多线程数据库插入死锁

2015-03-18 08:37:31 380 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

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PPO(Proximal Policy Optimization)算法原理及实现,详解近端策略优化接着上面的讲，PG方法一个很大的缺点就是参数更新慢，因为我们每更新一次参数都需要进行重新的采样，这其实是中on-policy的策略，即我们想要训练的agent和与环境进行交互的agent是同一个agent；与之对应的就是off-policy的策略，即想要训练的agent和与环境进行交互的agent不是同一个agent，简单来说，就是拿别人的经验来训练自己。举个下棋的例子，如果你是通过自己下棋来不断提升自己的棋艺，那么就是on-policy的，如果是通过看别人下棋来提升自己，那么就是off-policy的。阅读详情

package com.test;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.locks.Lock;
public class ThreadRead{

/**Java多线程读大文件
* @param args
*/
public static void main(String[] args) {
int start=(int)System.currentTimeMillis();
System.out.println(start+"");
Thread t1=new Thread(new MultiThreadDemo(),"A");
Thread t2=new Thread(new MultiThreadDemo(),"B");
t1.start();
t2.start();
int end=(int)System.currentTimeMillis();
System.out.println(end+"");
System.out.println((end-start)+" ");
}

}

class MultiThreadDemo implements Runnable{
private static BufferedReader br = null;
private List<String> list;

static{
try {
br = new BufferedReader(new FileReader("E:\\lineitem.tbl"),1024);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void display(List<String> list) {
int count = 0;
System.out.println(list.size());
for(String str:list) {
String[] arrtest = str.split("\\|");
count++;
String sql="insert into newtable (TableName,TupleNum,PropertyName,ElementValue) values (?,?,?,?)";
Connection conn = null;
PreparedStatement pstmt = null;
try {
conn = testThread.getConnection();
conn.setAutoCommit(false);
pstmt = testThread.getPstmt(conn, sql);
String recordName[]={"L_ORDERKEY","L_PARTKEY","L_SUPPKEY","L_LINENUMBER","L_QUANTITY",
"L_EXTENDEDPRICE","L_DISCOUNT","L_TAX","L_RETURNFLAG","L_LINESTATUS","L_SHIPDATE"
,"L_COMMITDATE", "L_RECEIPTDATE","L_SHIPINSTRUCT","L_SHIPMODE","L_COMMENT"};
for(int i=0;i<arrtest.length;i++){
pstmt.setString(1, "LINEITEM");
pstmt.setInt(2, count);
pstmt.setString(3, recordName[i]);
pstmt.setString(4, arrtest[i]);
pstmt.executeUpdate();
}
} catch (SQLException e) {
e.printStackTrace();
testThread.rollback(conn);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
testThread.close(pstmt);
testThread.close(conn);
}
// System.out.println(str);
}
}
@Override
public void run() {
// TODO Auto-generated method stub
String line = null;
int count=0;
while(true) {
this.list = new ArrayList<String>();
synchronized(br) {
try {
while((line = br.readLine()) != null) {
if(count<15) {
list.add(line);
count++;
}else {
list.add(line);
count = 0;
break;
}
}

} catch (IOException e) {
e.printStackTrace();
}
}
try {
Thread.sleep(1);
display(this.list);
} catch (Exception e) {
e.printStackTrace();
}
if(line == null)
break;
}
}
}

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