我的代码是用C#编写的,数据层使用LINQ to SQL来填充/加载分离的对象类。LINQ to SQL DAL,这是线程安全吗?
我最近更改了代码以使用多线程,并且我非常确定我的DAL不是线程安全的。
你能告诉我,如果PopCall()和Count()是线程安全的,如果不是我如何解决它们?
public class DAL
{
//read one Call item from database and delete same item from database.
public static OCall PopCall()
{
using (var db = new MyDataContext())
{
var fc = (from c in db.Calls where c.Called == false select c).FirstOrDefault();
OCall call = FillOCall(fc);
if (fc != null)
{
db.Calls.DeleteOnSubmit(fc);
db.SubmitChanges();
}
return call;
}
}
public static int Count()
{
using (var db = new MyDataContext())
{
return (from c in db.Calls select c.ID).Count();
}
}
private static OCall FillOCall(Model.Call c)
{
if (c != null)
return new OCall { ID = c.ID, Caller = c.Caller, Called = c.Called };
else return null;
}
}
独立式OCall类:
public class OCall
{
public int ID { get; set; }
public string Caller { get; set; }
public bool Called { get; set; }
}
谢谢! ,似乎你使用TrasactionScope,因为它是一个锁定语句,我认为TrasactionScope只能确保“全部或全部”SQL查询执行。它是否也阻止其他线程? – RuSh 2010-08-25 11:43:23
@sharru - 数据库在可序列化隔离时执行该操作。如前所述,UPDLOCK会更好地避免更多的时间边缘情况。 – 2010-08-25 17:17:38