C# 多线程并发处理数据库数据，发送信号等待处理完统一插入.
http://hi.baidu.com/jiang_yy_jiang/blog/item/23294013384be4c7f6039e2e.html
public class JPService
{
public JPService()
{
//设定最大的Net并发连接数
System.Net.ServicePointManager.DefaultConnectionLimit = 500;
ThreadPool.SetMinThreads(15 , 2);//设置最小的工作线程数和IO线程数
Config.Load();
}
private int MaxThread = 10;//最大的纠偏线程数
private static Random m_rand = new Random(Guid.NewGuid().GetHashCode());//创建随机数
private static object m_objLock = new object();//添加列表锁定
private AutoResetEvent[] InitAutoResetEvent()
{
//对每个线程提供一个完成信号，初始化为未终止状态
AutoResetEvent[] autoEvents = new AutoResetEvent[MaxThread];
for (int i = 0; i < MaxThread; i++)
autoEvents[i] = new AutoResetEvent(false);
return autoEvents;
}
/// <summary>
/// 将处理完的信息添加至List列表
/// </summary>
/// <param name="lst"></param>
/// <param name="info"></param>
public void AddItemToList(List<EntityJPGpsInfo> lst , EntityJPGpsInfo info)
{
lock (m_objLock)
{
lst.Add(info);
}
}
public void OnStart()
{
try
{
//在线程池中引入可执行的方法，一个循环不断判断
ThreadPool.QueueUserWorkItem(_ =>
{
//不断循环，直到当前有数据可以纠偏，则将该方法加入线程池
while (true)
{
AutoResetEvent[] autoEvents = InitAutoResetEvent();
List<EntityJPGpsInfo> lst = new List<EntityJPGpsInfo>();
//得到处理数据 集
DataSet ds = GetBeforeJP();
//验证数据是否存在（null）
if (!DataHelper.VerifyDataSet(ds))
{
Thread.Sleep(100);
continue; //如果检测DataSet可行，则继续
}
int iCount = ds.Tables[0].Rows.Count; //获取要处理的数据行数
int iBlock = (int)Math.Ceiling((double)iCount / MaxThread);//根据行数，线程数设定每个线程要处理的数据量
for (int i = 0; i < MaxThread; i++) //像线程池加入执行队列
{
ThreadPool.QueueUserWorkItem(data =>
{
int iIndex = (int)data;//线程序号0->MaxThread
DataRowCollection rows = ds.Tables[0].Rows;
for (int j = 0; j < iBlock; j++)
{
try
{
if (iIndex * iBlock + j >= iCount)//避免最后一个线程索引越界
break;
int iSequence = DataHelper.ReadInt(rows[iIndex * iBlock + j] , "SEQUENCE");
int iMCUID = DataHelper.ReadInt(rows[iIndex * iBlock + j] , "MCUID");
int iLng = DataHelper.ReadInt(rows[iIndex * iBlock + j] , "LONGITUDE") / 36;
int iLat = DataHelper.ReadInt(rows[iIndex * iBlock + j] , "LATITUDE") / 36;
DateTime dtmPostionTime = DataHelper.ReadDateTime(rows[iIndex * iBlock + j] , "POSITIONTIME");
DateTime dtmReceiveTime = DataHelper.ReadDateTime(rows[iIndex * iBlock + j] , "RECEIVETIME");
try
{
//请求指定网页地址进行处理返回结果
WebRequest jpRequest = WebRequest.Create(Config.BMSSettings.JPUrl + iLng.ToString() + "," + iLat.ToString() + "&t=" + m_rand.Next());
jpRequest.Method = "get";
jpRequest.ContentType = "application/x-www-form-urlencoded";
jpRequest.Timeout = 8000;//设置超时
WebResponse jpResponse = jpRequest.GetResponse();
string strJP;
using (StreamReader sr = new StreamReader(jpResponse.GetResponseStream()))
{
strJP = sr.ReadToEnd();
if (!string.IsNullOrEmpty(strJP))
{
strJP = strJP.Remove(strJP.Length - 1 , 1);
string[] strs = strJP.Split(new char[] { ',' });
//处理完加入列表
AddItemToList(lst , new EntityJPGpsInfo(iSequence , iMCUID , Convert.ToInt32(strs[0]) * 36 , Convert.ToInt32(strs[1]) * 36 , dtmPostionTime , dtmReceiveTime));
}
}
jpResponse.Close();
}
catch (Exception ex)
{
LogHelper.Writeln("Error1:" + ex.Message);
}
}
catch (Exception e)
{
LogHelper.Writeln("Error2:" + e.StackTrace);
}
}
autoEvents[iIndex].Set();
} , i);
}
//等待收到所有的信号
ManualResetEvent.WaitAll(autoEvents);
InsertToDB(lst); //处理完集体插入到数据库
}
});
}
catch (Exception exc)
{
LogHelper.Writeln("Error3：" + exc.StackTrace);
}
}
/// <summary>
/// 数据库提取预处理数据
/// </summary>
/// <returns>预处理数据集</returns>
public DataSet GetBeforeJP()
{
OracleParameter[] paras = new OracleParameter[]
{
OracleHelper.MakeOutParam("curCursor",OracleType.Cursor)
};
return OracleHelper.ExecuteDataSet(Config.BMSSettings.ConnectionString , "SP_GIS_GET_BEFOREJP" , paras);
}
/// <summary>
/// 全部循环插入到数据库
/// </summary>
/// <param name="lst">插入数据列表</param>
public void InsertToDB(List<EntityJPGpsInfo> lst)
{
using (OracleConnection conn = OracleHelper.GetConnection(Config.BMSSettings.ConnectionString))
{
conn.Open();
OracleCommand command = conn.CreateCommand();
OracleTransaction trans = conn.BeginTransaction();
try
{
command.Transaction = trans;
command.Parameters.AddRange(new OracleParameter[]
{
new OracleParameter("iSequence",OracleType.Number),
new OracleParameter("iMCUID",OracleType.Number),
new OracleParameter("iLongitude",OracleType.Number),
new OracleParameter("iLatitude",OracleType.Number),
new OracleParameter("dtmPositionTime",OracleType.DateTime),
new OracleParameter("dtmReceiveTime",OracleType.DateTime)
});
foreach (EntityJPGpsInfo info in lst)
{
command.Parameters[0].Value = info.Sequence;
command.Parameters[1].Value = info.MCUID;
command.Parameters[2].Value = info.Longitude;
command.Parameters[3].Value = info.Latitude;
command.Parameters[4].Value = info.PositionTime;
command.Parameters[5].Value = info.ReceiveTime;
command.CommandType = CommandType.StoredProcedure;
command.CommandText = "SP_GIS_ADD_JP";
command.ExecuteNonQuery();
}
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
throw ex;
}
}
}
}
该小程序，主要是实现纠偏，将Oracle数据库中所有需要纠偏的数据全部提取出来存入DataSet，然后使用网络上使用的纠偏地址（程序未给出，设置在配置文件中了）全部纠偏。
纠偏部分为了加快运行速度和效率，使用了多线程，根据总数据条数分配每个线程该纠偏多少条，每次解决一条数据加入到List列表，每个线程有一个完成信号，等所有的线程任务完成时，统一将List中的数据遍历插入到数据库。
文章注明来源： http://hi.baidu.com/jiang_yy_jiang