出口锁
我有锁
7出口锁
8个被锁定
8出口锁
我有锁
9出口锁