我编写了一小段代码,可以从多个线程快速读取和写入字典。我使用 ReaderWriterLockSlim 来保护代码,但仍因涉嫌尝试添加重复密钥而收到异常。
ReaderWriterLockSlim _lock = new ReaderWriterLockSlim();
Dictionary<int, int> _dict = new Dictionary<int, int>();
public SafeDictionaryTester()
{
for (int i = 0; i < 7; i++)
{
_dict.Add(i, i);
}
}
internal void Execute()
{
for (int i = 7; i < 10000; i++)
{
if (i % 6 == 0)
new Thread(new ThreadStart(delegate { Print(6); })).Start();
else if (i % 5 == 0)
new Thread(new ThreadStart(delegate { Print(5); })).Start();
else if (i % 4 == 0)
new Thread(new ThreadStart(delegate { Print(4); })).Start();
else if (i % 3 == 0)
new Thread(new ThreadStart(delegate { Print(3); })).Start();
else if (i % 2 == 0)
new Thread(new ThreadStart(delegate { Print(2); })).Start();
else if (i % 1 == 0)
new Thread(new ThreadStart(delegate { Print(1); })).Start();
new Thread(new ThreadStart(delegate
{
_lock.EnterWriteLock();
try
{
_dict.Add(i, i); // Exception after random number of loops
Console.WriteLine(i.ToString() + " added");
}
finally
{
_lock.ExitWriteLock();
}
})).Start();
}
}
private void Print(int i)
{
_lock.EnterReadLock();
try
{
int obj;
if (_dict.TryGetValue(i, out obj))
{
Console.WriteLine(obj);
}
else
{
throw new Exception();
}
}
finally
{
_lock.ExitReadLock();
}
}
请注意,没有线程的确切代码可以完美执行。